Visceral Fat Dysfunctions in the Rat Social Isolation Model of Psychosis

Social isolation shortens lifespan through oxidative stress in ants

Social isolation negatively affects health, induces detrimental behaviors, and shortens lifespan in social species. Little is known about the mechanisms underpinning these effects because model species are typically short-lived and non-social. Using colonies of the carpenter ant Camponotus fellah, we show that social isolation induces hyperactivity, alters space-use, and reduces lifespan via changes in the expression of genes with key roles in oxidation-reduction and an associated accumulation of reactive oxygen species. These physiological effects are localized to the fat body and oenocytes, which perform liver-like functions in insects. We use pharmacological manipulations to demonstrate that the oxidation-reduction pathway causally underpins the detrimental effects of social isolation on behavior and lifespan. These findings have important implications for our understanding of how social isolation affects behavior and lifespan in general.

Therapeutic potential of NOX inhibitors in neuropsychiatric disorders

RATIONALE

Neuropsychiatric disorders encompass a broad category of medical conditions that include both neurology as well as psychiatry such as major depressive disorder, autism spectrum disorder, bipolar disorder, schizophrenia as well as psychosis.

OBJECTIVE

NADPH-oxidase (NOX), which is the free radical generator, plays a substantial part in oxidative stress in neuropsychiatric disorders. It is thought that elevated oxidative stress as well as neuroinflammation plays a part in the emergence of neuropsychiatric disorders. Including two linked with membranes and four with subunits of cytosol, NOX is a complex of multiple subunits. NOX has been linked to a significant source of reactive oxygen species in the brain. NOX has been shown to control memory processing and neural signaling. However, excessive NOX production has been linked to cardiovascular disorders, CNS degeneration, and neurotoxicity. The increase in NOX leads to the progression of neuropsychiatric disorders.

RESULT

Our review mainly emphasized the characteristics of NOX and its various mechanisms, the modulation of NOX in various neuropsychiatric disorders, and various studies supporting the fact that NOX might be the potential therapeutic target for neuropsychiatric disorders.

CONCLUSION

Here, we summarizes various pharmacological studies involving NOX inhibitors in neuropsychiatric disorders.

Serum NOX1 and Raftlin as New Potential Biomarkers of Interest in Schizophrenia: A Preliminary Study

Introduction

There is increasing evidence that oxidative stress (OS) and neuroinflammation play a role in the neuroprogression of schizophrenia (SCZ). Promising novel candidates which have been proposed in the search for biomarkers of psychotic illness include NADPH oxidase 1,2 (NOX1,2) and raftlin. NOX1 from the NOX family is the main source of physiological reactive oxygen species (ROS) and raftlin, the main lipid raft protein, is associated with inflammatory processes. The aim of the present study was to evaluate serum NOX1 and raftlin levels in chronic stable patients with SCZ.

Methods

We measured serum NOX1 and raftlin levels from 45 clinically stable patients with SCZ and 45 healthy controls (HCs) matched for age, sex, and body-mass index. The Positive and Negative Syndrome Scale was applied to the patient group to evaluate the severity of psychotic symptoms.

Results

NOX1 and raftlin levels in the patients were statistically significantly higher than the HCs (NOX1 p<0.001, raftlin p<0.001). Both parameters showed very good diagnostic performance (NOX1 AUC = 0.931, raftlin AUC = 0.915). We obtained positive and significant correlations between serum levels of both biomarkers and symptom severity.

Discussion

This preliminary study indicating elevations in serum NOX1 and raftlin levels in patients with SCZ supports the importance of OS and inflammatory processes in the etiopathogenesis of the illness.

Acetate-mediated-obestatin modulation attenuates adipose-hepatic dysmetabolism in high fat diet-induced obese rat model

PURPOSE

Approximately 650 million of world adult population is affected by obesity, which is characterized by adipose and hepatic metabolic dysfunction. Short chain fatty acids (SCFAs) have been linked to improved metabolic profile. However, the effect of SCFAs, particularly acetate on adipose-hepatic dysfunction is unclear. Therefore, the present study investigated the role of acetate on adipose-hepatic metabolic dysfunction and the possible involvement of obestatin in high fat diet-induced obese Wistar rats.

METHODS

Adult male Wistar rats (160-190 g) were allotted into groups (n = 6/group): Control, acetate-treated, obese and obese + acetate-treated groups received vehicle (distilled water), sodium acetate (200 mg/kg), 40% HFD and 40% HFD plus sodium acetate respectively. The administration lasted for 12 weeks.

RESULTS

HFD caused increased body weight gain and visceral adiposity, insulin resistance, hyperinsulinemia and increased pancreatic-β cell function and plasma/hepatic triglyceride and total cholesterol as well as decreased adipose triglyceride and total cholesterol, increased plasma, adipose, and hepatic malondialdehyde, TNF-α, uric acid, lactate production and plasma/adipose but not gamma-glutamyl transferase and decreased plasma, adipose, and hepatic nitric oxide, glucose-6-phosphate dehydrogenase (G6PD), glutathione (GSH) and obestatin concentration compared to the control group. Notwithstanding, treatment with acetate attenuated the alterations.

CONCLUSIONS

The results demonstrate that high fat diet-induced obesity is characterized with adipose and hepatic lipid dysmetabolism, which is associated with obestatin suppression. Findings also suggest that acetate provide protection against adipose and hepatic metabolic perturbations by restoring obestatin as well as G6PD/GSH-dependent antioxidant system.

Social isolation triggers oxidative status and impairs systemic and hepatic insulin sensitivity in normoglycemic rats

Drug-naïve psychotic patients show metabolic and hepatic dysfunctions. The rat social isolation model of psychosis allows to investigate mechanisms leading to these disturbances to which oxidative stress crucially contributes. Here, we investigated isolation-induced central and peripheral dysfunctions in glucose homeostasis and insulin sensitivity, along with redox dysregulation. Social isolation did not affect basal glycemic levels and the response to glucose and insulin loads in the glucose and insulin tolerance tests. However, HOMA-Index value were increased in isolated (ISO) rats. A hypothalamic reduction of AKT phosphorylation and a trend toward an increase in AMPK phosphorylation were observed following social isolation, accompanied by reduced GLUT-4 levels. Social isolation also induced a reduction of phosphorylation of the insulin receptor, of AKT and GLUT-2, and a decreased phosphorylation of AMPK in the liver. Furthermore, a significant reduction in hepatic CPT1 and PPAR-α levels was detected. ISO rats also showed significant elevations in hepatic ROS amount, lipid peroxidation and NOX4 expression, whereas no differences were detected in NOX2 and NOX1 levels. Expression of SOD2 in the mitochondrial fraction and SOD1 in the cytosolic fraction was not altered following social isolation, whereas SOD activity was increased. Furthermore, a decrease of hepatic CAT and GSH amount was observed in ISO rats compared to GRP animals. Our data suggest that the increased oxidant status and antioxidant capacity modifications may trigger hepatic and systemic insulin resistance, by altering signal hormone pathway and sustaining subsequent alteration of glucose homeostasis and metabolic impairment observed in the social isolation model of psychosis.

Reduced calorie diet combined with NNMT inhibition establishes a distinct microbiome in DIO mice

Treatment with a nicotinamide N-methyltransferase inhibitor (NNMTi; 5-amino-1-methylquinolinium) combined with low-fat diet (LD) promoted dramatic whole-body adiposity and weight loss in diet-induced obese (DIO) mice, rapidly normalizing these measures to age-matched lean animals, while LD switch alone was unable to restore these measures to age-matched controls in the same time frame. Since mouse microbiome profiles often highly correlate with body weight and fat composition, this study was designed to test whether the cecal microbiomes of DIO mice treated with NNMTi and LD were comparable to the microbiomes of age-matched lean counterparts and distinct from microbiomes of DIO mice maintained on a high-fat Western diet (WD) or subjected to LD switch alone. There were minimal microbiome differences between lean and obese controls, suggesting that diet composition and adiposity had limited effects. However, DIO mice switched from an obesity-promoting WD to an LD (regardless of treatment status) displayed several genera and phyla differences compared to obese and lean controls. While alpha diversity measures did not significantly differ between groups, beta diversity principal coordinates analyses suggested that mice from the same treatment group were the most similar. K-means clustering analysis of amplicon sequence variants by animal demonstrated that NNMTi-treated DIO mice switched to LD had a distinct microbiome pattern that was highlighted by decreased Erysipelatoclostridium and increased Lactobacillus relative abundances compared to vehicle counterparts; these genera are tied to body weight and metabolic regulation. Additionally, Parasutterella relative abundance, which was increased in both the vehicle- and NNMTi-treated LD-switched groups relative to the controls, significantly correlated with several adipose tissue metabolites' abundances. Collectively, these results provide a novel foundation for future investigations.

Acetate supplementation restores testicular function by modulating Nrf2/PPAR-γ in high fat diet-induced obesity in Wistar rats

Purpose

Several studies have established impaired testicular function in obese male population, including the young males with childhood obesity, contributing to increased male infertility, which is a universal trend in the last few decades. Short chain fatty acids (SCFAs) have been recently demonstrated to inhibit progression to metabolic comorbidities. The present study therefore hypothesized that SCFAs, acetate attenuates testicular dysfunction in high fat diet (HFD)-induced obese rat model, possibly by modulating Nrf2/PPAR-γ.

Methods

Adult male Wistar rats weighing 160-190 g were randomly allotted into three groups (n = 6/group): The groups received vehicle (distilled water), 40% HFD and sodium acetate (200 mg/kg) plus 40% HFD respectively. The administration lasted for 12 weeks.

Results

HFD caused obesity, which is characterized with increased body weight and visceral adiposity and insulin resistance/hyperinsulinemia. In addition, it increased testicular lipid deposition, malondialdehyde, pro-inflammatory mediators, lactate/pyruvate ratio, γ-Glutamyl transferase, and circulating leptin as well as decreased testicular glutathione, nitric oxide, Nrf2, PPAR-γ and circulating follicle stimulating hormone and testosterone without a significant change in testicular lactate dehydrogenase, blood glucose and luteinizing hormone when compared to the control group. Nevertheless, administration of acetate reversed the HFD-induced alterations.

Conclusion

The present results demonstrates that HFD causes obesity-driven testicular dysfunction, associated with testicular lipid deposition, oxidative stress, and inflammation. The study in addition suggests the restoration of testicular function in obese animals by acetate, an effect that is accompanied by elevated Nrf2/PPAR-γ.

Acetate rescues defective brain-adipose metabolic network in obese Wistar rats by modulation of peroxisome proliferator-activated receptor-γ

We investigated the hypothesis that acetate ameliorates brain-adipose metabolic dysfunction (BAMED) in high fat diet (HFD)-induced obesity, possibly by modulation of peroxisome proliferator-activated receptor-γ (PPAR-γ). Ten-week-old male Wistar rats were randomly assigned into four groups (n = 6/group): Control, acetate and obese with or without acetate groups received vehicle (distilled water; po), acetate (200 mg/kg, po) and 40% HFD with or without acetate respectively. The treatments lasted for 12 weeks. Obese animals showed increase in body weight, visceral fat mass, insulin and triglyceride-glucose index and a reduction in insulin sensitivity. In addition, obese animals also showed increase in plasma/hypothalamic and adipose pyruvate dehydrogenase kinase-4, lactate-pyruvate ratio, malondialdehyde, γ-glutamyl transferase, and a decrease in glucose-6-phosphate dehydrogenase, glutathione, nitric oxide and PPAR-γ. HFD also elevated plasma/hypothalamic lipid and decreased adipose lipid profile, increased hypothalamic and adipose tumor necrosis factor-α, interleukin-6 and histone deacetylase (HDAC), and elevated plasma/adipose leptin. These alterations were reversed by concomitant administration of acetate. The present results demonstrate that obesity is characterized by BAMED, which is accompanied by altered HDAC/PPAR-γ. The results in addition suggest that acetate, an HDAC inhibitor rescues BAMED with consequent normalization of body weight and visceral fat mass by modulation of PPAR-γ and suppression of oxidative stress.

Sodium acetate ameliorated systemic and renal oxidative stress in high-fructose insulin-resistant pregnant Wistar rats

Pregnancy is an insulin-resistant condition especially at near term predisposing maternal kidneys to hyperinsulinemia-induced oxidative stress. The impact of fructose on renal metabolic dysregulation and oxidative stress in pregnancy requires elucidation. Short-chain fatty acids (SCFAs) are known for protective roles in oxidative stress conditions. Therefore, the study aimed at investigating fructose-induced glucose dysregulation and renal oxidative stress in pregnant and non-pregnant rats and the possible preventive role of SCFA, acetate. Thirty female Wistar rats were grouped (n = 5/group). Three groups were made pregnant (P); the other three remained non-pregnant (NP). Both pregnant and non-pregnant rats received drinking water (control), 10% fructose (w/v) (NP+F or P+F), and 10% (w/v) fructose plus sodium acetate (200 mg/kg) (NP+F+A or P+F+A) for 3 weeks. Renal and plasma glutathione antioxidant index (GSH/GSSG), G6PDH, and adenosine were significantly lower in NP+F and P+F groups compared with control while renal and plasma adenosine deaminase (ADA), xanthine oxidase (XO), uric acid (UA), lactate dehydrogenase (LDH), and malonaldehyde (MDA) were significantly elevated in NP+F and P+F groups compared with controls. HOMA-IR showed marked impairment in both NP+F and P+F groups. The P+F group revealed greater suppression in plasma and renal G6PDH-dependent antioxidant index, adenosine, and aggravation of LDH, MDA compared with the NP+F group (p < 0.05). Sodium acetate reduces plasma and renal surrogate oxidative stress markers, improved G6PD-dependent antioxidant index, and HOMA-IR in NP+F and P+F groups. Pregnancy exacerbates fructose-induced insulin resistance and renal oxidative stress whereas acetate ameliorated fructose-induced redox and glucose dysregulation in pregnant and non-pregnant rats.

Metabolic profile of methylazoxymethanol model of schizophrenia in rats and effects of three antipsychotics in long-acting formulation

Mortality in psychiatric patients with severe mental illnesses reaches a 2-3 times higher mortality rate compared to the general population, primarily due to somatic comorbidities. A high prevalence of cardiovascular morbidity can be attributed to the adverse metabolic effects of atypical antipsychotics (atypical APs), but also to metabolic dysregulation present in drug-naïve patients. The metabolic aspects of neurodevelopmental schizophrenia-like models are understudied. This study evaluated the metabolic phenotype of a methylazoxymethanol (MAM) schizophrenia-like model together with the metabolic effects of three APs [olanzapine (OLA), risperidone (RIS) and haloperidol (HAL)] administered via long-acting formulations for 8 weeks in female rats. Body weight, feed efficiency, serum lipid profile, gastrointestinal and adipose tissue-derived hormones (leptin, ghrelin, glucagon and glucagon-like peptide 1) were determined. The lipid profile was assessed in APs-naïve MAM and control cohorts of both sexes. Body weight was not altered by the MAM model, though cumulative food intake and feed efficiency was lowered in the MAM compared to CTR animals. The effect of the APs was also present; body weight gain was increased by OLA and RIS, while OLA induced lower weight gain in the MAM rats. Further, the MAM model showed lower abdominal adiposity, while OLA increased it. Serum lipid profile revealed MAM model-induced alterations in both sexes; total, HDL and LDL cholesterol levels were increased. The MAM model did not exert significant alterations in hormonal parameters except for elevation in leptin level. The results support intrinsic metabolic dysregulation in the MAM model in both sexes, but the MAM model did not manifest higher sensitivity to metabolic effects induced by antipsychotic treatment.

The role of oxidative stress in cardiovascular disease caused by social isolation and loneliness

Loneliness and social isolation are common sources of chronic stress in modern society. Epidemiological studies have demonstrated that loneliness and social isolation increase mortality risk as much as smoking or alcohol consumption and more than physical inactivity or obesity. Loneliness in human is associated with higher blood pressure whereas enhanced atherosclerosis is observed in animal models of social isolation. Loneliness and social isolation lead to activation of the hypothalamic-pituitary-adrenocortical (HPA) axis, enhanced sympathetic nerve activity, impaired parasympathetic function and a proinflammatory immune response. These mechanisms have been implicated in the development of cardiovascular disease conferred by social isolation although a causal relationship has not been established so far. There is evidence that oxidative stress is likely to be a key molecular mechanism linking chronic psychosocial stress to cardiovascular disease. NADPH oxidase-mediated oxidative stress in the hypothalamus has been shown to be required for social isolation-induced HPA axis activation in socially isolated rats. Oxidative stress in the rostral ventrolateral medulla is also a key regulator of sympathetic nerve activity. In the vasculature, oxidative stress increases vascular tone and promote atherogenesis through multiple mechanisms. Thus, preventing oxidative stress may represent a therapeutic strategy to reduce the detrimental effects of social stress on health.

The impact of statins on physical activity and exercise capacity: an overview of the evidence, mechanisms, and recommendations

PURPOSE

Statins are among the most widely prescribed medications worldwide. Considered the 'gold-standard' treatment for cardiovascular disease (CVD), statins inhibit HMG-CoA reductase to ultimately reduce serum LDL-cholesterol levels. Unfortunately, the main adverse event of statin use is the development of muscle-associated problems, referred to as SAMS (statin-associated muscle symptoms). While regular moderate physical activity also decreases CVD risk, there is apprehension that physical activity may induce and/or exacerbate SAMS. While much work has gone into identifying the epidemiology of SAMS, only recent research has focused on the extent to which these muscle symptoms are accompanied by functional declines. The purpose of this review is to provide an overview of possible mechanisms underlying SAMS and summarize current evidence regarding the relationship between statin treatment, physical activity, exercise capacity, and SAMS development.

METHODS

PubMed and Google Scholar databases were used to search the most relevant and up-to-date peer-reviewed research on the topic.

RESULTS

The mechanism(s) behind SAMS, including altered mitochondrial metabolism, reduced coenzyme Q10 levels, reduced vitamin D levels, impaired calcium homeostasis, elevated extracellular glutamate, and genetic polymorphisms, still lack consensus and remain up for debate. Our summation of the evidence leads us to suggest that the etiology of SAMS development is likely multifactorial. Our review also demonstrates that there is limited evidence for statins impairing exercise adaptations or reducing exercise capacity for the majority of the investigated populations.

CONCLUSION

The available evidence indicates that the benefits of engaging in physical activity while on statin medication largely outweigh the risks.

l-glutamine supplementation exerts cardio-renal protection in estrogen-progestin oral contraceptive-treated female rats

Glycogen and lipid disruptions represent a spectrum of metabolic disorders that are crucial risk factors for cardiovascular disease in estrogen-progestin oral contraceptive (COC) users. l-glutamine (GLN) has been shown to exert a modulatory effect in metabolic disorders-related syndromes. We therefore hypothesized that GLN supplementation would protect against myocardial and renal glycogen-lipid mishandling in COC-treated animals by modulation of Glucose-6-phosphate dehydrogenase (G6PD) and xanthine oxidase (XO) activities. Adult female Wistar rats were randomly allotted into control, GLN, COC and COC + GLN groups (six rats per group). The groups received vehicle (distilled water, p.o.), GLN (1 g/kg), COC containing 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel and COC plus GLN respectively, daily for 8 weeks. Data showed that treatment with COC led to metabolically-induced obesity with correspondent increased visceral and epicardial fat mass. It also led to increased plasma, myocardial and renal triglyceride, free fatty acid, malondialdehyde (MDA), XO activity, uric acid content and decreased glutathione content and G6PD activity. In addition, COC increased myocardial but not renal glycogen content, and increased myocardial and renal glycogen synthase activity, increased plasma and renal lactate production and plasma aspartate transaminase/alanine aminotransferase (AST/ALT) ratio. However, these alterations were attenuated when supplemented with GLN except plasma AST/ALT ratio. Collectively, the present results indicate that estrogen-progestin oral contraceptive causes metabolically-induced obesity that is accompanied by differential myocardial and renal metabolic disturbances. The findings also suggest that irrespective of varying metabolic phenotypes, GLN exerts protection against cardio-renal dysmetabolism by modulation of XO and G6PD activities.

Ketamine administration induces early and persistent neurochemical imbalance and altered NADPH oxidase in mice

Administration in adulthood of subanaesthetic doses of ketamine, an NMDA receptor (NMDA-R) antagonist, is commonly used to induce psychotic-like alterations in rodents. The NADPH oxidase (NOX) derived-oxidative stress has been shown to be implicated in ketamine-induced neurochemical dysfunctions and in the loss of parvalbumin (PV)-positive interneurons associated to the administration of this NMDA receptor antagonist in adult mice. However, very few data are available on the effects of early ketamine administration and its contribution to the development of long-term dysfunctions leading to psychosis. Here, by administering a subanaesthetic dose of ketamine (30 mg/kg i.p.) to mice at postnatal days (PNDs) 7, 9 and 11, we aimed at investigating early neurochemical and oxidative stress-related alterations induced by this NMDA-R antagonist in specific brain regions of mice pups, i.e. prefrontal cortex (PFC) and nucleus accumbens (NAcc) and to assess whether these alterations lasted until the adult period. To this purpose, we evaluated glutamatergic, glutamine and GABAergic tissue levels, as well as PV amount in the PFC, both two hours after the last ketamine injection (PND 11) and at 10  weeks of age. Dopamine (DA) tissue levels and DA turnover were also evaluated in the NAcc at the same time points. Levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a reliable biomarker of oxidative stress, as well as of the free radical producers NOX1 and NOX2 enzymes, were also assessed in both PFC and NAcc of ketamine-treated pups and adult mice. Ketamine-treated pups showed increased cortical levels of glutamate (GLU) and glutamine, as well as similar GABA amount compared to controls, together with an early reduction of cortical PV levels. In the adult period, the same was observed for GLU and PV, whereas GABA levels were increased and no changes in glutamine amount were detected. Ketamine administration in early life induced a decrease in DA tissue levels and an increase of DA turnover which were also detectable at 10 weeks of age. These alterations were accompanied by 8-OHdG elevations in both PFC and NAcc at the two considered life stages. The expression of NOX1 was significantly reduced in these brain regions following ketamine administration at early life stages, while, in the adult period, significant elevation of this enzyme was observed. Levels of NOX2 were found increased at both time points. Our results suggest that an early increase of NOX2-derived oxidative stress may contribute to the development of neurochemical imbalance in PFC and NAcc, induced by ketamine administration. Modifications of NOX1 expression might represent, instead, an early response of the developing brain to a neurotoxic insult, followed by a later attempt to counterbalance ketamine-related detrimental effects.

Rosuvastatin improves olanzapine's effects on behavioral impairment and hippocampal, hepatic and metabolic damages in isolated reared male rats

BACKGROUND & AIM

Schizophrenia is a chronic, disabling neurological illness. This study investigated the effect of rosuvastatin (RSU) addition to the antipsychotic drug: olanzapine (OLZ) in treatment of post-weaning isolation rearing (IR) damaging effect and assessed behavioral impairment, metabolic and hepatic abnormalities, oxidative stress, and inflammatory markers.

METHODS

Treatment with OLZ (6 mg/kg, P.O.) and/or RSU (10 mg/kg, I.P.) have been started 6 weeks after isolation. We assessed behavioral tests, serum cortisol level, and hippocampal content of neurotransmitters. In addition, we assessed histopathology, inflammatory and oxidative stress markers of hippocampus, liver and adipose tissue RESULTS: Treatment of IR animals with OLZ, and/or RSU significantly counteracted the changes in hippocampus, liver and adipose tissue induced by post-weaning IR. Co-treatment of IR rats with both OLZ and RSU showed additive effects in some areas like improving both tumor necrosis factor alpha (TNFα) in both hippocampus and liver, histopathology of liver, oxidative stress markers of adipose tissue, β₃ adrenergic receptors (ADRβ₃), serum cortisol and total cholesterol. In addition, RSU alone alleviated the damage of IR rats by the same efficacy as OLZ with more benefit in cognition and exploration.

CONCLUSION

post-weaning IR as a model has behavioral, hippocampal, hepatic and marked metabolic changes more relevant to schizophrenia than drug-induced models. These effects were ameliorated by RSU and/or OLZ that are explained by their antioxidant, anti-inflammatory, anti-stress and anti-hyperlipidemic properties. Interestingly, co-treatment with both drugs showed a better effect.

Vinpocetine mitigates aluminum-induced cognitive impairment in socially isolated rats

Several reports have highlighted the role of vinpocetine in Alzheimer's disease (AD). However, the role of vinpocetine in AD under social isolation conditions has not yet been elucidated. Henceforth, this study aimed to investigate the potential neuroprotective effect of vinpocetine in aluminum-induced AD model associated with social isolation. Social isolation increased the escape latency in Morris water maze (MWM) test, elevated the immobility score and decreased swimming score in forced swimming test (FST) in aluminum treated rats. However, vinpocetine enhanced acquisition in MWM test and exerted anti-depressive effect in FST. The histopathological examination showed marked deterioration in the cerebral cortex and hippocampus of AD isolated rats, while vinpocetine revealed overt improvement. In addition, the levels of amyloid-β protein (Aβ), phosphorylated-tau (Ser396), malondialdehyde (MDA), interleukin 1-beta (IL-1β), tumor necrosis alpha (TNFα), p- Glycogen synthase kinase-3β (p-GSK3β) (Tyr216), and β-secretase (BACE1) gene expression were increased in socially isolated aluminum treated rats, yet, vinpocetine treatment reversed these deteriorating effects. Hence, this study provides profound insights into the role of vinpocetine in AD particularly in the conditions of social isolation. The effects of vinpocetine might be attributed not only to its antioxidant and anti-inflammatory properties, but also to its suppressing effect on GSK3β activity and its downstream BACE1.

Dentate Gyrus Immaturity in Schizophrenia

Hippocampal abnormalities have been heavily implicated in the pathophysiology of schizophrenia. The dentate gyrus of the hippocampus was shown to manifest an immature molecular profile in schizophrenia subjects, as well as in various animal models of the disorder. In this position paper, we advance a hypothesis that this immature molecular profile is accompanied by an identifiable immature morphology of the dentate gyrus granule cell layer. We adduce evidence for arrested maturation of the dentate gyrus in the human schizophrenia-affected brain, as well as multiple rodent models of the disease. Implications of this neurohistopathological signature for current theory regarding the development of schizophrenia are discussed.

Oral ethinylestradiol-levonorgestrel attenuates cardiac glycogen and triglyceride accumulation in high fructose female rats by suppressing pyruvate dehydrogenase kinase-4

Fructose (FRU) intake has increased dramatically in recent decades with a corresponding increased incidence of insulin resistance (IR), particularly in young adults. The use of oral ethinylestradiol-levonorgestrel (EEL) formulation is also common among young women worldwide. The present study aimed at determining the effect of EEL on high fructose-induced cardiac triglyceride (TG) and glycogen accumulation. The study also investigated the possible involvement of pyruvate dehydrogenase kinase-4 (PDK-4) in EEL and/or high fructose metabolic effects on the heart. Ten-week-old female Wistar rats were allotted into four groups. The control, EEL, FRU, and EEL + FRU rats received distilled water (vehicle, p.o.), 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel (p.o.), 10% fructose (w/v), and 1.0 μg ethinylestradiol plus 5.0 μg levonorgestrel and 10% fructose, respectively, daily for 8 weeks. Data showed that EEL or high fructose caused IR' impaired glucose tolerance' hyperlipidemia' increased plasma lactate, lactate dehydrogenase, PDK-4, uric acid, xanthine oxidase (XO), adenosine deaminase (ADA), malondialdehyde (MDA), cardiac uric acid, TG, TG/HDL- cholesterol, glycogen synthesis, MDA, and visceral fat content and reduced glutathione. High fructose also resulted in impaired pancreatic β-cell function, hyperglycemia, and increased cardiac PDK-4, lactate synthesis, and mass. Nonetheless, these alterations were ameliorated in EEL plus high fructose rats. This study demonstrates that high fructose-induced myocardial TG and glycogen accumulation is attributable to increased PDK-4. Besides, EEL could be a useful pharmacological utility for protection against cardiac dysmetabolism by inhibiting PDK-4.

The Wnt Signaling Pathway Effector TCF7L2 Mediates Olanzapine-Induced Weight Gain and Insulin Resistance

Olanzapine is a widely used atypical antipsychotic medication for treatment of schizophrenia and is often associated with serious metabolic abnormalities including weight gain and impaired glucose tolerance. These metabolic side effects are severe clinical problems but the underpinning mechanism remains poorly understood. Recently, growing evidence suggests that Wnt signaling pathway has a critical role in the pathogenesis of schizophrenia and molecular cascades of antipsychotics action, of which Wnt signaling pathway key effector TCF7L2 is strongly associated with glucose homeostasis. In this study, we aim to explore the characteristics of metabolic disturbance induced by olanzapine and to elucidate the role of TCF7L2 in this process. C57BL/6 mice were subject to olanzapine (4 mg/kg/day), or olanzapine plus metformin (150 mg/kg/day), or saline, respectively, for 8 weeks. Metabolic indices and TCF7L2 expression levels in liver, skeletal muscle, adipose, and pancreatic tissues were closely monitored. Olanzapine challenge induced remarkably increased body weight, fasting insulin, homeostasis model assessment-insulin resistance index, and TCF7L2 protein expression in liver, skeletal muscle, and adipose tissues. Notably, these effects could be effectively ameliorated by metformin. In addition, we found that olanzapine-induced body weight gain and insulin resistance actively influence the expression of TCF7L2 in liver and skeletal muscle, and elevated level of insulin determines the increased expression of TCF7L2 in adipose tissue. Our results demonstrate that TCF7L2 participates in olanzapine-induced metabolic disturbance, which presents a novel mechanism for olanzapine-induced metabolic disturbance and a potential therapeutic target to prevent the associated metabolic side effects.