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Fabio TASCEDDA
Professore Ordinario
Dipartimento di Scienze della Vita sede ex-Scienze Biomediche
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Pubblicazioni
2024
- Low TGF-β1 plasma levels are associated with cognitive decline in Down syndrome
[Articolo su rivista]
Grasso, Margherita; Fidilio, Annamaria; L’Episcopo, Francesca; Recupero, Marilena; Barone, Concetta; Bacalini, Maria Giulia; Benatti, Cristina; Giambirtone, Maria Concetta; Caruso, Giuseppe; Greco, Donatella; Di Nuovo, Santo; Romano, Corrado; Ferri, Raffaele; Buono, Serafino; Cuello, A. Claudio; Blom, Johanna Maria Catharina; Tascedda, Fabio; Piazza, Pier Vincenzo; De La Torre, Rafael; Caraci, Filippo
abstract
2024
- New Psychometric Strategies for the Evaluation of Affective, Cognitive,
and Psychosocial Functioning in Unipolar versus Bipolar Depression:
Impact of Drug Treatment
[Articolo su rivista]
Guerrera, Claudia Savia; Platania, Giuseppe Alessio; Varrasi, Simone; De Vivo, Simona; Pirrone, Concetta; Vezzosi, Venera Francesca; Tascedda, Fabio; Drago, Filippo; Di Nuovo, Santo; Blom, Johanna M. C.; Castellano, Sabrina; Caraci, Filippo
abstract
Background: Different studies have been conducted to understand how patients with unipolar and bipolar depression differ in terms of cognitive and affective symptoms as well as in psychosocial function. Furthermore, the impact of antidepressants, second-generation antipsychotics, and mood stabilizers on these dimensions needs to be characterized, as well as the best psychometric approach to measure changes after pharmacological treatment. Objectives: This study aims to analyze the impact of psychotropic drugs on cognitive, affective, and psychosocial functioning in MDD and BD patients; to test the sensitivity of psychometric tools for measuring those changes; also, to understand how psychosocial abilities are associated with affective and cognitive dimensions in patients with MDD and BD. Methods: A total of 22 patients with MDD and 21 patients with BD in the depressive phase were recruited. Several psychometric tests were administered to assess affective, cognitive, and psychosocial symptoms before and after 12 weeks of drug treatment (T0 and T1) with different psychotropic drugs including second-generation antidepressants, second-generation antipsychotics and mood stabilizers (lamotrigine). Results: MDD patients showed significant improvement in MoCA, Delayed Recall of Rey's 15 Words and HDRS, while a significant worsening was detected on Digit Span Backwards and on FAST scores. Instead, patients with BD showed significant improvements in the MoCA as the MDD patients, but only a trend of improvement (non-statistically significant) on the BDI-II. A positive correlation was detected in both groups between FAST and HDRS and BDI-II scores, especially in BD patients. Conclusion: Our results demonstrate that drug treatment with psychotropic drugs can improve cognitive and affective symptoms, but not all psychometric tools may be equally sensitive to detect those changes in MDD vs. BD patients. Moreover, we found that affective and cognitive dimensions can be considered as different psychopathological dimensions both in unipolar and bipolar depression.
2024
- Snails go on a fast when acetylsalicylic acid comes along with heat stress: A possible effect of HSPs and serotonergic system on the feeding response
[Articolo su rivista]
Batabyal, A.; Rivi, V.; Benatti, C.; Blom, J. M. C.; Tascedda, F.; Lukowiak, K.
abstract
: A novel food followed by sickness, causes a taste-specific conditioned aversion, known as the 'Garcia effect'. We recently found that both a heat shock stressor (30 °C for 1 h - HS) and the bacterial lipopolysaccharide (LPS) can be used as 'sickness-inducing' stimuli to induce a Garcia effect in the pond snail Lymnaea stagnalis. Additionally, if snails are exposed to acetylsalicylic acid (ASA) present in aspirin tablets before the LPS injection, the formation of the Garcia effect is prevented. Here, we hypothesized that exposing snails to crushed aspirin before the HS (ASA-HS) would prevent the HS-induced 'sickness state' and - therefore -the Garcia effect. Unexpectantly, the ASA-HS procedure induced a generalized and long-lasting feeding suppression. We thus investigate the molecular effects underlying this phenomenon. While the exposure to the HS alone resulted in a significant upregulation of the mRNA levels of the Heat Shock Protein 70 (HSP 70) in snails' central ring ganglia, the ASA-HS procedure induced an even greater upregulation of HSP70, suggesting that the ASA-HS combination causes a severe stress response that inhibits feeding. Additionally, we found that the ASA-HS procedure induced a significant downregulation of the mRNA levels of genes involved with the serotoninergic system which regulates feeding in snails. Finally, the ASA-HS procedure prevented HS-induced upregulation of the mRNA levels of key neuroplasticity genes. Our study indicates that two sickness-inducing stimuli can have different physiological responses even if behavioral outcomes are similar under some learning contexts.
2023
- A Novel Behavioral Display in Lymnaea Induced by Quercetin and Hypoxia
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Tascedda, F.; Blom, J. M. C.; Lukowiak, K.
abstract
The pond snail Lymnaea stagnalis employs aerial respiration under hypoxia and can be operantly conditioned to reduce this behavior. When applied individually, a heat shock (30 7C for 1 h) and the flavonoid quercetin enhance long-term memory formation for the operant conditioning of aerial respiration. However, when snails are exposed to quercetin before the heat shock, long-term memory is no longer enhanced. This is because quercetin prevents the heat-induced upregulation of heat-shock proteins 70 and 40. When we tested the memory outcome of operant conditioning due to the simultaneous exposure to quercetin and 30 7C, we found that Lymnaea entered a quiescent survival state. The same behavioral response occurred when snails were simultaneously exposed to quercetin and pond water made hypoxic by bubbling nitrogen through it. Thus, in this study, we performed six experiments to propose a physiological explanation for that curious behavioral response. Our results suggest that bubbling nitrogen in pond water, heating pond water to 30 7C, and bubbling nitrogen in 30 7C pond water create a hypoxic environment, to which organisms may respond by upregulating the heat-shock protein system. On the other hand, when snails experience quercetin together with these hypoxic conditions, they can no longer express the physiological stress response evoked by heat or hypoxia. Thus, the quiescent survival state could be an emergency response to survive the hypoxic condition when the heat-shock proteins cannot be activated.
2023
- A network study to differentiate suicide attempt risk profiles in male and female patients with major depressive disorder
[Articolo su rivista]
Sarti, P.; Colliva, C.; Varrasi, S.; Guerrera, C. S.; Platania, G. A.; Boccaccio, F. M.; Castellano, S.; Pirrone, C.; Pani, L.; Tascedda, F.; di Nuovo, S.; Caraci, F.; Blom, J. M. C.
abstract
Suicide attempts are a possible consequence of Major Depressive Disorder (MDD), although their prevalence varies across different epidemiological studies. Suicide attempt is a significant predictor of death by suicide, highlighting its importance in understanding and preventing tragic outcomes. Researchers are increasingly recognizing the need to study the differences between males and females, as several distinctions emerge in terms of the characteristics, types and motivations of suicide attempts. These differences emphasize the importance of considering gender-specific factors in the study of suicide attempts and developing tailored prevention strategies. We conducted a network analysis to represent and investigate which among multiple neurocognitive, psychosocial, demographic and affective variables may prove to be a reliable predictor for identifying the 'suicide attempt risk' (SAR) in a sample of 81 adults who met DSM-5 criteria for MDD. Network analysis resulted in differences between males and females regarding the variables that were going to interact and predict the SAR; in particular, for males, there is a stronger link toward psychosocial aspects, while for females, the neurocognitive domain is more relevant in its mnestic subcomponents. Network analysis allowed us to describe otherwise less obvious differences in the risk profiles of males and females that attempted to take their own lives. Different neurocognitive and psychosocial variables and different interactions between them predict the probability of suicide attempt unique to male and female patients.
2023
- ADOLESCENCE AS A CRITICAL TIME-WINDOW FOR NEUROINFLAMMATION IN THE MOUSE: WHY SEX
MATTERS
[Abstract in Rivista]
Toscano, Ylenia; Benatti, Cristina; Alboni, Silvia; Ciani, Miriam; Rigillo, Giovanna; Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract
2023
- Behavioral and Transcriptional Effects of Short or Prolonged Fasting on the Memory Performances of Lymnaea stagnalis
[Articolo su rivista]
Rivi, Veronica; Benatti, Cristina; Actis, Pietro; Tascedda, Fabio; Blom, Johanna Maria Catharina
abstract
Introduction: The Garcia effect, a solid learning paradigm, was used to investigate the molecular and behavioral effects induced by different lengths of fasting on the cognitive functions in the pond snail Lymnaea stagnalis, a valid model systemMethods: Three experimental groups were used: Moderately hungry snails, food-deprived for 1 day (D1 snails), severely hungry snails (D5 snails), fasting for 5 days, and satiated snails with ad libitum access to food (AL snails). In the Garcia effect, a single pairing of an appetitive stimulus with a heat stressor results in a learned taste-specific negative hedonic shift. D5 snails were injected with bovine insulin and D1 snails with the insulin receptor antibody (Ab). As a control group, AL snails were injected with saline. Gene expression analyses were performed by Real-time PCR in snails' central nervous system (CNS).Results: AL snails are 'average learners', D1 snails are the best performers, whereas the D5 ones do not show the Garcia effect. Severely fasting snails injected with insulin 3h before the training procedure, show the Garcia effect, whereas injecting 1-day fasting snails with insulin receptor Ab blocks their ability to express memory. The differences in memory performances are associated with changes in the expression levels of selected targets involved in neuronal plasticity, energy homeostasis, and stress response.Discussion: Our results suggest that short-term fasting creates an optimal internal state in L. stagnalis' CNS, allowing a spike in insulin release and an upregulation of genes involved in neuroplasticity. Long-term fasting, instead, upregulates genes involved in energy homeostasis and animal survival.
2023
- Comparison of behavioural and transcriptional responses to a heat stressor between freshly collected and an inbred strain of Lymnaea
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Tascedda, F.; Blom, J. M. C.; Lukowiak, K.
abstract
Different populations of organisms occurring across varying thermal regimes show diversity in responses to heat stress. We use a "common garden experimental" approach designed to deal with phenotypic plasticity to study in Lymnaea stagnalis (Linnaeus, 1758) the behavioural and molecular responses to a heat shock in laboratory-inbred snails (W-strain) and freshly collected snails (Stony strain) from ponds. In the W-strain, which has been reared under standardized temperatures for generations, the exposure to 30 degrees C for 1 h (heat shock, HS) when experienced after a novel "taste" results in a taste-specific aversion known as the "Garcia effect". This learned avoidance requires the upregulation of heat shock proteins (HSPs). In contrast, freshly collected Stony strain, which experiences temperature fluctuations regularly, does not exhibit a Garcia effect. Here, we found that (1) Stony-strain snails have higher basal mRNA levels of HSPs than W-strain ones; (2) in the W-strain, the training procedure to cause the Garcia effect upregulates the mRNA levels of HSPs and key neuroplasticity-related genes such as CREB1 and GRIN1; (3) in Stony-strain snails, the same training procedure fails to alter the mRNA levels of those targets. These data suggest that Stony-strain snails do not perceive the HS as a stressor because of the higher HSP basal mRNA levels, which may confer a higher thermal tolerance.
2023
- Dysbindin, D3 receptors, and their genetic interaction differently regulate neuroplasticity genes in the mouse brain
[Abstract in Atti di Convegno]
Rivi, V.; Benatti, C.; Blom, J. M. C.; Pani, L.; Brunello, N.; Drago, F.; Papaleo, F.; Torrisi, S.; Leggio, G.; Tascedda, F.
abstract
2023
- Environmental enrichment influences mouse hippocampal neuroinflammatory response
[Abstract in Rivista]
Rigillo, Giovanna; Benatti, Cristina; Toscano, Ylenia; Tascedda, Fabio; Pani, Luca; Brunello, Nicoletta; Alboni, Silvia
abstract
Background:
Many studies have shown the positive effects of environmental enrichment on brain plasticity with significant implications for development, behavior, learning, memory, and recovery from brain damage (1).
Experimental and clinical studies report that one’s living environment can modulate cellular and molecular responses in the brain, counteracting cognitive decline, alleviating anxiety, and depressive behaviours, as well as moderating the outcome of pharmacological treatments (2). Neuroinflammation has been well established as an important factor in the aetiopathogenesis and progression of brain disorders. It can affect neural development and alters hippocampal plasticity thus resulting in cognitive impairments. Neuroinflammation is characterized by a dysregulation of the NLRP3 inflammasome activation, an increase in the expression of inflammatory cytokines, and a decrease of neurotrophic factors (3). Behavioral and neurochemical changes, caused by neuroinflammation, have been most frequently investigated through peripheral administration of lipopolysaccharide (LPS), which can, directly and indirectly, affect the central nervous system (4).
Based on these premises, the aim of this study was to explore the molecular effects of the quality of the living environment in modulating the LPS-induced neuroinflammatory response in the hippocampus of wild-type mice.
Methods:
Male C57BL6J mice (13 weeks-old) were randomly housed in Impoverished (IE) or Enriched Environment (EE) condition for 28 days, then exposed to LPS (0.830 mg/Kg, i.p.) or saline (SAL). Twenty-four hours after injection hippocampi were removed for gene expression analysis performed by means of qRT-PCR. Data from groups were analyzed by Two-way ANOVA followed by Tukey’s post hoc test.
Results:
The analysis of the environmental effects on the LPS signaling system highlighted the downregulation of the membrane-bound protein LBP, the receptor TLR4 and the co-receptor cluster CD14 expression levels in EE-housed animals compared to their counterparts. The exposure to an EE condition was able to attenuate the LPS-induced increase of TLR4 and NLRP3 inflammasome mRNA levels. Gene expression analysis revealed a significant downregulation of the pro-inflammatory cytokines IL-1β and TNFα levels in EE-housed mice while LPS exposure strongly increased IL-1β and TNFα mRNA levels irrespective of the housing conditions.
Moreover, EE-exposed mice showed a significant upregulation of BDNF hippocampal mRNA levels, although no effects were observed after LPS treatment in both conditions.
Conclusions: Our results displayed the beneficial effect of EE in regulating the expression of inflammatory mediators involved in the LPS-induced response in the hippocampus, a key area for learning, memory, and emotion. These data suggest that living environment may exert a positive and protective role on the brain by reducing susceptibility toward neurodegenerative or neuropsychiatric disorders.
2023
- Farmaci antidepressivi parte II: SNRI e farmaci multimodali
[Capitolo/Saggio]
Benatti, Cristina; Alboni, Silvia; Brunello, Nicoletta; Pani, Luca; Tascedda, Fabio
abstract
2023
- Hydroxypropyl-β-Cyclodextrin Depletes Membrane Cholesterol and Inhibits SARS-CoV-2 Entry into HEK293T-ACEhi Cells
[Articolo su rivista]
Alboni, Silvia; Secco, Valentina; Papotti, Bianca; Vilella, Antonietta; Pia Adorni, Maria; Zimetti, Francesca; Schaeffer, Laurent; Tascedda, Fabio; Zoli, Michele; Leblanc, Pascal; Villa, Erica
abstract
2023
- Investigating the interactions between multiple memory stores in the pond snail Lymnaea stagnalis
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Blom, J. M. C.; Tascedda, F.; Lukowiak, K.
abstract
The pond snail Lymnaea stagnalis exhibits various forms of associative learning including (1) operant conditioning of aerial respiration where snails are trained not to open their pneumostome in a hypoxic pond water environment using a weak tactile stimulus to their pneumostome as they attempt to open it; and (2) a 24 h-lasting taste-specific learned avoidance known as the Garcia effect utilizing a lipopolysaccharide (LPS) injection just after snails eat a novel food substance (carrot). Typically, lab-inbred snails require two 0.5 h training sessions to form long-term memory (LTM) for operant conditioning of aerial respiration. However, some stressors (e.g., heat shock or predator scent) act as memory enhancers and thus a single 0.5 h training session is sufficient to enhance LTM formation lasting at least 24 h. Here, we found that snails forming a food-aversion LTM following Garcia-effect training exhibited enhanced LTM following operant condition of aerial respiration if trained in the presence of the food substance (carrot) they became averse to. Control experiments led us to conclude that carrot becomes a ‘sickness’ risk signal and acts as a stressor, sufficient to enhance LTM formation for another conditioning procedure.
2023
- LPS-Induced Garcia Effect and Its Pharmacological Regulation Mediated by Acetylsalicylic Acid: Behavioral and Transcriptional Evidence
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Lukowiak, K.; Benatti, C.; Rigillo, G.; Tascedda, F.; Blom, J. M. C.
abstract
Lymnaea stagnalis learns and remembers to avoid certain foods when their ingestion is followed by sickness. This rapid, taste-specific, and long-lasting aversion—known as the Garcia effect—can be formed by exposing snails to a novel taste and 1 h later injecting them with lipopolysaccharide (LPS). However, the exposure of snails to acetylsalicylic acid (ASA) for 1 h before the LPS injection, prevents both the LPS-induced sickness state and the Garcia effect. Here, we investigated novel aspects of this unique form of conditioned taste aversion and its pharmacological regulation. We first explored the transcriptional effects in the snails’ central nervous system induced by the injection with LPS (25 mg), the exposure to ASA (900 nM), as well as their combined presentation in untrained snails. Then, we investigated the behavioral and molecular mechanisms underlying the LPS-induced Garcia effect and its pharmacological regulation by ASA. LPS injection, both alone and during the Garcia effect procedure, upregulated the expression levels of immune- and stress-related targets. This upregulation was prevented by pre-exposure to ASA. While LPS alone did not affect the expression levels of neuroplasticity genes, its combination with the conditioning procedure resulted in their significant upregulation and memory formation for the Garcia effect.
2023
- No food for thought: An intermediate level of food deprivation enhances memory in Lymnaea
[Articolo su rivista]
Kagan, Diana; Rivi, Veronica; Benatti, Cristina; Tascedda, Fabio; Blom, Johanna M C; Lukowiak, Ken
abstract
: Nutritional status plays an important role in cognitive functioning but there is disagreement on the role that food deprivation plays in learning and memory. In this study, we investigated the behavioral and transcriptional effects induced by different lengths of food deprivation: 1 day, which is a short-time period of food deprivation, and 3 days, which is an 'intermediate' level of food deprivation. Snails were subjected to different feeding regimens and then trained for operant conditioning of aerial respiration where they received a single 0.5h training session followed by a long-term memory (LTM) test 24h later. Immediately after the memory test, snails were sacrificed and the expression levels of key genes for neuroplasticity, energy balance, and stress response were measured in the central ring ganglia. We found that 1 day of food deprivation was not sufficient to enhance snails' LTM formation and subsequently did not result in any significant transcriptional effects. However, 3 days of food deprivation resulted in enhanced LTM formation and caused the upregulation of neuroplasticity and stress-related genes and the downregulation of serotonin-related genes. These data provide further insight into how nutritional status and related molecular mechanisms impact cognitive function.
2023
- Novel taste, sickness, and memory: Lipopolysaccharide to induce a Garcia-like effect in inbred and wild strains of Lymnaea stagnalis
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Blom, J. M.; Tascedda, F.; Lukowiak, K.
abstract
Food is not only necessary for our survival but also elicits pleasure. However, when a novel food is followed sometime later by nausea or sickness animals form a long-lasting association to avoid that food. This phenomenon is called the ‘Garcia effect’. We hypothesized that lipopolysaccharide (LPS) could be used as the sickness-inducing stimulus to produce a Garcia-like effect in inbred and wild populations of Lymnaea stagnalis. We first demonstrated that the injection of 25 μg (6.25 µg/mL) of Escherichia coli-derived LPS serotype O127:B8 did not by itself alter snails’ feeding behavior. Then we showed that the presentation of a novel appetitive stimulus (i.e., carrot slurry) and LPS resulted in a taste-specific and long-lasting feeding suppression (i.e., the Garcia-like effect). We also found strain-specific variations in the duration of the long-term memory (LTM). That is, while the LTM for the Garcia-like effect in W-strain snails persisted for 24h, LTM persisted for 48h in freshly collected Margo snails and their F1 offspring. Finally, we demonstrated that the exposure to a non-steroidal anti-inflammatory drug, aspirin (acetylsalicylic acid) before the LPS injection prevented both the LPS-induced sickness state and the Garcia-like effect from occurring. The results of this study may pave the way for new research that aims at (1) uncovering the conserved molecular mechanisms underlying the Garcia-like effect, (2) understanding how cognitive traits vary within and between species, and (3) creating a holistic picture of the complex dialogue between the immune and central nervous systems.
2023
- Predictors of functional outcome in patients with major depression and bipolar disorder: A dynamic network approach to identify distinct patterns of interacting symptoms
[Articolo su rivista]
Platania, Giuseppe Alessio; Savia Guerrera, Claudia; Sarti, Pierfrancesco; Varrasi, Simone; Pirrone, Concetta; Popovic, Dina; Ventimiglia, Andrea; De Vivo, Simona; Cantarella, Rita Anna; Tascedda, Fabio; Drago, Filippo; Di Nuovo, Santo; Colliva, Chiara; Caraci, Filippo; Castellano, Sabrina; Blom, Johanna M C
abstract
: The purpose of this study is to use a dynamic network approach as an innovative way to identify distinct patterns of interacting symptoms in patients with Major Depressive Disorder (MDD) and patients with Bipolar Type I Disorder (BD). More precisely, the hypothesis will be testing that the phenotype of patients is driven by disease specific connectivity and interdependencies among various domains of functioning even in the presence of underlying common mechanisms. In a prospective observational cohort study, hundred-forty-three patients were recruited at the Psychiatric Clinic "Villa dei Gerani" (Catania, Italy), 87 patients with MDD and 56 with BD with a depressive episode. Two nested sub-groups were treated for a twelve-week period, which allowed us to explore differences in the pattern of symptom distribution (central vs. peripheral) and their connectedness (strong vs weak) before (T0) and after (T1) treatment. All patients underwent a complete neuropsychological evaluation at baseline (T0) and at T1. A network structure was computed for MDD and BD patients at T0 and T1 from a covariance matrix of 17 items belonging to three domains-neurocognitive, psychosocial, and mood-related (affective) to identify what symptoms were driving the networks. Clinically relevant differences were observed between MDD and BD, at T0 and after 12 weeks of pharmacological treatment. At time T0, MDD patients displayed an affective domain strongly connected with the nodes of psychosocial functioning, while direct connectivity of the affective domain with the neurocognitive cluster was absent. The network of patients with BD, in contrast, revealed a cluster of highly interconnected psychosocial nodes but was guided by neurocognitive functions. The nodes related to the affective domain in MDD are less connected and placed in the periphery of the networks, whereas in BD they are more connected with psychosocial and neurocognitive nodes. Noteworthy is that, from T0 to T1 the "Betweenness" centrality measure was lower in both disorders which means that fewer "shortest paths" between nodes pass through the affective domain. Moreover, fewer edges were connected directly with the nodes in this domain. In MDD patients, pharmacological treatment primarily affected executive functions which seem to improve with treatment. In contrast, in patients with BD, treatment resulted in improvement of overall connectivity and centrality of the affective domain, which seems then to affect and direct the overall network. Though different network structures were observed for MDD and BD patients, data suggest that treatment should include tailored cognitive therapy, because improvement in this central domain appeared to be fundamental for better outcomes in other domains. In sum, the advantage of network analysis is that it helps to predict the trajectory of future phenotype related disease manifestations. In turn, this allows new insights in how to balance therapeutic interventions, involving different fields of function and combining pharmacological and non-pharmacological treatment modalities.
2023
- Prey populations with different predation histories show differences in behavioral and transcriptional effects under acute predation threat
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Tascedda, F.; Blom, J. M. C.; Lukowiak, K.
abstract
Predator detection induces both behavioral and physiological responses in prey organisms. Our model organism, the pond snail Lymnaea stagnalis, shows multiple defensive behaviors in response to predator cues. In this study, we investigated and compared the transcriptional effects induced by the exposure to a predator scent (i.e., crayfish effluent - CE) in a strain of lab-inbred snails (i.e., W snails), which have been raised and maintained under standardized laboratory conditions for generations and a strain of freshly collected snails (i.e., Margo snails), which live in a crayfish-free pond. Neither the W- strain nor the Margo Lake snails used in this study have actually experienced crayfish. However, the W strain innately recognizes crayfish as a threat. We found that, following the exposure to CE, both strains showed significantly higher mRNA levels of serotonin-related genes. This is important, as the serotonergic system modulates predator detection and vigilance behaviors in pond snails. However, the expression levels of CREB1 and HSP70 were only upregulated in CE-exposed W snails but not in Margo ones. As CREB1 plays a key role in learning and memory formation, whereas HSP70 is involved in stress response, we investigated whether these differences in CREB1 and HSP70 mRNA levels would reflect differences in predator-induced learning (e.g., configural learning). We found that only W snails formed configural learning memory, whereas Margo snails did not. Thus, while both the strains molecularly respond to the CE by upregulating the serotoninergic system, only W snails behaviorally recognize CE as a threat and, therefore, form configural learning.
2023
- Role of dopamine D3 receptors, dysbindin, and their functional interaction on the expression of key
genes for neuroplasticity in the mouse brain
[Abstract in Rivista]
Rivi, Veronica; Benatti, Cristina; Blom, Johanna; Pani, Luca; Brunello, Nicoletta; Drago, Filippo; Papaleo, Francesco; Torrisi, Sebastiano; Salomone, Salvatore; Leggio Gian, Marco; Tascedda, Fabio
abstract
2023
- Safety and Efficacy of Red Yeast Rice Phytocomplex and Lovastatin: a Comparative Analysis
[Relazione in Atti di Convegno]
Rigillo, G; Baini, G; Miraldi, E; Pani, L; Tascedda, F; Biagi, M
abstract
In the last 20 years, the demand for red yeast rice-based food supplements has significantly increased as consumers have been looked for natural alternatives to manage blood cholesterol levels without the adverse effects associated with synthetic statins. Actually, monacolin K, derived from red yeast rice (RYR) and chemically identical to lovastatin, inhibits 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, offering a natural alternative to synthetic drugs. In 2018, despite the health claim approved in 2011, the European Food Safety Authority (EFSA) raised concerns about the safety of monacolin K consumption, especially for vulnerable populations, and highlighted the lack of knowledge on RYR phytocomplex. Consequently, in 2021, the European Commission established a new maximum intake limit < 2.99 mg/day for monacolins.
This study aimed to investigate the safety and efficacy of RYR phytocomplex compared to the sole monacolin K (=lovastatin) by analyzing eight different RYR samples with different monacolin K and secondary monacolins content. Efficacy was evaluated through a validated cell-free enzymatic assay, while an integrated in vitro simulated digestion and in silico ADME prediction were employed to compare the pharmacokinetics of different samples and lovastatin. The safety of RYR was assessed by monitoring cytotoxicity in intestinal, hepatic, kidney, and skeletal muscle cells using cell viability assays. Furthermore, muscle damage-related targets and myokines were measured by qRT-PCR in myoblasts exposed to prolonged non-toxic stimuli.
Results demonstrated that RYR samples have a large chemical variability not only related to monacolin K content, in lactone and hydroxy-acid form, but also as regards pigments, secondary monacolins, polyphenols, and triterpenes. The enzymatic test revealed that all samples were more effective in inhibiting HMG-CoA activity than lovastatin at equivalent monacolin K content. Although secondary monacolins had a weaker effect than monacolin K, a synergistic effect was observed within the phytocomplex. Additionally, the phytocomplex facilitated higher bioaccessibility of monacolin K in RYR compared to lovastatin. Regarding cell viability, lovastatin and RYR samples exhibited no toxic effects up to 150 g/mL on intestinal, hepatic, and kidney cells; however, variable effects were observed on skeletal muscle cells at medium-high concentrations. Nevertheless, at physiological non-toxic concentrations, RYR samples did not impact the expression levels of myokine IL-6, autophagy factors, and catabolic markers of protein balance, unlike synthetic statin.
These results suggest that RYR and lovastatin share similar biological activities, but the phytocomplex's contribution from secondary monacolins, pigments, polyphenols, and triterpenes ensure a superior safety profile for this botanical food supplement. However, it is important to note that the composition of RYR phytocomplex can vary significantly between different products on the market. This variability highlights the need for standardization and quality control measures to ensure the safety and efficacy of this botanical food supplement. In conclusion, our study provides evidence supporting the enhanced efficacy, bioaccessibility, and safety profile of RYR phytocomplex compared to lovastatin demonstrating its potential as a natural and effective option for hypercholesterolemia management.
2023
- The Role of Dopamine D3 Receptors, Dysbindin, and Their Functional Interaction in the Expression of Key Genes for Neuroplasticity and Neuroinflammation in the Mouse Brain
[Articolo su rivista]
Rivi, Veronica; Benatti, Cristina; Blom, Johanna; Pani, Luca; Brunello, Nicoletta; Drago, Filippo; Papaleo, Francesco; Caraci, Filippo; Geraci, Federica; Torrisi, Sebastiano Alfio; Leggio, Gian Marco; Tascedda, Fabio
abstract
2023
- The dynamic interaction between symptoms and pharmacological treatment in patients with major depressive disorder: the role of network intervention analysis
[Articolo su rivista]
Guerrera, C. S.; Platania, G. A.; Boccaccio, F. M.; Sarti, P.; Varrasi, S.; Colliva, C.; Grasso, M.; De Vivo, S.; Cavallaro, D.; Tascedda, F.; Pirrone, C.; Drago, F.; Di Nuovo, S.; Blom, J. M. C.; Caraci, F.; Castellano, S.
abstract
Introduction: The Major Depressive Disorder (MDD) is a mental health disorder that affects millions of people worldwide. It is characterized by persistent feelings of sadness, hopelessness, and a loss of interest in activities that were once enjoyable. MDD is a major public health concern and is the leading cause of disability, morbidity, institutionalization, and excess mortality, conferring high suicide risk. Pharmacological treatment with Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin Noradrenaline Reuptake Inhibitors (SNRIs) is often the first choice for their efficacy and tolerability profile. However, a significant percentage of depressive individuals do not achieve remission even after an adequate trial of pharmacotherapy, a condition known as treatment-resistant depression (TRD). Methods: To better understand the complexity of clinical phenotypes in MDD we propose Network Intervention Analysis (NIA) that can help health psychology in the detection of risky behaviors, in the primary and/or secondary prevention, as well as to monitor the treatment and verify its effectiveness. The paper aims to identify the interaction and changes in network nodes and connections of 14 continuous variables with nodes identified as "Treatment" in a cohort of MDD patients recruited for their recent history of partial response to antidepressant drugs. The study analyzed the network of MDD patients at baseline and after 12 weeks of drug treatment. Results: At baseline, the network showed separate dimensions for cognitive and psychosocial-affective symptoms, with cognitive symptoms strongly affecting psychosocial functioning. The MoCA tool was identified as a potential psychometric tool for evaluating cognitive deficits and monitoring treatment response. After drug treatment, the network showed less interconnection between nodes, indicating greater stability, with antidepressants taking a central role in driving the network. Affective symptoms improved at follow-up, with the highest predictability for HDRS and BDI-II nodes being connected to the Antidepressants node. Conclusion: NIA allows us to understand not only what symptoms enhance after pharmacological treatment, but especially the role it plays within the network and with which nodes it has stronger connections.
2023
- The nexus of social alliances and diverse moral domains: a bedrock for participatory clinical research
[Articolo su rivista]
Blom, Johanna; Rivi, Veronica; Tascedda, Fabio; Pani, Luca
abstract
2023
- VORTIOXETINE ATTENUATES NEUROINFLAMMATION BY MODULATING THE NOD-LIKE RECEPTOR FAMILY PYRIN DOMAIN CONTAINING 3 INFLAMMASOME ACTIVATION IN MICROGLIA: IMPLICATIONS FOR COGNITIVE FUNCTION
[Abstract in Rivista]
Rigillo, G.; Ciani, M.; Benatti, C.; Blom, J. M. C.; Tascedda, F.; Pani, L.; Alboni, S.; Brunello, N.
abstract
Vortioxetine (VTX) is a multimodal antidepressant with an
extensive pharmacological profile that includes modulation of various neurotransmitter
systems, neuroprotective activity, and beneficial effects on cognitive
functions. Recent research has revealed a novel aspect of VTX's activity - its antiinflammatory
effects - that suggests an intriguing molecular mechanism may
underpin its therapeutic benefits. Neuroinflammation, dysfunctional neurogenesis
and neurotransmission, and dysregulation of the hypothalamus–
pituitary–adrenal (HPA) axis are all pivotal in the onset and progression of
depression. One particular immune-inflammatory pathway overactivated in
brain disorders is the NOD-like receptor family pyrin domain containing 3
(NLRP3) inflammasome, a multiprotein complex. This complex's activation is
mediated by NF-kB and reactive oxygen species (ROS) signalling pathways,
leading to caspase-1-dependent release of the proinflammatory cytokines, IL-1β
and IL-18. Mounting evidence implicates NLRP3 inflammasome in neuroinflammation-
related disorders, with its activation associated with cognitive
function impairment. Of note, microglia, the resident immune cells crucial for
brain plasticity, express high levels of the NLRP3-inflammasome components.
Our initial findings indicate that VTX exerts a region-dependent modulatoryeffect on the NLRP3-inflammasome system in a LPS-induced memory impairment
in vivo model. Furthermore, VTX's ability to modulate immune response
suggests that microglia could be a direct target of the drug.
AIM: In light of the compelling evidence surrounding the role of the NLRP3
inflammasome in cognitive dysfunctions and the recent discovery of VTX's anti-inflammatory
activity, we aimed to investigate the molecular effects induced by
VTX pre-treatment in the presence or absence of the inflammasome-inducer LPS
in a well-established in vitro model of mouse microglia: BV2 cells.
METHODS: To dissect the influence of VTX pre-treatment (24h) on the NLRP3
inflammasome signaling pathway and microglial polarization, we analyzed gene
and protein expression in BV2 cells stimulated with LPS or vehicle for 6h. We also
scrutinized the activation/translocation of NF-kB and ROS release under these
conditions. We applied one-way or two-way ANOVA followed by Tukey’s post
hoc test for statistical analysis based on the experimental design.
RESULTS: Our data demonstrate that short-term exposure to LPS significantly
induces the activation/translocation of NF-kB signaling and ROS release in BV2
cells. We observed a time-dependent transcriptional upregulation of the
inflammasome complex, IL-1β and IL-18, and microglial pro-inflammatory targets
post-LPS stimulation, alongside a downregulation of the anti-inflammatory
factors. Interestingly, a pre-treatment with VTX (10 nM) for 24h effectively
modulated the LPS-induced NF-kB translocation and ROS production compared
to control cells. Cells pre-treated with VTX exhibited lower levels of LPS-induced
NLRP3 inflammasome- and microglia pro-inflammatory-related targets. However,
VTX did not influence the expression of anti-inflammatory factors in both
unstimulated and LPS-stimulated BV2 cells.
CONCLUSIONS: Our findings reinforce the emerging evidence that supports
VTX's anti-inflammatory activity. This activity is mediated via modulation of the
inflammasome signaling pathway, which plays a pivotal role in the inflammatory
response of microglia cells.
2022
- A flavonoid, quercetin, is capable of enhancing long-term memory formation if encountered at different times in the learning, memory formation, and memory recall continuum
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Blom, J. M.; Tascedda, F.; Lukowiak, K.
abstract
A major extrinsic factor influencing memory and neuro-cognitive performances across taxa is diet. Studies from vertebrates have shown the effects of a flavonoid rich diet on cognitive performance, but the mechanism underlying this action is still poorly understood. A common and abundant flavonoid present in numerous food substances is quercetin (Q). The present study provides the first support for Q-modulated enhancement of cognitive function in an invertebrate model, the pond snail Lymnaea stagnalis, after an operant conditioning procedure. We found that when snails were exposed to Q 3 h before or after a single 0.5 h training session, which typically results in memory lasting ~ 3 h, they formed a long-term memory (LTM) lasting for at least 24 h. Additionally, we assessed the effects of the combined presentation of a single reinforcing stimulus (at 24 h post-training or 24 h before training) and Q-exposure on both LTM formation and reconsolidation. That is, when applied within 3 h of critical periods of memory, Q regulates four different phases: (1) acquisition (i.e., a learning event), (2) consolidation processes after acquisition, (3) memory recall, and (4) memory reconsolidation. In all these phases Q-exposure enhanced LTM persistence.
2022
- Aspirin reverts lipopolysaccharide-induced learning and memory impairment: first evidence from an invertebrate model system
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Tascedda, F.; Blom, J. M. C.; Lukowiak, K.
abstract
By employing a reductionistic (but not simplistic) approach using an established invertebrate model system, the pond snail Lymnaea stagnalis, we investigated whether (1) lipopolysaccharide (LPS)-induced inflammation would cause a sickness state and impair cognitive function, and-if so-(2) would aspirin (acetylsalicylic acid-ASA) restore the impaired cognition. To test our hypotheses, we first determined if the injection of 25 mg (6.25 μg/mL) of Escherichia coli-derived LPS serotype O127:B8 altered homeostatic behavior, aerial respiration, and then determined if LPS altered memory formation when this behavior was operantly conditioned. Next, we determined if ASA altered the LPS-induced changes in both aerial respiration and cognitive functions. LPS induced a sickness state that increased aerial respiration and altered the ability of snails to form or recall long-term memory. ASA reverted the LPS-induced sickness state and thus allowed long-term memory both to be formed and recalled. We confirmed our hypotheses and provided the first evidence in an invertebrate model system that an injection of LPS results in a sickness state that obstructs learning and memory, and this impairment can be prevented by a non-steroidal anti-inflammatory.
2022
- Deciphering the central immunomodulatory effects of a vortioxetine pretreatment on the LPS-induced inflammatory cascade
[Abstract in Atti di Convegno]
Ciani, M.; Toscano, Y.; Benatti, C.; Blom, J. M. C.; Tascedda, F.; Alboni, S.; Brunello, N.
abstract
2022
- Editorial: Digital biomarkers in testing the safety and efficacy of new drugs in mental health: A collaborative effort of patients, clinicians, researchers, and regulators
[Articolo su rivista]
Blom, Johanna Maria Catharina; Benatti, Cristina; Mascalzoni, Deborah; Tascedda, Fabio; Pani, Luca
abstract
2022
- Fluoride affects memory by altering the transcriptional activity in the central nervous system of Lymnaea stagnalis
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Wiley, B.; Benatti, C.; Tascedda, F.; Blom, J. M. C.; Lukowiak, K.
abstract
Fluoride (F-), has been found to affect learning and memory in several species. In this study, we exposed an F--naïve, inbred strain of Lymnaea stagnalis to a concentration of F- similar to that naturally occurring in wild ponds. We found that the exposure to F- before the configural learning procedure obstructs the memory formation and blocks the configural learning-induced upregulation of CREB1, GRIN1, and HSP70 in snails' central ring ganglia. Along with altering the mRNA levels of these key genes for memory formation, a single acute F- exposure also upregulates Cytochrome c Oxidase, a major regulatory enzyme of the electron transport chain, which plays direct or indirect roles in reactive oxygen species production. As the central nervous system is sensitive to oxidative stress and consistent with previous studies from mammals, our results suggest a potential role of oxidative stress in memory impairment. To our knowledge, this is the first study investigating the neuronal mechanism of memory impairment in an invertebrate species that is exposed to natural F- levels.
2022
- Gut microbiota alterations promote traumatic stress susceptibility associated with p-cresol-induced dopaminergic dysfunctions
[Articolo su rivista]
Laudani, Samuele; Torrisi, Sebastiano A; Alboni, Silvia; Bastiaanssen, Thomaz F S; Benatti, Cristina; Rivi, Veronica; Moloney, Rachel D; Fuochi, Virginia; Furneri, Pio M; Drago, Filippo; Salomone, Salvatore; Tascedda, Fabio; Cryan, John F; Leggio, Gian Marco
abstract
Mounting evidence suggests a link between gut microbiota abnormalities and post-traumatic stress disorder (PTSD). However, whether and how the gut microbiota influences PTSD susceptibility is poorly understood. Here using the arousal-based individual screening model, we provide evidence for pre-trauma and post-trauma gut microbiota alterations in susceptible mice exhibiting persistent PTSD-related phenotypes. A more in-depth analysis revealed an increased abundance of bacteria affecting brain processes including myelination, and brain systems like the dopaminergic neurotransmission. Because dopaminergic dysfunctions play a key role in the pathophysiological mechanisms subserving PTSD, we assessed whether these alterations in gut microbiota composition could be associated with abnormal levels of metabolites inducing dopaminergic dysfunctions. We found high levels of the l-tyrosine-derived metabolite p-cresol exclusively in the prefrontal cortex of susceptible mice. We further uncovered abnormal levels of dopamine and DOPAC, together with a detrimental increase of dopamine D3 receptor expression, exclusively in the prefrontal cortex of susceptible mice. Conversely, we observed either resilience mechanisms aimed at counteracting these p-cresol-induced dopaminergic dysfunctions or myelination-related resilience mechanisms only in the prefrontal cortex of resilient mice. These findings reveal that gut microbiota abnormalities foster trauma susceptibility and thus it may represent a promising target for therapeutic interventions.
2022
- Identification and characterization of the kynurenine pathway in the pond snail Lymnaea stagnalis
[Articolo su rivista]
Benatti, Cristina; Rivi, Veronica; Alboni, Silvia; Grilli, Andrea; Castellano, Sara; Pani, Luca; Brunello, Nicoletta; Blom, Johanna Maria Catharina; Bicciato, Silvio; Tascedda, Fabio
abstract
2022
- Microglial diversity along the hippocampal longitudinal axis impacts synaptic plasticity in adult male mice under homeostatic conditions
[Articolo su rivista]
De Felice, E; Gonçalves de Andrade, E; Golia, M T; González Ibáñez, F; Khakpour, M; Di Castro, M A; Garofalo, S; Di Pietro, E; Benatti, C; Brunello, N; Tascedda, F; Kaminska, B; Limatola, C; Ragozzino, D; Tremblay, M E; Alboni, S; Maggi, L
abstract
The hippocampus is a plastic brain area that shows functional segregation along its longitudinal axis, reflected by a higher level of long-term potentiation (LTP) in the CA1 region of the dorsal hippocampus (DH) compared to the ventral hippocampus (VH), but the mechanisms underlying this difference remain elusive. Numerous studies have highlighted the importance of microglia-neuronal communication in modulating synaptic transmission and hippocampal plasticity, although its role in physiological contexts is still largely unknown. We characterized in depth the features of microglia in the two hippocampal poles and investigated their contribution to CA1 plasticity under physiological conditions. We unveiled the influence of microglia in differentially modulating the amplitude of LTP in the DH and VH, showing that minocycline or PLX5622 treatment reduced LTP amplitude in the DH, while increasing it in the VH. This was recapitulated in Cx3cr1 knockout mice, indicating that microglia have a key role in setting the conditions for plasticity processes in a region-specific manner, and that the CX3CL1-CX3CR1 pathway is a key element in determining the basal level of CA1 LTP in the two regions. The observed LTP differences at the two poles were associated with transcriptional changes in the expression of genes encoding for Il-1, Tnf-α, Il-6, and Bdnf, essential players of neuronal plasticity. Furthermore, microglia in the CA1 SR region showed an increase in soma and a more extensive arborization, an increased prevalence of immature lysosomes accompanied by an elevation in mRNA expression of phagocytic markers Mertk and Cd68 and a surge in the expression of microglial outward K+ currents in the VH compared to DH, suggesting a distinct basal phenotypic state of microglia across the two hippocampal poles. Overall, we characterized the molecular, morphological, ultrastructural, and functional profile of microglia at the two poles, suggesting that modifications in hippocampal subregions related to different microglial statuses can contribute to dissect the phenotypical aspects of many diseases in which microglia are known to be involved.
2022
- Non-psychotropic Cannabis sativa L. phytocomplex modulates microglial inflammatory response through CB2 receptors-, endocannabinoids-, and NF-κB-mediated signaling
[Articolo su rivista]
Borgonetti, V.; Benatti, C.; Governa, P.; Isoldi, G.; Pellati, F.; Alboni, S.; Tascedda, F.; Montopoli, M.; Galeotti, N.; Manetti, F.; Miraldi, E.; Biagi, M.; Rigillo, G.
abstract
Cannabis sativa L. is increasingly emerging for its protective role in modulating neuroinflammation, a complex process orchestrated among others by microglia, the resident immune cells of the central nervous system. Phytocannabinoids, especially cannabidiol (CBD), terpenes, and other constituents trigger several upstream and downstream microglial intracellular pathways. Here, we investigated the molecular mechanisms of a CBD- and terpenes-enriched C. sativa extract (CSE) in an in vitro model of neuroinflammation. We evaluated the effect of CSE on the inflammatory response induced by exposure to lipopolysaccharide (LPS) in BV-2 microglial cells, compared with CBD and β-caryophyllene (CAR), CB2 receptors (CB2r) inverse and full agonist, respectively. The LPS-induced upregulation of the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α was significantly attenuated by CSE and only partially by CBD, whereas CAR was ineffective. In BV-2 cells, these anti-inflammatory effects exerted by CSE phytocomplex were only partially dependent on CB2r modulation and they were mediated by the regulation of enzymes responsible for the endocannabinoids metabolism, by the inhibition of reactive oxygen species release and the modulation of JNK/p38 cascade with consequent NF-κB p65 nuclear translocation suppression. Our data suggest that C. sativa phytocomplex and its multitarget mechanism could represent a novel therapeutic strategy for neuroinflammatory-related diseases.
2022
- Prenatal stress induces a depressive-like phenotype in adolescent rats: The key role of TGF-β1 pathway
[Articolo su rivista]
Fidilio, A.; Grasso, M.; Caruso, G.; Musso, N.; Begni, V.; Privitera, A.; Torrisi, S. A.; Campolongo, P.; Schiavone, S.; Tascedda, F.; Leggio, G. M.; Drago, F.; Riva, M. A.; Caraci, F.
abstract
Stressful experiences early in life, especially in the prenatal period, can increase the risk to develop depression during adolescence. However, there may be important qualitative and quantitative differences in outcome of prenatal stress (PNS), where some individuals exposed to PNS are vulnerable and develop a depressive-like phenotype, while others appear to be resilient. PNS exposure, a well-established rat model of early life stress, is known to increase vulnerability to depression and a recent study demonstrated a strong interaction between transforming growth factor-β1 (TGF-β1) gene and PNS in the pathogenesis of depression. Moreover, it is well-known that the exposure to early life stress experiences induces brain oxidative damage by increasing nitric oxide levels and decreasing antioxidant factors. In the present work, we examined the role of TGF-β1 pathway in an animal model of adolescent depression induced by PNS obtained by exposing pregnant females to a stressful condition during the last week of gestation. We performed behavioral tests to identify vulnerable or resilient subjects in the obtained litters (postnatal day, PND > 35) and we carried out molecular analyses on hippocampus, a brain area with a key role in the pathogenesis of depression. We found that female, but not male, PNS adolescent rats exhibited a depressive-like behavior in forced swim test (FST), whereas both male and female PNS rats showed a deficit of recognition memory as assessed by novel object recognition test (NOR). Interestingly, we found an increased expression of type 2 TGF-β1 receptor (TGFβ-R2) in the hippocampus of both male and female resilient PNS rats, with higher plasma TGF-β1 levels in male, but not in female, PNS rats. Furthermore, PNS induced the activation of oxidative stress pathways by increasing inducible nitric oxide synthase (iNOS), NADPH oxidase 1 (NOX1) and NOX2 levels in the hippocampus of both male and female PNS adolescent rats. Our data suggest that high levels of TGF-β1 and its receptor TGFβ-R2 can significantly increase the resiliency of adolescent rats to PNS, suggesting that TGF-β1 pathway might represent a novel pharmacological target to prevent adolescent depression in rats.
2022
- The Use of Psychotropic Medication in Pediatric Oncology for Acute Psychological and Psychiatric Problems: Balancing Risks and Benefits
[Articolo su rivista]
Blom, Johanna M C; Barisone, Elena; Bertolotti, Marina; Caprino, Daniela; Cellini, Monica; Clerici, Carlo Alfredo; Colliva, Chiara; Favara-Scacco, Cinzia; Di Giuseppe, Silvia; Jankovic, Momcilo; Pancaldi, Alessia; Pani, Luca; Poggi, Geraldina; Rivi, Veronica; Tascedda, Fabio; Torta, Riccardo; Scarponi, Dorella
abstract
Severe acute behavioral and emotional problems represent one of the most serious treatment-related adverse effects for children and adolescents who have cancer. The critical and severe nature of these symptoms often makes necessary the use of psychotropic drugs. A working group composed of experts in multiple disciplines had the task of creating an agreement regarding a management plan for severe acute behavioral and emotional problems (SABEPs) in children and adolescents treated for cancer. To obtain global information on the use of psychotropic drugs in pediatric oncology, the working group first developed and mailed a 15-item questionnaire to many Italian pediatric oncology centers. Overall, an evident lack of knowledge and education regarding the use of psychotropic medications for the treatment of SABEPs was found. Thus, by referring to an adapted version of the Delphi method of consensus and standard methods for the elaboration of clinical questions (PICOs), the working group elaborated evidence-based recommendations for psychotropic drugs in the pediatric oncology setting. Furthermore, based on a thorough multivariate analysis of needs and difficulties, a comprehensive management flow was developed to optimize therapeutic interventions, which allows more accurate and efficient matching of the acute needs of patients while guiding treatment options.
2022
- Too Hot to Eat: Wild and Lab-Bred Lymnaea stagnalis Differ in Feeding Response Following Repeated Heat Exposure
[Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Tascedda, F.; Blom, J. M.; Lukowiak, K.
abstract
AbstractAcute extreme heat events are increasing in frequency and intensity. Understanding their effects on ectothermic organisms' homeostasis is both important and urgent. In this study we found that the exposure to an acute heat shock (30 °C for 1 hour) repeated for a seven-day period severely suppressed the feeding behavior of laboratory-inbred (W-strain) Lymnaea stagnalis, whereas the first-generation offspring of freshly collected wild (F1 D-strain) snails raised and maintained under similar laboratory conditions did not show any alterations. The W-strain snails might have inadvertently been selected against heat tolerance since they were first brought into the laboratory many (∼70) years ago. We also posit that the F1 D-strain snails do not perceive the heat shock as a sufficient stressor to alter their feeding response because their parental populations in wild environments have repeatedly experienced temperature fluctuations, thus becoming more tolerant and resilient to heat. The different responses exhibited by two strains of the same species highlight the importance of selecting the most appropriate strain for addressing questions about the impacts of global warming on organisms' physiology and behavior.
2021
- Antioxidant Activity of Fluoxetine and Vortioxetine in a Non-Transgenic Animal Model of Alzheimer’s Disease
[Articolo su rivista]
Caruso, G.; Grasso, M.; Fidilio, A.; Torrisi, S. A.; Musso, N.; Geraci, F.; Tropea, M. R.; Privitera, A.; Tascedda, F.; Puzzo, D.; Salomone, S.; Drago, F.; Leggio, G. M.; Caraci, F.
abstract
Depression is a risk factor for the development of Alzheimer's disease (AD). A neurobiological and clinical continuum exists between AD and depression, with neuroinflammation and oxidative stress being involved in both diseases. Second-generation antidepressants, in particular selective serotonin reuptake inhibitors (SSRIs), are currently investigated as neuroprotective drugs in AD. By employing a non-transgenic AD model, obtained by intracerebroventricular (i.c.v.) injection of amyloid-β (Aβ) oligomers in 2-month-old C57BL/6 mice, we recently demonstrated that the SSRI fluoxetine (FLX) and the multimodal antidepressant vortioxetine (VTX) reversed the depressive-like phenotype and memory deficits induced by Aβ oligomers rescuing the levels of transforming growth factor-β1 (TGF-β1). Aim of our study was to test FLX and VTX for their ability to prevent oxidative stress in the hippocampus of Aβ-injected mice, a brain area strongly affected in both depression and AD. The long-term intraperitoneal (i.p.) administration of FLX (10 mg/kg) or VTX (5 and 10 mg/kg) for 24 days, starting 7 days before Aβ injection, was able to prevent the over-expression of inducible nitric oxide synthase (iNOS) and NADPH oxidase 2 (Nox2) induced by Aβ oligomers. Antidepressant pre-treatment was also able to rescue the mRNA expression of glutathione peroxidase 1 (Gpx1) antioxidant enzyme. FLX and VTX also prevented Aβ-induced neurodegeneration in mixed neuronal cultures treated with Aβ oligomers. Our data represent the first evidence that the long-term treatment with the antidepressants FLX or VTX can prevent the oxidative stress phenomena related to the cognitive deficits and depressive-like phenotype observed in a non-transgenic animal model of AD.
2021
- Carnosine Protects Macrophages against the Toxicity of Aβ1-42 Oligomers by Decreasing Oxidative Stress
[Articolo su rivista]
Caruso, Giuseppe; Benatti, Cristina; Musso, Nicolò; Fresta, Claudia G.; Fidilio, Annamaria; Spampinato, Giorgia; Brunello, Nicoletta; Bucolo, Claudio; Drago, Filippo; Lunte, Susan M.; Peterson, Blake R.; Tascedda, Fabio; Caraci, Filippo
abstract
2021
- Digital Phenotyping and Dynamic Monitoring of Adolescents Treated for Cancer to Guide Intervention: Embracing a New Era
[Articolo su rivista]
Blom, J. M. C.; Colliva, C.; Benatti, C.; Tascedda, F.; Pani, L.
abstract
2021
- Vortioxetine Prevents Lipopolysaccharide-Induced Memory Impairment Without Inhibiting the Initial Inflammatory Cascade
[Articolo su rivista]
Alboni, S.; Benatti, C.; Colliva, C.; Radighieri, G.; Blom, J. M. C.; Brunello, N.; Tascedda, F.
abstract
Vortioxetine is a novel multimodal antidepressant that modulates a wide range of neurotransmitters throughout the brain. Preclinical and clinical studies have shown that vortioxetine exerts positive effects on different cognitive domains and neuroprotective effects. Considering the key role of microglial cells in brain plasticity and cognition, we aimed at investigating the effects of pretreatment with vortioxetine in modulating behavioral and molecular effects induced by an immune challenge: peripheral injection of lipopolysaccharide (LPS). To this purpose, C57BL/6J male mice were first exposed to a 28-day standard diet or vortioxetine-enriched diet, which was followed by an acute immune challenge with LPS. Sickness symptoms and depressive-like behaviors (anhedonia and memory impairment) were tested 6 and 24 h after exposure to LPS, respectively. Moreover, the expressions of markers of immune activation and M1/M2 markers of microglia polarization were measured in the dorsal and ventral parts of the hippocampus. The pretreatment with vortioxetine did not affect both LPS-induced sickness behavior and anhedonia but prevented the deficit in the recognition memory induced by the immune challenge. At the transcriptional level, chronic exposure to vortioxetine did not prevent LPS-induced upregulation of proinflammatory cytokines 6 h after the immune challenge but rather seemed to potentiate the immune response to the challenge also by affecting the levels of expression of markers of microglia M1 phenotype, like cluster of differentiation (CD)14 and CD86, in an area-dependent manner. However, at the same time point, LPS injection significantly increased the expression of the M2 polarization inducer, interleukin 4, only in the hippocampus of animals chronically exposed to vortioxetine. These results demonstrate that a chronic administration of vortioxetine specifically prevents LPS-induced memory impairment, without affecting acute sickness behavior and anhedonia, and suggest that hippocampal microglia may represent a cellular target of this novel antidepressant medication. Moreover, we provide a useful model to further explore the molecular mechanisms specifically underlying cognitive impairments following an immune challenge.
2021
- What can we teach Lymnaea and what can
Lymnaea teach us?
[Articolo su rivista]
Rivi, Veronica; Benatti, Cristina; Lukowiak, Ken; Colliva, Chiara; Alboni, Silvia; Tascedda, Fabio; Blom, Johanna M. C.
abstract
2020
- Antioxidant properties of second-generation antipsychotics: Focus on microglia
[Articolo su rivista]
Caruso, G.; Grasso, M.; Fidilio, A.; Tascedda, F.; Drago, F.; Caraci, F.
abstract
Recent studies suggest a primary role of oxidative stress in an early phase of the pathogenesis of schizophrenia and a strong neurobiological link has been found between dopaminergic system dysfunction, microglia overactivation, and oxidative stress. Different risk factors for schizophrenia increase oxidative stress phenomena raising the risk of developing psychosis. Oxidative stress induced by first-generation antipsychotics such as haloperidol significantly contributes to the development of extrapyramidal side effects. Haloperidol also exerts neurotoxic effects by decreasing antioxidant enzyme levels then worsening pro-oxidant events. Opposite to haloperidol, second-generation antipsychotics (or atypical antipsychotics) such as risperidone, clozapine, and olanzapine exert a strong antioxidant activity in experimental models of schizophrenia by rescuing the antioxidant system, with an increase in superoxide dismutase and glutathione (GSH) serum levels. Second-generation antipsychotics also improve the antioxidant status and reduce lipid peroxidation in schizophrenic patients. Interestingly, second-generation antipsychotics, such as risperidone, paliperidone, and in particular clozapine, reduce oxidative stress induced by microglia overactivation, decreasing the production of microglia-derived free radicals, finally protecting neurons against microglia-induced oxidative stress. Further, long-term clinical studies are needed to better understand the link between oxidative stress and the clinical response to antipsychotic drugs and the therapeutic potential of antioxidants to increase the response to antipsychotics.
2020
- Biological and neuropsychological markers of cognitive dysfunction in unipolar vs bipolar Depression: What evidence do we have?
[Articolo su rivista]
Platania, G. A.; Varrasi, S.; Castellano, S.; Godos, J.; Pirrone, C.; Petralia, M. C.; Cantarella, R. A.; Tascedda, F.; Guerrera, C. S.; Buono, S.; Caraci, F.; Blom, J. M. C.
abstract
Cognition is a critical aspect of psychopathology. The aim of this review is to evaluate and discuss evidence on the biological and neuropsychological markers of cognitive dysfunction in unipolar and bipolar Depression to improve the differential diagnosis and develop plans of personalized pharmacological treatment. The different use of biological and neuropsychological markers is reviewed and their use to support the clinical process and differential diagnosis is critically examined. While biological markers can help to reduce the risk of misdiagnosis, neuropsychological markers can be assessed more readily and with a less invasive methodology. To this end, additional research on the thresholds differentiating the cognitive dysfunction in unipolar and bipolar Depression should be conducted on specific psychometric tools proposed in this review. Most importantly future effort should be directed towards the validation of both types of markers specifically for these two populations. Finally this review contributes to the field by focusing on the clinical need of a precise differential diagnosis that, when put in a translational framework, should combine an integration of research and clinical practice allowing for a better understanding of mental health and for evidence-based clinical practice.
2020
- Lymnaea stagnalis as model for translational neuroscience research: from pond to bench
[Articolo su rivista]
Rivi, Veronica; Benatti, C; Colliva, C; Radighieri, G; Brunello, N; Tascedda, F; Blom, Johanna
abstract
The purpose of this review is to illustrate how a reductionistic, but sophisticated, approach based on the use of a simple model system such as the pond snail Lymnaea stagnalis (L. stagnalis), might be useful to address fundamental questions in learning and memory. L. stagnalis, as a model, provides an interesting platform to investigate the dialog between the synapse and the nucleus and vice versa during memory and learning. More importantly, the "molecular actors" of the memory dialogue are well-conserved both across phylogenetic groups and learning paradigms, involving single- or multi-trials, aversion or reward, operant or classical conditioning. At the same time, this model could help to study how, where and when the memory dialog is impaired in stressful conditions and during aging and neurodegeneration in humans and thus offers new insights and targets in order to develop innovative therapies and technology for the treatment of a range of neurological and neurodegenerative disorders.
2020
- Microfluidics as a novel tool for biological and toxicological assays in drug discovery processes: Focus on microchip electrophoresis
[Articolo su rivista]
Caruso, G.; Musso, N.; Grasso, M.; Costantino, A.; Lazzarino, G.; Tascedda, F.; Gulisano, M.; Lunte, S. M.; Caraci, F.
abstract
The last decades of biological, toxicological, and pharmacological research have deeply changed the way researchers select the most appropriate 'pre-clinical model'. The absence of relevant animal models for many human diseases, as well as the inaccurate prognosis coming from 'conventional' pre-clinical models, are among the major reasons of the failures observed in clinical trials. This evidence has pushed several research groups to move more often from a classic cellular or animal modeling approach to an alternative and broader vision that includes the involvement of microfluidic-based technologies. The use of microfluidic devices offers several benefits including fast analysis times, high sensitivity and reproducibility, the ability to quantitate multiple chemical species, and the simulation of cellular response mimicking the closest human in vivo milieu. Therefore, they represent a useful way to study drug-organ interactions and related safety and toxicity, and to model organ development and various pathologies 'in a dish'. The present review will address the applicability of microfluidic-based technologies in different systems (2D and 3D). We will focus our attention on applications of microchip electrophoresis (ME) to biological and toxicological studies as well as in drug discovery and development processes. These include high-throughput single-cell gene expression profiling, simultaneous determination of antioxidants and reactive oxygen and nitrogen species, DNA analysis, and sensitive determination of neurotransmitters in biological fluids. We will discuss new data obtained by ME coupled to laser-induced fluorescence (ME-LIF) and electrochemical detection (ME-EC) regarding the production and degradation of nitric oxide, a fundamental signaling molecule regulating virtually every critical cellular function. Finally, the integration of microfluidics with recent innovative technologies-such as organoids, organ-on-chip, and 3D printing-for the design of new in vitro experimental devices will be presented with a specific attention to drug development applications. This 'composite' review highlights the potential impact of 2D and 3D microfluidic systems as a fast, inexpensive, and highly sensitive tool for high-throughput drug screening and preclinical toxicological studies.
2020
- Psychosocial assessment of families caring for a child with acute lymphoblastic leukemia, epilepsy or asthma: Psychosocial risk as network of interacting symptoms
[Articolo su rivista]
Colliva, C.; Cellini, M.; Porta, F. D.; Ferrari, M.; Bergamini, B. M.; Guerra, A.; Di Giuseppe, S.; Pinto, A.; Capasso, R.; Caprino, D.; Ferrari, M.; Benatti, C.; Tascedda, F.; Blom, J. M. C.
abstract
The purpose of this study is to assess psychosocial risk across several pediatric medical conditions and test the hypothesis that different severe or chronic pediatric illnesses are characterized by disease specific enhanced psychosocial risk and that risk is driven by disease specific connectivity and interdependencies among various domains of psychosocial function using the Psychosocial Assessment Tool (PAT). In a multicenter prospective cohort study of 195 patients, aged 5-12, 90 diagnosed with acute lymphoblastic leukemia (ALL), 42 with epilepsy and 63 with asthma, parents completed the PAT2.0 or the PAT2.0 generic version. Multivariate analysis was performed with disease as factor and age as covariate. Graph theory and network analysis was employed to study the connectivity and interdependencies among subscales of the PAT while data-driven cluster analysis was used to test whether common patterns of risk exist among the various diseases. Using a network modelling approach analysis, we observed unique patterns of interconnected domains of psychosocial factors. Each pathology was characterized by different interdependencies among the most central and most connected domains. Furthermore, data-driven cluster analysis resulted in two clusters: patients with ALL (89%) mostly belonged to cluster 1, while patients with epilepsy and asthma belonged primarily to cluster 2 (83% and 82% respectively). In sum, implementing a network approach improves our comprehension concerning the character of the problems central to the development of psychosocial difficulties. Therapy directed at problems related to the most central domain(s) constitutes the more rational one because such an approach will inevitably carry over to other domains that depend on the more central function.
2020
- Redefining operant conditioning of escape behaviour in lymnaea stagnalis
[Articolo su rivista]
Benatti, C.; Rivi, V.; Colliva, C.; Radighieri, G.; Tascedda, F.; Blom, J. M. C.
abstract
The escape behaviour is one of the many behavioural responses that can be operantly conditioned in a stimulus-dependent manner in both vertebrates and invertebrates. By exposing the pond snail Lymnaea stagnalis repeatedly to a negative reinforcement its natural tendency to explore its surroundings can be operantly conditioned in both adult and aged snails. When adult snails were trained with 100 mM of KCl their number of escapes was significantly decreased and the latency to first escape was significantly increased. Our behavioural protocol allowed us to investigate memory acquisition, consolidation, and retrieval in pre-and post-training sessions over different days. From the 3rd day of training the learned response was strengthened: the number of the escapes in the post-test session remained significantly reduced even when animals were presented with distilled water. Moreover, adult snails exposed to the negative reinforcement for at least 4 days started to escape significantly less than the control group also in the pre-test session. This effect became more pronounced in the following days and was accompanied by a significant increase in the latency to first escape at the beginning of the pre-test on day 6 and 7. Aged snails, instead, showed selective deficiencies when operantly conditioned: memory retention appeared only after 7 days, while memory retrieval could not be induced. This redefined paradigm can help unravelling a variety of sophisticated cognitive phenomena in L. stagnalis and could be employed also to study the basis of memory impairment occurring during neuro-aging.
2019
- Cannabidiol-enriched Cannabis sativa L. extract modulates inflammatory-induced human peripheral mononuclear cells response
[Abstract in Atti di Convegno]
Rigillo, G; Borgonetti, V; Benatti, C; Governa, P; Tascedda, F; Biagi, M
abstract
2019
- Carnosine Decreases PMA-Induced Oxidative Stress and Inflammation in Murine Macrophages
[Articolo su rivista]
Caruso, Giuseppe; Fresta, Claudia G.; Fidilio, Annamaria; O’Donnell, Fergal; Musso, Nicolò; Lazzarino, Giacomo; Grasso, Margherita; Amorini, Angela M.; Tascedda, Fabio; Bucolo, Claudio; Drago, Filippo; Tavazzi, Barbara; Lazzarino, Giuseppe; Lunte, Susan M.; Caraci, Filippo
abstract
Carnosine is an endogenous dipeptide composed of β-alanine and L-histidine. This naturally occurring molecule is present at high concentrations in several mammalian excitable tissues such as muscles and brain, while it can be found at low concentrations in a few invertebrates. Carnosine has been shown to be involved in different cellular defense mechanisms including the inhibition of protein cross-linking, reactive oxygen and nitrogen species detoxification as well as the counteraction of inflammation. As a part of the immune response, macrophages are the primary cell type that is activated. These cells play a crucial role in many diseases associated with oxidative stress and inflammation, including atherosclerosis, diabetes, and neurodegenerative diseases. In the present study, carnosine was first tested for its ability to counteract oxidative stress. In our experimental model, represented by RAW 264.7 macrophages challenged with phorbol 12-myristate 13-acetate (PMA) and superoxide dismutase (SOD) inhibitors, carnosine was able to decrease the intracellular concentration of superoxide anions (O2−•) as well as the expression of Nox1 and Nox2 enzyme genes. This carnosine antioxidant activity was accompanied by the attenuation of the PMA-induced Akt phosphorylation, the down-regulation of TNF-α and IL-6 mRNAs, and the up-regulation of the expression of the anti-inflammatory mediators IL-4, IL-10, and TGF-β1. Additionally, when carnosine was used at the highest dose (20 mM), there was a generalized amelioration of the macrophage energy state, evaluated through the increase both in the total nucleoside triphosphate concentrations and the sum of the pool of intracellular nicotinic coenzymes. Finally, carnosine was able to decrease the oxidized (NADP+)/reduced (NADPH) ratio of nicotinamide adenine dinucleotide phosphate in a concentration dependent manner, indicating a strong inhibitory effect of this molecule towards the main source of reactive oxygen species in macrophages. Our data suggest a multimodal mechanism of action of carnosine underlying its beneficial effects on macrophage cells under oxidative stress and inflammation conditions.
2019
- Executive functioning in children with epilepsy: Genes matter
[Articolo su rivista]
Colliva, Chiara; Ferrari, Marta; Benatti, Cristina; Guerra, Azzurra; Tascedda, Fabio; Blom, Johanna Maria Catharina
abstract
Pediatric epilepsy has emerged as a chronic medical disease with a characteristic behavioral and cognitive phenotype, which includes compromised executive functioning (EF) and attention-related deficits. However, considerable interindividual variability exists; children often display very different or even opposite outcomes, and some children are more likely than others to develop neurocognitive problems in the face of similar individual and disease-related problems. The factors responsible for this interindividual variability are still largely unknown, but we do know that some genetic factors render the developing brain more susceptible to damage or traumatic experiences than others. Dopamine availability has a neuromodulatory function in the prefrontal cortex (PFC) and especially affects EF. Dopamine availability relates to polymorphisms in the gene encoding catechol-O-methyltransferase (COMT Val158Met), which in turn is affected by the methylation state of its promoter. Allelic variation of the methylenetetrahydrofolate reductase (MTHFR C677T) gene, alters methylation and may influence the methylation state of the COMT promoter. Given this, we tested the hypothesis that these polymorphisms interact in children with epilepsy, and that variability in allelic expression is associated with variability in cognitive phenotype. Executive function was tested directly and indirectly (parent-rated) in 42 children between 5 and 12 years of age. The MTHFR T allele carriers performed worse than MTHFR homozygous CC carriers on indirect EF, and a significant decline was observed when T allele carriers had at least one met allele of the COMT gene, especially on Working Memory. Direct EF was significantly compromised in COMT Val/Val carriers where reduced dopamine availability seems to confer a higher risk in a test that requests a high degree of executive attention and planning. This finding suggests that in children with epilepsy, genes that influence methylation and dopamine availability affect PFC-related EF. Therefore, we should consider genetic vulnerability as a polygenic risk, which might predispose for a particular phenotype and include specific genetic signatures as part of each patient's behavioral and cognitive profile from the moment that we start to take care of the child.
2019
- Fluoxetine and vortioxetine reverse depressive-like phenotype and memory deficits induced by Aβ1-42 oligomers in mice: A key role of transforming growth factor-β1
[Articolo su rivista]
Torrisi, S. A.; Geraci, F.; Tropea, M. R.; Grasso, M.; Caruso, G.; Fidilio, A.; Musso, N.; Sanfilippo, G.; Tascedda, F.; Palmeri, A.; Salomone, S.; Drago, F.; Puzzo, D.; Leggio, G. M.; Caraci, F.
abstract
Depression is a risk factor for the development of Alzheimer's disease (AD), and the presence of depressive symptoms significantly increases the conversion of mild cognitive impairment (MCI) into AD. A long-term treatment with antidepressants reduces the risk to develop AD, and different second-generation antidepressants such as selective serotonin reuptake inhibitors (SSRIs) are currently being studied for their neuroprotective properties in AD. In the present work, the SSRI fluoxetine and the new multimodal antidepressant vortioxetine were tested for their ability to prevent memory deficits and depressive-like phenotype induced by intracerebroventricular injection of amyloid-beta (1-42) (A beta(1-42)) oligomers in 2-month-old C57BL/6 mice. Starting from 7 days before A beta injection, fluoxetine (10 mg/kg) and vortioxetine (5 and 10 mg/kg) were intraperitoneally injected daily for 24 days. Chronic treatment with fluoxetine and vortioxetine (both at the dose of 10 mg/kg) was able to rescue the loss of memory assessed 14 days after A beta injection by the passive avoidance task and the object recognition test. Both antidepressants reversed the increase in immobility time detected 19 days after A beta injection by forced swim test. Vortioxetine exerted significant antidepressant effects also at the dose of 5 mg/kg. A significant deficit of transforming growth factor-beta 1 (TGF-beta 1), paralleling memory deficits and depressive-like phenotype, was found in the hippocampus of A beta -injected mice in combination with a significant reduction of the synaptic proteins synaptophysin and PSD-95. Fluoxetine and vortioxetine completely rescued hippocampal TGF-beta 1 levels in A beta -injected mice as well as synaptophysin and PSD-95 levels. This is the first evidence that a chronic treatment with fluoxetine or vortioxetine can prevent both cognitive deficits and depressive-like phenotype in a non-transgenic animal model of AD with a key contribution of TGF-beta 1.
2019
- Modulation of neuroplasticity-related targets following stress-induced acute escape deficit
[Articolo su rivista]
Benatti, C.; Radighieri, Giulia; Alboni, S.; Blom, J. M. C.; Brunello, N.; Tascedda, F.
abstract
Understanding resilience is a major challenge to improve current pharmacological therapies aimed at complementing psychological-based approaches of stress-related disorders. In particular, resilience is a multi-factorial construct where the complex network of molecular events that drive the process still needs to be resolved. Here, we exploit the acute escape deficit model, an animal model based on exposure to acute unavoidable stress followed by an escape test, to define vulnerable and resilient phenotypes in rats. Hippocampus and prefrontal cortex (PFC), two of the brain areas most involved in the stress response, were analysed for gene expression at two different time points (3 and 24 h) after the escape test. Total Brain-Derived Neurotrophic Factor (BDNF) was highly responsive in the PFC at 24-h after the escape test, while expression of BDNF transcript IV increased in the hippocampus of resistant animals 3 h post-test. Expression of memory enhancers like Neuronal PAS Domain Protein 4 (Npas4) and Activity-regulated cytoskeleton-associated protein (Arc) decreased in a time- and region-dependent fashion in both behavioural phenotypes. Also, the memory inhibitor Protein Phosphatase 1 (Ppp1ca) was increased in the hippocampus of resilient rats at 3 h post-test. Given the importance of neurotrophic factors and synaptic plasticity-related genes for the development of appropriate coping strategies, our data contribute to an additional step forward in the comprehension of the psychobiology of stress and resiliency.
2019
- P.1.04 Expression of histone variants H3.3 and H2a.z in the rat brain: Physiopathological and pharmacological implications
[Abstract in Rivista]
Radighieri, G.; Benatti, C.; Zoli, M.; Blom, J. M. C.; Brunello, N.; Tascedda, F.
abstract
In the overall context of epigenetic modifications in charge of managing genome plasticity and dynamics [1, 2], the role of nucleosomal loading of histone variants is becoming increasingly captivating. Two replication-independent isoforms of histones H3 and H2A, namely H3.3 and H2A.Z, have caught attention because of their involvement in neuronal plasticity processes, cognitive functions and behavioral outcomes. In fact, their incorporation/eviction in nucleosomes and their turnover in neurons influence chromatin accessibility and therefore transcription. H3.3 enrichment at gene bodies and promoters of genes involved in synaptic plasticity was proved to be positively correlated with their expression, while learning-induced H2A.Z eviction in specific genes promotes gene transcription, intervening in memory consolidation processes. H3.3 is encoded by H3f3a and H3f3b independent genes, generating identical proteins, namely H3.3A and H3.3B. Notably, H3f3b gene, but not H3f3a, was proved responsive to neuronal activating stimuli as well as environmental triggers and stressful procedures [3]. H2A.Z hypervariants H2A.Z.1 and H2A.Z.2, encoded respectively by H2afz and H2afv genes, regulate both basal and stimulus-induced neuronal gene expression of independent gene sets [4]. Starting from this evidence, the purpose of this study was to characterize basal expression levels of all genes encoding for the histones variants above mentioned in rodent hippocampus and prefrontal cortex (PFC), two brain regions closely related to brain plasticity, cognition and behavior. Adult male rats (n=7) were sacrificed, their brains removed and dissected. Total RNA extraction was performed, followed by total RNA reverse transcription and Real Time PCR, where specific forward and reverse primer were used for each gene encoding for H3.3 (H3f3a and H3f3b), H2A.Z (H2afz and H2afv) and endogenous control GAPDH. Statistical analysis was performed by means of one-way ANOVA; p<0.05 was considered as a threshold for statistically significant difference. Molecular analyses revealed that, for both hippocampus and PFC, H3f3a mRNA was more expressed at the steady-state compared to H3f3b (p<0.001), as happens for H2afz mRNA, which displays higher levels than H2afv (p<0.001). Moreover, comparing hippocampal and PFC mRNA levels for each variant, H3f3a and H3f3b expression was increased in the hippocampus with respect to the prefrontal cortex (p<0.001), and a comparable outcome was showed for H2afv (p<0.001) but not for H2afz (p>0.05). Our results suggest that 1) differential basal expression levels of genes encoding for H3.3 and H2A.Z may underlie unique gene responsiveness following different stimuli, as previously hypothesized by others [3,4], and this may be crucial in highly-responsive, pathological- and environment-related tissues like hippocampus and PFC; 2) striking lower steady-state expression of H3f3b and H2afv genes might imply a major sensitivity to neuronal inputs compared to their correspondent counterparts; 3) higher expression levels in the hippocampus with respect to the PFC might underpin brain-region specific expression and function for histone variants and their isoforms. Together, these data clear the way for further studies meant at investigating stimulus-dependent regulation of H3.3 and H2A.Z gene isoforms expression and their putative involvement in the physiopathology of brain and its diseases [5]. References [1] Rigillo, G., Vilella, A., Benatti, C., Schaeffer, L., Brunello, N., Blom, J.M.C., Zoli, M., Tascedda, F., 2018. LPS-induced histone H3 phospho(Ser10)-acetylation(Lys14) regulates neuronal and microglial neuroinflammatory response. Brain Behav Immun. https://doi.org/10.1016/j.bbi.2018.09.019. [2] Ottaviani, E., Accorsi, A., Rigillo, G., Malagoli, D., Blom, J.M., Tascedda, F., 2013. Epigenetic modification in neurons of the mollusc Pomacea canaliculata after immune challe
2019
- The many faces of mitochondrial dysfunction in depression: From pathology to treatment
[Articolo su rivista]
Caruso, G.; Benatti, C.; Blom, J. M. C.; Caraci, F.; Tascedda, F.
abstract
Introduction
The last years of neurobiological research have transformed the way we consider mental illnesses. We have gone from a deterministic genetic view to a broader vision that includes the involvement of non-cerebral systems. This is especially true for major depression (MD). Historically, MD has been perceived as a multifactorial disorder correlated to various neurobiological changes like neurotransmitter deficits, endocrine disturbances, impaired plasticity, and neural adaptation (Benatti et al., 2016). Indeed, the development and progression of depressive disorders has been conceived as the disruption of body allostasis, defined as the process of achieving stability of physiological and mental processes through dynamic change (Wang et al., 2019). The main player in the “allostatic game” is the brain, an organ designed to integrate signals from the periphery that anticipate fluctuations, changes, and needs and coordinates allostatic mediators in order to develop successful coping mechanisms that ultimately lead to an adaptative strategy and resilience (de Kloet et al., 2005).
The establishment and maintenance of these mechanisms requires large amounts of energy from the organism. Without energy, or in a partial lack of energy, the biological mechanisms necessary to respond appropriately to stimuli may not occur or be established incorrectly or abnormally.
Human and animal studies suggest an intriguing link between our body’s ability to produce energy and the brain’s ability to correctly perform the complex cellular and molecular processes involved in allostatic processes.
In eukaryotic cells, mitochondria are the powerhouse that produces and distributes energy to all other components. Functional or quantitative alterations of the ability of mitochondria to adequately supply energy can have important repercussions primarily on cellular processes and cascades of serial events (Herst et al., 2017) as well as on the correct functioning of the organism including mechanisms of brain plasticity, mood, and behavior in general (Allen et al., 2018). In this framework, it is particularly intriguing to think of the mitochondria as an active regulator of many of the biological phenomena involved in depression and in the efficacy of or resistance to the most widely used pharmacological treatments.
Once the energetic equilibrium is compromised, the body becomes more “vulnerable.” This is especially true for stress-related disorders, such as depression. In fact, depression is often associated with energetic imbalance leading to profound effects on the disease (Zuccoli et al., 2017). The driving questions then are as follows: What happens to the brain in the presence of an energetic imbalance? Does depression or depression-related symptoms impact mitochondrial energetic efficiency? Is antidepressant efficacy mediated by mitochondrial functionality?
2018
- LPS-induced histone H3 phospho(Ser10)-acetylation(Lys14) regulates neuronal and microglial neuroinflammatory response
[Articolo su rivista]
Rigillo, Giovanna; Vilella, Antonietta; Benatti, Cristina; Schaeffer, Laurent; Brunello, Nicoletta; Blom, Johanna M. C.; Zoli, Michele; Tascedda, Fabio
abstract
Epigenetic modifications of DNA and histone proteins are emerging as fundamental mechanisms by which neural cells adapt their transcriptional response to environmental cues, such as, immune stimuli or stress. In particular, histone H3 phospho(Ser10)-acetylation(Lys14) (H3S10phK14ac) has been linked to activation of specific gene expression. The purpose of this study was to investigate the role of H3S10phK14ac in a neuroinflammatory condition. Adult male rats received a intraperitoneal injection of lipopolysaccharide (LPS) (830 μg/Kg/i.p., n = 6) or vehicle (saline 1 mL/kg/i.p., n = 6) and were sacrificed 2 or 6 h later. We showed marked region- and time-specific increases in H3S10phK14ac in the hypothalamus and hippocampus, two principal target regions of LPS. These changes were accompanied by a marked transcriptional activation of interleukin (IL) 1β, IL-6, Tumour Necrosis Factor (TNF) α, the inducible nitric oxide synthase (iNOS) and the immediate early gene c-Fos. By means of chromatin immunoprecipitation, we demonstrated an increased region- and time-specific association of H3S10phK14ac with the promoters of IL-6, c-Fos and iNOS genes, suggesting that part of the LPS-induced transcriptional activation of these genes is regulated by H3S10phK14ac. Finally, by means of multiple immunofluorescence approach, we showed that increased H3S10phK14ac is cell type-specific, being neurons and reactive microglia, the principal histological types involved in this response. Present data point to H3S10phK14ac as a principal epigenetic regulator of neural cell response to systemic LPS and underline the importance of distinct time-, region- and cell-specific epigenetic mechanisms that regulate gene transcription to understand the mechanistic complexity of neuroinflammatory response to immune challenges.
2018
- Molecular changes associated with escitalopram response in a stress-based model of depression
[Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Blom, Johanna Maria Catharina; Mendlewicz, Julien; Tascedda, Fabio; Brunello, Nicoletta
abstract
Converging evidence points at hypothalamus-pituitary-adrenal (HPA) axis hyperactivity and neuroinflammation as important factors involved in the etiopathogenesis of major depressive disorder (MDD) and in therapeutic efficacy of antidepressants. In this study, we examined the molecular effects associated with a response to a week-long treatment with escitalopram in the chronic escape deficit (CED) model, a validated model of depression based on the induction of an escape deficit after exposure of rats to an unavoidable stress. We confirmed our previous result that a treatment with escitalopram (10 mg/kg) was effective after 7 days in reverting the stress-induced escape deficit in approximately 50% of the animals, separating responders from non-responders. Expression of markers of HPA axis functionality as well as several inflammatory mediators were evaluated in the hypothalamus, a key structure integrating signals from the neuro, immune, endocrine systems. In the hypothalamus of responder animals we observed a decrease in the expression of CRH and its receptors and an increase in GR protein in total and nuclear extracts; this effect was accompanied by a significant decrease in circulating corticosterone in the same cohort. Hypothalamic IL-1β and TNFα expression were increased in stressed animals, while CXCL2, IL-6, and ADAM17 mRNA levels were decreased in escitalopram treated rats regardless of the treatment response. These data suggest that efficacy of a one week treatment with escitalopram may be partially mediated by a decrease HPA axis activity, while in the hypothalamus the drug-induced effects on the expression of immune modulators did not correlate with the behavioural outcome.
2018
- Neither all anti-inflammatory drugs nor all doses are effective in accelerating the antidepressant-like effect of fluoxetine in an animal model of depression
[Articolo su rivista]
Alboni, Silvia; Benatti, Cristina; Capone, Giacomo; Tascedda, Fabio; Brunello, Nicoletta
abstract
Introduction: Non-steroidal anti-inflammatory drugs (NSAIDs) have been studied as possible adjunctive therapy in the treatment of depression. However, administering NSAIDs to increase the effectiveness of antidepressant has yielded inconsistent results. Methods: We evaluated the effect of the co-administration of fluoxetine (5 mg/kg) and flurbiprofen (5 mg/kg) or fluoxetine (5 mg/kg) and celecoxib (5 mg/kg) in the chronic escape deficit (CED) model of depression after 7 days of treatment. The co-administration of fluoxetine plus acetylsalicylic acid (ASA, 45 mg/kg i.p.) was used as a positive control. Moreover, we tested the behavioral effect of different doses (45, 22.5, and 11.25 mg/Kg i.p.) of ASA as potentiating agent of the effect of fluoxetine in the same paradigm. Results: Our study showed that only the co-administration of ASA with fluoxetine was able to revert the stress-induced condition of escape deficit after 7 days of treatment, and that the amplitude of the antidepressant-like effect of ASA was dose dependent. In the same experimental conditions, celecoxib with fluoxetine only partially resolved the stress-induced impaired behavior while flurbiprofen/fluoxetine cotreatment was ineffective. Limitations: Our study is still exploratory, more doses, longer treatment regimens, and different behavioral outcomes must be investigated to draw a clear conclusion. Conclusion: Our results further stress the importance of the type and dose when NSAIDs are associated with antidepressants to ameliorate a clinical response.
2018
- Neurobiological links between depression and AD: The role of TGF-β1 signaling as a new pharmacological target
[Articolo su rivista]
Caraci, Filippo; Spampinato, Simona Federica; Morgese, Maria Grazia; Tascedda, Fabio; Salluzzo, Maria Grazia; Giambirtone, Maria Concetta; Caruso, Giuseppe; Munafò, Antonio; Torrisi, Sebastiano Alfio; Leggio, Gian Marco; Trabace, Luigia; Nicoletti, Ferdinando; Drago, Filippo; Sortino, Maria Angela; Copani, Agata
abstract
In the last several years a large number of studies have demonstrated the neurobiological and clinical continuum between depression and Alzheimer's disease (AD). Depression is a risk factor for the development of AD, and the presence of depressive symptoms significantly increases the conversion of Mild Cognitive Impairment (MCI) into AD. Common pathophysiological events have been identified in depression and AD, including neuroinflammation with an aberrant Tumor Necrosis Factor-α (TNF-α) signaling, and an impairment of Brain-Derived Neurotrophic Factor (BDNF) and Transforming-Growth-Factor-β1 (TGF-β1) signaling.TGF-β1 is an anti-inflammatory cytokine that exerts neuroprotective effects against amyloid-β (Aβ)-induced neurodegeneration, and it has a key role in memory formation and synaptic plasticity. TGF-β1 plasma levels are reduced in major depressed patients (MDD), correlate with depression severity, and significantly contribute to treatment resistance in MDD. The deficit of Smad-dependent TGF-β1 signaling is also an early event in AD pathogenesis, which contributes to inflammaging and cognitive decline in AD. A long-term treatment with antidepressants such as selective-serotonin-reuptake inhibitors (SSRIs) is known to reduce the risk of AD in patients with depression and, SSRIs, such as fluoxetine, increase the release of TGF-β1 from astrocytes and exert relevant neuroprotective effects in experimental models of AD.We propose the TGF-β1 signaling pathway as a common pharmacological target in depression and AD, and discuss the potential rescue of TGF-β1 signaling by antidepressants as a way to prevent the transition from depression to AD.
2017
- Circulating phagocytes: The ancient and conserved interface between immune and neuroendocrine function
[Articolo su rivista]
Malagoli, Davide; Mandrioli, Mauro; Tascedda, Fabio; Ottaviani, Enzo
abstract
Immune and neuroendocrine functions display significant overlap in highly divergent and evolutionarily distant models such as molluscs, crustaceans, insects and mammals. Fundamental players in this crosstalk are professional phagocytes: macrophages in vertebrates and immunocytes in invertebrates. Although they have different developmental origins, macrophages and immunocytes possess comparable functions and differentiate under the control of evolutionarily conserved transcription factors. Macrophages and immunocytes share their pools of receptors, signalling molecules and pathways with neural cells and the neuro-endocrine system. In crustaceans, adult transdifferentiation of circulating haemocytes into neural cells has been documented recently. In light of developmental, molecular and functional evidence, we propose that the immune-neuroendocrine role of circulating phagocytes pre-dates the split of protostomian and deuterostomian superphyla and has been conserved during the evolution of the main groups of metazoans.
2017
- Lymnaea stagnalis as model of neuropsychiatric disorders
[Articolo su rivista]
Tascedda, F.
abstract
This paper describes the advantages of
adopting a molluscan model for studying the
biological basis of some central nervous system
pathologies affecting humans. In particular, I will
focus on the freshwater snail Lymnaea stagnalis,
which is already the subject of electrophysiological
studies related to learning and memory, as well as
ecotoxicological studies
2017
- Mitochondrial energy metabolism of rat hippocampus after treatment with the antidepressants desipramine and fluoxetine
[Articolo su rivista]
Villa, Roberto Federico; Ferrari, Federica; Bagini, Laura; Gorini, Antonella; Brunello, Nicoletta; Tascedda, Fabio
abstract
Alterations in mitochondrial functions have been hypothesized to participate in the pathogenesis of depression, because brain bioenergetic abnormalities have been detected in depressed patients by neuroimaging in vivo studies. However, this hypothesis is not clearly demonstrated in experimental studies: some suggest that antidepressants are inhibitors of mitochondrial metabolism, while others observe the opposite. In this study, the effects of 21-day treatment with desipramine (15 mg/kg) and fluoxetine (10 mg/kg) were examined on the energy metabolism of rat hippocampus, evaluating the catalytic activity of regulatory enzymes of mitochondrial energy-yielding metabolic pathways. Because of the micro-heterogeneity of brain mitochondria, we have distinguished between (a) non-synaptic mitochondria (FM) of neuronal perikaryon (post-synaptic compartment) and (b) intra-synaptic light (LM) and heavy (HM) mitochondria (pre-synaptic compartment). Desipramine and fluoxetine changed the catalytic activity of specific enzymes in the different types of mitochondria: (a) in FM, both drugs enhanced cytochrome oxidase and glutamate dehydrogenase, (b) in LM, the overall bioenergetics was unaffected and (c) in HM only desipramine increased malate dehydrogenase and decreased the activities of Electron Transport Chain Complexes. These results integrate the pharmacodynamic features of desipramine and fluoxetine at subcellular level, overcoming the previous conflicting data about the effects of antidepressants on brain energy metabolism, mainly referred to whole brain homogenates or to bulk of cerebral mitochondria. With the differentiation in non-synaptic and intra-synaptic mitochondria, this study demonstrates that desipramine and fluoxetine lead to adjustments in the mitochondrial bioenergetics respect to the energy requirements of pre- and post-synaptic compartments.
2017
- Transcriptional effect of serotonin in the ganglia of Lymnaea stagnalis
[Articolo su rivista]
Benatti, Cristina; Colliva, Chiara; Blom, Johanna Maria Catharina; Ottaviani, Enzo; Tascedda, Fabio
abstract
The serotonin system (5HT) is highly conserved in both vertebrates and invertebrates, and numerous evidence supports a biological link between 5HT and numerous animal function. In the present paper we evaluated the transcriptional effects of a serotonergic stimulation on selected targets involved in 5HT signalling and neurotransmission in the central nervous system of the great pond snail Lymnaea stagnalis. Adult snails were treated acutely (6 h) or chronically (48 h) with either 5-hydroxytrypthophan (5-HTP 1mM), the immediate precursor of serotonin, fluoxetine (FLX 1μM), a selective serotonin reuptake inhibitor, or a combination of two. The central ring ganglia were dissected and used for q-PCR gene expression analysis. Transcription was strongly induced following a chronic, but not an acute, exposure to 5-HTP in the ganglia of Lymnaea. In particular, LymCREB1 and LymP2X mRNA levels were decreased following a 6 h exposure and increased in snails receiving 5-hydroxytryptophan for 48 h. Interestingly, this effect was reduced when snails were exposed chronically to both 5-HTP and FLX, suggesting a role for SERT in mediating the effect of 5-hydroxytryptophan. These data suggest that L. stagnalis is suited to unravel the complexity of the serotonin signaling pathway.
2016
- Biologically active peptides in molluscs
[Articolo su rivista]
Tascedda, Fabio; Ottaviani, Enzo
abstract
The immune and neuroendocrine systems of invertebrates, as well as vertebrates, share a common pool of molecules that have been conserved throughout evolution. Now we add a new interface to this bidirectional interaction, demonstrating the involvement of the gut system, showing that these three systems use the same biologically active peptides.
2016
- Changes in the NMR Metabolic Profile of Live Human Neuron-Like SH-SY5Y Cells Exposed to Interferon-α2
[Articolo su rivista]
Valeria, Righi; Schenetti, Luisa; Mucci, Adele; Benatti, Stefania; Tascedda, Fabio; Brunello, Nicoletta; Carmine, Pariante M; Alboni, Silvia
abstract
Interferon (IFN)-α2 is an extensively therapeutically used pro-inflammatory cytokine. Though its efficacy in controlling viral replication and tumor cells proliferation, administration of IFN-α2 is often associated with the development of central side effects. Magnetic resonance spectroscopy studies have demonstrated that IFN-α2 administration affects brain metabolism, however the exact nature of this effect is not completely known. We hypothesized that IFN-α2 can affect metabolic activity of human neuron-like SH-SY5Y cells which possess many characteristics of neurons and represent one of the most used models for studying mechanisms involved in neurotoxicity or neuroprotection. To test our hypothesis we have characterized the metabolic signature of live SH-SY5Y, and their conditioned media, after 24 and 72 h of exposure to vehicle or IFN-α2 (100 ng/ml) by using High Resolution-Magic Angle Spinning (HR-MAS) Nuclear Magnetic Resonance (NMR) spectroscopy. Our results revealed that 1) the use of HR-MAS NMR is ideally suitable for the characterization of the metabolic profile of live cells and their conditioned media without extraction procedures; and 2) a 72 h exposure to IFN-α2 increases the level of metabolites involved in maintaining energetic (including creatine and lactate) and osmotic (such as myo-inositol, scyllo-inositol, taurine and glycerophosphorylcholine) balances in neuron-like cells and of metabolic waste products (namely lactate, ethanol and acetate), glycine and glutamine in their growth media. These results may contribute to gain more knowledge about the IFN-α2 induced effect on the brain and support the interpretation of magnetic resonance spectroscopy studies performed in humans.
2016
- Disease-induced neuroinflammation and depression
[Articolo su rivista]
Benatti, Cristina; Blom, Johanna Maria Catharina; Rigillo, Giovanna; Alboni, Silvia; Zizzi, Francesca; Torta, Riccardo; Brunello, Nicoletta; Tascedda, Fabio
abstract
Progression of major depression, a multifactorial disorder with a neuroinflammatory signature, seems to be associated with the disruption of body allostasis. High rates of comorbidity between depression and specific medical disorders, such as, stroke, chronic pain conditions, diabetes mellitus, and human immunodeficiency virus (HIV) infection, have been extensively reported. In this review, we discuss how these medical disorders may predispose an individual to develop depression by examining the impact of these disorders on some hallmarks of neuroinflammation known to be impaired in depressed patients: altered permeability of the blood brain barrier, immune cells infiltration, activated microglia, increased cytokines production, and the role of inflammasomes. In all four pathologies, blood brain barrier integrity was altered, allowing the infiltration of peripheral factors, known to activate resident microglia. Evidence indicated morphological changes in the glial population, increased levels of circulating pro-inflammatory cytokines or increased production of these mediators within the brain, all fundamental in neuroinflammation, for the four medical disorders considered. Moreover, activity of the kynurenine pathway appeared to be enhanced. With respect to the inflammasome NLRP3, a new target whose role in neuroinflammation is emerging as being important, accumulating data suggest its involvement in the pathogenesis of brain injury following stroke, chronic pain conditions, diabetes mellitus or in HIV associated immune impairment. Finally, data gathered over the last 10 years, indicate and confirm that depression, stroke, chronic pain, diabetes, and HIV infection share a combination of underlying molecular, cellular and network mechanisms leading to a general increase in the neuroinflammatory burden for the individual.
2016
- Effect of desipramine and fluoxetine on energy metabolism of cerebral mitochondria
[Articolo su rivista]
Villa, Roberto Federico; Ferrari, Federica; Gorini, Antonella; Brunello, Nicoletta; Tascedda, Fabio
abstract
Brain bioenergetic abnormalities in mood disorders were detected by neuroimaging in vivo studies in humans. Because of the increasing importance of mitochondrial pathogenetic hypothesis of Depression, in this study the effects of sub-chronic treatment (21 days) with desipramine (15 mg/kg) and fluoxetine (10 mg/kg) were evaluated on brain energy metabolism. On mitochondria in vivo located in neuronal soma (somatic) and on mitochondria of synapses (synaptic), the catalytic activities of regulatory enzymes of mitochondrial energy-yielding metabolic pathways were assayed.Antidepressants in vivo treatment modified the activities of selected enzymes of different mitochondria, leading to metabolic modifications in the energy metabolism of brain cortex: (a) the enhancement of cytochrome oxidase activity on somatic mitochondria; (b) the decrease of malate, succinate dehydrogenase and glutamate-pyruvate transaminase activities of synaptic mitochondria; (c) the selective effect of fluoxetine on enzymes related to glutamate metabolism.These results overcome the conflicting data so far obtained with antidepressants on brain energy metabolism, because the enzymatic analyses were made on mitochondria with diversified neuronal in vivo localization, i.e. on somatic and synaptic. This research is the first investigation on the pharmacodynamics of antidepressants studied at subcellular level, in the perspective of (i) assessing the role of energy metabolism of cerebral mitochondria in animal models of mood disorders, and (ii) highlighting new therapeutical strategies for antidepressants targeting brain bioenergetics.
2016
- Erratum to: Changes in the NMR Metabolic Profile of Live Human Neuron-Like SH-SY5Y Cells Exposed to Interferon-α2 (J Neuroimmune Pharmacol, 2015, DOI 10.1007/s11481-015-9641-x)
[Altro]
Righi, Valeria; Schenetti, Luisa; Mucci, Adele; Benatti, Stefania; Tascedda, Fabio; Brunello, Nicoletta; Pariante, Carmine M.; Alboni, Silvia
abstract
Erratum
2016
- Fluoxetine prevents Aβ1-42-induced toxicity via a paracrine signaling mediated by transforming-growth-factor-β1
[Articolo su rivista]
Caraci, Filippo; Tascedda, Fabio; Merlo, Sara; Benatti, Cristina; Spampinato, Simona F.; Munafò, Antonio; Leggio, Gian Marco; Nicoletti, Ferdinando; Brunello, Nicoletta; Drago, Filippo; Sortino, Maria Angela; Copani, Agata
abstract
Selective reuptake inhibitors (SSRIs), such as fluoxetine and sertraline, increase circulating Transforming-Growth-Factor-β1 (TGF-β1) levels in depressed patients, and are currently studied for their neuroprotective properties in Alzheimer's disease. TGF-β1 is an anti-inflammatory cytokine that exerts neuroprotective effects against β-amyloid (Aβ)-induced neurodegeneration. In the present work, the SSRI, fluoxetine, was tested for the ability to protect cortical neurons against 1 μM oligomeric Aβ1-42-induced toxicity. At therapeutic concentrations (100 nM-1 μM), fluoxetine significantly prevented Aβ-induced toxicity in mixed glia-neuronal cultures, but not in pure neuronal cultures. Though to a lesser extent, also sertraline was neuroprotective in mixed cultures, whereas serotonin (10 nM-10 μM) did not mimick fluoxetine effects. Glia-conditioned medium collected from astrocytes challenged with fluoxetine protected pure cortical neurons against Aβ toxicity. The effect was lost in the presence of a neutralizing antibody against TGF-β1 in the conditioned medium, or when the specific inhibitor of type-1 TGF-β1 receptor, SB431542, was added to pure neuronal cultures. Accordingly, a 24 h treatment of cortical astrocytes with fluoxetine promoted the release of active TGF-β1 in the culture media through the conversion of latent TGF-β1 to mature TGF-β1. Unlike fluoxetine, both serotonin and sertraline did not stimulate the astrocyte release of active TGF-β1. We conclude that fluoxetine is neuroprotective against Aβ toxicity via a paracrine signaling mediated by TGF-β1, which does not result from a simplistic SERT blockade.
2016
- The proinflammatory cytokine interleukin 18 regulates feeding by acting on the bed nucleus of the stria terminalis
[Articolo su rivista]
Francesconi, Walter; Sánchez Alavez, Manuel; Berton, Fulvia; Alboni, Silvia; Benatti, Cristina; Mori, Simone; Nguyen, William; Zorrilla, Eric; Moroncini, Gianluca; Tascedda, Fabio; Conti, Bruno
abstract
The proinflammatory cytokine IL-18 has central anorexigenic effects and was proposed to contribute to loss of appetite observed during sickness. Here we tested in the mouse the hypothesis that IL-18 can decrease food intake by acting on neurons of the bed nucleus of the stria terminalis (BST), a component of extended amygdala recently shown to influence feeding via its projections to the lateral hypothalamus (LH). We found that both subunits of the heterodimeric IL-18 receptor are highly expressed in the BST and that local injection of recombinant IL-18 (50 ng/ml) significantly reduced c-fos activation and food intake for at least 6 h. Electrophysiological experiments performed in BST brain slices demonstrated that IL-18 strongly reduces the excitatory input on BST neurons through a presynaptic mechanism. The effects of IL-18 are cell-specific and were observed in Type III but not in Type I/II neurons. Interestingly, IL-18-sensitve Type III neurons were recorded in the juxtacapsular BST, a region that contains BST-LH projecting neurons. Reducing the excitatory input on Type III GABAergic neurons, IL-18 can increase the firing of glutamatergic LH neurons through a disinhibitory mechanism. Imbalance between excitatory and inhibitory activity in the LH can induce changes in food intake. Effects of IL-18 were mediated by the IL-18R because they were absent in neurons from animals null for IL-18Rα (Il18ra-/-), which lack functional IL-18 receptors. In conclusion, our data show that IL-18 may inhibit feeding by inhibiting the activity of BST Type III GABAergic neurons.
2016
- Use of Psychotropic Drugs for Acute Psychiatric and Behavioral Problems in Paediatric Oncology: A Multi-Center Study
[Abstract in Atti di Convegno]
Blom, Johanna Maria Catharina; Bertolotti, M; Barisone, E; Di Giuseppe, S; Scarponi, D; Vignola, V; Migliozzi, C; Pancaldi, Alessia; Cellini, M; Tascedda, Fabio
abstract
Background/Objectives: : Children and adolescents diagnosed with cancer are forced in the most unexpected way to cope with an extraordinary, highly unlikely event. Such an experience can be extremely disruptive. When symptoms become pathological and impair a child's development and functioning, early intervention is warranted. Given that severe childhood and adolescent adversities may negatively impact adult mental health, our aim was to critically examine, the advantages and disadvantages of acute symptom management and (short-term) psychopharmacological interventions in these severely ill patients.
Design/Methods: Twenty-one patients (1-18 years old) diagnosed with cancer were enrolled in five centers. Categorical variables were analyzed with descriptive statistics and open-ended questions were examined qualitatively. Because of the importance of developmental phase, patients were divided in three age groups: 1) aged 1-6: 2) >6-11; and 3) >11-18. Variables included age, gender, the type of cancer, treatment protocol, oncologic treatment complications, the use of corticosteroids, methotrexate and vincristine, first onset of psychiatric symptoms, treatment approach to symptoms, and the possible presence of side effects due to psychotropic drugs.
Results: The development of psychiatric problems differed according to tumour type and treatment protocol. Also, age was an important factor: younger children (< 6 years) and adolescents (>12) were more vulnerable, especially when the CNS was directly or indirect involved. Finally, the necessity to use psychotropic drugs was related to treatment phase (the first six months of treatment), and to treatments involving corticosteroids.
Conclusion: Psychotropic drug use in children is still extremely controversial, and seems like a catch-22, in which a true solution or desired outcome is almost impossible. However, efficient and prompt management of mainly acute behavioral or psychiatric symptoms during treatment might help improve quality of life as well as psychological, functional, and medical outcomes for a child or adolescent who is trying to handle their cancer.
2015
- Molluscs as models for translational medicine
[Articolo su rivista]
Tascedda, Fabio; Malagoli, Davide; Accorsi, Alice; Rigillo, Giovanna; Blom, Johanna Maria Catharina; Ottaviani, Enzo
abstract
This paper describes the advantages of adopting a molluscan model for studying the biological basis of some central nervous system pathologies affecting humans. In particular, we will focus on the freshwater snail Lymnaea stagnalis, which is already the subject of electrophysiological studies related to learning and memory, as well as ecotoxicological studies. The genome of L. stagnalis has been sequenced and annotated but the gene characterization has not yet been performed. We consider the characterization of the gene networks that play crucial roles in development and functioning of the central nervous system in L. stagnalis, an important scientific development that comparative biologists should pursue. This important effort would add a new experimental model to the limited number of invertebrates already used in studies of translational medicine, the discipline that seeks to improve human health by taking advantage of knowledge collected at the molecular and cellular levels in non-human organisms.
2015
- P.2.a.012 Co-administration of fluoxetine with acetylsalicylic acid, but not flurbiprofen or celecoxib, for one week shows an antidepressant-like effect
[Abstract in Rivista]
Alboni, Silvia; Benatti, Cristina; Tascedda, Fabio; Brunello, Nicoletta
abstract
Increasing evidence is now demonstrating the involvement of the immune system and in particular of their effectors, cytokines, in the development and progression of depression. In particular, it is worth underlying how pro-inflammatory cytokines appear to be increased in blood or brain of patients with major depression (MD) and that pharmacological use of pro-inflammatory cytokines (i.e. interferon alpha) may induce MD. These data suggest a role for inflammation in the pathogenesis of depression and that anti-inflammatory drugs may be used as an adjunctive therapy in the treatment of MD. However, some studies reported contradictory results and suggest that adverse effects may contraindicate the use of anti-inflammatory agents in the treatment of depression. Nevertheless, non-steroidal anti-inflammatory drugs (NSAIDs) can have different mechanisms of action also depending on the dose. This is true for the therapeutic effects as well as for the unwanted side effects.
On this basis, the present study aimed at evaluating the behavioural effect of the co-administration of fluoxetine (FLX, 5 mg/kg i.p.) with different NSAIDs in the chronic escape model of depression (CED). The CED model of depression possesses face, construct and pharmacological validity and is based on the induction, and maintenance, of an escape deficit upon exposing rats to unavoidable stressors. We previously demonstrated that, in this model, the stress-induced impaired behaviour can be resolved by one week of treatment with the co-administration of FLX (5 mg/kg/i.p.) plus acetylsalicylic acid (ASA, 45 mg/kg i.p.) but not FLX alone [1]. Here we evaluated the effect of the co-administration of FLX and flurbiprofen (FLB, an inhibitor of Cox-1 and Cox-2, 5 mg/kg, p.o.) or celecoxib (CLX, a selective COX2 inhibitor, 5 mg/kg, p.o.) in the CED model after 7 days of treatment. The co-administration FLX plus ASA (45mg/kg i.p.) was used as a positive control. Morever we tested the behavioral effect of different doses (45, 22.5 and 11.25 mg/Kg i.p.) of ASA as potentiating agent of the effect of fluoxetine.
Our study shows that only the co-administration of ASA with FLX reverted the stress-induced condition of escape deficit after 7 days of treatment. Moreover, the amplitude of the antidepressant-like effect was dose dependent. The percentage of the antidepressant response was about 90%, 60% and 40% for animals receiving FLX (5 mg/kg/i.p.) plus ASA at the dose of 45, 22.5 or 11.25 mg/Kg i.p. respectively. Both flurbiprofen and celecoxib, when administered together with FLX for 7 days, failed to induce an antidepressant-like effects in the CED model. Higher dose of FLB (50 mg/Kg p.o.) and CLX (20 mg/Kg p.o.) were also tested, but they were associated to high mortality rate (80% and 25% respectively).
These data demonstrated that neither all NSAIDs, nor all doses, may be useful in the treatment of depression while adverse effects can be potentiated or induced by the co-administration with antidepressants. Unraveling the cellular and molecular mechanisms behind the dissimilar behavioral response elicited by different anti-inflammatory drugs can contribute to understand the role of inflammation in the etiopathogensis of MD and to improve patient care.
[1] Brunello, N., Alboni, S., Capone, G., Benatti, C., Blom, J.M., Tascedda, F., Kriwin, P., Mendlewicz, J., 2006 Shortened onset of action of antidepressants in major depression using acetylsalicylic acid augmentation: a pilot open-label study. Int Clin Psychopharmacol. 21:227-31.
2015
- RESILIENCY OF CHILDREN AND ADOLESCENTS DURING TREATMENT OF ACUTE LYMPHOBLASTIC LEUKEMIA: THE USE OF 5-HTT AND BDNF POLYMORPHISMS AS BIOMARKERS
[Abstract in Rivista]
Blom, Johanna Maria Catharina; Pomicino, L; Migliozzi, C; Montanari, L; Rigillo, Giovanna; Zanazzo, G; Cellini, M; Benatti, Cristina; Tascedda, Fabio
abstract
Background/Objectives: Why are some children more likely than others to develop resilience in the face of similar levels of trauma exposure as compared to others who do not. It is increasingly clear that there are critical roles for predisposing genetic and environmental influences in differentially mediating psychological risk. Resilience differs from traditional concepts of risk and protection in its focus on individual variations in response to comparable experiences. Here, we tested the hypothesis that anxiety and depression as well as neural repair and plasticity related polymorphisms may partly account for the difference in resilience observed during treatment for acute lymphoblastic leukemia (ALL).
Design/Methods: Forty-five patients (1-18 yrs old) diagnosed with ALL were enrolled in two centers (protocol AIEOP-BFM-2009) and genotyped for 5HTT and BDNF (val66met). Patients and their family were subjected to a short screening battery, psychosocial testing (PAT2.1) and a specific assessment of their resiliency during treatment. The resiliency scale was composed of three subscales: Sense of Mastery (MAS), Sense of Relatedness (REL), and Emotional Reactivity (REA).
Results: Patients with the SL allele of 5HTTLPR had a more compromised score in some areas of resiliency than patients with the LL allele; the presence of the S allele most affected emotional reactivity REA and sense of mastery MAS. Furthermore, age was an important factor, as younger children displayed a reduced trust and tolerance versus their surroundings. This then contributed importantly to an overall reduction in their overall resiliency. Also, resiliency was reduced one year into therapy while vulnerability was significantly enhanced.
Conclusion: Genes regulating susceptibility to stress, such as 5HTTLPR and BDNF, may help to predict susceptibility towards the development of resiliency in children and adolescents treated for cancer, and may play a critical role as a predisposing factor in differentially dealing efficiently with the emotional risks related to cancer and its treatment.
2014
- Behavioural and transcriptional effects of escitalopram in the chronic escape deficit model of depression
[Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Blom, Johanna Maria Catharina; Gandolfi, Francesco; Mendlewicz, Julien; Brunello, Nicoletta; Tascedda, Fabio
abstract
The study of depression is facing major challenges: first, the need to develop new drugs with a faster onset of action and second, fulfilling the unmet needs of treatment resistant patients with more effective compounds. The chronic escape deficit (CED) is a valid and useful model of depression and is based on the induction of an escape deficit after exposure of rats to an unavoidable stress. This behavioural model provides a method for evaluating the capacity of a treatment to revert the escape deficit. The majority of antidepressant drugs need to be administered for at least 3-4 weeks in order to revert the escape deficit. A 7-day treatment with escitalopram reverted the stress-induced escape deficit in approximately 50% of the animals. Escitalopram treatment decreased anxiety-related behaviours in stressed animals, by increasing the time spent in the central part of the arena with respect to saline treated stressed animals, without affecting exploratory related behaviours. Gene expression profiling was carried out in the hippocampus to identify new targets associated with the effects of stress or with the different response to escitalopram. By combining a well-validated animal model with gene expression analysis we demonstrated that the CED model may represent a perfect tool for studying treatment-resistant depression.
2014
- Interleukin 18 activates MAPKs and STAT3 but not NF-κB in hippocampal HT-22 cells
[Articolo su rivista]
Alboni, Silvia; Montanari, C; Benatti, Cristina; Sanchez Alavez, M; Rigillo, Giovanna; Blom, Johanna Maria Catharina; Brunello, Nicoletta; Conti, B; Pariante, Mc; Tascedda, Fabio
abstract
Interleukin (IL)-18 is a cytokine previously demonstrated to participate in neuroinflammatory processes. Since the components of the IL-18 receptor complex are expressed in neurons throughout the brain, IL-18 is also believed to directly influence neuronal function. Here we tested this hypothesis on mouse hippocampal neurons by measuring the effects of IL-18 on three pathways previously shown to be regulated by this cytokine in non-neuronal cells: the MAPK pathways, p38 and ERK1/2 MAPKs, STAT3 and NF-κB. Experiments were carried out in vitro using the immortalized hippocampal neuronal line HT-22 or in vivo following i.c.v. injection with recombinant mouse IL-18. We showed that IL-18 did not activate NF-κB in HT-22 cells whereas it induced a rapid (within 15min) activation of the MAPK pathways. Moreover, we demonstrated that IL-18 treatment enhanced P-STAT3 (Tyr705)/STAT3 ratio in the nucleus of HT-22 cells after 30-60min of exposure. A similar increase in P-STAT3 (Tyr705)/STAT3 ratio was observed in the whole hippocampus one hour after i.c.v. injection. These data demonstrate that IL-18 can act directly on neuronal cells affecting the STAT3 pathway; therefore, possibly regulating the expression of specific genes within the hippocampus. This effect may help to explain some of the IL-18-induced effects on synaptic plasticity and functionality within the hippocampal system.
2014
- Successful treatment of HIV-1 infection increases the expression of a novel, short transcript for IL-18 receptor α chain
[Articolo su rivista]
Nasi, Milena; Alboni, Silvia; Pinti, Marcello; Tascedda, Fabio; Benatti, Cristina; Benatti, Stefania; Gibellini, Lara; DE BIASI, Sara; Borghi, Vanni; Brunello, Nicoletta; Mussini, Cristina; Cossarizza, Andrea
abstract
The importance of interleukin (IL)-18 in mediating immune activation during HIV infection has recently emerged. IL-18 activity is regulated by its receptor (IL-18R), formed by an α and a β chain, the IL-18-binding protein, and the newly identified shorter isoforms of both IL-18R chains. We evaluated gene expression of the IL-18/IL-18R system in peripheral blood mononuclear cells from HIV+ patients. Compared with healthy donors, IL-18 expression decreased in patients with primary infection. The IL-18Rα short transcript expression was strongly upregulated by successful highly active antiretroviral therapy. HIV progression and its treatment can influence the expression of different components of the complex IL-18/IL-18R system.
2014
- Tumors in invertebrates
[Articolo su rivista]
Tascedda, Fabio; Ottaviani, Enzo
abstract
Tumors are ectopic masses of tissue formed by due to an abnormal cell proliferation. In this review tumors of several invertebrate species are examined. The description of tumors in invertebrates may be a difficult task, because the pathologists are usually inexperienced with invertebrate tissues, and the experts in invertebrate biology are not familiar with the description of tumors. As a consequence, the terminology used in defining the tumor type is related to that used in mammalian pathology, which can create misunderstandings in some occasions.
2013
- Chronic antidepressant treatments resulted in altered expression of genes involved in inflammation in the rat hypothalamus
[Articolo su rivista]
Alboni, Silvia; Benatti, Cristina; Montanari, Claudia; Tascedda, Fabio; Brunello, Nicoletta
abstract
To gain insight into the possible immune targets of antidepressant, we evaluated the expression of several inflammatory mediators in the hypothalamus of rats chronically (28 days) treated with the serotonin selective reuptake inhibitor fluoxetine (5mg/kg, i.p.) or the tricyclic compound imipramine (15 mg/kg, i.p.). We focused our attention on the hypothalamus as it plays a key role in determining many of the somatic symptoms experienced by depressed patients. This brain region, critical also for expression of motivated behaviours, participates in the control of the hypothalamic-pituitary-adrenal axis activity and in stress response as well as coordinates physiological functions such as sleep and food intake that have been found altered in a high percentage of depressed patients. Notably, hypothalamus is a key structure for brain cytokine expression and function as it integrates signals from the neuro, immune, endocrine systems. By means of quantitative Real Time PCR experiments we demonstrated that a chronic treatment with either fluoxetine or imipramine resulted in a reduction of IL-6 and IFN-γ mRNAs and increased IL-4 mRNA expression in the rat hypothalamus. Moreover, we demonstrated that hypothalamic expression of members of IL-18 system was differentially affected by chronic antidepressant treatments. Chronically administered fluoxetine decreased IL-8 and CX3CL1 hypothalamic expression, while a chronic treatment with imipramine decreased p11 mRNA. Our data suggest that a shift in the balance of the inflammation toward an anti-inflammatory state in the hypothalamus may represent a common mechanism of action of both the chronic treatments with fluoxetine and imipramine.
2013
- Epigenetic modification in neurons of the mollusc Pomacea canaliculata after immune challenge
[Articolo su rivista]
Ottaviani, Enzo; Accorsi, Alice; Rigillo, Giovanna; Malagoli, Davide; Joan M. C., Blom; Tascedda, Fabio
abstract
In human and rodents, the transcriptional response of neurons to stress is related to epigenetic modifications of both DNA and histone proteins. To assess the suitability of simple invertebrate models in studying the basic mechanisms of stress-related epigenetic modifications, we analyzed epigenetic modifications in neurons of the freshwater snail Pomacea canaliculata after the injection of Escherichia coli-derived lipopolysaccharide (LPS). The phospho-acetylation of histone H3, together with the induction of stress-related factors, c-Fos and HSP70, were evaluated in large and small neurons of the pedal ganglia of sham- and LPS-injected snails. Immunocytochemical investigations showed that after LPS injection, the immunopositivity towards phospho (Ser10)-acetyl (Lys14)-histone H3 and c-Fos increases in the nuclei of small gangliar neurons. Western blot analysis confirmed a significant increase of phospho (Ser10)-acetyl (Lys14)-histone H3 in nuclear extracts from 2h LPS-injected animals. c-Fos protein levels were significantly augmented 6h after LPS injection. Immunocytochemistry and western blot indicated that no changes occurred in HSP70 distribution and protein levels. To our knowledge this is the first demonstration of epigenetic changes in molluscan neurons after an immune challenge and indicate the gastropod P. canaliculata as a suitable model for evolutionary and translational studies on stress-related epigenetic modifications.
2013
- Interferon alpha exposure increases the expression of the enzymes belonging to the kynurenine pathway in an in vitro model of human neurons: SH-SY5Y cells
[Abstract in Rivista]
Alboni, Silvia; Benatti, Cristina; Claudia, Montanari; Benatti, Stefania; Tascedda, Fabio; Cannazza, Giuseppe; Pariante Carmine, M; Brunello, Nicoletta
abstract
The past two decades have witnessed a burgeoning area of pre-clinical and clinical research linking psychiatric illnesses – particularly major depression (MD) – to activation of the inflammatory immune system. One of the stronger evidence supporting a causal role for inflammation in leading MD comes from reports indicating that depressive symptoms frequently develop in patients undergoing immunotherapy with cytokines, such as interferon (IFN)-α, for the treatment of malignancies or chronic viral infection. Although INF-alpha- induced effects on the brain made of IFN-α a model to study the influence of pro-inflammatory cytokines in the CNS and behavior the molecular mechanisms underlying these effects are far from being fully understood.
It has been proposed that IFN-α may contribute to the etiology of MD by inducing indolamine 2,3-dioxygenase (IDO) expression and thus unbalancing in the tryptophan/kynurenine metabolism toward the production of neurotoxic metabolites and\or reducing serotonin (5-HT) availability. IDO catalyzes the initial rate-limiting step in tryptophan degradation along the kynurenine pathway (KP). Kynurenine, the initial product of tryptophan degradation, is further catalysed into neurotoxic end-products through steps catalyzed by kynurenine 3-monooxygenase (KMO) and kynureninase (Kynu). However, Kynurenine can also be catabolised by kynurenine aminotransferase (KAT), into kynurenic acid, a potentially neuroptotective agent. A role for a disturbance in the equilibrium between neurotoxic/ neuropoptective end KP endproducts producing an alteration in the neuroprotective–neurodegenerative balance in the brain of patients with MD, has been proposed in the neurodegeneration hypothesis of depression.
Given that we previously demonstrated that IFN-α induces toxic effects in an in vitro model of human neurons (human SH-SY5Y neuroblastoma cells) we were aim to investigate the effects of IFN-α on KP in these cells.
Our studies show that IFN-α exposure increased the expression of all the kynurenergic enzymes investigated (IDO, KMO, Kynu and KAT). More particularly strongly induced the expression of IDO mRNA (more than 900 –fold) in SH-SY5Y cells. Similar effects on kynurenergic enzyme expression were also observed when SH-SY5Y cells where differentiated with all-trans retinoic acid (in presence of neurotrophic support and in serum deprived conditions). We also demonstrated that INF-α decreased 5-HT levels whereas increased the kynurenine levels in the medium of both differentiated as well not differentiated SH-SY5Y cells.
2013
- N-acetyl-cysteine prevents toxic oxidative effects induced by IFN-α in human neurons.
[Articolo su rivista]
Alboni, Silvia; Gibellini, Lara; Montanari, Claudia; Benatti, Cristina; Benatti, Stefania; Tascedda, Fabio; Brunello, Nicoletta; Cossarizza, Andrea; Pariante, Carmine M.
abstract
Currently IFN-α is widely used for effective treatment of viral infections and several malignancies. However, IFN-α can cause neuropsychiatric disturbances and mental impairments, including fatigue, insomnia, depression, irritability and cognitive deficits. Molecular and cellular mechanisms leading to such side-effects are still poorly understood. Neurons seem to be an important target in mediating cellular effects induced by exposure to this cytokine, but so far little is known about IFN-α-induced effects on these cells. We have investigated the ability of IFN-α (2-100 ng/ml) to induce damage and toxicity to the human neuroblastoma SH-SY5Y cell line, commonly used for studying such phenomena, and the mechanisms underlying these effects. After 24 h treatment, IFN-α increased mitochondrial activity, whereas cell density was reduced in a dose- and time-dependent manner. This effect did not depend on reduced cell proliferation, but rather the activation of apoptosis, as revealed by an increased Bax:Bcl-2 mRNA ratio after 72-h IFN-α exposure. At this time-point, IFN-α also reduced the expression of the brain-derived neurotrophic factor gene, and induced an increase in reactive oxygen species (ROS). A co-treatment with N-acetyl-cysteine (NAC; 5 mm), a potent antioxidant and mitochondrial modulator, was able to counteract all of these IFN-α-induced effects. These findings demonstrated that IFN-α induces neurotoxicity and apoptosis that is, in part, very likely due to mitochondrial damages and production of ROS. We suggest that NAC, already tested for the treatment of psychiatric disorders, may be useful to prevent IFN-α-induced central side-effects in a safe and effective way.
2013
- The injection of LPS induces epigenetic changes in Pomacea canaliculata neurons. XIII Meeting of the Italian Association of Developmental and Comparative Immunology, Palermo, Inv. Surv. J., 10: 16, 2013
[Abstract in Rivista]
Accorsi, Alice; Rigillo, Giovanna; Malagoli, Davide; Blom, Johanna Maria Catharina; Tascedda, Fabio; Ottaviani, Enzo
abstract
The injection of LPS induces epigenetic changes in Pomacea canaliculata neurons
2012
- Interferon-alpha exposure increases the
expression of enzymes of the kynurenine
pathway and induces apoptosis in a model of
human neurons
[Abstract in Rivista]
Alboni, Silvia; Benatti, Cristina; Montanari, Claudia; Tascedda, Fabio; C. M., Pariante; Brunello, Nicoletta
abstract
Major depression (MD) is associated with a profound unbalance
between the nervous-, the endocrine- and the immune- systems.
This suggests the possibility that molecules that regulate the
homeostasis of these systems may contribute to the development
of MD. For instance, some cytokines, important neuro-endocrineimmuno
modulators, have been proposed to have a role in MD
as supported by the observation that activation of immune system
with therapeutically used cytokines may induce MD.
IFN-a is an innate immune cytokine with potent antiviral and
anti-proliferative properties that is used to treat viral infections,
such as hepatitis C, and certain cancers. Despite therapeutic
efficacy in these illnesses, it has been observed that IFN-a exposure
may be associated with important side effects including
neuropsychological and behavioural changes that overlap with
MD.
Although IFN-a- induced effects on the brain make IFN-alpha a
model to study the influence of pro-inflammatory cytokines in the
CNS and behavior, the molecular mechanisms underlying these
effects are far from being fully understood.
It has been proposed that cytokines may contribute to the
etiology of MD by inducing indolamine 2,3-dioxygenase (IDO)
expression. IDO catalyzes the initial rate-limiting step in tryptophan
(TPR) degradation along the kynurenine pathway (KP).
Kynurenine, the initial product of TPR degradation, is further
catalysed into neurotoxic end-products through steps catalyzed by
kynurenine 3-monooxygenase (KMO) and kynureninase (Kynu).
However, Kynurenine can also be catabolised by kynurenine
aminotransferase (KAT), into kynurenic acid, a potentially neuroprotective
agent. A role for a disturbance in the KP in the
neuroprotective–neurodegenerative balance in the brain of patients
with MD, has been proposed in the neurodegeneration hypothesis
of depression.
This prompted us to investigate the effects of IFN-a on the
expression of the IDO, KMO, Kynu and KAT mRNAs in an in
vitro model of human neurons: SH-SY5Y (human neuroblastoma)
cells. We also evaluated the IFN-a-induced effect on cell viability and number in these cells. Finally, because cell number results
from the balance between cell proliferation and cell elimination,
we measured cell proliferation and apoptosis in SH-SY5Y cells
after IFN-a exposure. The same experiments were performed in
differentiated SH-SY5Y cells with retinoic acid (RA) and Brain-
Derived Neurotrophic Factor (BDNF).
Our studies show that IFN-a exposure increased the expression
of all the kynurenergic enzymes investigated (with an unbalance
of the KP toward the synthesis of neurotoxic end-products) and in
more particularly strongly induced the expression of IDO mRNA
(more than 900-fold) in SH-SY5Y cells. We also demonstrated
that IFN-a reduced in a dose- (2, 20, 50 and 100 ng/ml) and time-
(24, 48 and 72 hrs) dependent manner the cell number and induces
apoptosis in SH-SY5Y cells. Similar results were obtained in SHSY5Y
RA/BDNF differentiated cells.
Together our results clearly enlighten the cytotoxic effects of
IFN-a in this in vitro model of human neurons. Moreover, our
findings provide further information on the molecular pathways
involved in cytokine-induced effects in the brain and add a piece
to the puzzle of what and how these factors or pathways may
contribute to the pathogenesis of MD.
2012
- Transcriptional profiles underlying vulnerability and resilience in rats exposed to an acute unavoidable stress
[Articolo su rivista]
Benatti, Cristina; Valensisi, Cristina; Blom, Johanna Maria Catharina; Alboni, Silvia; Montanari, Claudia; Ferrari, Francesco; Tagliafico, Enrico; Julien, Mendlewicz; Brunello, Nicoletta; Tascedda, Fabio
abstract
A complex interplay between gene and environment influences the vulnerability or the resilience to stressful events. In the acute escape deficit (AED) paradigm, rats exposed to an acute unavoidable stress (AUS) develop impaired reactivity to noxious stimuli. Here we assessed the behavioral and molecular changes in rats exposed to AUS. A genome-wide microarray experiment generated a comprehensive picture of changes in gene expression in the hippocampus and the frontal cortex of animals exposed or not to AUS. Exposure to AUS resulted in two distinct groups of rats with opposite behavioral profiles: one developing an AED, called “stress vulnerable,” and one that did not develop an AED, called “stress resilient.” Genome-wide profiling revealed a low percentage of overlapping mechanisms in the two areas, suggesting that, in the presence of stress, resilience or vulnerability to AUS is sustained by specific changes in gene expression that can either buffer or promote the behavioral and molecular adverse consequences of stress. Specifically, we observed in the frontal cortex a downregulation of the transcript coding for interferon-β and leukemia inhibitory factor in resilient rats and an upregulation of neuroendocrine related genes, growth hormone and prolactin, in vulnerable rats. In the hippocampus, the muscarinic M2 receptor was downregulated in vulnerable but upregulated in resilient rats. Our findings demonstrate that opposite behavioral responses did not correspond to opposite regulatory changes of the same genes, but resilience rather than vulnerability to stress was associated with specific changes, with little overlap, in the expression of patterns of genes.
2011
- Central effects of a local inflammation in three commonly used mouse strains with a different anxious phenotype
[Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Montanari, Claudia; Caggia, Federica; Tascedda, Fabio; Brunello, Nicoletta; Blom, Johanna Maria Catharina
abstract
As in humans, genetic background in rodents may influence a peculiar set of behavioural traits such as sensitivity to pain and stressors or anxiety-related behaviours. Therefore, we tested the hypothesis that mice with different genetic backgrounds [outbred (CD1), inbred (C57BL/6J) and hybrid (B6C3F1) adult male mice] display altered reactivity to pain, stress and anxiety related behaviours. We demonstrated that B6C3F1 mice displayed the more anxious phenotype with respect to C57BL/6J or CD1 animals, with the latter being the less anxious strain when tested in an open field and on an elevated plus maze. No difference was observed across strains in thermal sensitivity to a radiant heat source. Mice were then treated with a sub-plantar injection of the inflammatory agent Complete Freund's Adjuvant (CFA), 24h later they were hyperalgesic with respect to saline exposed animals, irrespective of strain. We then measured intra-strain differences and CFA-induced inter-strain effects on the expression of various genes with a recognized role in pain and anxiety: BDNF, IL-6, IL-1β, IL-18 and NMDA receptor subunits in the mouse thalamus, hippocampus and hypothalamus. The more anxious phenotype observed in B6C3F1 hybrid mice displayed lower levels of BDNF mRNA in the hippocampus and hypothalamus when compared to outbred CD1 and C57BL/6J inbred mice. CFA led to a general decrease in central gene expression of the evaluated targets especially in CD1 mice, while BDNF hypothalamic downregulation stands out as a common effect of CFA in all three strains evaluated
2011
- Constitutive and LPS-regulated expression of interleukin-18 receptor beta variants in the mouse brain
[Articolo su rivista]
Alboni, Silvia; Montanari, Claudia; Benatti, Cristina; Blom, Johanna Maria Catharina; Simone, Ml; Brunello, Nicoletta; Caggia, Federica; Guidotti, G; Marcondes, Mc; Sanchez Alavez, M; Conti, B; Tascedda, Fabio
abstract
Interleukin (IL)-18 is a pro-inflammatory cytokine that is proposed to be involved in physiological as well as pathological conditions in the adult brain. IL-18 acts through a heterodimer receptor comprised of a subunit alpha (IL-18Rα) required for binding, and a subunit beta (IL-18Rβ) necessary for activation of signal transduction. We recently demonstrated that the canonical alpha binding chain, and its putative decoy isoform, are expressed in the mouse central nervous system (CNS) suggesting that IL-18 may act on the brain by directly binding its receptor. Considering that the co-expression of the beta chain seems to be required to generate a functional receptor and, a short variant of this chain has been described in rat and human brain, in this study we have extended our investigation to IL-18Rβ in mouse. Using a multi-methodological approach we found that: (1) a short splice variant of IL-18Rβ was expressed in the CNS even if at lower levels compared to the full-length IL-18Rβ variants, (2) the canonical IL-18Rβ is expressed in the CNS particularly in areas and nuclei belonging to the limbic system as previously observed for IL-18Rα and finally (3) we have also demonstrated that both IL-18Rβ isoforms are up-regulated in different brain areas three hours after a single lipopolysaccharide (LPS) injection suggesting that IL-18Rβ in the CNS might be involved in mediating the endocrine and behavioral effects of LPS. Our data highlight the considerable complexity of the IL-18 regulation activity in the mouse brain and further support an important central role for IL-18.
2011
- Stress induces altered CRE/CREB pathway activity and BDNF expression in the hippocampus of glucocorticoid receptor-impaired mice
[Articolo su rivista]
Alboni, Silvia; Tascedda, Fabio; Corsini, Daniela; Benatti, Cristina; Caggia, Federica; Capone, Giacomo; Barden, N; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract
The gene coding for the neurotrophin Brain-Derived Neurotrophic Factor (BDNF) is a stress-responsive gene. Changes in its expression may underlie some of the pathological effects of stress-related disorders like depression. Data on the stress-induced regulation of the expression of BDNF in pathological conditions are rare because often research is conducted using healthy animals. In our experiments, we used transgenic mice with glucocorticoid receptor impaired (GR-i) expression in the hypothalamus created as a tool to study the neuroendocrine changes occurring in stress-related disorders. First, under basal condition, GR-i mice displayed lower levels of BDNF exons IX and IV and decreased CRE(BDNF) binding activity with respect to wild-type (WT) mice in the hippocampus. Then, we exposed GR-i and WT mice to an acute restraint stress (ARS) to test the hypothesis that GR-i mice display: 1] different ARS induced expression of BDNF, and 2] altered activation of signaling pathways implicated in regulating BDNF gene expression in the hippocampus with respect to WT mice. Results indicate that ARS enhanced BDNF mRNA expression mainly in the CA3 hippocampal sub-region of GR-i mice in the presence of enhanced levels of pro-BDNF protein, while no effect was observed in WT mice. Moreover, ARS reduced CREB signaling and binding to the BDNF promoter in GR-i mice but enhanced signaling and binding, possibly through ERK1/2 activation, in WT mice. Thus, life-long central GR dysfunction resulted in an altered sensitivity at the transcriptional level that may underlie an impaired response to an acute psycho-physical stress.
2010
- Time-dependent effects of escitalopram on brain derived neurotrophic factor (BDNF) and neuroplasticity related targets in the central nervous system of rats
[Articolo su rivista]
Alboni, Silvia; Benatti, Cristina; Capone, Giacomo; Corsini, Daniela; Caggia, Federica; Tascedda, Fabio; Mendlewicz, J; Brunello, Nicoletta
abstract
Chronic treatment with antidepressants affects several proteins linked to neuroplasticity, particularly brain derived neurotrophic factor (BDNF): this leads eventually to their therapeutic effects. It is possible that also for putative early therapeutic onset, antidepressants may act by promoting cellular adaptations linked to neuroplasticity. Escitalopram, known to be already effective in preclinical models of depression after 7 days, allowed us to investigate whether two effective treatment regimens (7 and 21 days) may contribute to synaptic plasticity by acting on BDNF signalling. We focused our attention on two regulators of BDNF transcription, CREB and CaRF (calcium responsive factor), and on kinases, CaMKII, ERK1/2 and p38 MAPK, linked to BDNF that play a distinctive role in synaptic plasticity. We evaluated whether the effects of escitalopram on these targets may be different in brain areas involved in the depressive symptomatology (hippocampus, frontal and prefrontal cortex). Here we demonstrate that escitalopram regulates intracellular pathways linked to neuroplasticity at both the time points evaluated in an area-specific manner. While the two escitalopram-treatment regimens failed to affect gene expression in the rat frontal cortex, 7days of treatment with escitalopram activated intracellular pathways linked to BDNF and increased the levels of Pro-BDNF in the rat prefrontal cortex. Moreover, 21 days of treatment with escitalopram decreased CREB/BDNF signalling while increasing p38 levels in the rat hippocampus. Even if further experiments with different antidepressant strategies will be needed, our data suggest that escitalopram efficacy may be mediated by early and late effects on synaptic plasticity in selective brain areas.
2009
- Chronic treatment with the selective NOP receptor antagonist [Nphe1,Arg14,Lys15]N/OFQ-NH2 (UFP-101) reverses the behavioural and biochemical effects of unpredictable chronic mild stress in rats
[Articolo su rivista]
Vitale, Giovanni; Ruggieri, Valentina; Filaferro, Monica; Frigeri, Claudio; Alboni, Silvia; Tascedda, Fabio; Brunello, Nicoletta; Guerrini, R; Cifani, C; Massi, M.
abstract
Introduction The present study was designed to assess the antidepressant effects of UFP-101, a selective nociceptin/orphanin FQ peptide (NOP) receptor antagonist, in a validated animal model of depression: the chronic mild stress (CMS). Materials and methods and Results UFP-101 (5, 10 and 20 nmol/rat; i.c.v., once a day for 21 days) dose- and time-dependently reinstated sucrose consumption in stressed animals without affecting the same parameter in non-stressed ones. In the forced swimming test, UFP-101 reduced immobility of stressed rats from day 8 of treatment. After a 3-week treatment, rats were killed for biochemical evaluations. UFP-101 abolished increase in serum corticosterone induced by CMS and reverted changes in central 5-HT/5-HIAA ratio. The behavioural and biochemical effects of UFP-101 mimicked those of imipramine, the reference antidepressant drug, administered at the dose of 15 mg/kg (i.p.). Co-administration of nociceptin/orphanin FQ (5 nmol/rat, from day 12 to 21) prevented the effects of UFP-101. Brain-derived neurotrophic factor mRNA and protein in hippocampus were not reduced by CMS nor did UFP-101 modify these parameters. Discussion and Conclusion This study demonstrated that chronic treatment with UFP-101 produces antidepressant-like effects in rats subjected to CMS supporting the proposal that NOP receptors represent a candidate target for the development of innovative antidepressant drugs.
2009
- Early neonatal inflammation affects adult pain reactivity and anxiety related traits in mice: genetic background counts
[Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Capone, Giacomo; Corsini, Daniela; Caggia, Federica; Brunello, Nicoletta; Tascedda, Fabio; Blom, Johanna Maria Catharina
abstract
Protracted or recurrent pain and inflammation in the early neonatal period may cause long-lasting changes in central neural function. However, more research is necessary to better characterize the long-term behavioral sequelae of such exposure in the neonatal period. Objectives: (1) to study whether timing of postnatal exposure to persistent inflammation alters responsiveness to thermal pain in the adult animal; (2) to assess whether animals experiencing early postnatal chronic inflammation display altered anxiety related behavior; (3) to study the importance of genetic background. Newborn mice (outbred strain, CD1 and F1 hybrid strain, B6C3F1) received an injection of Complete Freund's Adjuvant (CFA) or saline on either postnatal day 1 or 14 (PND1; PND14) into the left hind paw. Pain to radiant heat and anxiety were examined in 12-week-old adult animals. Adult baseline PWL was significantly decreased in CD1 mice exposed to CFA on PND 1 and 14 as compared to their saline treated counterparts. B6C3F1 mice exposed to CFA on PND14 showed markedly reduced baseline PWL compared to the PND14 saline group. Persistent inflammation experienced by B6C3F1 mice on PND1 failed to affect baseline adult thermal responsiveness. Adult mice, CD1 and B6C3F1, displayed low anxiety traits only if they had been exposed to persistent inflammation on PND1 and not on PND14. Our research suggests a role for genetic background in modulating long-term behavioral consequences of neonatal persistent inflammation: the data support the hypothesis that pain experienced very early in life differentially affects adult behavioral and emotional responsiveness in outbred (CD1) and hybrid mice (B6C3F1).
2009
- Gene expression profile of the hippocampus of a behavioural model of depression
[Abstract in Rivista]
Valensisi, Cristina; Caggia, Federica; Alboni, Silvia; Benatti, Cristina; Ferrari, F; Mendlewicz, J; Blom, Johanna Maria Catharina; Brunello, Nicoletta; Tascedda, Fabio
abstract
Although the neurobiological basis of depression has not been fully elucidated, numerous studies have emphasized that in the etiology of depression stress may be the most significant cause, together with genetic vulnerability. Stress induces a coordinated and complex response that is adaptive and integral to survival. The brain's ability to adapt and change over time is refered to neuroplasticity and long-term plasticity in the brain requires changes in gene expression. However, exposure to intense or chronic stressors leads to an increased risk for the development of stress-related disorders including major depression. Numerous studies demonstrate that neuronal atrophy and loss of plasticity occur in hippocampus in response to stress and depression. Therefore, the hippocampal region may play a central role in depressive illness. Likewise changes in gene expression underlying the plasticity of hippocampal structures appear to be relevant in undenstanding the molecular and cellular mechanisms involved in the etiology as well as the treatment of depression, and the mechanisms leading vulnerability or resilience to stress. In fact, humans display a remarkable heterogeneity in their responses to stress and adversity. Although we are beginning to understand how maladaptive neurobiological changes may contribute to depression, relatively little is known about the molecular mechanisms that may underlie stress resilience. Here we set out to investigate the changes in the gene expression profile underlying the effects of stress on the hippocampus using a behavioural paradigm of depression, the chronic escape deficit model [1], which is based on the modified reactivity of rats to external stimuli, the escape deficit, induced by exposure to intense and unavoidable stress. The chronic escape deficit model starts as an acute escape deficit which can be indefinitely sustained by repeated administration of mild stressors. This approach has proved to be a valid and useful model of depression because it consider depressive symptoms like behavioural despair. We performed gene expression profiling in the rat hippocampus, using GeneChip Rat Exon Array (Affymetrix). Using this new platform we carried out analyses of gene expression on three different levels: gene, transcript and exon level analyses. The behavioural results showed that exposure to intense and unavoidable stressful procedure induced escape deficit only in 60% of them. Whereas the animals remaining display a behaviour apparently identical to control animals which did not undergo the stressful procedure. Comparing gene expression profiles and performing functional analysis on differently expressed genes we have indicated multiple pathways that may be involved in the underlying mechanisms of stress condition associated with escape deficit. Moreover we identified possible cellular functions and biological processes that could represent targets that may contribute to mediate the effects of stress on the hippocampal plasticity. Such as, gene expression profiling of stress-vulnerable and stress-resilient animals revealed distinct transcriptional profiles, suggesting that resilient behaviour represents an active neurobiological process and not simply the absence of vulnerability.
2009
- Mapping of the full length and the truncated interleukin-18 receptor alpha in the mouse brain
[Articolo su rivista]
Alboni, Silvia; Cervia, D; Ross, B; Montanari, Claudia; Gonzalez, As; Sanchez Alavez, M; Marcondes, Mc; De Vries, D; Sugama, S; Brunello, Nicoletta; Blom, Johanna Maria Catharina; Tascedda, Fabio; Conti, B.
abstract
The cytokine IL-18 acts on the CNS both in physiological and pathological conditions. Its action occurs through the heterodimeric receptor IL-18Rα β. To better understand IL-18 central effects, we investigated in the mouse brain the distribution of two IL-18Rα transcripts, a full length and an isoform lacking the intracellular domain hypothesized to be a decoy receptor. Both isoforms were expressed in neurons throughout the brain primarily with overlapping distribution but also with some unique pattern. These data suggest that IL-18 may modulate neuronal functions and that its action may be regulated through expression of a decoy receptor.
2009
- Microarray analysis in hippocampus of rats treated with escitalopram in the chronic escape deficit model of depression
[Abstract in Rivista]
Caggia, Federica; Valensisi, Cristina; Alboni, Silvia; Benatti, Cristina; Corsini, Daniela; F., Ferrari; Tagliafico, Enrico; J., Mendlewicz; Tascedda, Fabio; Brunello, Nicoletta
abstract
Currently, the biological bases of depression and the
molecular mechanisms underlying antidepressant action
are not completely understood. Valuable tools to better
understand the pathophysiology of this disease are
behavioural models of depression eventually combined
with genome-wide gene expression analysis.
The Chronic Escape Deficit (CED) is a validated
behavioural model of depression, based on the induction of
an escape deficit after exposure of rats to an unavoidable
stress. This model allows to evaluate the capacity of a
treatment to revert the escape deficit. The antidepressant
drugs tested in CED model need to be administered for
at least 3−4 weeks in order to revert the escape deficit [1,2].
In this study, we demonstrated that already after one
week of treatment with Escitalopram, a widely used SSRI,
50% of the animals responded reverting the escape deficit
induced. Moreover, the other 50% of treated animals did
not respond also after 3−4 weeks of treatment.
Since in the CED model the behavioural alteration is
induced by stress application and reverted by escitalopram
treatment in only half of animals, the aims of our
study were two fold: (i) to investigate transcriptional
changes activated by stress; (ii) to study the different
gene expression pattern involved into mechanisms of
the response and not response to the pharmacological
treatment. To address these issues we performed a
microarray experiment in the rat hippocampus using
Affymetrix GeneChip Rat Exon 1.0 ST evaluating both
gene-level and exon-level expression profiling on the
whole genome.
Total RNA extracted from hippocampus of each animal
was utilized to chip a single array using the Affymetrix
protocols. 20 single arrays were utilized for data analysis
and divided into five replicates for each experimental
group (control, stress, stress-escitalopram responders and
stress escitalopram-not responders).
Using two parallel analyses (gene level and exon level)
of raw data files carried out in Expression Console
software using iterPLIER algorithms, we identified genes
and exons that were differentially regulated in each
pairwise comparison considered. The exons identified in this study were examinated
for their biological association to gene ontology
(GO) categories using eGOn software. Moreover, all
exons differentially expressed were also uploaded
into Ingenuity Pathways Analysis (Ingenuity® Systems,
www.ingenuity.com) in order to identify molecular
pathways and functions related to stress and escitalopram
response.
Our results suggest that stress may exert a negative
effect on gene transcription since the largest number of
genes was downregulated. Moreover from our data it
seems that a different pattern of gene expression exhibits
between animals that respond and that did not respond to
escitalopram treatment.
Functional analysis of exon dataset, arising from
stress protocol and escitalopram treatment, reflects
interesting different biological features. More specifically,
the biological functions regard both molecular and cellular
functions, such as cellular growth and proliferation, gene
expression and signal transduction, as well as involvement
of central neurotransmission and immune response.
We believe that this pharmacogenomic approach will be
helpful to understand the molecular mechanisms involved
in the pathogenesis of depression as well as in the response
to antidepressant drugs.
2008
- Impaired stress-induced regulation of brain derived neurotrophic factor expression in hippocampus of glucocorticoid receptor impaired mice: Model of depression
[Abstract in Rivista]
Alboni, Silvia; Corsini, Daniela; Caggia, Federica; Benatti, Cristina; Capone, Giacomo; Barden, N; Blom, Johanna Maria Catharina; Tascedda, Fabio; Brunello, Nicoletta
abstract
Objective: The gene codifying for the neurotrophin Brain Derived Nurotrophic
Factor (BDNF) is a stress-responsive gene and alteration in its expression may
be important in producing some of the pathophysiological effects of stress in
the hippocampus as seen in stress-related pathologies like depression. While the
effects of stress procedures on the regulation of BDNF expression was widely
investigated in hippocampus of healthy control animals, the stress-induced effects
on BDNF hippocampal expression in “pathological” condition are still lacking.
In order to deepen our knowledge in the understanding of the effects of an acute
stressful procedure on molecular targets of synaptic plasticity we used transgenic
mice with impaired glucocorticoid receptor (GR-i) expression that represent an
animal model of depression. The hypothesis was tested that a single period of
restraint stress (6 hours) affects BDNF mRNA expression in the hippocampus
of GR-i mice differently than in wild-type (WT) mice.
Methods: Using real time RT-PCR we evaluated the effects of a 6 hours acute
stress on the levels of BDNF coding exon VIII and the activity regulated BDNF
exon IV mRNA. In the WT and in the GR-i animals, the hippocampal levels of
the two BDNF exons, immediately after the stress ended, were significantly lower
in stressed animals with the respect to respective control unstressed animals.
However, for the BDNF exon IV mRNA the reduction is most pronounced inWT animals and two-way ANOVA followed by Bonferroni posttest revealed a
significant interaction between stress response and genotype at the level of BDNF
exon IV mRNA expression.
Results: The BDNF gene is a very complex gene regulated by a wide array of
stimuli and signalling pathways. An electophoresis mobility shift assay (EMSA)
was used to study DNA-binding activity of two transcription factors with an
important role in controlling synaptic plasticity most likely trough an involvement
BDNF: the cAMP responsive element binding (CREB) protein and the nuclear
factor kB (Nf-kB). Taken together, our results show a different binding activity
of these transcription factors in GR-i mice with respect to WT mice following
acute stressful conditions.
Conclusion: The identification of the molecular mechanisms activated by
stress in GR-i mice model of depression may contribute to the development
of new strategies that reducing neuron vulnerability to stress and prevent
neurophatologocal alteration in the hippocampus.
2008
- Microarray analysis of the chronic escape deficit model of
depression: Effects of escitalopram treatment in hippocampus
[Abstract in Rivista]
Caggia, Federica; Valensisi, Cristina; Alboni, Silvia; Benatti, Cristina; Corsini, Daniela; Ferrari, F; Tagliafico, Enrico; Mendlewicz, J; Brunello, Nicoletta; Tascedda, Fabio
abstract
Objective: Currently, the biological bases of depression and the molecular
mechanisms underlying antidepressant action are not completely understood.
Behavioural models of depression and genome-wide gene expression analysis
can be relevant to better understand the pathophysiology of this disease. Chronic
escape deficit is a valid and useful model of depression and is based on the
induction of an escape deficit after exposure of rats to unavoidable stress. This
behavioural model allows to evaluate the capacity of a treatment to revert the
escape deficit. The majority of antidepressant drugs need to be administered
for at least 3−4 weeks in order to revert the escape deficit. In this study, we
demonstrated that only one week of treatment with Escitalopram, a widely used
SSRI, is effective in the chronic escape deficit model of depression. Also, our
study demonstrated that only 50% of the animals receiving ESC responded to
the treatment. The mechanisms underlying the action of escitalopram are still
poorly understood and the molecular targets and pathways involved remain to be
identified. In order to identify the biological target involved in the response to
escitalopram, we performed a microarray experiment using the chronic escape
deficit model of depression after a 7 day treatment with escitalopram.
Methods: Gene expression patterns in the rat hippocampus were analyzed
using Affymetrix GeneChip Rat Exon 1.0 ST evaluating both gene-level and
exon-level expression profiling on the whole genome. Total RNA extracted from
hippocampus of each treated animal was utilized to chipping a single array using
the Affymetrix protocols. 20 single arrays were utilized for data analysis and
divided into five replicates for each experimental group (naive, stress, escitalopram
responders and not responders). With two parallel analyses (gene level and
exon level) of raw data files carried out in Expression Console software using
iterPLIER algorithms, we identified various transcripts that were differentially
regulated in each pairwise comparison. In order to identify biological processes
and signalling networks regulated by escitalopram response, we performed a
functional analysis using Ingenuity web tool.
Results: Functional annotation of selected genes reflected interesting different
biological features between escitalopram responders and not responders. More
specifically, the biological functions regard cellular growth and proliferation,
gene expression and signal transduction.
Conclusion: We believe that this pharmacogenomic approach will be helpful
to understand the molecular mechanisms involved in the pathogenesis of
depression as well as in the response to antidepressant drugs.
2008
- Molecular effects of subchronic andchronic treatment with escitalopram inthe rat central nervous system
[Abstract in Rivista]
Benatti, Cristina; Alboni, Silvia; Capone, Giacomo; Corsini, Daniela; Caggia, Federica; Blom, Johanna Maria Catharina; Tascedda, Fabio; Brunello, Nicoletta
abstract
A clear understanding of the mechanisms behind depressionand its treatment is a critical issue for amelioratethe effectiveness of existing antidepressants. Acutely,antidepressant drugs increase synaptic concentrations ofmonoamines, but clinical efficacy requires several weeksof continuous treatment, proposing a key role for timedependentneural adaptations, perhaps induced by acutesynaptic actions, in their therapeutic efficacy.Escitalopram is the S(+) enantiomer of citalopram, oneof the most widely prescribed serotonin selective reuptakeinhibitor (SSRIs) antidepressants. In the chronic mildstress model of depression sucrose intake was alreadynormalized after one week of treatment.We evaluated the effects of a subchronic or a chronictreatment with escitalopram on expression levels of someof the main targets of antidepressant drugs such as theneurotrophin Brain Derived Neurotrophic Factor (BDNF),the transcription factors cAMP Response Element Binding(CREB) [1] Protein and Calcium Responsive Factor(CaRF).Sprague-Dawley rats were treated for 7 days (subchronic)or 21 days (chronic) with either escitalopram(10 mg/kg die i.p) or saline (1 mL/kg die); BDNF, CREBand CaRF mRNAs were evaluated using RNAse ProtectionAssay in hippocampus and prefrontal cortex.No difference was observed on BDNF, CREB andCaRF expression in the hippocampus of rats treatedsubchronically with escitalopram with respect to the grouptreated with saline. In contrast a significant inductionof BDNF mRNA was observed in prefrontal cortexof escitalopram-treated animals with respect to salinetreated ones. CaRF expression patterns were similar.Escitalopram for 7 days caused a significant induction ofCaRF mRNA with respect to the group treated with saline(p<0.05; Dunnett t-test), on the other hand CREB mRNAremained unaffected. Following a chronic treatment withEscitalopram, BDNF, CREB and CaRF mRNA levels weresignificantly decreased with respect to the group treatedwith saline in hippocampus (p<0.05; Dunnett t-test),while a 21 day treatment with escitalopram failed toproduce changes in gene expression in prefrontal cortex.These results showed that escitalopram is able todifferentially affect BDNF, CREB and CaRF expressionwith respect to treatment duration and that the observedeffects are area-specific.Consequently, to further investigate the possiblemolecular mechanisms underlying the observed effectson gene expression we evaluated by western blottingsome of the main signalling pathways regulating CREB aswell as BDNF expression, such as p38 MAPK (Mitogen-Activated Protein Kinase), CaMKII (Calcium CalmodulineKinase), ERK 1/2 (Extracellular Signal-Regulated Kinase)and CREB itself [1].Our study demonstrates that:1. A subchronic treatment with escitalopram inducesBDNF and CaRF expression in prefrontal cortexprobably through activation of p38 MAPK signallingpathway.2. A 21 day escitalopram treatment reduces hippocampalBDNF, CaRF, CREB gene expression and also CREBphosphorylated nuclear levels.Spatially distinct signalling pathways may be involvedin mediating the differential effect on gene expressionobserved following either a subchronic or a chronictreatment with escitalopram.
2007
- Combined effect of antidepressant and anti-inflammatory drugs in an animal model of depressio
[Abstract in Rivista]
Brunello, Nicoletta; Alboni, Silvia; Benatti, Cristina; Corsini, Daniela; Capone, Giacomo; Tascedda, Fabio; J., Mendlewicz
abstract
The delay in the onset of action of antidepressants remains
one of the unsolved issues in the treatment of depression despite
the availability of safe and effective drugs. It has been
known for years that depression may share identical symptoms
as those in inflammatory reaction and that immune function and
inflammation markers are altered in psychiatric patients. This
suggests to use anti-inflammatory drugs as an adjunctive therapy
for depression. We previously demonstrated that the combination
of acetylsalicylic acid (ASA) with Fluoxetine (FLX) accelerated
and potentiated the effect of the antidepressant in the chronic
escape model of depression (Brunello et al., 2006). These results,
together with preliminary clinical data in major depressed nonresponder
patients, suggest that ASA might accelerate the onset
of action of SSRIs (Mendlewicz et al., 2006).
Preclinical and clinical studies have recently reported that
Escitalopram (ESC), the active enantiomer of citalopram, shows
a faster onset of action compared to other antidepressants.
The aim of our study was to compare the effect of one week
of combined treatment with ESC plus ASA vs. ESC alone in the
chronic escape deficit model of depression. Significant response
after one week of treatment was present in about 50% of the
animals receiving ESC (10 mg/kg/day) alone and in about 75% of
the rats receiving ESC plus ASA (45 mg/kg/day).
These results suggest that the co-administration of ASA with
ESC increased the response to treatment in reverting the behavioural
despair induced by stress in rats, thus confirming the
specific effect of combined therapy.
2006
- Acetylsalicylic acid accelerates the antidepressant effect of fluoxetine in a rat model of depression
[Abstract in Rivista]
Capone, Giacomo; Alboni, Silvia; Benatti, Cristina; Tascedda, Fabio; Blom, Johanna Maria Catharina; J., Mendlewicz; Brunello, Nicoletta
abstract
Depression currently ranks fourth among the major causesof disability worldwide and by 2020, it is estimated thatunipolar major depression will rank second as a sourceof lost disability-adjusted life years (DALYs) worldwide(Murray and Lopez, 1997). To date however no singleagent is effective in all patients treated, probably due tothe different neurobiological alterations occurring for thedisorder and to individual differences in pharmacogeneticand pharmacodynamic parameters.Different therapies have been proposed to amelioratethe clinical responses of antidepressant drugs throughaugmentation or combination strategies.Another achievement in the development of newtreatments is to reduce the latency of clinical effect ofantidepressant drugs known to be characterized by 4-6weeks lag phase.Evidence has accumulated suggesting that majordepression is associated with dysfunction of inflammatorymediators and that psychiatric symptoms may occur duringinflammatory diseases. Moreover antidepressants show ananti-inflanmlatory action possibly related to their clinicalefficacy. In fact, an improvement in psychiatric symptomshas been recently reported in patients treated with antiinflammatorydrugs for other indications.These data imply that inflammation may be involved inthe pathogenesis of depression and that anti-inflanm~atorydrugs may be used as an adjunctive therapy.Among anti-inflammatory drugs acetylsalicylic acid(ASA) has been shown to act on the brain serotonergicsystem and to have a neuroprotective effect in vitro aswell as in vivo.Aim of the present study was to evaluate the effectsof combined treatment fluoxetine (FLX) plus ASA andASA alone in a behavioural model of depression:the chronic escape deficit (Gambarana et al., 2001).The chronic escape deficit model is based on themodified reactivity of rats to external stimuli inducedby exposure to unavoidable stress and allows evaluatingthe capacity of a treatment to revert the condition ofescape deficit. In this model, FLX alone needs to beadministered for at least 3 weeks in order to revert thiscondition.Our results showed that ASA (45 mg/kg) did not possessantidepressant properties in the chronic escape deficitmodel at any time tested. A combined treatment of FLX(5 mg/kg) and ASA (45 mg/kg) completely reverted thecondition of escape deficit as early as after 7 days, theeffect being already partially present after 4 days. Theeffect was maintained after 14 and 21 days of treatment.In the same experimental condition the effect of FLX(5 mg/kg) was significant only at 21 days, as previouslydemonstrated by other groups.The exact nature of the mechanisms underlying theabove behavioural effects are still unknown, neverthelessseveral hypotheses can be formulated. Further biochemicaland genetic researches could help to clarify the targets ofaction of the combined treatment FLX plus ASA for thedevelopment of more active and faster acting molecules.
2006
- Acetylsalicylic acid accelerates the antidepressant effect of fluoxetine in the chronic escape deficit model of depression
[Articolo su rivista]
Brunello, Nicoletta; Alboni, Silvia; Capone, Giacomo; Benatti, Cristina; Blom, Johanna Maria Catharina; Tascedda, Fabio; Kriwin, P; Mendlewicz, J.
abstract
Evidence has accumulated suggesting that major depression is associated with dysfunction of inflammatory mediators. Moreover, antidepressants show an antiinflammatory action possibly related to their clinical efficacy. An improvement in psychiatric symptoms has been recently reported in patients treated with antiinflammatory drugs for other indications. These data imply that inflammation may be involved in the pathogenesis of depression and that anti-inflammatory drugs may be used as an adjunctive therapy. The aim of the present study was to evaluate the behavioural effect of the co-administration of acetylsalicylic acid (ASA, 45 mg/kg or 22.5 mg/kg) and fluoxetine (FLX, 5 mg/kg) in the chronic escape deficit model of depression. The chronic escape deficit model is based on the modified reactivity of rats to external stimuli induced by exposure to unavoidable stress and allows evaluation of the capacity of a treatment to revert the condition of escape deficit. In this model, FLX alone needs to be administered for at least 3 weeks to revert this condition. Our results show that combined treatment of fluoxetine and ASA completely reverted the condition of escape deficit by as early as 7 days, the effect being already partially present after 4 days. The effect was maintained after 14 and 21 days of treatment. ASA alone was ineffective at any time tested and the effect of fluoxetine was significant only at 21 days. These results, together with clinical data from preliminary results, suggest that ASA might accelerate the onset of action of selective serotonin reuptake inhibitor antidepressants.
2006
- Behavioural and molecular effects of the combined treatment fluoxetine plus acetylsalicylic acid in a rat model of depression
[Abstract in Rivista]
Alboni, Silvia; Capone, Giacomo; Benatti, Cristina; Tascedda, Fabio; Blom, Johanna Maria Catharina; Mendlewicz, J; Brunello, Nicoletta
abstract
Current treatments for depression are inadequate for many patients,
and different therapies have been proposed to ameliorate the
clinical responses of antidepressant drugs through augumentation
or combination strategies. Another achievement in the development
of new treatments is to reduce the latency of clinical effect of
antidepressant drugs known to be characterized by 4−6 weeks lag
phase. Evidence has accumulated suggesting that major depression
is associated with dysfunction of inflammatory mediators and that
psychiatric symptoms may occur during inflammatory diseases.
Moreover antidepressants show an anti-inflammatory action possibly
related to their clinical efficacy. In fact, an improvement
in psychiatric symptoms has been recently reported in patients
treated with anti-inflammatory drugs for other indications. These
data imply that inflammation may be involved in the pathogenesis
of depression and that anti-inflammatory drugs may be used
as an adjunctive therapy. Among the anti-inflammatory drugs
the Acetylsalicylic acid has been shown to act on the brain
serotonergic system and to have a neuroprotective effect toward brain damage. Aim of the present study was to evaluate the effects
of combined treatment fluoxetine (FLX) plus acetylsalicylic acid
(ASA) in a behavioural model of depression: the chronic escape
deficit. The chronic escape deficit model is based on the modified
reactivity of rats to external stimuli induced by exposure to unavoidable
stress and allows evaluating the capacity of a treatment
to revert the condition of escape deficit. In this model, FLX alone
needs to be administered for at least 3 weeks in order to revert
this condition. Our results showed that ASA (45 mg/kg) did not
possess antidepressant properties in the chronic escape deficit
model at any time tested. A combined treatment of FLX (5 mg/kg)
and ASA (45 mg/kg) completely reverted the condition of escape
deficit as early as after 7 days, the effect being already partially
present after 4 days. The effect was maintained after 14 and
21 days of treatment. In the same experimental condition the effect
of FLX (5 mg/kg) was significant only at 21 days, as previously
demonstrated by other groups. The exact nature of the mechanisms
underlying the above behavioural effects are still unknown, nevertheless
several hypotheses can be formulated. Moreover, because
a role for the neurotrophin BDNF was proposed in the clinical response
to antidepressant treatment, we have determined the effect
of combined treatment FLX plus ASA on hippocampal BDNF
mRNA and protein in the same behavioural model. Ours data
demonstrated that the hippocampal levels of BDNF mRNA were
significantly increased with respect to control groups (naive and
stressed) only in the animals responding (number of escape 10
out of 30 trials) to the combined treatment. Further biochemical
and genetic researches could help to clarify the targets of action
of the combined treatment FLX plus ASA for the development of
more active and faster molecules.
2006
- Early postnatal chronic inflammation produces long-term changes in pain behavior and N-methyl-D-aspartate receptor subtype gene expression in the central nervous system of adult mice
[Articolo su rivista]
Blom, Johanna Maria Catharina; Benatti, Cristina; Alboni, Silvia; Capone, Giacomo; Ferraguti, Chiara; Brunello, Nicoletta; Tascedda, Fabio
abstract
The objective of this study was to test whether postnatal chronic inflammation resulted in altered reactivity to pain later in life when reexposed to the same inflammatory agent and whether this alteration correlated with brain-region-specific patterns of N-methyl-D-aspartate (NMDA) receptor subtype gene expression. Neonatal mouse pups received a single injection of complete Freund's adjuvant (CFA) or saline into the left hind paw on postnatal day 1 or 14. At 12 weeks of age, both neonatal CFA- and saline-treated animals received a unilateral injection of CFA in the left hind paw. Adult behavioral responsiveness of the left paw to a radiant heat source was determined in mice treated neonatally with saline or CFA before and after receiving CFA as adults. Twenty-four hours later, brains were dissected and NMDA receptor subunit gene expression was determined in four different brain areas by using an RNase protection assay. The results indicated that NMDA receptor subtype gene expression in adult mice exposed to persistent neonatal peripheral inflammation was brain region specific and that NMDA gene expression and pain reactivity differed according to the day of neonatal CFA exposure. Similarly, adult behavioral responsiveness to a noxious radiant heat source differed according to the age of neonatal exposure to CFA. The data suggest a possible molecular basis for the hypothesis that chronic persistent inflammation experienced early during development may permanently alter the future behavior and the sensitivity to pain later in life, especially in response to subsequent or recurrent inflammatory events
2006
- Effects of acute stress on brain-derived neurotrophic factor in the hippocampus of transgenic mouse model of depression
[Abstract in Rivista]
Alboni, Silvia; Blom, Johanna Maria Catharina; Corsini, Daniela; Benatti, Cristina; Capone, Giacomo; Ferraguti, Chiara; N., Barden; Tascedda, Fabio; Brunello, Nicoletta
abstract
Brain-Derived Neurotrophic Factor (BDNF) is a member of the neurotrophin family which includes a group of molecules important for the development and the maintenance of the nervous system. Since BDNF is highly expressed in the hippocampus, the action and regulation of this neurotrophin in this area has become subject of intense study. The gene codifying for BDNF is a stress responsive gene and alterations in its expression may be important in regulating some of the physiological and pathophysiological effects of chronic and acute stress in the hippocampus. Different studies show that several types of stress reduce BDNF expression in the hippocampus of control animals [Smith et al., 1995] and these works led to a neurotrophic hypothesis of depression [Nestler et al., 2002]. Nevertheless, the effect of stress on BDNF gene expression may differ between a "normal" and a "pathological" brain. In our study, we used transgenic mice with glucocorticoid receptor impaired (GRi) expression created [Pepin et al., 1992], as a tool to study the neuroendocrine changes observed in stress-related disorders, such as major depression. This GRi mouse model is characterized by dysfunctional glucocorticoid inhibitory feedback and an excessive activation of the hypothalamic pituitar~adrenal (HPA) axis, that can be restored by antidepressant drugs' treatment. The hypothesis was tested that a single period of 30 minutes of restraint stress affects BDNF expression in the hippocampus of GRi mice differently than in wildtype (WT) mice. Using RNase protection assay and in situ hybridization we had assessed the BDNF mRNA hippocampal levels, while the levels of BDNF and its precursor, pro-BDNF were analyzed by western blotting. Our results indicated that 30 minutes of restraint enhanced BDNF mRNA expression in the CA3 hippocampal subregion of GRi mice; the same stress procedure induced also a statistically significant increase of pro- BDNF level in hippocampus of GRi mice. No effect of acute stress was observed in the WT at the level of the expression of BDNE Moreover, we evaluated the effects of restraint on signalling pathways implicated in the regulation of BDNF expression (mitogen-activated protein kinase and calcium/calmodulin-dependent kinase cascades) that converge on the phosphorylation of CREB that we found down-regulated in the hippocampus of GRi mice and up-regulated in WT mice. Our data suggest that, in the presence of psychophysiological stress (restraint stress), GRi mice display altered hippocampal regulation in BDNF gene expression. Thus, life-long central GR dysfunction may negatively affects neural functioning by limiting the capacity to cope with change or acute stress, which could be a predisposing or determining factor in depression. Understanding the mechanisms underlying the induction of BDNF mRNA and accumulation of pro-BDNF in the hippocampus of GRi mice, may help to clarify the molecular basis of action of this neurotrophin and contribute to the development of new strategies reducing the vulnerability of neurons to stress, thus preventing neuropathological alterations in the hippocampus.
2005
- Neonatal persistent inflammation alters pain response and NMDA receptor expression in adult mice
[Abstract in Rivista]
Benatti, Cristina; Alboni, Silvia; Ferraguti, Chiara; Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract
Infant pain is of critical interest, especially with respect to premature infants and other high-risk neonates that experience many invasive and traumatic procedures early in development. The early neonatal period is characterized by great plasticity and reorganization. Sustained activation of central nervous circuits, caused by protracted and recurrent pain, may cause long-lasting changes in central neural function thus affecting developmental outcome and behavioural responsiveness to pain or stress later in life. However little is known about the neurobiological substrates underlying this ``memory'' process. The aim of our study was twofold:to study whether timing of postnatal exposure to a persistent inflammatory insult alters the responsiveness to thermal pain in the adult animal;given the role of the NMDA receptor in pain processing as well as in learning and memory, to examine if NMDA receptor subtype gene expression in specific areas of the cns is influenced by neonatal inflammation.Methods: Newborn mice received a single injection of Complete Freund's Adjuvant (CFA) or saline on either postnatal day 1, 3 or 14 (P1, P3 and P14) into the left hind paw. At twelve weeks of age paw withdrawal latency (PWL) of each animal was tested both in basal condition and 24h after an unilateral injection of 100 μL of CFA in the left hind paw. Mice were then killed by cervical dislocation and cerebral areas were removed. Using a sensitive RNAse protection assay, NMDA receptor subunit (NR1, NR2A, NR2B, NR2C) gene expression was evaluated in different brain areas; all data were processed by one-way ANOVA (p < 0.05).Results: Baseline paw withdrawal latency was significantly decreased in animals exposed to CFA at day 1 and 14 as compared to their saline exposed counterparts. Animals exposed to CFA at postnatal day 3 showed a significant increase in paw withdrawal latency with respect to saline injected animals. Twenty-four hours later a unilateral injection of CFA into the left hind paw, a significant decrease in paw withdrawal latency was observed in all experimental groups with respect to baseline values. PWL of P1 saline treated animals after CFA exposure was significantly higher than P3 and P14 saline treated mice. Adult mice exposed to an injection with CFA on postnatal day 1 exhibited reduced expression of the NMDA receptor subtype NR1 and NR2C in the hippocampus while mRNA levels for NR2A and NR2B did not differ between CFA treated and untreated mice. Exposure to CFA on postnatal day 3 and 14 did not affect adult expression levels of NMDA receptor subunits in the hippocampus. NMDA receptor subunit expression displayed a different profile in the thalamus. Exposure to CFA at P1 and P3 did not alter NMDA receptor subunit expression while exposure to CFA at P14 resulted in enhanced expression of the NR2A and NR2B subunits.Conclusions: These findings indicate that changes in NMDA receptor subtype gene expression in adult mice exposed to persistent neonatal peripheral inflammation are brain region specific and that NMDA gene expression and pain reactivity differ according to the day of neonatal exposure to CFA.
2005
- New combination therapies from animal to human
[Abstract in Rivista]
Brunello, Nicoletta; Alboni, Silvia; Benatti, Cristina; Capone, Giacomo; Tascedda, Fabio; Blom, Johanna Maria Catharina; J., Mendlewicz
abstract
Evidence has accumulated suggesting that major depression is associated with dysfunction of inflammatory mediators. Antidepressants interfere with the synthesis and release of cytokines and do not exert behavioral effects in animal models of depression when hippocampal neurogenesis is blocked, a phenomenon which is occurring in the presence of inflammation. The anti-inflammatory drug acetylsalicylic acid (ASA), besides inhibiting the cyclooxigenase pathway, interacts with central serotonergic system, by increasing serotonin levels in cortex and reducing the density of different serotonin receptor subtypes. These neurochemical effects suggest a role of ASA in the treatment of depression. Therefore we studied the effect of ASA and fluoxetine combined treatment in a behavioral model of depression. The chronic escape deficit model is based on the modified reactivity of rats to external stimuli induced by exposure to unavoidable stress and allows evaluating the capacity of a treatment to revert the condition of escape deficit. Any kind of antidepressant drug needs to be administered for at least 3 weeks in order to revert this condition. The combined treatment of fluoxetine and ASA completely reverted the condition of escape deficit as early as after 7 days, the effect being already partially present after 4 days. The effect was maintained after 14 and 21 days of treatment. ASA alone was ineffective at any time tested and the effect of fluoxetine was significant only at 21 days. Given these preclinical results, an open clinical study has been started using the combination SSRI-ASA in treatment resistant depressed patients. Preliminary results suggest a potential accelerating effect of ASA in combination to SSRI.
2004
- Chronic treatment with desipramine and fluoxetine modulate BDNF, CaMKK alpha and CaMKK beta mRNA levels in the hippocampus of transgenic mice expressing antisense RNA against the glucocorticoid receptor
[Articolo su rivista]
J., Vinet; Carra, Serena; Blom, Johanna Maria Catharina; Brunello, Nicoletta; N., Barden; Tascedda, Fabio
abstract
Antidepressants up-regulate the cAMP response element binding protein (CREB) and the brain-derived neurotrophic factor (BDNF) in hippocampus and these effects contribute to the protection of hippocampal neurons from stressful stimuli such as high glucocorticoid levels. CREB can be activated by both protein kinase A and by Ca2+-calmodulin-dependent protein kinases (CaMKs), which are in turn phosphorylated by their upstream activators CaMKKalpha and CaMMKKbeta. Using in situ hybridization, we examined the effects of chronic treatment with fluoxetine (FLU) or desipramine (DMI) on BDNF, CaMKKalpha and CaMKKbeta mRNAs in the hippocampus of wild-type (Wt) and transgenic (TG) mice characterized by glucocorticoid receptor (GR) dysfunction. Basal levels of CaMKKbeta were down regulated in the CA3 region of TG mice. DMI decreased the expression of both CaMKKalpha and CaMMKKbeta in the CA3 region of Wt mice. FLU up-regulated BDNF mRNA levels in the CA3 of TG animals while both FLU and DMI increased BDNF gene expression in the dentate gyrus (DG) of TG animals. Our results demonstrate a different regulation of BDNF expression by antidepressant drugs in the hippocampus of Wt and TG animals. Moreover, for the first time, a role for CaMKKs in the mechanism of action of antidepressant agents, at least in the hippocampus, is reported. These data are discussed in view of interactions existing between CaMK pathway and GR-mediated gene transcription.
2004
- Regulation of CREB function in rat frontal cortex after combined treatment with Fluoxetine and Olanzapine
[Abstract in Rivista]
Capone, Giacomo; Alboni, Silvia; Blom, Johanna Maria Catharina; Ferraguti, Chiara; Brunello, Nicoletta; Tascedda, Fabio
abstract
Statement of the Study: Generally, drugs used in the treatment of depression
exert their therapeutic effect after 4/6 weeks and only in 60–65% of patients. The
search for an adequate and faster treatment of major depression is one of the main
challenges in neuropsychopharmacology. Recently, a clinical study of treatmentresistant
depressed patients without a psychotic component, showed that after
only one week of treatment, Fluoxetine (a selective serotonin reuptake inhibitor
antidepressant) and Olanzapine (an atypical antipsychotic agent) produced a
higher level of improvement than either monotherapy alone (Shelton et al., American
Journal of Psychiatry 158(1), 131–134, 2001). Furthermore, preclinical data,
using microdialysis, indicated that the combination of Olanzapine and Fluoxetine
resulted in an increase in the extracellular levels of dopamine and norepinephrine
in the rat prefrontal cortex, an effect that was significantly bigger than after treatment
with either drug alone (Zhang et al., Neuropsychopharmacology 23(3),250–
262, 2000). However, it is not yet completely understood which intracellular
signaling pathway could be involved in the fast response (seen in clinical trials)
to Fluoxetine plus Olanzapine co-treatment.
Methods: Since antidepressant and antipsychotic drugs affect the cyclic
adenosine monophosphate (cAMP) pathway, including the expression of the
cAMP response element binding protein (CREB), the levels of CREB mRNA
and CREB nuclear protein, total and phosphorylated, were studied in the frontal
cortex of rats using RNase protection assay and Western Blotting analysis
respectively. Four experimental groups were used: rats were treated for one,
five or ten days with either saline, Fluoxetine (ip 10 mg/Kg), Olanzapine (sc
1 mg/Kg) or combined Fluoxetine plus Olanzapine (10 mg/Kg and 1 mg/Kg).
Summary of Results: Our results show that the level of phosphorylated
CREB Ser133 was significantly increased in the frontal cortex of rats receiving
the combined treatment regimen (Fluoxetine plus Olanzapine) for five days. No
effect was observed in acutely and ten day treated rats.
Conclusion: This specific effect on CREB phosphorylation levels after five
days of combined treatment with Fluoxetine plus Olanzapine might represent
one of the mechanisms underlying the faster response to this therapy recently
observed in several clinical trials.
2004
- Restraint stress increases the expression of brain derived neurotrophic factor in the hippocampus of a mouse model of depression
[Abstract in Rivista]
Alboni, Silvia; Benatti, Cristina; Blom, Johanna Maria Catharina; Ferraguti, Chiara; Tascedda, Fabio; Barden, N; Brunello, Nicoletta
abstract
Statement of the study: Brain-Derived Neurotrophic Factor (BDNF) is a
member of the neurotrophin family which includes a group of molecules
important for the development and the maintenance of the nervous system.
Since BDNF is highly expressed in the hippocampus, the action and regulation
of BDNF in this particular area has become subject of intense study. Single or
repeated immobilization stress markedly reduces both BDNF mRNA and protein
levels in rat hippocampus. Consequently, BDNF is considered a stress-responsive
gene, and it has been recently suggested that alterations in the expression of this
growth factor may be important in regulating some of the physiological and
pathophysiological effects of stress on the hippocampus.
Stress-induced changes observed in the hippocampus of experimental animals
resulted in a novel hypothesis attributing a central role to neurotrophic factors
in both the etiology of depression and as well as in its treatment. However,
the effects of stress on neurotrophic factors in the hippocampus of depressed
patients remain unknown. In fact, the expression pattern of a large array of
genes affected by depression or antidepressant drugs, such as BDNF, may differ
between a normal and a pathological brain.
Methods: In these experiments, we used transgenic (TG) mice deficient in
glucocorticoid receptor (GR) functioning. This TG mouse was created as a model
to study the neuroendocrine changes occurring in stress-related disorders, such as
major depression. We evaluated the hypothesis that a single period of 30 minutes of restraint stress affects BDNF mRNA expression in the hippocampus of TG
mice differently than in WT mice.
Summary of results: BDNF mRNA was significantly increased by the stress
procedure only in the hippocampus of TG mice, the induction being specific for
the CA3 subregion as revealed by in situ hybridization.
Moreover, we found that stress down-regulated CREB phosphorylation in the
hippocampus of TG mice whereas it upregulated the level of phosphorylated
CREB Ser133 in WT mice.
Conclusion: These data suggest that, in the presence of emotional stress, lifelong
central glucocorticoid receptor dysfunction results in altered hippocampal
sensitivity, with respect to the level of neurotrophic gene expression.
The understanding of the mechanisms through which psychological stress
(such as restraint stress) induces BDNF mRNA in the hippocampus of TG
mice, may help to clarify the biological and molecular basis of the action of
neurotrophic factors and may contribute to the development of new strategies that
will ultimately reduce the vulnerability of neurons and prevent neuropathological
alterations in the hippocampus.
2003
- Cellular mechanisms and second messengers: relevance to the psychopharmacology of bipolar disorders
[Articolo su rivista]
Brunello, Nicoletta; Tascedda, Fabio
abstract
The discovery of lithium's efficacy as a mood-stabilizing agent revolutionized the treatment of patients with bipolar disorder and after five decades, lithium continues to be the mainstay of treatment for bipolar disorder. Recent research on the molecular mechanism underlying the therapeutic effect of lithium has focused on how it changes the activities of cellular signal transduction systems, especially the cyclic AMP and phosphomositide second-messenger systems. Considerable data suggest that carbamazepine and valproate (VPA) are an alternative or adjunctive treatment to lithium. VPA, despite being dissimilar structurally to lithium, shares most of the effects of lithium at the level of protein kinase C (PKC). Like lithium, VPA reduces the activity of PKC and reduces the protein levels of different PKC isoforms, however the effects of VPA appear to be largely independent of inositol. The ton-term efficacy of VPA and lithium in bipolar disorder suggested that modulation of gene expression might be an important target for these drugs. Both VPA and lithium altered the expression of the early inducible genes for c-fos and cjun thus promoting the expression of specific proteins. The genes known to be regulated by the AP-1 family of transcription factors include genes for various neuropeptides, neurotrophins, receptors, transcription factors, enzymes, proteins that bind to cytoskeletal elements, and cytoprotective proteins such as bcl-2. In conclusion chronic treatment with lithium and other mood stabilizers, by regulating transcriptional factors, may modulate the expression of a variety of genes that compensate for aberrant signalling associated with the pathophysiology of bipolar disorder.
2003
- Cloning of mouse Ca2+/calmodulin-dependent protein kinase kinase beta (CaMKKbeta) and characterization of CaMKKbeta and CaMKKalpha distribution in the adult mouse brain.
[Articolo su rivista]
Vinet, Jonathan; Carra, Serena; Blom, Johanna Maria Catharina; Harvey, M; Brunello, Nicoletta; Barden, N; Tascedda, Fabio
abstract
The Ca(2+)/calmodulin-dependent protein kinase kinases alpha and beta (CaMKKs alpha and beta) are novel members of the CaM kinase family. The CaMKKbeta was cloned from mouse brain. The deduced amino acid sequence shared 96.43% homology with the rat CaMKKbeta. Both the alpha and beta isoforms were widely distributed throughout the adult mouse brain. Additionally, all peripheral tissues examined displayed CaMKK alpha and beta expression.
2003
- Psicofarmacologia clinica
[Traduzione in Volume]
Blom, Johanna Maria Catharina; Daniela, Tardito; Fabio, Fumagalli; Tascedda, Fabio
abstract
Il volume raccoglie le acquisizioni più recenti sull'utilizzo clinico delle principali classi di psicofarmaci impiegati nella terapia delle patologie psichiatriche di più rilevante intersse sociale. Si divide in due sezioni principali: le classi di farmaci psichiatrici e i trattamenti psicofarmacologici. Nella Sezione I, per ogni molecola all'interno di una specifica classe, sono commentati i dati di studi preclinici e in fase clinica; inoltre, sono illustrati gli aspetti farmacodinamici e farmacocinetici, le indicazioni terapeutiche, i dosaggi, gli effetti collaterali e le interazioni con altri farmaci, psichiatrici e non psichiatrici. La Sezione II presenta lo stato dell'arte della terapia farmacologica nelle principali malattie psichiatriche. Gli autori descrivono, inoltre, la farmacoterapia in speciali popolazioni, come i bambini e gli adolescenti, i pazienti affetti da malattie sistemiche e gli anziani. Alcuni capitoli son infine dedicati alla psicofarmacoterapia in situazioni particolari, quali la gravidanza, l'allattamento e le emergenze. Particolare cura è stata posta nelladattare la descrizione delle singole molecole alla realtà italiana: sono stati inseriti alcini farmaci non in commercio negli Stati Uniti ma venduti in Italia; inoltre, laddove la legislazione del nostro Paese differisce da quella americana, si è provveduto a fornire indicazioni di sicuro riferimento per lo specialista italiano. Questo volume è una preziosa fonte di informazioni per psichatri, psicofarmacologi, neurologi, geriatri e specializzandi, nonché un valido strumento di approfondimento per gli studenti delle Facoltà di Medicina e Farmacia.
2002
- Altered regulation of CREB by chronic antidepressant administration in the brain of transgenic mice with impaired glucocorticoid receptor function.
[Articolo su rivista]
Blom, Johanna Maria Catharina; Tascedda, Fabio; Carra, Serena; Ferraguti, Chiara; Barden, N; Brunello, Nicoletta
abstract
Various effects of antidepressant drugs on gene transcription have been described and altered gene expression has been proposed as being a common biological basis underlying depressive illness. One target for the common action of antidepressants is a modifying effect on the regulation of postreceptor pathways and genes related to the cAMP cascade. Recent studies have demonstrated that long-term antidepressant treatment resulted in sustained activation of the cyclic adenosine 3',5'-monophosphate system and in increased expression of the transcription factor cAMP response element binding protein (CREB). A transgenic animal model of depression with impaired glucocorticoid receptor function was used to investigate the effect of chronic antidepressant treatments on CREB expression in different brain areas. Wild-type and transgenic mice received one administration of saline, desipramine, or fluoxetine, daily for 21 days. The effects of antidepressants on CREB mRNA were analyzed using a sensitive RNase protection assay. Antidepressant treatment resulted in a neuroanatomically and animal specific expression pattern of CREB. Our findings suggest that life-long central glucocorticoid receptor dysfunction results in an altered sensitivity with respect to the effects of antidepressants on the expression of CREB.
2002
- Cognitive deficits and changes in gene expression of NMDA receptors after prenatal methylmercury exposure
[Articolo su rivista]
Baraldi, Mario; Zanoli, Paola; Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract
Previous studies showed learning and memory deficit in adult rats that were prenatally exposed to methylmercury chloride (MMC) in an advanced stage of pregnancy (15 days). Under these conditions, the cognitive deficits found at 60 days of age paralleled particularly changes in the N-methyl-D-aspartate (NMDA) receptor characteristics. In the present study, we report the behavioral effects of a single oral dose of MMC (8 mg/kg) administered earlier at gestational day 8. The use of different learning and memory tests (passive avoidance, object recognition, water maze) showed a general cognitive impairment in the in utero-exposed rats tested at 60 days of age compared with matched controls. Considering the importance of the glutamatergic receptor system and its endogenous ligands in learning and memory process regulation, we surmised that MMC could affect the gene expression of NMDA receptor subtypes. The use of a sensitive RNase protection assay allowed the evaluation of gene expression of two families of NMDA receptors (NR-1 and NR-2 subtypes). The result obtained in 60-day-old rats prenatally exposed to MMC, showed increased mRNA levels of the NR-2B subunit in the hippocampus but not in the frontal cortex. The data suggest that the behavioral abnormalities of MMC-exposed rats might be ascribed to a neurotoxic effect of the metal that alters the gene expression of a specific NMDA receptor subunit in the hippocampus.
2001
- Modulation of glutamate receptors in response to the novel antipsychotic olanzapine in rats.
[Articolo su rivista]
Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta; Zolin, K; Gennarelli, Massimo; Colzi, A; Bravi, D; Carra, Serena; Racagni, G; Riva, M. A.
abstract
BACKGROUND:A disturbance in glutamate neurotransmission has been hypothesized in schizophrenia. Hence, the beneficial effects of pharmacological treatment may be related to adaptive changes taking place in this neurotransmitter system.METHODS:In this study, we investigated the modulation of ionotropic and metabotropic glutamate receptors in the rat brain following acute or chronic exposure to the novel antipsychotic olanzapine.RESULTS:In accordance with the clear distinction between classical and atypical drugs, olanzapine did not alter glutamate receptor expression in striatum. Chronic, not acute, exposure to olanzapine was capable of up-regulating hippocampal mRNA levels for GluR-B and GluR-C, two alpha-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid (AMPA)-forming subunits. This effect could be relevant for the improvement of schizophrenic alterations, which are thought to depend on dysfunction of the glutamatergic transmission within the hippocampal formation. We also found that the expression of group II glutamate metabotropic receptors was up-regulated in the frontal cortex after chronic exposure to clozapine, and to a lesser extent olanzapine, but not with haloperidol.CONCLUSIONS:The adaptive mechanisms taking place in glutamatergic transmission might prove useful in ameliorating some of the dysfunction observed in the brain of schizophrenic patients.
1999
- Regulation of ionotropic glutamate receptors in the rat brain in response to the atypical antipsychotic seroquel (quetiapine fumarate). .
[Articolo su rivista]
Tascedda, Fabio; E., Lovati; Blom, Johanna Maria Catharina; P., Muzzioli; Brunello, Nicoletta; G., Racagni; M. A., Riva
abstract
The interplay between dopamine and glutamate appears to
be relevant in the etiopathology of schizophrenia. Although
currently used antipsychotics do not interact with
glutamatergic receptors, previous results have
demonstrated that the expression profile of ionotropic
glutamate receptors can be regulated by drugs such as
haloperidol or clozapine. In the present investigation, the
mRNA levels for NMDA and AMPA receptor subunits
were measured after chronic treatment with the novel
antipsychotic agent Seroquel (quetiapine fumarate,
quetiapine) as compared to haloperidol and clozapine.
Similarly to the prototype atypical clozapine, quetiapine
reduced the mRNA expression for NR-1 and NR-2C, two
NMDA forming subunits, in the nucleus accumbens.
Furthermore, quetiapine, but not haloperidol or clozapine,
increased the hippocampal expression for the AMPA
subunits GluR-B and GluR-C. The differences between
classical and atypical antipsychotics, as well as among the
novel agents, might be relevant for specific aspects of their
therapeutic activity and could provide valuable information
for the role of glutamate in specific symptoms of
schizophrenia.
1999
- Selective modulation of fibroblast growth factor-2 expression in the rat brain by the atypical antipsychotic clozapine
[Articolo su rivista]
Riva, Ma; Molteni, R; Tascedda, Fabio; Massironi, A; Racagni, G.
abstract
In the present paper we investigated, in the rat brain, the expression of basic fibroblast growth factor (FGF-2) in response to the atypical antipsychotic clozapine. We found that acute or chronic administration of this compound produced a selective increase of FGF-2 mRNA and protein in the striatum. Although acute injection of clozapine did increase FGF-2 expression in parietal cortex and nucleus accumbens we found that, following repeated administration, the induction of the trophic molecule was taking place only at striatal level. The analysis of other antipsychotic drugs did not provide conclusive evidence for the molecular mechanisms involved in clozapine-induced elevation of FGF-2. In fact, chronic administration of classical neuroleptics, haloperidol and chlorpromazine, did not alter the expression of FGF-2. Furthermore the novel drugs quetiapine and olanzapine, despite some similarities in their receptor profiles, were similarly ineffective. Hence these data suggest that, among antipsychotic drugs, the induction of FGF-2 is unique to clozapine. On the basis of the neuroprotective activity of this trophic molecule, our data might be relevant for the potential use of clozapine in tardive dyskinesia and parkinsonism, which develop during long term administration of classical neuroleptic drugs. (C) 1999 Elsevier Science Ltd. All rights reserved.
1997
- Regulation of NMDA receptor subunit messenger RNA levels in the rat brain following acute and chronic exposure to antipsychotic drugs.
[Articolo su rivista]
Riva, M. A.; Tascedda, Fabio; Lovati, E.; Racagni, G.
abstract
Based on anatomical and biochemical observations a role of glutamate in schizophrenia has been postulated. In the present work we
have investigated the gene expression for two families of NMDA receptor subunits ŽNR-1 and NR-2. following acute and chronic
treatment with typical Žhaloperidol. and atypical Žclozapine. antipsychotic drug ŽAPD. in rats. A single injection of the two drugs elicited
a significant increase in the mRNA levels of NR-2B in the nucleus accumbens, whereas only haloperidol was able to elevate NR-2A and
NR-2B in the hippocampus. Following a 21 day treatment, significant differences in the regulatory pattern of NMDA-R subunits were
observed. Haloperidol increased their mRNA levels in striatum whereas clozapine, consistent with its relatively weaker influence on
nigro-striatal dopamine function, did not change the expression of NR subunits in this region. Both APD’s were able to decrease the
expression of NR-2 subunits in the hypothalamus, but only clozapine was capable of reducing NR-2C in frontal cortex and accumbens.
The regulation of NMDA-R subunits in specific brain regions may represent a novel and important mechanism through which APD’s
exert some of their effects on brain function.
1996
- Acute and chronic changes in K+-induces depolarization alter NMDA and nNOS gene expression in cultured cerebellar granule cells.
[Articolo su rivista]
Tascedda, Fabio; Molteni, R; Racagni, G; Riva, M. A.
abstract
The influence of low or high (10 or 25 mM) K+-induced membrane depolarization on the mRNA levels for NMDA receptor subunits
was investigated by RNase protection assay in cultured rat cerebellar granule cells. Cells, maintained for 7 days in K~5, a condition that
promotes their survival and maturation, express the highest levels of NR- 1 and NR-2A mRNA, whereas NR-2B is maximally expressed in
cells grown in K~- o. Acute changes in medium K ÷ concentration had a significant effect on the mRNA levels for NMDA receptor
subunits. A concomitant reduction of NR-2A mRNA and induction of NR-2B was observed following a 24-h shift of the culture medium
from K~- 5 to K~- o. Under these circumstances NR-2C, not detected in basal conditions, became expressed. Neuronal nitric oxide synthase,
an enzyme linked to NMDA receptor activation, was also influenced by growth conditions. Its expression, higher under low excitation
(K~-o), is induced in the shift from K~- 5 to K~- o and is markedly decreased in the opposite situation. These data indicate that several factors
may influence the expression of NMDA receptor subunits and consequently may modulate the function of this receptor complex and its
adaptation to acute and chronic changes in neuronal activity.
1994
- Regulation of NMDA receptor subunit mRNA expression in the rat brain during postnatal development
[Articolo su rivista]
Riva, M. A.; Tascedda, Fabio; Molteni, R.; Racagni, G.
abstract
Different NMDA receptor subunits have been recently cloned. The present paper describes the developmental profile of expression of the NR-1 subunit and three NR-2 subunits (A, B, C) in the rat central nervous system. A sensitive RNase protection assay was employed to determine simultaneously the mRNA levels of these receptor subunits. We found low levels of NR-1 mRNA (comprising all different splicing isoforms) in newborn rats with a progressive increase of its expression in the following 2–3 weeks. NR-2 subunits can be regarded as ‘modulatory’ since their expression can produce differences in the properties of NMDA receptors. More than one NR-2 subunits can be expressed in the same brain region. NR-2A and NR-2C are concomitantly expressed in the cerebellum and during development their mRNAs increase with a similar profile from low levels in P-8 rats to maximal expression in P-21 animals. NR-2A and NR-2B are concomitantly expressed in several brain regions with a different ontogenetic profile. In the hippocampus NR-2B mRNA increases rapidly during the first week of life as compared to the NR-2A subunits which at this time is expressed to low levels indicating that NR-2B will probably be dominant in determining the NMDA properties during the first period of life. Our data can provide a molecular correlate with properties of NMDA receptors such as voltage dependent Mg2+ block and deactivation kinetics which undergo significant changes during development and have been shown to depend upon the NR-2 subunit co-expressed with the common NR-1 subunit in various brain regions.
1994
- Short and long term induction of basic fibroblast growth factor gene expresion in rat CNS following kainic acid injection.
[Articolo su rivista]
Riva, M. A.; Donati, E; Tascedda, Fabio; Zolli, M; Racagni, G.
abstract
Both RNase protection assay and in situ hybridization were used to investigate the effect of intraperitoneal injection of kainate on the messenger RNA levels for basic fibroblast growth factor in the rat central nervous system.
Limbic motor seizures were produced by kainate injection and this event was followed by a significant elevation of basic fibroblast growth factor gene expression in rat hippocampus and striatum 6 h after the convulsant injection. The increase in hippocampus was maximal at 24 h and it was delayed with respect to nerve growth factor induction, which peaked 3 h after kainate injection. Animals that suffered prolonged seizure activity also showed a significant elevation of basic fibroblast growth factor gene expression four and 14 days after kainate, when no changes in nerve growth factor gene expression were observed. We show that, within the hippocampus, the increase of basic fibroblast growth factor messenger RNA was localized in dentate gyrus and the CA1 layer 6 and 24 h after kainate injection. Long-term effects on its gene expression were measurable only in the CA1 hippocampal subfield, where major cell damage and astrocytosis have been reported to occur following kainate-induced seizure activity [Ben-Ari Y. et al. (1981) Neuroscience7, 1361–1391; Lothman E. W. and Collins R. C. (1981) Brain Res.218, 299–318; Schwob J. E. et al. (1980) Neuroscience5, 991–1014]. Indeed, the animals which displayed elevated messenger RNA levels for basic fibroblast growth factor four and 14 days after kainate injection showed a marked induction of messenger RNA expression for the astroglial marker glial fibrillary acidic protein.
These results indicate that the glutamate analogue kainate produces short- and long-term increases of basic fibroblast growth factor messenger RNA expression with a specific anatomical pattern. Therefore, the gene expression for this neurotrophic factor is probably regulated by neuronal activity at early points in time, whereas the induction observed at later time points is related to adaptive mechanisms taking place following kainate-induced neuronal degeneration.