Sex and the Estrous-Cycle Phase Influence the Expression of G Protein-Coupled Estrogen Receptor 1 (GPER) in Schizophrenia: Translational Evidence for a New Target.

Schizophrenia is a mental disorder with sex bias in disease onset and symptom severity. Recently, it was observed that females present more severe symptoms in the perimenstrual phase of the menstrual cycle. The administration of estrogen also alleviates schizophrenia symptoms. Despite this, little is known about symptom fluctuation over the menstrual cycle and the underlying mechanisms. To address this issue, we worked with the two-hit schizophrenia animal model induced by neonatal exposure to a virus-like particle, Poly I:C, associated with peripubertal unpredictable stress exposure. Prepulse inhibition of the startle reflex (PPI) in male and female mice was considered analogous to human schizophrenia-like behavior. Female mice were studied in the proestrus (high-estrogen estrous cycle phase) and diestrus (low-estrogen phase). Additionally, we evaluated the hippocampal mRNA expression of estrogen synthesis proteins; TSPO and aromatase; and estrogen receptors ERα, ERß, and GPER. We also collected peripheral blood mononuclear cells (PBMCs) from male and female patients with schizophrenia and converted them to induced microglia-like cells (iMGs) to evaluate the expression of GPER. We observed raised hippocampal expression of GPER in two-hit female mice at the proestrus phase without PPI deficits and higher levels of proteins related to estrogen synthesis, TSPO, and aromatase. In contrast, two-hit adult males with PPI deficits presented lower hippocampal mRNA expression of TSPO, aromatase, and GPER. iMGs from male and female patients with schizophrenia showed lower mRNA expression of GPER than controls. Therefore, our results suggest that GPER alterations constitute an underlying mechanism for sex influence in schizophrenia.

Clozapine prescription trends in Brazil in the last decade

Objective: Clozapine is a second-generation antipsychotic indicated for treatment-resistant schizophrenia. Studies in several countries have shown a low rate of clozapine use despite the fact that approximately 30% of schizophrenia cases are treatment-resistant. In Brazil, few studies have addressed the frequency and variety of antipsychotic use in individuals diagnosed with schizophrenia (ICD F20). The objective of this study was to measure the rates of clozapine use in this population in the last decade using Brazilian Ministry of Health data. Methods: Prescriptions made between 2010 and 2020 in all 26 states and the Federal District registered at the Outpatient Information System Database from the Brazilian Health System (SIASUS) were evaluated. Results: A total of 25,143,524 prescriptions were recorded in this period, with clozapine representing 8.86% of all antipsychotics. The most frequently prescribed antipsychotic for patients with schizophrenia was olanzapine (35.8%), followed by quetiapine (27.5%). From 2010 to 2020, the rate of clozapine prescriptions in Brazil increased from 7.2% to 10.9%. Conclusions: Despite a slight increase in prescriptions in the last decade, clozapine is still underutilized in Brazil.

Animal Model of Neonatal Immune Challenge by Lipopolysaccharide: A Study of Sex Influence in Behavioral and Immune/Neurotrophic Alterations in Juvenile Mice.

INTRODUCTION: The prenatal/perinatal exposure to infections may trigger neurodevelopmental alterations that lead to neuropsychiatric disorders such as autism spectrum disorder (ASD). Previous evidence points to long-term behavioral consequences, such as autistic-like behaviors in rodents induced by lipopolysaccharide (LPS) pre- and postnatal (PN) exposure during critical neurodevelopmental periods. Additionally, sex influences the prevalence and symptoms of ASD. Despite this, the mechanisms underlying this influence are poorly understood. We aim to study sex influences in behavioral and neurotrophic/inflammatory alterations triggered by LPS neonatal exposure in juvenile mice at an approximate age of ASD diagnosis in humans. METHODS: Swiss male and female mice on PN days 5 and 7 received a single daily injection of 500 µg/kg LPS from Escherichia coli or sterile saline (control group). We conducted behavioral determinations of locomotor activity, repetitive behavior, anxiety-like behavior, social interaction, and working memory in animals on PN25 (equivalent to 3-5 years old of the human). To determine BDNF levels in the prefrontal cortex and hippocampus, we used animals on PN8 (equivalent to a human term infant) and PN25. In addition, we evaluated iba-1 (microglia marker), TNFα, and parvalbumin expression on PN25. RESULTS: Male juvenile mice presented repetitive behavior, anxiety, and working memory deficits. Females showed social impairment and working memory deficits. In the neurochemical analysis, we detected lower BDNF levels in brain areas of female mice that were more evident in juvenile mice. Only LPS-challenged females presented a marked hippocampal expression of the microglial activation marker, iba-1, and increased TNFα levels, accompanied by a lower parvalbumin expression. DISCUSSION/CONCLUSION: Male and female mice presented distinct behavioral alterations. However, LPS-challenged juvenile females showed the most prominent neurobiological alterations related to autism, such as increased microglial activation and parvalbumin impairment. Since these sex-sensitive alterations seem to be age-dependent, a better understanding of changes induced by the exposure to specific risk factors throughout life represents essential targets for developing strategies for autism prevention and precision therapy.

Involvement of anti-inflammatory, antioxidant, and BDNF up-regulating properties in the antipsychotic-like effect of the essential oil of Alpinia zerumbet in mice: a comparative study with olanzapine.

The current drug therapy for schizophrenia effectively treats acute psychosis and its recurrence; however, this mental disorder's cognitive and negative symptoms are still poorly controlled. Antipsychotics present important side effects, such as weight gain and extrapyramidal effects. The essential oil of Alpinia zerumbet (EOAZ) leaves presents potential antipsychotic properties that need further preclinical investigation. Here, we determined EAOZ effects in preventing and reversing schizophrenia-like symptoms (positive, negative, and cognitive) induced by ketamine (KET) repeated administration in mice and putative neurobiological mechanisms related to this effect. We conducted the behavioral evaluations of prepulse inhibition of the startle reflex (PPI), social interaction, and working memory (Y-maze task), and verified antioxidant (GSH, nitrite levels), anti-inflammatory [interleukin (IL)-6], and neurotrophic [brain-derived neurotrophic factor (BDNF)] effects of this oil in hippocampal tissue. The atypical antipsychotic olanzapine (OLZ) was used as standard drug therapy. EOAZ, similarly to OLZ, prevented and reversed most KET-induced schizophrenia-like behavioral alterations, i.e., sensorimotor gating deficits and social impairment. EOAZ had a modest effect on the prevention of KET-associated working memory deficit. Compared to OLZ, EOAZ showed a more favorable side effects profile, inducing less cataleptic and weight gain changes. EOAZ efficiently protected the hippocampus against KET-induced oxidative imbalance, IL-6 increments, and BDNF impairment. In conclusion, our data add more mechanistic evidence for the anti-schizophrenia effects of EOAZ, based on its antioxidant, anti-inflammatory, and BDNF up-regulating actions. The absence of significant side effects observed in current antipsychotic drug therapy seems to be an essential benefit of the oil.

Low-dose candesartan prevents schizophrenia-like behavioral alterations in a neurodevelopmental two-hit model of schizophrenia.

Schizophrenia is a severe mental disorder with complex etiopathogenesis. Based on its neurodevelopmental features, an animal model induced by "two-hit" based on perinatal immune activation followed by peripubertal unpredictable stress was proposed. Sex influences the immune response, and concerning schizophrenia, it impacts the age of onset and symptoms severity. The neurobiological mechanisms underlying the influence of sex in schizophrenia is poorly understood. Our study aimed to evaluate sex influence on proinflammatory and oxidant alterations in male and female mice exposed to the two-hit model of schizophrenia, and its prevention by candesartan, an angiotensin II type 1 receptor (AT1R) blocker with neuroprotective properties. The two-hit model induced schizophrenia-like behavioral changes in animals of both sexes. Hippocampal microglial activation alongside the increased expression of NF-κB, and proinflammatory cytokines, namely interleukin (IL)-1ß and TNF-α, were observed in male animals. Conversely, females presented increased hippocampal and plasma levels of nitrite and plasma lipid peroxidation. Peripubertal administration of low-dose candesartan (0.3 mg/kg PO) prevented behavioral, hippocampal, and systemic changes in male and female mice. While these results indicate the influence of sex on inflammatory and oxidative changes induced by the two-hit model, candesartan was effective in both males and females. The present study advances the neurobiological mechanisms underlying sex influence in schizophrenia and opens new avenues to prevent this devasting mental disorder.

Sex influences in the preventive effects of N-acetylcysteine in a two-hit animal model of schizophrenia.

BACKGROUND: Schizophrenia (SCZ) is a neurodevelopmental disorder influenced by patient sex. Mechanisms underlying sex differences in SCZ remain unknown. A two-hit model of SCZ combines the exposure to perinatal infection (first-hit) with peripubertal unpredictable stress (PUS, second-hit). N-acetylcysteine (NAC) has been tested in SCZ because of the involvement of glutathione mechanisms in its neurobiology. AIMS: We aim to investigate whether NAC administration to peripubertal rats of both sexes could prevent behavioral and neurochemical changes induced by the two-hit model. METHODS: Wistar rats were exposed to polyinosinic:polycytidylic acid (a viral mimetic) or saline on postnatal days (PND) 5-7. On PND30-59 they received saline or NAC 220 mg/kg and between PND40-48 were subjected to PUS or left undisturbed. On PND60 behavioral and oxidative alterations were evaluated in the prefrontal cortex (PFC) and striatum. Mechanisms of hippocampal memory regulation such as immune expression of G protein-coupled estrogen receptor 1 (GPER), α7-nAChR and parvalbumin were also evaluated. RESULTS: NAC prevented sensorimotor gating deficits only in females, while it prevented alterations in social interaction, working memory and locomotor activity in both sexes. Again, in rats of both sexes, NAC prevented the following neurochemical alterations: glutathione (GSH) and nitrite levels in the PFC and lipid peroxidation in the PFC and striatum. Striatal oxidative alterations in GSH and nitrite were observed in females and prevented by NAC. Two-hit induced hippocampal alterations in females, namely expression of GPER-1, α7-nAChR and parvalbumin, were prevented by NAC. CONCLUSION: Our results highlights the influences of sex in NAC preventive effects in rats exposed to a two-hit schizophrenia model.

Shared microglial mechanisms underpinning depression and chronic fatigue syndrome and their comorbidities.

In 2011, it was reviewed that a) there is a strong co-occurrence between major depression and chronic fatigue syndrome (CFS), with fatigue and physio-somatic symptoms being key symptoms of depression, and depressive symptoms appearing during the course of CFS; and b) the comorbidity between both disorders may in part be explained by activated immune-inflammatory pathways, including increased translocation of Gram-negative bacteria and increased levels of pro-inflammatory cytokines, such as interleukin (IL)-1. Nevertheless, the possible involvement of activated microglia in this comorbidity has remained unclear. This paper aims to review microglial disturbances in major depression, CFS and their comorbidity. A comprehensive literature search was conducted using the PubMed / MEDLINE database to identify studies, which are relevant to this current review. Depressed patients present neuroinflammatory alterations, probably related to microglial activation, while animal models show that a microglial response to immune challenges including lipopolysaccharides is accompanied by depressive-like behaviors. Recent evidence from preclinical studies indicates that activated microglia have a key role in the onset of fatigue. In chronic inflammatory conditions, such as infections and senescence, microglia orchestrate an inflammatory microenvironment thereby causing fatigue. In conclusion, based on our review we may posit that shared immune-inflammatory pathways and especially activated microglia underpin comorbid depression and CFS. As such, microglial activation and neuro-inflammation may be promising targets to treat the overlapping manifestations of both depression and CFS.

N-acetylcysteine attenuates nicotine-induced kindling in female periadolescent rats.

Kindling is a form of behavioral sensitization that is related to the progression of several neuropsychiatric disorders such as bipolar disorder. We recently demonstrated that female periadolescent rats are more vulnerable to nicotine (NIC)-induced kindling than their male counterparts. Furthermore, we evidenced that decreases in brain antioxidative defenses may contribute to this gender difference. Here we aimed to determine the preventive effects of the antioxidant N-acetyl cysteine (NAC) against NIC-kindling in female periadolescent rats. To do this female Wistar rats at postnatal day 30 received repeated injections of NIC 2mg/kg, i.p. every weekday for up to 19 days. NAC90, 180 or 270 mg/kg, i.p. was administered 30 min before NIC. The levels of glutathione (GSH), superoxide dismutase (SOD) activity, lipid peroxidation (LP) and nitrite were determined in the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST). The development of kindling occurred at a median time of 16.5 days with 87.5% of NIC animals presenting stage 5 seizures in the last day of drug administration. NAC270 prevented the occurrence of kindling. NIC-kindled animals presented decreased levels of GSH and increased LP in the PFC, HC and ST, while SOD activity was decreased in the ST. NAC180 or 270 prevented the alterations in GSH induced by NIC, but only NAC270 prevented the alterations in LP. Nitrite levels increased in the ST of NAC270 pretreated NIC-kindled animals. Taken together we demonstrated that NAC presents anti-kindling effects in female animals partially through the restoration of oxidative alterations.

Preclinical Evidences for an Antimanic Effect of Carvedilol.

Oxidative imbalance, alterations in brain-derived neurotrophic factor (BDNF), and mitochondrial dysfunction are implicated in bipolar disorder (BD) pathophysiology and comorbidities, for example, cardiovascular conditions. Carvedilol (CVD), a nonselective beta-blocker widely used for the treatment of hypertension, presents antioxidant and mitochondrial stabilizing properties. Thus, we hypothesized that CVD would prevent and/or reverse mania-like behavioral and neurochemical alterations induced by lisdexamfetamine dimesylate (LDX). To do this, male Wistar rats were submitted to two different protocols, namely, prevention and reversal. In the prevention treatment the rats received daily oral administration (mg/kg) of CVD (2.5, 5 or 7.5), saline, valproate (VAL200), or the combination of CVD5 + VAL100 for 7 days. From the 8th to 14th day LDX was added. In the reversal protocol LDX was administered for 7 days with the drugs being added from the 8th to 14th day of treatment. Two hours after the last administration the behavioral (open field and social interaction) and neurochemical (reduced glutathione, lipid peroxidation, and BDNF) determinations were performed. The results showed that CVD prevented and reversed the behavioral and neurochemical alterations induced by LDX. The administration of CVD5 + VAL100 potentiated the effect of VAL200 alone. Taken together these results demonstrate a possible antimanic effect of CVD in this preclinical model.

Alpha-lipoic acid alone and combined with clozapine reverses schizophrenia-like symptoms induced by ketamine in mice: Participation of antioxidant, nitrergic and neurotrophic mechanisms.

Oxidative stress has important implications in schizophrenia. Alpha-lipoic acid (ALA) is a natural antioxidant synthesized in human tissues with clinical uses. We studied the effect of ALA or clozapine (CLZ) alone or in combination in the reversal of schizophrenia-like alterations induced by ketamine (KET). Adult male mice received saline or KET for 14 days. From 8th to 14th days mice were additionally administered saline, ALA (100 mg/kg), CLZ 2.5 or 5 mg/kg or the combinations ALA+CLZ2.5 or ALA+CLZ5. Schizophrenia-like symptoms were evaluated by prepulse inhibition of the startle (PPI) and locomotor activity (positive-like), social preference (negative-like) and Y maze (cognitive-like). Oxidative alterations (reduced glutathione - GSH and lipid peroxidation - LP) and nitrite in the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) and BDNF in the PFC were also determined. KET caused deficits in PPI, working memory, social interaction and hyperlocomotion. Decreased levels of GSH, nitrite (HC) and BDNF and increased LP were also observed in KET-treated mice. ALA and CLZ alone reversed KET-induced behavioral alterations. These drugs also reversed the decreases in GSH (HC) and BDNF and increase in LP (PFC, HC and ST). The combination ALA+CLZ2.5 reversed behavioral and some neurochemical parameters. However, ALA+CLZ5 caused motor impairment. Therefore, ALA presented an antipsychotic-like profile reversing KET-induced positive- and negative-like symptoms. The mechanism partially involves antioxidant, neurotrophic and nitrergic pathways. The combination of ALA+CLZ2.5 improved most of the parameters evaluated in this study without causing motor impairment demonstrating, thus, that possibly when combined with ALA a lower dose of CLZ is required.

Prevention and reversal of ketamine-induced schizophrenia related behavior by minocycline in mice: Possible involvement of antioxidant and nitrergic pathways.

It has been hypothesized that oxidative imbalance and alterations in nitrergic signaling play a role in the neurobiology of schizophrenia. Preliminary evidence suggests that adjunctive minocycline treatment is efficacious for cognitive and negative symptoms of schizophrenia. This study investigated the effects of minocycline in the prevention and reversal of ketamine-induced schizophrenia-like behaviors in mice. In the reversal protocol, animals received ketamine (20 mg/kg per day intraperitoneally or saline for 14 days, and minocycline (25 or 50 mg/kg daily), risperidone or vehicle treatment from days 8 to 14. In the prevention protocol, mice were pretreated with minocycline, risperidone or vehicle prior to ketamine. Behaviors related to positive (locomotor activity and prepulse inhibition of startle), negative (social interaction) and cognitive (Y maze) symptoms of schizophrenia were also assessed. Glutathione (GSH), thiobarbituric acid-reactive substances (TBARS) and nitrite levels were measured in the prefrontal cortex, hippocampus and striatum. Minocycline and risperidone prevented and reversed ketamine-induced alterations in behavioral paradigms, oxidative markers (i.e. ketamine-induced decrease and increase in GSH levels and TBARS content, respectively) as well as nitrite levels in the striatum. These data provide a rationale for evaluating minocycline as a novel psychotropic agent and suggest that its mechanism of action includes antioxidant and nitrergic systems.