Pioglitazone abolishes autistic-like behaviors via the IL-6 pathway

Interleukin-6 produces behavioral deficits in pre-pubescent mice independent of neuroinflammation

Maternal inflammation during pregnancy increases the offspring's risk of developing autism, ADHD, schizophrenia, and depression. Epidemiologic studies have demonstrated that maternal infections stimulate the production of interleukin-6 (IL-6), which can cross the placenta and fetal blood-brain barrier to alter brain development with functional and behavioral consequences. To model the effects of increased IL-6 between weeks 24-30 of human gestation, we injected male and female mice with 75 ng IL-6 twice daily, from P3 to P6. Our published studies have shown that this increases circulating IL-6 two-fold, alters post-pubescent ultrasonic vocalization patterns, reduces sociability, and increases self-grooming. However, most neurodevelopmental disorders in humans manifest in children as young as 2 years of age. Hence, a critical unexplored question is whether behavioral changes in immune activation models can be detected in pre-pubescent mice. Therefore, we evaluated early communication, sociability, and repetitive behaviors in pre-pubescent mice following the IL-6 treatment. A second open question is whether the cellular and behavioral changes are secondary to systemic or neuroinflammation. To address this question, we profiled 18 cytokines and chemokines in the circulation and CNS and evaluated eight immune cell types in P7 male and female brains following systemic IL-6 administration. We found an increase in ultrasonic vocalizations with simpler morphologies produced by the IL-6-injected male pups and a decrease in frequency in the female vocalizations upon removal from the nest at P7. The IL-6-treated male pups also socially interacted less when introduced to a novel mouse vs. controls as juveniles and spent almost twice as much time grooming themselves, a phenotype not present in the females. Tactile sensitivity was also increased, but only in the IL-6-treated female mice. The IL-6-treated mice had increased circulating IL-6 and IL-7 and reduced IL-13 at P7 that were no longer elevated at P14. There were no changes in brain levels of IL-6, IL-10, IL-13 or IL-17A mRNAs at P7. Altogether, these studies show that changes in the three core behavioral domains associated with several psychiatric disorders can be detected early in pre-pubescent mice following a transient developmental increase in IL-6. Yet, these behavioral alterations do not require neuroinflammation.

Ketamine impairs the performance of male mice in novel recognition object test and reduces the immunoreactivity of GAD67 in the hippocampus: Role of pioglitazone

Schizophrenia is a mental disorder characterized by positive, negative, and cognitive symptoms which is treated with antipsychotics. However, these drugs present several side effects and, some schizophrenia symptoms, like cognitive, are difficult to treat. The peroxisome proliferator-activated receptors-gamma (PPAR-γ) are expressed in dopaminergic neurons of the midbrain participating in the modulation of dopamine-mediated behavior . We investigated the effects of pioglitazone, an agonist of PPAR-γ, on the behavioral alterations induced by ketamine and, whether alterations in monoamine oxidase (MAO) activity, glutamic acid decarboxylase (GAD67), PPAR-γ or tyrosine hydroxylase (TH) immunoreactivity in brain tissues are involved in these effects. Male mice received ketamine (30 mg/kg), intraperitoneally, for 14 consecutive days, and pioglitazone (3 or 9 mg/kg), by gavage (day 8 up to day 14). Ketamine decreased nail-biting increasing the time exploring the center of the open field on day 8 and the number of rearing evaluated 30 min after its administration on day 14. Furthermore, ketamine decreased the percentage of investigation in the NOR test and the immunoreactivity of GAD67 in the hippocampus. No significant changes were found in other behavioral and biochemical tests. Pioglitazone attenuated the effects of ketamine on rearing and GAD67 immunoreactivity in the hippocampus, recovering the ketamine effects on NOR test. At a dose of 9 mg/kg, pioglitazone alone reduced the immunoreactivity of GAD67 in the hippocampus. Pioglitazone at both doses recovered the cognitive symptoms induced by ketamine an effect that seems to involve the modulation of GAD67 immunoreactivity in the hippocampus. In conclusion, pioglitazone improved the effects of ketamine on the NOR test which was, at least in part, associated with the modulation of GAD67 immunoreactivity in the hippocampus suggesting its beneficial role in cognitive symptoms.

Bi-allelic NRXN1α deletion in microglia derived from iPSC of an autistic patient increases interleukin-6 production and impairs supporting function on neuronal networking

Autism spectrum disorder (ASD) is a set of heterogeneous neurodevelopmental conditions, with a highly diverse genetic hereditary component, including altered neuronal circuits, that has an impact on communication skills and behaviours of the affected individuals. Beside the recognised role of neuronal alterations, perturbations of microglia and the associated neuroinflammatory processes have emerged as credible contributors to aetiology and physiopathology of ASD. Mutations in NRXN1, a member of the neurexin family of cell-surface receptors that bind neuroligin, have been associated to ASD. NRXN1 is known to be expressed by neurons where it facilitates synaptic contacts, but it has also been identified in glial cells including microglia. Asserting the impact of ASD-related genes on neuronal versus microglia functions has been challenging. Here, we present an ASD subject-derived induced pluripotent stem cells (iPSC)-based in vitro system to characterise the effects of the ASD-associated NRXN1 gene deletion on neurons and microglia, as well as on the ability of microglia to support neuronal circuit formation and function. Using this approach, we demonstrated that NRXN1 deletion, impacting on the expression of the alpha isoform (NRXN1α), in microglia leads to microglial alterations and release of IL6, a pro-inflammatory interleukin associated with ASD. Moreover, microglia bearing the NRXN1α-deletion, lost the ability to support the formation of functional neuronal networks. The use of recombinant IL6 protein on control microglia-neuron co-cultures or neutralizing antibody to IL6 on their NRXN1α-deficient counterparts, supported a direct contribution of IL6 to the observed neuronal phenotype. Altogether, our data suggest that, in addition to neurons, microglia are also negatively affected by NRXN1α-deletion, and this significantly contributes to the observed neuronal circuit aberrations.

Neuroprotective effect of PPAR gamma agonist in rat model of autism spectrum disorder: Role of Wnt/β-catenin pathway

BACKGROUND

The clinical manifestation of autism spectrum disorder (ASD) is linked to the disruption of fundamental neurodevelopmental pathways. Emerging evidences claim to have an upregulation of canonical Wnt/β-catenin pathway while downregulation of PPARγ pathway in ASD. This study aims to investigate the therapeutic potential of pioglitazone, a PPARγ agonist, in rat model of ASD. The study further explores the possible role of PPARγ and Wnt/β-catenin pathway and their interaction in ASD by using their modulators.

MATERIAL AND METHODS

Pregnant female Wistar rats received 600 mg/kg of valproic acid (VPA) to induce autistic symptoms in pups. Pioglitazone (10 mg/kg) was used to evaluate neurobehaviors, relative mRNA expression of inflammatory (IL-1β, IL-6, IL-10, TNF-α), apoptotic markers (Bcl-2, Bax, & Caspase-3) and histopathology (H&E, Nissl stain, Immunohistochemistry). Effect of pioglitazone was evaluated on Wnt pathway and 4 μg/kg dose of 6-BIO (Wnt modulator) was used to study the PPARγ pathway.

RESULTS

ASD model was established in pups as indicated by core autistic symptoms, increased neuroinflammation, apoptosis and histopathological neurodegeneration in cerebellum, hippocampus and amygdala. Pioglitazone significantly attenuated these alterations in VPA-exposed rats. The expression study results indicated an increase in key transcription factor, β-catenin in VPA-rats suggesting an upregulation of canonical Wnt pathway in them. Pioglitazone significantly downregulated the Wnt signaling by suppressing the expression of Wnt signaling-associated proteins. The inhibiting effect of Wnt pathway on PPARγ activity was indicated by downregulation of PPARγ-associated protein in VPA-exposed rats and those administered with 6-BIO.

CONCLUSION

In the present study, upregulation of canonical Wnt/β-catenin pathway was demonstrated in ASD rat model. Pioglitazone administration significantly ameliorated these symptoms potentially through its neuroprotective effect and its ability to downregulate the Wnt/β-catenin pathway. The antagonism between the PPARγ and Wnt pathway offers a promising therapeutic approach for addressing ASD.

Choline chloride shows gender-dependent positive effects on social deficits, learning/memory impairments, neuronal loss and neuroinflammation in the lipopolysaccharide-induced rat model of autism

The neuroprotective effects of choline chloride, an essential nutrient, a precursor for the acetylcholine and synthesis of membrane phospholipids, have been associated with neurological and neurodegenerative diseases. Its contribution to autism spectrum disorder, a neurodevelopmental disorder, remains unknown. Thus, we aimed to evaluate the effects of choline chloride on social behaviours, and histopathological and biochemical changes in a rat autism model. The autism model was induced by administration of 100 μg/kg lipopolysaccharide (LPS) on the 10th day of gestation. Choline chloride treatment (100 mg/kg/day) was commenced on PN5 and maintained until PN50. Social deficits were assessed by three-chamber sociability, open field, and passive avoidance learning tests. Tumour necrosis factor alpha (TNF-α), interleukin-2 (IL) and IL-17, nerve growth factor (NGF), and glutamate decarboxylase 67 (GAD67) levels were measured to assess neuroinflammatory responses. In addition, the number of hippocampal and cerebellar neurons and glial fibrillary acidic protein (GFAP) expression were evaluated. Social novelty and passive avoidance learning tests revealed significant differences in choline chloride-treated male rats compared with saline-treated groups. TNF-α, IL-2, and IL-17 were significantly decreased after choline chloride treatment in both males and females. NGF and GAD67 levels were unchanged in females, while there were significant differences in males. Histologically, significant changes in terms of gliosis were detected in hippocampal CA1 and CA3 regions and cerebellum in choline chloride-treated groups. The presence of ameliorative effects of choline chloride treatment on social behaviour and neuroinflammation through neuroinflammatory, neurotrophic, and neurotransmission pathways in a sex-dependent rat model of LPS-induced autism was demonstrated.

Acute rapamycin treatment reveals novel mechanisms of behavioral, physiological, and functional dysfunction in a maternal inflammation mouse model of autism and sensory over-responsivity

Maternal inflammatory response (MIR) during early gestation in mice induces a cascade of physiological and behavioral changes that have been associated with autism spectrum disorder (ASD). In a prior study and the current one, we find that mild MIR results in chronic systemic and neuro-inflammation, mTOR pathway activation, mild brain overgrowth followed by regionally specific volumetric changes, sensory processing dysregulation, and social and repetitive behavior abnormalities. Prior studies of rapamycin treatment in autism models have focused on chronic treatments that might be expected to alter or prevent physical brain changes. Here, we have focused on the acute effects of rapamycin to uncover novel mechanisms of dysfunction and related to mTOR pathway signaling. We find that within 2 hours, rapamycin treatment could rapidly rescue neuronal hyper-excitability, seizure susceptibility, functional network connectivity and brain community structure, and repetitive behaviors and sensory over-responsivity in adult offspring with persistent brain overgrowth. These CNS-mediated effects are also associated with alteration of the expression of several ASD-,ion channel-, and epilepsy-associated genes, in the same time frame. Our findings suggest that mTOR dysregulation in MIR offspring is a key contributor to various levels of brain dysfunction, including neuronal excitability, altered gene expression in multiple cell types, sensory functional network connectivity, and modulation of information flow. However, we demonstrate that the adult MIR brain is also amenable to rapid normalization of these functional changes which results in the rescue of both core and comorbid ASD behaviors in adult animals without requiring long-term physical alterations to the brain. Thus, restoring excitatory/inhibitory imbalance and sensory functional network modularity may be important targets for therapeutically addressing both primary sensory and social behavior phenotypes, and compensatory repetitive behavior phenotypes.

Ameliorating effect of pioglitazone on prenatal valproic acid-induced behavioral and neurobiological abnormalities in autism spectrum disorder in rats

Autism spectrum disorder (ASD) is a neurodevelopment disorder that mainly arises due to abnormalities in different brain regions, resulting in behavioral deficits. Besides its diverse phenotypical features, ASD is associated with complex and varied etiology, presenting challenges in understanding its precise neuro-pathophysiology. Pioglitazone was reported to have a fundamental role in neuroprotection in various other neurological disorders. The present study aimed to investigate the therapeutic potential of pioglitazone in the prenatal valproic acid (VPA)-model of ASD in Wistar rats. Pregnant female Wistar rats received VPA on Embryonic day (E.D12.5) to induce autistic-like-behavioral and neurobiological alterations in their offspring. VPA-exposed rats presented core behavioral symptoms of ASD such as deficits in social interaction, poor spatial and learning behavior, increased anxiety, locomotory and repetitive activity, and decreased exploratory activity. Apart from these, VPA exposure also stimulated neurochemical and histopathological neurodegeneration in various brain regions. We administered three different doses of pioglitazone i.e., 2.5, 5, and 10 mg/kg in rats to assess various parameters. Of all the doses, our study highlighted that 10 mg/kg pioglitazone efficiently attenuated the autistic symptoms along with other neurochemical alterations such as oxidative stress, neuroinflammation, and apoptosis. Moreover, pioglitazone significantly attenuated the neurodegeneration by restoring the neuronal loss in the hippocampus and cerebellum. Taken together, our study suggests that pioglitazone exhibits therapeutic potential in alleviating behavioral abnormalities induced by prenatal VPA exposure in rats. However, further research is needed to fully understand and establish pioglitazone's effectiveness in treating ASD.

Behavioral analysis in laboratory rats: Challenges and usefulness of 50-kHz ultrasonic vocalizations

Many rodent species emit and detect vocalizations in the ultrasonic range. Rats use three classes of ultrasonic vocalizations depending on developmental stage, experience and the behavioral situation. Calls from one class emitted by juvenile and adult rats, the so-called 50-kHz calls, are typical for appetitive and social situations. This review provides a brief historical account on the introduction of 50-kHz calls in behavioral research followed by a survey of their scientific applications focusing on the last five years, where 50-kHz publications reached a climax. Then, specific methodological challenges will be addressed, like how to measure and report 50-kHz USV, the problem of assignment of acoustic signals to a specific sender in a social situation, and individual variability in call propensity. Finally, the intricacy of interpreting 50-kHz results will be discussed focusing on the most prevalent ones, namely as communicative signals and/or readouts of the sender's emotional status.

Rosiglitazone attenuates amyloid beta and glial fibrillary acidic protein in the hippocampus and neuroinflammation associated learning and memory impairments in rats

OBJECTIVE

The aim of the current study was to investigate the beneficial effects of rosiglitazone (Rosi) on amyloid beta(Aβ) and glial fibrillary acidic protein (GFAP) in the hippocampus and neuroinflammation-associated learning and memory impairments in rats.

MATERIALS AND METHODS

The rats were grouped and treated as follows: (1) Control in which saline and vehicle were administered instead of LPS and Rosi respectively. (2) Lipopolysaccharide (LPS) group in which LPS was dissolved in saline and injected (1 mg/kg) intraperitoneally. Vehicle was administered instead of Rosi in this group. (3-5) LPS+ Rosi 1, LPS+ Rosi 3, and LPS+ Rosi 5 groups in them 1, 3, or 5 mg/kg of Rosi respectively was administered 30 min before LPS. The treatments were done for two weeks. In the first week, Rosi or its vehicle was injected 30 min before LPS. In the second week, the treatments were the same as the first week and behavioral tests were also carried out in the second week. The hippocampal tissues were finally detached for biochemical assessment.

RESULTS

The results showed that Rosi reversed increased levels of Aβ, GFAP, interleukin (IL)- 6, tumor necrosis factor-α (TNF-α), nitric oxide (NO) metabolites, and malondialdehyde (MDA) due to LPS injection. Rosi also reversed attenuating effects of LPS on IL-10 and thiol concentration and activities of catalase (CAT) and superoxide dismutase (SOD). In the Morris water maze test, the LPS group had a longer latency to find the platform while spent a shorter time spent in the target quadrant in the probe trial than the control group. In the passive avoidance test, the animals of the LPS group had a shorter delay to enter the dark chamber than the animals of the control group. Treatment with Rosi reversed these parameters.

CONCLUSION

The findings showed Rosi attenuated Aβ, GFAP, and oxidative stress in the hippocampus and neuroinflammation-associated learning and memory impairments in rats.

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

CTNNB1 in neurodevelopmental disorders

CTNNB1 is the gene that encodes β-catenin which acts as a key player in the Wnt signaling pathway and regulates cellular homeostasis. Most CTNNB1-related studies have been mainly focused on its role in cancer. Recently, CTNNB1 has also been found involved in neurodevelopmental disorders (NDDs), such as intellectual disability, autism, and schizophrenia. Mutations of CTNNB1 lead to the dysfunction of the Wnt signaling pathway that regulates gene transcription and further disturbs synaptic plasticity, neuronal apoptosis, and neurogenesis. In this review, we discuss a wide range of aspects of CTNNB1 and its physiological and pathological functions in the brain. We also provide an overview of the most recent research regarding CTNNB1 expression and its function in NDDs. We propose that CTNNB1 would be one of the top high-risk genes for NDDs. It could also be a potential therapeutic target for the treatment of NDDs.

The Strategy of Targeting Peroxisome Proliferator-Activated Receptor (PPAR) in the Treatment of Neuropsychiatric Disorders

Peroxisome proliferator-activated receptors (PPARs) are nonsteroid nuclear receptors and transcription factors that regulate several neuroinflammatory and metabolic processes, recently involved in several neuropsychiatric conditions, including Alzheimer's disease, Parkinson's disease, major depressive disorder, post-traumatic stress disorder (PTSD), schizophrenia spectrum disorders, and autism spectrum disorders. PPARs are ligand-activated receptors that, following stimulation, induce neuroprotective effects by decreasing neuroinflammatory processes through inhibition of the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) expression and consequent suppression of pro-inflammatory cytokine production. PPARs heterodimerize with the retinoid X-receptor (RXR) and bind to PPAR-responsive regulatory elements (PPRE) in the promoter region of target genes involved in lipid metabolism, synthesis of cholesterol, catabolism of amino acids, and inflammation. Interestingly, PPARs are considered functionally part of the extended endocannabinoid (eCB) system that includes the classic eCB, anandamide, which act at cannabinoid receptor types 1 (CB1) and 2 (CB2) and are implicated in the pathophysiology of stress-related neuropsychiatric disorders. In preclinical studies, PPAR stimulation improves anxiety and depression-like behaviors by enhancing neurosteroid biosynthesis. The peculiar functional role of PPARs by exerting anti-inflammatory and neuroprotective effects and their expression localization in neurons and glial cells of corticolimbic circuits make them particularly interesting as novel therapeutic targets for several neuropsychiatric disorders characterized by underlying neuroinflammatory/neurodegenerative mechanisms. Herein, we discuss the pathological hallmarks of neuropsychiatric conditions associated with neuroinflammation, as well as the pivotal role of PPARs with a special emphasis on the subtype alpha (PPAR-α) as a suitable molecular target for therapeutic interventions.

Canagliflozin alleviates valproic acid-induced autism in rat pups: Role of PTEN/PDK/PPAR-γ signaling pathways

Autism is complex and multifactorial, and is one of the fastest growing neurodevelopmental disorders. Canagliflozin (Cana) is an antidiabetic drug that exhibits neuroprotective properties in various neurodegenerative syndromes. This study investigated the possible protective effect of Cana against the valproic acid (VPA)-induced model of autism. VPA was injected subcutaneously (SC) into rat pups at a dose of 300 mg/kg, twice daily on postnatal day-2 (PD-2) and PD-3, and once on PD-4 to induce an autism-like syndrome. Graded doses of Cana were administered (5 mg/kg, 7.5 mg/kg, and 10 mg/kg, P.O.) starting from the first day of VPA injections and continued for 21 days. At the end of the experiment, behavioral tests and histopathological alterations were assessed. In addition, the gene expression of peroxisome proliferator-activated receptor γ (PPAR γ), lactate dehydrogenase A (LDHA), pyruvate dehydrogenase kinase (PDK), cellular myeloctomatosis (c-Myc) with protein expression of glucose transporter-1 (GLUT-1), phosphatase and tensin homolog (PTEN), and level of acetylcholine (ACh) were determined. Treatment with Cana significantly counteracted histopathological changes in the cerebellum tissues of the brain induced by VPA. Cana (5 mg/kg, 7.5 mg/kg, and 10 mg/kg) improved sociability and social preference, enhanced stereotypic behaviors, and decreased hyperlocomotion activity, in addition to its significant effect on the canonical Wnt/β-catenin pathway via the downregulation of gene expression of LDHA (22%, 64%, and 73% in cerebellum tissues with 51%, 60%, and 75% in cerebrum tissues), PDK (27%, 50%, and 67% in cerebellum tissues with 34%, 66%, and 77% in cerebrum tissues), c-Myc (35%, 44%, and 72% in cerebellum tissues with 19%, 58%, and 79% in cerebrum tissues), protein expression of GLUT-1 (32%, 48%, and 49% in cerebellum tissues with 30%, 50%, and 54% in cerebrum tissues), and elevating gene expression of PPAR-γ (2, 3, and 4 folds in cerebellum tissues with 1.5, 3, and 9 folds in cerebrum tissues), protein expression of PTEN (2, 5, and 6 folds in cerebellum tissues with 6, 6, and 10 folds in cerebrum tissues), and increasing the ACh levels (4, 5, and 7 folds) in brain tissues. The current study confirmed the ameliorating effect of Cana against neurochemical and behavioral alterations in the VPA-induced model of autism in rats.

Demonstration of Ameliorating Effect of Vardenafil Through Its Anti-Inflammatory and Neuroprotective Properties in Autism Spectrum Disorder Induced by Propionic Acid on Rat Model

Introduction: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with complex etiology. In this study, we aimed to determine the ameliorating effects of vardenafil in the ASD rat model induced by propionic acid (PPA) in terms of neurobehavioral changes and also support these effects with histopathological changes, brain biochemical analysis and magnetic resonance spectroscopy (MRS) findings.Materials and Methods: Twenty-one male rats were randomly assigned into 3 groups. Group 1 (control, 7 rats) did not receive treatment. Rats in groups 2 and 3 were given PPA at the dose of 250 mg/kg/day intraperitoneally for 5 days. After PPA administration, animals in group 2 (PPAS, 7 rats) were given saline and animals in group 3 (PPAV, 7 rats) were given vardenafil. Behavioral tests were performed between the 20th and 24th days of the study. The rats were taken for MRS on the 25^th day. At the end of the study, brain levels of interleukin-2 (IL-2), IL-17, tumor necrosis factor-α, nerve growth factor, cGMP and lactate levels were measured. In the cerebellum and the CA1 and CA3 regions of the hippocampus, counts of neurons and Purkinje cells and glial fibrillary acidic protein (associated with gliosis) were evaluated histologically.Results: Three chamber sociability and passive avoiding test, histopathological results, lactate levels derived from MRS, and biochemical biomarkers revealed significant differences among the PPAV and PPAS groups.Conclusion: We concluded that vardenafil improves memory and social behaviors and prevent loss of neuronal and Purkinje cell through its anti-inflammatory and neuroprotective effect.

Modestly increasing systemic interleukin-6 perinatally disturbs secondary germinal zone neurogenesis and gliogenesis and produces sociability deficits

Epidemiologic studies have demonstrated that infections during pregnancy increase the risk of offspring developing Schizophrenia, Autism, Depression and Bipolar Disorder and have implicated interleukin-6 (IL-6) as a causal agent. However, other cytokines have been associated with the developmental origins of psychiatric disorders; therefore, it remains to be established whether elevating IL-6 is sufficient to alter the trajectory of neural development. Furthermore, most rodent studies have manipulated the maternal immune system at mid-gestation, which affects the stem cells and progenitors in both the primary and secondary germinal matrices. Therefore, a question that remains to be addressed is whether elevating IL-6 when the secondary germinal matrices are most active will affect brain development. Here, we have increased IL-6 from postnatal days 3-6 when the secondary germinal matrices are rapidly expanding. Using Nestin-Cre^ERT2 fate mapping we show that this transient increase in IL-6 decreased neurogenesis in the dentate gyrus of the dorsal hippocampus, reduced astrogliogenesis in the amygdala and decreased oligodendrogenesis in the body and splenium of the corpus callosum all by ∼ 50%. Moreover, the IL-6 treatment elicited behavioral changes classically associated with neurodevelopmental disorders. As adults, IL-6 injected male mice lost social preference in the social approach test, spent ∼ 30% less time socially engaging with sexually receptive females and produced ∼ 50% fewer ultrasonic vocalizations during mating. They also engaged ∼ 50% more time in self-grooming behavior and had an increase in inhibitory avoidance. Altogether, these data provide new insights into the biological mechanisms linking perinatal immune activation to complex neurodevelopmental brain disorders.

Promising drug repurposing approach targeted for cytokine storm implicated in SARS-CoV-2 complications

A global threat has emerged in 2019 due to the rapid spread of Coronavirus disease (COVID-19). As of January 2021, the number of cases worldwide reached 103 million cases and 2.22 million deaths which were confirmed as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This global pandemic galvanized the scientific community to study the causative virus (SARS-CoV2) pathogenesis, transmission, and clinical symptoms. Remarkably, the most common complication associated with this disease is the cytokine storm which is responsible for COVID-19 mortality. Thus, targeting the cytokine storm with new medications is needed to hamper COVID-19 complications where the most prominent strategy for the treatment is drug repurposing. Through this strategy, several steps are skipped especially those required for testing drug safety and thus may help in reducing the dissemination of this pandemic. Accordingly, the aim of this review is to outline the pathogenesis, clinical features, and immune complications of SARS-CoV2 in addition to suggesting several repurposed drugs with their plausible mechanism of action for possible management of severe COVID-19 cases.

Dose-dependent effects of prenatal exposure of pioglitazone, the PPARγ agonist, on the hippocampus development and learning and memory performance of rat offspring

It is known that pioglitazone, defined as a PPARγ agonist, has neuron-protective properties in nervous system disorders. The aim of this study is to investigate the effects of pioglitazone administration at different doses during prenatal period on the neurons, glial cells and learning-memory levels in the hippocampus of rat offspring. Pregnant rats were divided into three groups; Low-Dose Pioglitazone (LDP), High-Dose Pioglitazone (HDP) and control (C) (n = 3). Pregnant rats in the HDP and LDP groups were given pioglitazone at 30 mg/kg and 5 mg/kg doses, respectively, by gavage once a day during their pregnancy. No procedure was applied to the rats in the control group. Morris water tank test was applied to offspring obtained from postnatal 24th to 28th day. The offspring were sacrificed on the 29th postal day and their brain tissues removed. Stereological, histopathological and immunohistochemical techniques were used to analyze brain tissues. As a result of the analysis, it was observed that there were delays in learning and memory, the number of pyramidal neurons decreased, and the density of cells stained with glial fibrillar acidic protein (GFAP) positive increased in the HDP group compared to the other groups (p < 0.05). No significant difference was found between the LDP and control groups in terms of these parameters (p > 0.05). Our results showed that pioglitazone administered in the prenatal period had an effect on the hippocampus development and learning and memory performance of rats, depending on the dose.

Bidirectional communication between mast cells and the gut-brain axis in neurodegenerative diseases: Avenues for therapeutic intervention

Although the global incidence of neurodegenerative diseases has been steadily increasing, especially in adults, there are no effective therapeutic interventions. Neurodegeneration is a heterogeneous group of disorders that is characterized by the activation of immune cells in the central nervous system (CNS) (e.g., mast cells and microglia) and subsequent neuroinflammation. Mast cells are found in the brain and the gastrointestinal tract and play a role in "tuning" neuroimmune responses. The complex bidirectional communication between mast cells and gut microbiota coordinates various dynamic neuro-cellular responses, which propagates neuronal impulses from the gastrointestinal tract into the CNS. Numerous inflammatory mediators from degranulated mast cells alter intestinal gut permeability and disrupt blood-brain barrier, which results in the promotion of neuroinflammatory processes leading to neurological disorders, thereby offsetting the balance in immune-surveillance. Emerging evidence supports the hypothesis that gut-microbiota exert a pivotal role in inflammatory signaling through the activation of immune and inflammatory cells. Communication between inflammatory cytokines and neurocircuits via the gut-brain axis (GBA) affects behavioral responses, activates mast cells and microglia that causes neuroinflammation, which is associated with neurological diseases. In this comprehensive review, we focus on what is currently known about mast cells and the gut-brain axis relationship, and how this relationship is connected to neurodegenerative diseases. We hope that further elucidating the bidirectional communication between mast cells and the GBA will not only stimulate future research on neurodegenerative diseases but will also identify new opportunities for therapeutic interventions.

Immune Modulatory Treatments for Autism Spectrum Disorder

Several lines of evidence from family history studies, immunogenetics, maternal immune activation, neuroinflammation, and systemic inflammation support an immune subtype of autism spectrum disorder (ASD). Current Food and Drug Administration-approved medications for ASD do not address the underlying pathophysiology of ASD, have not consistently been shown to address the core symptoms of ASD, and are currently only approved for treating irritability in children and adolescents. In this article, we review the immune modulatory effects of the 2 currently Food and Drug Administration-approved treatments for ASD. We then provide an overview of current data on emerging treatments for ASD from multiple fields of medicine with immune modulatory effects. Although further research is needed to more clearly establish the efficacy and safety of immune modulatory treatments, early data on repurposing medications used to treat systemic inflammation for ASD demonstrate potential benefit and further research is warranted.

Exenatide, a GLP-1 analog, has healing effects on LPS-induced autism model: Inflammation, oxidative stress, gliosis, cerebral GABA, and serotonin interactions

Previous studies have established anti-inflammatory, antioxidant, and neuroprotective effects of Exenatide in the central nervous system. Since these mechanisms are thought to have important roles in the pathophysiology of autism, we hypothesized that Exenatide may have healing effects in autism. We tested this hypothesis by examining the effects of Exenatide in an experimental autism model created by lipopolysaccharide (LPS) exposure in the womb, with behavioral tests, histopathological examinations, and biochemical measurements. The autism model was created by administration of LPS (i.p) to pregnant rats on the 10th day of their pregnancy at a dose of 100 µg/kg. On postnatal 21st day, a total of four groups were formed from offspring with regard to sex distribution and treatment. After a 45-day treatment, behavioral analysis tests were performed on rats. Subsequently, the rats were sacrificed and biochemical analysis [superoxide dismutase, tumor necrotizing factor alpha, nerve growth factor, 5-hydroxyindoleacetic acid, and glutamic acid decarboxylase-67] and histopathological analysis were performed. On the 10th day of the intrauterine period, LPS exposure was found to disrupt behavioral findings, increase inflammation and hippocampal gliosis, and decrease 5-HIAA, GAD-67, and NGF, especially in male rats. However, among the rats exposed to LPS in the intrauterine period, recipients of Exenatide demonstrated significant amelioration of findings. Exenatide therapy shows positive effects on behavioral disorders in an LPS-induced autism model. This agent probably exerts its effects by suppressing inflammation and oxidative stress and reducing hippocampal gliosis. In addition, Exenatide has also been shown to positively affect cerebral serotonergic and GABAergic effects.

Alteration of Gut Microbiota in Autism Spectrum Disorder: An Overview

The microbiota-gut-brain axis, which refers to the bidirectional communication pathway between gut bacteria and the central nervous system, has a profound effect on important brain processes, from the synthesis of neurotransmitters to the modulation of complex behaviors such as sociability and anxiety. Previous studies have revealed that the gut microbiota is potentially related to not only gastrointestinal disturbances, but also social impairment and repetitive behavior-core symptoms of autism spectrum disorder (ASD). Although studies have been conducted to characterize the microbial composition in patients with ASD, the results are heterogeneous. Nevertheless, it is clear that there is a difference in the composition of the gut microbiota between ASD and typically developed individuals, and animal studies have repeatedly suggested that the gut microbiota plays an important role in ASD pathophysiology. This possibility is supported by abnormalities in metabolites produced by the gut microbiota and the association between altered immune responses and the gut microbiota observed in ASD patients. Based on these findings, various attempts have been made to use the microbiota in ASD treatment. The results reported to date suggest that microbiota-based therapies may be effective for ASD, but largescale, well-designed studies are needed to confirm this.

Development of the Korean Form of the Premonitory Urge for Tics Scale: A Reliability and Validity Study

Objectives

This study aimed to evaluate the reliability and validity of the Korean Form of the Premonitory Urge for Tics Scale (K-PUTS).

Methods

Thirty-eight patients with Tourette's disorder who visited Jeonbuk National University Hospital were assessed with the K-PUTS. Together with the PUTS, the Yale Global Tic Severity Scale (YGTSS), the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS), the attention-deficit/hyperactivity disorder (ADHD) rating scale (ARS), and the Adult ADHD Self-Report Scale (ASRS) were implemented to evaluate concurrent and discriminant validity.

Results

The internal consistency of items on the PUTS was high, with a Cronbach's α of 0.79. The test-retest reliability of the PUTS, which was administered at 2 weeks to 2 months intervals, showed high reliability with a Pearson correlation coefficient of 0.60. There was a significant positive correlation between the overall PUTS score and the YGTSS score, showing concurrent validity. There was no correlation between the PUTS, CY-BOCS, and ASRS scores, demonstrating the discriminant validity of the PUTS. Factor analysis for construct validity revealed three factors: "presumed functional relationship between the tic and the urge to tic," "the quality of the premonitory urge," and "just right phenomena."

Conclusion

The results of this study indicate that the K-PUTS is a reliable and valid scale for rating premonitory urge of tics.

Developmental IL-6 Exposure Favors Production of PDGF-Responsive Multipotential Progenitors at the Expense of Neural Stem Cells and Other Progenitors

Interleukin-6 (IL-6) is increased in maternal serum and amniotic fluid of children subsequently diagnosed with autism spectrum disorders. However, it is not clear how increased IL-6 alters brain development. Here, we show that IL-6 increases the prevalence of a specific platelet-derived growth factor (PDGF)-responsive multipotent progenitor, with opposite effects on neural stem cells and on subsets of bipotential glial progenitors. Acutely, increasing circulating IL-6 levels 2-fold above baseline in neonatal mice specifically stimulated the proliferation of a PDGF-responsive multipotential progenitor accompanied by increased phosphorylated STAT3, increased Fbxo15 expression, and decreased Dnmt1 and Tlx expression. Fate mapping studies using a Nestin-CreERT2 driver revealed decreased astrogliogenesis in the frontal cortex. IL-6-treated mice were hyposmic; however, olfactory bulb neuronogenesis was unaffected. Altogether, these studies provide important insights into how inflammation alters neural stem cells and progenitors and provide new insights into the molecular and cellular underpinnings of neurodevelopmental disorders associated with maternal infections.

Dietary Approaches to the Management of Autism Spectrum Disorders

This chapter reviews the literature surrounding autism spectrum disorders (ASD) and their relation to gastrointestinal (GI), behavioral, neurological, and immunological functioning. Individuals with ASD often have poor GI health, including bowel motility issues, autoimmune and/or other adverse responses to certain foods, and lack of necessary nutrient absorption. These issues may be caused or exacerbated by restrictive behavioral patterns (e.g., preference for sweet and salty foods and/or refusal of healthy foods). Those individuals with GI issues tend to demonstrate more behavioral deficits (e.g., irritability, agitation, hyperactivity) and also tend to have an imbalance in overall gut microbiome composition, thus corroborating several studies that have implicated brain-gut pathways as potential mediators of behavioral dysfunction.We examine the literature regarding dietary approaches to managing ASDs, including elimination diets for gluten, casein, or complex carbohydrates, a ketogenic diet, and a low oxalate diet. We also explore the research examining dietary supplements such as fatty acids, pro- and prebiotics, vitamins, minerals, glutathione, phytochemicals, and hormones. The research on dietary approaches to managing ASDs is limited and the results are mixed. However, a few approaches, such as the gluten-free/casein-free diet, fatty acid supplementation, and pre/probiotics have generally demonstrated improved GI and associated behavioral symptoms. Given that GI issues seem to be overrepresented in ASD populations, and that GI issues have been associated with a number behavioral and neurological deficits, dietary manipulation may offer a cheap and easily implemented approach to improve the lives of those with ASD.

Gender Related Changes in Gene Expression Induced by Valproic Acid in A Mouse Model of Autism and the Correction by S-adenosyl Methionine. Does It Explain the Gender Differences in Autistic Like Behavior?

In previous studies we produced autism like behavioral changes in mice by Valproic acid (VPA) with significant differences between genders. S-adenosine methionine (SAM) prevented the autism like behavior in both genders. The expression of 770 genes of pathways involved in neurophysiology and neuropathology was studied in the prefrontal cortex of 60 days old male and female mice using the NanoString nCounter. In females, VPA induced statistically significant changes in the expression of 146 genes; 71 genes were upregulated and 75 downregulated. In males, VPA changed the expression of only 19 genes, 16 were upregulated and 3 downregulated. Eight genes were similarly changed in both genders. When considering only the genes that were changed by at least 50%, VPA changed the expression of 15 genes in females and 3 in males. Only Nts was similarly downregulated in both genders. SAM normalized the expression of most changed genes in both genders. We presume that genes that are involved in autism like behavior in our model were similarly changed in both genders and corrected by SAM. The behavioral and other differences between genders may be related to genes that were differently affected by VPA in males and females and/or differently affected by SAM.

The influence of neuroinflammation in Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by deficits in social communication and restricted or repetitive behaviours. The clinical presentation of ASD is highly variable and diagnosis is based on the presence of impaired social communication and repetitive and/or restricted behaviours. Although the precise pathophysiologies underlying ASD are unclear, growing evidence supports a role for dysregulated neuroinflammation. The potential involvement of microglia and astrocytes reactive to inflammatory stimuli in ASD has generated much interest due to their varied roles including in mounting an immune response and regulating synaptic function. Increased numbers of reactive microglial and astrocytes in both ASD postmortem tissue and animal models have been reported. Whether dysregulation of glial subtypes exacerbates alterations in neural connectivity in the brain of autistic patients is not well explored. A role for the gut-brain axis involving microbial-immune-neuronal cross talk is also a growing area of neuroinflammation research. Greater understanding of these interactions under patho/physiological conditions and the identification of consistent immune profile abnormalities can potentially lead to more reliable diagnostic measures and treatments in ASD.

Beneficial effects of pioglitazone, a selective peroxisome proliferator-activated receptor-γ agonist in prenatal valproic acid-induced behavioral and biochemical autistic like features in Wistar rats

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder in children. It is diagnosis by two main behavioral phenotypes i.e. social-communication impairments and repetitive behavior. ASD is complex disorder with unsolved etiology due to multiple genes involvement, epigenetic mechanism and environmental factors. Valproic acid (VPA), a teratogen is known to induce characteristic features related to ASD in rodents. Numerous studies suggest the potential therapeutic effects of peroxisome proliferator-activated receptor-gamma (PPAR-γ) in different brain disorders. This research evaluates the utility of selective agonist of PPAR-γ, pioglitazone in prenatal VPA induced experimental ASD symptomatology in Wistar rats. The prenatal administration of VPA has induced social impairment, repetitive behavior, hyperlocomotion, anxiety and low exploratory activity in rats. Also, prenatal VPA-treated rats have shown higher levels of oxidative stress (increased in thiobarbituric acid reactive species, and decreased in reduced glutathione level) and inflammation (increased in interleukin-6, tumor necrosis factor-alpha and decreased in interleukin-10) in the cerebellum, brainstem and prefrontal cortex. Treatment with pioglitazone significantly attenuated the prenatal VPA-induced social impairment, repetitive behavior, hyperactivity, anxiety and low exploratory activity. Furthermore, pioglitazone also reduced the prenatal VPA-induced oxidative stress and neuroinflammation in aforementioned brain regions. Hence, it may be concluded that pioglitazone may provide neurobehavioral and biochemical benefits in prenatal VPA-induced autistic phenotypes in rats.

Pioglitazone abolishes cognition impairments as well as BDNF and neurotensin disturbances in a rat model of autism

We have shown that exposure of rats to lipopolysaccharide (LPS) during gestation induces autistic-like behaviors in juvenile offspring and pioglitazone post treatment corrects social and communication deficits. The first objective of the present study was to evaluate the cognition of the rats, because this is also a behavioral sphere committed in autism. Second, biomarkers related to pioglitazone pathways and autism were studied to try to understand their mechanisms. We used our rat model of autism and pioglitazone was administered daily to these young offspring. T-maze spontaneous alternations tests, plasma levels of brain-derived neurotrophic factor (BDNF), beta-endorphin, neurotensin, oxytocin, and substance P were all studied. Exposure of rats to LPS during gestation induced cognitive deficits in the young offspring, elevated BDNF levels and decreased neurotensin levels. Daily postnatal pioglitazone treatment abolished cognition impairments as well as BDNF and neurotensin disturbances. Together with our previous studies, we suggest pioglitazone as a candidate for the treatment of autism, because it improved the responses of the three most typical autistic-like behaviors. BDNF and neurotensin also appeared to be related to the autistic-like behaviors and should be considered for therapeutic purposes.

Summary: Exposure of rats to lipopolysaccharide during gestation induced autistic-like behaviors in the juvenile offspring. Daily postnatal pioglitazone treatment abolished cognition impairments as well as brain-derived neurotrophic factor and neurotensin disturbances.

Maternal immune activation-induced PPARγ-dependent dysfunction of microglia associated with neurogenic impairment and aberrant postnatal behaviors in offspring

Maternal infection during pregnancy is an important factor involved in the pathogenesis of brain disorders in the offspring. Mounting evidence from maternal immune activation (MIA) animals indicates that microglial priming may contribute to neurodevelopmental abnormalities in the offspring. Because peroxisome proliferator-activated receptor gamma (PPARγ) activation exerts neuroprotective effects by regulating neuroinflammatory response, it is a pharmacological target for treating neurogenic disorders. We investigated the effect of PPARγ-dependent microglial activation on neurogenesis and consequent behavioral outcomes in male MIA-offspring. Pregnant dams on gestation day 18 received Poly(I:C) (1, 5, or 10 mg/kg; i.p.) or the vehicle. The MIA model that received 10 mg/kg Poly(I:C) showed significantly increased inflammatory responses in the maternal serum and fetal hippocampus, followed by cognitive deficits, which were highly correlated with hippocampal neurogenesis impairment in prepubertal male offspring. The microglial population in hippocampus increased, displayed decreased processes and larger soma, and had a higher expression of the CD11b, which is indicative of the M1 phenotype (classical activation). Activation of the PPARγ pathway by pioglitazone in the MIA offspring rescued the imbalance of the microglial activation and ameliorated the MIA-induced suppressed neurogenesis and cognitive impairments and anxiety behaviors. In an in vitro experiment, PPARγ-induced M2 microglia (alternative activation) promoted the proliferation and differentiation of neural precursor cells. These results indicated that the MIA-induced long-term changes in microglia phenotypes were associated with hippocampal neurogenesis and neurobehavioral abnormalities in offspring. Modulation of the microglial phenotypes was associated with a PPARγ-mediated neuroprotective mechanism in the MIA offspring and may serve as a potential therapeutic approach for prenatal immune activation-induced neuropsychiatric disorders.

Prevention or Amelioration of Autism-Like Symptoms in Animal Models: Will it Bring Us Closer to Treating Human ASD?

Since the first animal model of valproic acid (VPA) induced autistic-like behavior, many genetic and non-genetic experimental animal models for Autism Spectrum Disorder (ASD) have been described. The more common non-genetic animal models induce ASD in rats and mice by infection/inflammation or the prenatal or early postnatal administration of VPA. Through the establishment of these models, attempts have been made to ameliorate or even prevent ASD-like symptoms. Some of the genetic models have been successfully treated by genetic manipulations or the manipulation of neurotransmission. Different antioxidants have been used (i.e., astaxanthin, green tea, piperine) to reduce brain oxidative stress in VPA-induced ASD models. Agents affecting brain neurotransmitters (donepezil, agmatine, agomelatine, memantine, oxytocin) also successfully reduced ASD-like symptoms. However, complete prevention of the development of symptoms was achieved only rarely. In our recent study, we treated mouse offspring exposed on postnatal day four to VPA with S-adenosine methionine (SAM) for three days, and prevented ASD-like behavior, brain oxidative stress, and the changes in gene expression induced by VPA. In this review, we describe, in addition to our data, the existing literature on the prevention/amelioration of ASD-like symptoms. We also discuss the possible mechanisms underlying some of these phenomena. Finally, we describe some of the clinical trials in children with ASD that were carried out as a result of data from animal studies, especially those with polyunsaturated fatty acids (PUFAs).

Ultrasonic vocalizations as a tool in studying emotional states in rodent models of social behavior and brain disease

Rodents emit ultrasonic vocalizations (USVs) to communicate the presence of positive or negative emotional states and to coordinate social interactions. On this basis, USVs are increasingly being used as a behavioral readout in rodent studies of affect, motivation and social behavior. Notably, several investigations have demonstrated that rodents emit USVs when tested in experimental paradigms that are used in preclinical studies of psychiatric and neurological diseases. Moreover, it has been shown that calling behavior may be influenced by genetic and/or environmental factors (i.e., stress), early rearing conditions that have been implicated in brain disease, as well as psychoactive drugs. Hence, measuring USV emissions has emerged as a useful tool in studying the mechanisms that underlie the emotional disturbances featuring certain brain diseases, as well as in the development of suited pharmacological therapies. This review provides an overview of the behavioral significance of USV emissions and describes the contexts that promote calling behavior in rats and mice. Moreover, the review summarizes the current evidence concerning the use of USVs as a marker of affect in rat and mouse models of sociability, psychiatric diseases and neurological diseases, and discusses the strengths and current limitations of using USVs as a behavioral readout in rodent studies of emotional behavior. This article is part of the Special Issue entitled 'The neuropharmacology of social behavior: from bench to bedside'.