Lymphomononuclear cells from multiple sclerosis patients spontaneously produce high levels of oncostatin M, tumor necrosis factors a

Proinflammatory cytokines are deemed to play a pivotal role in the pathogenesis of multiple sclerosis (MS). They provide signals for T-cell activatio

Original Article

The pancreas taken from the frog (Rana nigromaculata) was fixed in 1% OsO_4 and sliced into ultrathin sections for electron microscopic studies. The following observations were made: 1. A great \u27number of minute granules found in the cytoplasm of a pancreatic cell were called the microsomes, which were divided into two types, the C-microsome and S-microsome. 2. Electron microsopic studies of the ergastoplasm showed that it is composed of the microsome granules and A-substance. The microsomes were seen embedded in the A-substance which was either filamentous or membranous. The membranous structure, which was called the Am-membrane, was seen to form a sac, with a cavity of varying sizes, or to form a lamella. 3. The Am-membrane has close similarity to α-cytomembrane of Sjostrand, except that the latter is rough-surfaced. It was deduced that the Am-membrane, which is smooth-surfaced, might turn into the rough-surfaced α-cytomembrane. 4. There was the Golgi apparatus in the supranuclear region of a pancreatic cell. It consisted of the Golgi membrane, Golgi vacuole and. Golgi vesicle. 5. The mitochondria of a pancreatic cell appeared like long filaments, and some of them were seen to ramify. 6. The membrane of mitochondria, i. e. the limiting membrane, consisted of the Ammembrane. The mitochondria contained a lot of A-substances, as well as the C-microsomes and S-microsomes. When the mitochondria came into being, there appeared inside them chains of granules, which appeared like strips of beads, as the outgrowths of the A-substance and the microsome granules attached to the Am-membrane. They are the so-called cristae mitochondriales. 7. The secretory granules originate in the microsomes. They came into being when the microsomes gradually thickened and grew in size as various substances became adhered to them. Some of the secretory granules were covered with a membrane and appeared like what they have called the intracisternal granule of Palade.It seemed that this was a phenomenon attendant upon the dissolution and liqutefaction of the secretory granule. 8. Comparative studies were made of the ergastoplasm of the pancreatic cells from the frogs in hibernation, the frogs artificially hungered, the frogs which were given food after a certain period of fasting, the frogs to which pilocarpine was given subcutaneously, and the very young, immature frogs. The studies revealed that the ergastoplasm of the pancreatic cells greatly varied in form with the difference in nutritive condition and with different developmental stages of the cell. The change in form and structure occured as a result of transformation of the microsomes and A-substance. The ergastoplasm, even after it has come into being, might easily be inactivated if nutrition is defective. The ergastoplasm is concerned in the secretory mechanism, which is different from the secretory phenomenon of the secretory granules. It would seem that structurally the mitochondria have no direct relation to this mechanism

Prenatal N-acetyl-cysteine administration moderates the long-term negative effects of maternal obesity in adolescent male and female mouse offspring

Obesity during pregnancy may affect offspring developmental trajectories representing a risk factor for mental health. Amongst the mechanisms called into question inflammation, oxidative stress and the hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis appear as the most suitable. We investigated the emotional phenotype of male and female offspring of dams exposed to a high-fat diet (HFD, a mouse model of maternal obesity) before and during pregnancy. We also tested the efficacy of N-acetyl-cysteine (NAC – an antioxidant) in preventing the negative effects of HFD. We focused on adolescence, an age of main vulnerability for the onset of psychopathologies. Female C57BL/6N mice were fed HFD for 13 weeks and, after 5 weeks, were also exposed to NAC (1 g/kg b.w.) via drinking water, until delivery. Emotionality was assessed in 35-45-day-old adolescent mice by means of the elevated-plus-maze (EPM) and social interaction tests (SIT). A forced swimming test was used both to evaluate depressive-like behaviour as well as a stressful challenge to measure HPA axis reactivity. NAC was effective in moderating body weight gain in HFD-treated dams. Prenatal HFD reduced exploratory behaviours in the EPM in periadolescent offspring; NAC administration resulting in increased social interactions in the offspring of HFD dams. Analyses of depression-like behaviours, HPA axis functionality and brain transcriptomics are currently ongoing for mechanistic insight. Data from these studies indicate that the long-term effects of maternal obesity may be mediated by changes in oxidative stress and point to NAC as a potential preventive strategy. ERANET-NEURON-JTC 2018 (Mental Disorders) Project ‘‘EMBED”

Surface-bound Tat inhibits antigen-specific CD8(+) T-cell activation in an integrin-dependent manner

Objective:The identification of still unrevealed mechanisms affecting the anti-HIV CD8(+) T-cell response in HIV-1 infection.Design:Starting from the observation that anti-Tat immunization is associated with improved CD8(+) T-cell immunity, we developed both in-vitro and ex-vivo assays to characterize the effects of extra-cellular Tat on the adaptive CD8(+) T-cell response.Methods:The effects of Tat on CD8(+) T-cell activation were assayed using CD8(+) T-cell clones specific for either cellular (MART-1) or viral (HIV-1 Nef) antigens, and HIV-1 Gag-specific CD8(+) T cells from HIV-1 patients.Results:The interaction between CD8(+) T lymphocytes and immobilized Tat, but not its soluble form, inhibits peptide-specific CD8(+) T-lymphocyte activation. The inhibition does not depend on Tat trans-activation activity, but on the interaction of the Tat RGD domain with 51 and v3 integrins. Impaired CD8(+) T-cell activation was also observed in cocultures of CD8(+) T cells with HIV-1-infected cells. Anti-Tat Abs abrogate the inhibitory effect, consistently with the evidence that extracellular Tat accumulates on the cell membrane of virus-producing cells. The Tat-induced inhibition of cell activation associates with increased apoptosis of CD8(+) T cells. Finally, the inhibition of cell activation also takes place in Gag-specific CD8(+) T lymphocytes from HIV-1-infected patients.Conclusion:Our results support the idea that CD8(+) T-cell apoptosis induced by surface-bound extracellular Tat can contribute to the dysregulation of the CD8(+) T-cell adaptive response against HIV as well as other pathogens present in AIDS patients

Prenatal N-acetyl-cysteine administration alleviates the long-term effects of maternal obesity of adolescent male and female mouse offspring

Introduction. High-fat diet (HFD) consumption during pregnancy may act as a prenatal stressor affecting foetal brain developmental and representing an important risk factor for mental health. Indeed, offspring of obese mothers are prenatally over-exposed to increased levels of oxidative stress, hormones and pro-inflammatory cytokines, that all together can dramatically alter the development of neuronal circuits involved in the regulation of behaviour and mood. N-acetyl-cysteine (NAC) is a promising antioxidant compound that has revealed beneficial effects in the treatment of psychopathology. Aim. The aim of this study was to evaluate the general neurodevelopment, the social behaviour and the emotional phenotype of male and female offspring of dams exposed to a HFD (a mouse model of maternal obesity) before and during pregnancy. Furthermore, we tested the efficacy of prenatal NAC administration in preventing the negative effects of maternal HFD. We focused on adolescence, an age of main vulnerability for the onset of psychopathologies. Methods. Female C57BL/6N mice were fed either HFD (energy 5.56 kcal/g, fat 58%, carbohydrate 25.5% and protein 16.4%) or control diet (CD, energy 4.07 kcal/g, fat 10.5%, carbohydrate 73.1% and protein 16.4%) for 13 weeks and, after 5 weeks, were also exposed to NAC (1 g/kg body weight) via drinking water, until delivery. The general neurodevelopment of offspring was assessed through the Homing test at post-natal day (PND) 10; emotionality and social behaviour were assessed during adolescence (PND 35-45) by means of the elevated-plus-maze (EPM) and social interaction tests (SIT). A forced swimming test was used both to evaluate depressive-like behaviour as well as a stressful challenge to measure hypothalamic-pituitary-adrenal (HPA) axis reactivity. Transcriptomic analysis on hippocampus were performed in order to identify mechanisms of action of both HFD and NAC. Data were analysed using parametric analysis of variance (ANOVA) with Prenatal diet (HFD vs. CD), Prenatal treatment (NAC vs. WATER), Sex (females vs. males) as between subjects factors and time blocks as within-subjects repeated measures (i.e. body weight). Post hoc comparisons were performed using the Tukey’s test. Results. NAC was effective in moderating body weight gain in HFD-fed dams (Diet x Treatment x time p=0.0078, post hoc HFD-WATER vs. HFD-NAC p<0.05). Neither HFD or NAC affected neurodevelopment of offspring at PND 10. Prenatal HFD reduced exploratory behaviours in the EPM (main effect of Prenatal diet in frequency of crossings p=0.0001; frequency of head dipping p=0.0292; frequency of wall-rearing p=0.0255) and decreased sociability (Prenatal diet x Prenatal treatment in the duration of sniff the cospecific subject p=0.0002, post hoc CD-WATER vs. HFD-WATER p<0.05) in the SIT in periadolescent offspring. Prenatal NAC administration was effective in preventing social anxiety in offspring of HFD-fed dams (post hoc HFD-WATER vs. HFD NAC p<0.05). HPA axis functionality and brain transcriptomics are currently ongoing for mechanistic insight. Conclusions. Data from this study indicate that the long-term effects of maternal obesity may be mediated by changes in oxidative stress and point to NAC as a potential preventive strategy. ERANET-NEURON-JTC 2018 (Mental Disorders) Project ‘‘EMBED”

Surface-bound Tat inhibits antigen-specific CD8⁺ T-cell activation in an integrin-dependent manner.

OBJECTIVE:: The identification of still unrevealed mechanisms affecting the anti-HIV CD8 T-cell response in HIV-1 infection. DESIGN:: Starting from the observation that anti-Tat immunization is associated with improved CD8 T-cell immunity, we developed both in-vitro and ex-vivo assays to characterize the effects of extra-cellular Tat on the adaptive CD8 T-cell response. METHODS:: The effects of Tat on CD8 T-cell activation were assayed using CD8 T-cell clones specific for either cellular (MART-1) or viral (HIV-1 Nef) antigens, and HIV-1 Gag-specific CD8 T cells from HIV-1 patients. RESULTS:: The interaction between CD8 T lymphocytes and immobilized Tat, but not its soluble form, inhibits peptide-specific CD8 T-lymphocyte activation. The inhibition does not depend on Tat trans-activation activity, but on the interaction of the Tat RGD domain with α5β1 and αvβ3 integrins. Impaired CD8 T-cell activation was also observed in cocultures of CD8 T cells with HIV-1-infected cells. Anti-Tat Abs abrogate the inhibitory effect, consistently with the evidence that extracellular Tat accumulates on the cell membrane of virus-producing cells. The Tat-induced inhibition of cell activation associates with increased apoptosis of CD8 T cells. Finally, the inhibition of cell activation also takes place in Gag-specific CD8 T lymphocytes from HIV-1-infected patients. CONCLUSION:: Our results support the idea that CD8 T-cell apoptosis induced by surface-bound extracellular Tat can contribute to the dysregulation of the CD8 T-cell adaptive response against HIV as well as other pathogens present in AIDS patients

N-acetyl-cysteine administration during foetal life improves social behaviour and restores hippocampal BDNF levels in adolescent mice prenatally exposed to a high-fat diet

Maternal obesity may affect foetal programming representing a risk for adult mental health. Oxidative stress and inflammation associated with maternal obesity can alter the maturation of neuronal circuits affecting behaviour and mood. We investigated the emotional phenotype of male and female mouse offspring born from a high-fat diet (HFD) fed dams. We also tested the efficacy of N-acetyl-cysteine (NAC – an antioxidant) in preventing the negative effects of HFD. We focused on adolescence, an age of main vulnerability for the onset of psychopathology. Female C57BL/6N mice were fed HFD for 13 weeks and, after 5 weeks, were also exposed to NAC (1 g/kg b.w.) via drinking water, until delivery. The neurodevelopment of offspring was assessed through the homing test. Emotionality was assessed in 35-45-day-old adolescent mice through elevated-plus-maze (EPM) and social interaction tests (SIT). Transcriptomic analysis of hippocampal tissue were performed to identify mechanisms of action of both HFD and NAC. NAC was effective in moderating body weight gain in HFD-fed dams. Neither HFD or NAC affected offspring development. Regardless of sex, prenatal HFD reduced exploration and decreased sociability, in EPM and SIT respectively. Prenatal HFD decreased hippocampal levels of BDNF in female offspring. Prenatal NAC administration prevented social anxiety and restored BDNF levels in the HFD group. Data indicate long-term effects of maternal obesity on dams’ weight, offspring’s behaviour and hippocampal BDNF levels. These effects may be mediated by changes in oxidative stress as NAC was effective as a preventive agent. ERANET-NEURON-JTC 2018 (Mental Disorders) Project “EMBED”

Prenatal N-acetyl-cysteine prevents social anxiety and modulates hippocampal inflammatory-and plasticity-related genes in adolescent mice prenatally exposed to a high-fat diet

High-fat diet (HFD) consumption during pregnancy is associated with increased oxidative stress (OS) and low-grade chronic inflammation, and may affect fetal brain development, setting the stage for increased vulnerability to mood disorders later in life [1,2]. However, the biological mechanisms underlying the negative long-term effects of maternal HFD are poorly understood. N-acetyl-cysteine (NAC) is a promising antioxidant compound [3] that has revealed beneficial effects in the treatment of psychopathology. The aim of this study was to investigate inflammation, OS and hypothalamic-pituitary-adrenal (HPA) axis reactivity in a mouse model of maternal HFD as potential mechanisms affecting brain development and emotional behavior in the offspring. The prenatal NAC treatment was tested to prevent the negative effects of maternal HFD on adolescent offspring, an age of main vulnerability for the onset of psychopathologies. Female C57BL/6N mice were fed either HFD (energy 5.56 kcal/g, fat 58%, carbohydrate 25.5% and protein 16.4%) or control diet (CD, energy 4.07 kcal/g, fat 10.5%, carbohydrate 73.1% and protein 16.4%) before and during pregnancy (13 weeks); after 5 weeks on diets, half of them received NAC (1g/kg) for 8 weeks, until delivery. Emotionality and social behavior of male and female adolescent offspring (35-45 days) were assessed through the elevated plus maze (EPM) and the social interaction test (SIT); HPA axis functionality was assessed measuring plasma corticosterone levels by ELISA under basal conditions and following an acute stress. Gene expression levels of CD68, Bdnf and Nrf2 were measured in hippocampus as markers of microglial activation, brain plasticity and antioxidant capacity respectively by RealTime PCR. Data were analyzed using parametric analysis of variance (ANOVA) with diet (HFD vs. CD), treatment (NAC vs. WATER), sex (females vs. males) as between subjects factors. Post hoc comparisons were performed using the Tukey’s test. Prenatal exposure to HFD affected sociability reducing social behaviors (p<0.01, post hoc HFD-WATER vs. CD-WATER p<0.05) in the SIT and reduced exploration in the EPM (frequency of crossings p<0.01; head dipping p=0.0292; wall-rearing p=0.0255). As for the HPA axis functionality, reduced levels of basal corticosterone were found in HFD males (p<0.01, post hoc HFD-WATER vs. CD-WATER p<0.05). Moreover, prenatal HFD decreased hippocampal Bdnf levels in females (p<0.01, post hoc HFD-WATER vs. CD-WATER p<0.05), while males showed increased CD68 expression (p<0.01). Prenatal NAC administration prevented social anxiety, restored HPA axis basal activity in males and Bdnf levels in females (p<0.01, post hoc HFD-WATER vs. HFD-NAC p<0.05). In addition, hippocampal levels of Nrf2 resulted increased in both males and females (p<0.01), suggesting that NAC may act, at least in part, through an upregulation of this important regulator of brain antioxidant defenses. Overall, these data showed that maternal HFD induces long-term negative effects on the adolescent offspring, affecting brain, neuroendocrine system and emotional/social behavior. These effects are partially prevented by prenatal administration of NAC suggesting that immune and OS pathways may play an important role in fetal programming of mental disorders. Funding: ERANET-NEURON-JTC-2018 Project EMBE