Increased oxidative stress in the cerebellum and peripheral immune cells leads to exaggerated autism-like repetitive behavior due to deficiency of antioxidant response in BTBR T + tf/J mice

Neurometabolite differences in Autism as assessed with Magnetic Resonance Spectroscopy: A systematic review and meta-analysis

1H-Magnetic Resonance Spectroscopy (MRS) is a non-invasive technique that can be used to quantify the concentrations of metabolites in the brain in vivo. MRS findings in the context of autism are inconsistent and conflicting. We performed a systematic review and meta-analysis of MRS studies measuring glutamate and gamma-aminobutyric acid (GABA), as well as brain metabolites involved in energy metabolism (glutamine, creatine), neural and glial integrity (e.g. n-acetyl aspartate (NAA), choline, myo-inositol) and oxidative stress (glutathione) in autism cohorts. Data were extracted and grouped by metabolite, brain region and several other factors before calculation of standardised effect sizes. Overall, we find significantly lower concentrations of GABA and NAA in autism, indicative of disruptions to the balance between excitation/inhibition within brain circuits, as well as neural integrity. Further analysis found these alterations are most pronounced in autistic children and in limbic brain regions relevant to autism phenotypes. Additionally, we show how study outcome varies due to demographic and methodological factors , emphasising the importance of conforming with standardised consensus study designs and transparent reporting.

Central Causation of Autism/ASDs via Excessive [Ca2+]i Impacting Six Mechanisms Controlling Synaptogenesis during the Perinatal Period: The Role of Electromagnetic Fields and Chemicals and the NO/ONOO(-) Cycle, as Well as Specific Mutations

The roles of perinatal development, intracellular calcium [Ca2+]i, and synaptogenesis disruption are not novel in the autism/ASD literature. The focus on six mechanisms controlling synaptogenesis, each regulated by [Ca2+]i, and each aberrant in ASDs is novel. The model presented here predicts that autism epidemic causation involves central roles of both electromagnetic fields (EMFs) and chemicals. EMFs act via voltage-gated calcium channel (VGCC) activation and [Ca2+]i elevation. A total of 15 autism-implicated chemical classes each act to produce [Ca2+]i elevation, 12 acting via NMDA receptor activation, and three acting via other mechanisms. The chronic nature of ASDs is explained via NO/ONOO(-) vicious cycle elevation and MeCP2 epigenetic dysfunction. Genetic causation often also involves [Ca2+]i elevation or other impacts on synaptogenesis. The literature examining each of these steps is systematically examined and found to be consistent with predictions. Approaches that may be sed for ASD prevention or treatment are discussed in connection with this special issue: The current situation and prospects for children with ASDs. Such approaches include EMF, chemical avoidance, and using nutrients and other agents to raise the levels of Nrf2. An enriched environment, vitamin D, magnesium, and omega-3s in fish oil may also be helpful.

Apigenin Alleviates Autistic-like Stereotyped Repetitive Behaviors and Mitigates Brain Oxidative Stress in Mice

Studying the involvement of nicotinic acetylcholine receptors (nAChRs), specifically α7-nAChRs, in neuropsychiatric brain disorders such as autism spectrum disorder (ASD) has gained a growing interest. The flavonoid apigenin (APG) has been confirmed in its pharmacological action as a positive allosteric modulator of α7-nAChRs. However, there is no research describing the pharmacological potential of APG in ASD. The aim of this study was to evaluate the effects of the subchronic systemic treatment of APG (10-30 mg/kg) on ASD-like repetitive and compulsive-like behaviors and oxidative stress status in the hippocampus and cerebellum in BTBR mice, utilizing the reference drug aripiprazole (ARP, 1 mg/kg, i.p.). BTBR mice pretreated with APG (20 mg/kg) or ARP (1 mg/g, i.p.) displayed significant improvements in the marble-burying test (MBT), cotton-shredding test (CST), and self-grooming test (SGT) (all p < 0.05). However, a lower dose of APG (10 mg/kg, i.p.) failed to modulate behaviors in the MBT or SGT, but significantly attenuated the increased shredding behaviors in the CST of tested mice. Moreover, APG (10-30 mg/kg, i.p.) and ARP (1 mg/kg) moderated the disturbed levels of oxidative stress by mitigating the levels of catalase (CAT) and superoxide dismutase (SOD) in the hippocampus and cerebellum of treated BTBR mice. In patch clamp studies in hippocampal slices, the potency of choline (a selective agonist of α7-nAChRs) in activating fast inward currents was significantly potentiated following incubation with APG. Moreover, APG markedly potentiated the choline-induced enhancement of spontaneous inhibitory postsynaptic currents. The observed results propose the potential therapeutic use of APG in the management of ASD. However, further preclinical investigations in additional models and different rodent species are still needed to confirm the potential relevance of the therapeutic use of APG in ASD.

Brain glutathione and GABA+ levels in autistic children

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by social communication challenges and repetitive behaviors. Altered neurometabolite levels, including glutathione (GSH) and gamma-aminobutyric acid (GABA), have been proposed as potential contributors to the biology underlying ASD. This study investigated whether cerebral GSH or GABA levels differ between a cohort of children aged 8-12 years with ASD (n = 52) and typically developing children (TDC, n = 49). A comprehensive analysis of GSH and GABA levels in multiple brain regions, including the primary motor cortex (SM1), thalamus (Thal), medial prefrontal cortex (mPFC), and supplementary motor area (SMA), was conducted using single-voxel HERMES MR spectroscopy at 3T. The results revealed no significant differences in cerebral GSH or GABA levels between the ASD and TDC groups across all examined regions. These findings suggest that the concentrations of GSH (an important antioxidant and neuromodulator) and GABA (a major inhibitory neurotransmitter) do not exhibit marked alterations in children with ASD compared to TDC. A statistically significant positive correlation was observed between GABA levels in the SM1 and Thal regions with ADHD inattention scores. No significant correlation was found between metabolite levels and hyper/impulsive scores of ADHD, measures of core ASD symptoms (ADOS-2, SRS-P) or adaptive behavior (ABAS-2). While both GSH and GABA have been implicated in various neurological disorders, the current study provides valuable insights into the specific context of ASD and highlights the need for further research to explore other neurochemical alterations that may contribute to the pathophysiology of this complex disorder.

The effect of inhibiting hindbrain A2 noradrenergic neurons by 6-Hydroxydopamine on lipopolysaccharide-treated male rats autistic animal model

Autism spectrum disorder (ASD) is a complex neurodevelopmental illness that often emerges in early childhood. The incidence of ASD has shown a notable rise in recent years. ASD is defined by deficits in social communication, and presence of rigid and repetitive behaviors and interests. The underlying mechanisms of ASD remain elusive. Multiple studies have documented the presence of neuroinflammation and increased levels of inflammatory cytokines, specifically, IL-6, TNF, and NF-κB, in various brain regions, including the prefrontal cortex (PFC) and hippocampus in individuals with ASD. Noradrenergic neurons play a crucial role in brain development and the regulation of motor, behavioral, and memory functions. This study sought to examine the impact of intracerebroventricular (icv.) injection of the neurotoxin, 6-hydroxydopamine (6-OHDA), in the caudal dorsal vagal complex A2 neurons on various neuroinflammatory pathways at the hippocampus and PFC in valproic acid (VPA) autistic animal model. This was done in conjunction with an intraperitoneal (i.p.) injection of Lipopolysaccharides (LPS) in animal models with VPA-induced autism. We specifically examined the impact of the caudal fourth ventricle 6-OHDA icv. injection and LPS (i.p.) injection on self-grooming behavior. We measured the mRNA expression of IL-6, TNF-a, and NF-κB using qRT-PCR, and the protein expression of COX-2, GPX-1, p-AMPK, and AMPK using western blot analysis. The self-grooming activity was considerably higher in the combined treatment group (6-OHDA icv. + LPS i.p.) compared to the control group. A substantial increase observed in the expression of IL-6, TNF-α, and NF-κB genes in the PFC of the treatment group that received icv. Administration of 6-OHDA, compared to the control group. The VPA-autism rats that received the combo treatment exhibited a slight increase in the expression level of NF-κB gene in the hippocampus, compared to the control group. At the PFC, we noticed a substantial drop in the expression of the antioxidant protein GPX-1 in the group that received the combo treatment compared to the control group. Our data investigates a novel aspect that the 6-OHDA-induced inhibition of hindbrain A2 neurons could be influencing the neuroinflammatory pathways in the PFC and hippocampus of autistic animal models.

Worsening of imiquimod-induced psoriasiform inflammation in mice by environmental pollutant, di-(2-ethylhexyl) phthalate through dysregulation in IL-17A and Nrf2/iNOS signaling in peripheral myeloid and CD4 + T cells

Psoriasis is a devastating autoimmune illness resulting from excessive keratinocyte growth and leukocyte infiltration into the dermis/epidermis. In the pathogenesis of psoriasis, different immune cells such as myeloid cells and CD4 + T cells play a key role. Th17/Th1 immune responses and oxidant-antioxidant responses are critical in regulation of psoriatic inflammation. Di-2-ethylhexyl phthalate (DEHP) is one of the well-known plasticizers and has widespread use worldwide. DEHP exposure through ingestion may produce harmful effects on the skin through systemic inflammation and oxidative stress, which may modify psoriatic inflammation. However, the effect of oral DEHP exposure on inflammatory cytokines and Nrf2/iNOS signaling in myeloid cells and CD4 + T cells in the context of psoriatic inflammation has not been investigated earlier. Therefore, this study explored the effect of DEHP on systemic inflammation in myeloid cells (IL-6, IL-17A, IL-23), Th17 (p-STAT3, IL-17A, IL-23R, TNF-α), Th1 (IFN-γ), Treg (Foxp3, IL-10), and Nrf2/iNOS signaling in imiquimod (IMQ)-induced mouse model of psoriasis-like inflammation. Our study showed increased Th17 signaling in imiquimod model which was further aggravated by DEHP exposure. Further, Nrf2 and iNOS signaling were also elevated in IMQ model where DEHP exposure further increased iNOS expression but did not modify the Nrf2 expression. Most importantly, IL-17A levels were also elevated in myeloid cells along with IL-6 which were further elevated by DEHP exposure. Overall, this study shows that IL-17A signaling is upregulated, whereas there is deficiency of Nrf2/HO-1 signaling by DEHP exposure in mice with psoriasiform inflammation. These observations suggest that DEHP aggravates IL-17A-mediated signaling both in CD4 + T cells as well as myeloid cells which is linked to exacerbation of IMQ-induced psoriatic inflammation in mice. Strategies that counteract the effect of DEHP exposure in the context of psoriatic inflammation through downregulation of IL-17A may be fruitful.

Brain Glutathione and GABA+ levels in autistic children

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by social communication challenges and repetitive behaviors. Altered neurometabolite levels, including glutathione (GSH) and gamma-aminobutyric acid (GABA), have been proposed as potential contributors to the biology underlying ASD. This study investigated whether cerebral GSH or GABA levels differ between a large cohort of children aged 8-12 years with ASD (n=52) and typically developing children (TDC, n=49). A comprehensive analysis of GSH and GABA levels in multiple brain regions, including the primary motor cortex (SM1), thalamus (Thal), medial prefrontal cortex (mPFC), and supplementary motor area (SMA), was conducted using single-voxel HERMES MR spectroscopy at 3T. The results revealed no significant differences in cerebral GSH or GABA levels between the ASD and TDC groups across all examined regions. These findings suggest that the concentrations of GSH (an important antioxidant and neuromodulator) and GABA (a major inhibitory neurotransmitter) do not exhibit marked alterations in children with ASD compared to TDC. A statistically significant positive correlation was observed between GABA levels in the SM1 and Thal regions with ADHD inattention scores. No significant correlation was found between metabolite levels and hyper/impulsive scores of ADHD, measures of core ASD symptoms (ADOS-2, SRS-P) or adaptive behavior (ABAS-2). While both GSH and GABA have been implicated in various neurological disorders, the current study provides valuable insights into the specific context of ASD and highlights the need for further research to explore other neurochemical alterations that may contribute to the pathophysiology of this complex disorder.

Exposure to Methylmercury at Juvenile Stage Worsens Autism-like Symptoms in Adult BTBR T+tf/J Mice Due to Lack of Nuclear Factor Erythroid 2-Related Factor 2 Signaling Upregulation in Periphery and Brain

Autism spectrum disorder (ASD) is a multifaceted developmental condition that first appears in infancy. The condition is characterized by recurrent patterns in behavior and impairments in social and vocalization abilities. Methylmercury is a toxic environmental pollutant, and its derivatives are the major source of organic mercury to human beings. Inorganic mercury, which is released from a variety of pollutants into oceans, rivers, and streams, is transformed into methylmercury by bacteria and plankton in the water, which later builds up in fish and shellfish, and then enters humans through the consumption of fish and shellfish and increases the risk of developing ASD by disturbing the oxidant-antioxidant balance. However, there has been no prior research to determine the effect of juvenile exposure of methylmercury chloride on adult BTBR mice. Therefore, the current study evaluated the effect of methylmercury chloride administered during the juvenile stage on autism-like behavior (three-chambered sociability, marble burying, self-grooming tests) and oxidant-antioxidant balance (specifically Nrf2, HO-1, SOD-1, NF-kB, iNOS, MPO, and 3-nitrotyrosine) in the peripheral neutrophils and cortex of adult BTBR and C57BL/6 (B6) mice. Our results show that exposure to methylmercury chloride at a juvenile stage results in autism-like symptoms in adult BTBR mice which are related to a lack of upregulation of the Nrf2 signaling pathway as demonstrated by no significant changes in the expression of Nrf2, HO-1, and SOD-1 in the periphery and cortex. On the other hand, methylmercury chloride administration at a juvenile stage increased oxidative inflammation as depicted by a significant increase in the levels of NF-kB, iNOS, MPO, and 3-nitrotyrosine in the periphery and cortex of adult BTBR mice. This study suggests that juvenile exposure to methylmercury chloride contributes to the worsening of autism-like behavior in adult BTBR mice through the disruption of the oxidant-antioxidant balance in the peripheral compartment and CNS. Strategies that elevate Nrf2 signaling may be useful to counteract toxicant-mediated worsening of ASD and may improve quality of life.

Preventive effect of quercetin-Loaded nanophytosome against autistic-like damage in maternal separation model: The possible role of Caspase-3, Bax/Bcl-2 and Nrf2

The autism is an abnormality in the neuronal advance which starts before age 3 recognized by defective behaviors. This study aimed to make quercetin-loaded nanophytosomes (QNP) on behavioral deficits, cerebellar oxidative stress and apoptosis in an autistic-like model caused by maternal separation (MS). The newborn rats are randomly categorized into seven groups, including control, positive control, disease, and diseases treated with quercetin (10 and 40 mg/kg) and QNP (10 and 40 mg/kg). Pups exposed to MS for 3 h per day from postnatal days (PND) 1-9 showed behavioral impairment in adult rats compared to control group. The oral administration of quercetin and QNP was constantly started after the lactation period (21 postnatal days) for three weeks. Autistic-like behaviors, antioxidant parameters, and Nrf2, Bax/Bcl-2, and Caspase-3 expressions were surveyed in the cerebellum. Quercetin (40 mg/kg) treated improved some behavioral disorders. Also, the improvement of oxidative stress parameters, Nrf2 and apoptotic factors gene expression was observed in the cerebellum of quercetin (40 mg/kg) treated (p < 0.01). QNP treatment (10 and 40 mg/kg) significantly ameliorated anxiety-like behaviors, line crossing, and grooming index (p < 0.001), lipid peroxidation (p < 0.001), and increased catalase (CAT) (p < 0.001), superoxide dismutase (SOD) (p < 0.001), glutathione peroxidase (GPx) (p < 0.001) activity, and glutathione (GSH) levels (p < 0.05). Moreover, QNP significantly reduced Caspase-3 and Bax expression (p < 0.001), but increased Bcl-2, and Nrf2 expressions (p < 0.001). These findings indicated that QNP due to its high bioavailability was more effective than quercetin can be reduced autistic-like behavior, oxidative and apoptotic damages in the model of MS rats.

Oxidative stress and neuroimmune proteins in a mouse model of autism

Oxidative stress including decreased antioxidant enzyme activities, elevated lipid peroxidation, and accumulation of advanced glycation end products in the blood from children with autism spectrum disorders (ASD) has been reported. The mechanisms affecting the development of ASD remain unclear; however, toxic environmental exposures leading to oxidative stress have been proposed to play a significant role. The BTBRT+Itpr3tf/J (BTBR) strain provides a model to investigate the markers of oxidation in a mouse strain exhibiting ASD-like behavioral phenotypes. In the present study, we investigated the level of oxidative stress and its effects on immune cell populations, specifically oxidative stress affecting surface thiols (R-SH), intracellular glutathione (iGSH), and expression of brain biomarkers that may contribute to the development of the ASD-like phenotypes that have been observed and reported in BTBR mice. Lower levels of cell surface R-SH were detected on multiple immune cell subpopulations from blood, spleens, and lymph nodes and for sera R-SH levels of BTBR mice compared to C57BL/6 J (B6) mice. The iGSH levels of immune cell populations were also lower in the BTBR mice. Elevated protein expression of GATA3, TGM2, AhR, EPHX2, TSLP, PTEN, IRE1α, GDF15, and metallothionein in BTBR mice is supportive of an increased level of oxidative stress in BTBR mice and may underpin the pro-inflammatory immune state that has been reported in the BTBR strain. Results of a decreased antioxidant system suggest an important oxidative stress role in the development of the BTBR ASD-like phenotype.

Impairments in operant probabilistic reversal learning in BTBR T+tf/J male and female mice

Autism spectrum disorder (ASD) presents with two core symptoms, impairments in social communication and the presence of restricted, repetitive behaviors (RRBs). RRBs are commonly linked to a lack of behavioral flexibility, having a significant negative impact on daily functioning for ASD individuals and their caregivers. Commonly utilized tests of behavioral flexibility employ a traditional deterministic reward approach where choices are either correct or incorrect throughout testing. The incorporation of an 80 %/20 % probabilistic reversal learning paradigm allows for the examination of flexible behavior in the face of variable outcomes, a more ecologically relevant approach. In this task, one specific choice is reinforced on 80 % of trials and the opposite or incorrect choice is reinforced on 20% of trials. Upon successful discrimination learning, the reward contingencies are switched so that the correct choice is now reinforced 20% of trials and the incorrect choice reinforced 80 % of trials, making it the new optimal choice. This translational task has been previously validated in ASD individuals and animal models of ASD, including the BTBR T + tf/J strain. Our lab and others have demonstrated that male BTBR T + tf/J mice have higher expression of lower order RRBs and display deficits in spatial probabilistic reversal learning tasks using a T-maze apparatus. Instead, female BTBR mice do not express the same lower order RRBs and results are mixed on whether females demonstrate similar probabilistic reversal learning deficits in a T-maze. Therefore, the purpose of this study was to assess the validity of using operant chambers to examine BTBR mouse performance on an 80 %/20 % probabilistic reversal learning task and to also examine the sex-specific differences in reversal learning performance in both mouse strains. Results show that BTBR mice, irrespective of sex, were impaired on the reversal learning, requiring more days and trials to reach reversal criterion compared to C57BL/6J mice. These results parallel previous strain findings in the spatial dependent T-maze task in male mice. Further error analysis showed that the impaired behavioral flexibility was due to elevated regressive errors and lose-shift probabilities. BTBR mice have more difficulty maintaining new choice patterns compared to C57BL/6J mice, which supports findings utilizing a spatial T-maze task. Together, these findings further support the use of the BTBR mouse as preclinical models of ASD due to their validity as an ASD model.

Effects of Salvia miltiorrhiza active compounds on placenta-mediated pregnancy complications

Placenta-mediated pregnancy complications (PMPCs), including preeclampsia (PE), fetal growth restriction (FGR), and recurrent spontaneous abortion (RSA), occur in approximately 5% of pregnancies and are caused by abnormal placenta development. The development of effective therapies for PMPCs is still challenging due to the complicated pathogenesis, such as disrupted vascular homeostasis and subsequent abnormal placentation. Synthetic drugs have been recommended for treating PMPCs; however, they tend to cause adverse reactions in the mother and fetus. Salvia miltiorrhiza (S. miltiorrhiza) has potential effects on PMPCs owing to its advantages in treating cardiovascular disorders. S. miltiorrhiza and its active compounds could attenuate the symptoms of PMPCs through anticoagulation, vasodilation, antioxidation, and endothelial protection. Thus, in this review, we summarize the literature and provide comprehensive insights on S. miltiorrhiza and its phytochemical constituents, pharmacological activities, and on PMPCs, which would be valuable to explore promising drugs.

Protein kinase C beta relieves autism-like behavior in EN2 knockout mice via upregulation of the FTO/PGC-1α/UCP1 axis

Increasing evidence suggests that disruption of neuron activity contributes to the autistic phenotype. Thus, we aimed in this study to explore the role of protein kinase C beta (PKCβ) in the regulation of neuron activity in an autism model. The expression of PKCβ in the microarray data of autism animal models was obtained from the Gene Expression Omnibus database. Then, mice with autism-like behavior were prepared in EN2 knockout (^-/- ) mice. The interaction between PKCβ on fat mass and obesity-associated protein (FTO) as well as between PGC-1α and uncoupling protein 1 (UCP1) were characterized. The effect of FTO on the N⁶ -methyladenosine (m6A) modification level of proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) was assayed. Following transfection of overexpressed PKCβ and/or silenced UCP1, effects of PKCβ and UCP1 in autism-like behaviors in EN2^-/- mice were analyzed. Results showed that PKCβ was downregulated in EN2^-/- mouse brain tissues or neurons. PKCβ promoted the expression and stability of FTO, which downregulated the m6A modification level of PGC-1α to promote its expression. Moreover, PGC-1α positively targeted the expression of UCP1. PKCβ knockdown enhanced sociability and spatial exploration ability, and reduced neuron apoptosis in EN2^-/- mouse models of autism, which was reversed by UCP1 overexpression. Collectively, PKCβ overexpression leads to activation of the FTO/m6A/PGC-1α/UCP1 axis, thus inhibiting neuron apoptosis and providing neuroprotection in mice with autism-like behavior.

Untargeted Metabolomic Analysis Reveals the Metabolic Disturbances and Exacerbation of Oxidative Stress in the Cerebral Cortex of a BTBR Mouse Model of Autism

The etiology and pathology of autism spectrum disorders (ASDs) are still poorly understood, which largely limit the treatment and diagnosis of ASDs. Emerging evidence supports that abnormal metabolites in the cerebral cortex of a BTBR mouse model of autism are involved in the pathogenesis of autism. However, systematic study on global metabolites in the cerebral cortex of BTBR mice has not been conducted. The current study aims to characterize metabolic changes in the cerebral cortex of BTBR mice by using an untargeted metabolomic approach based on UPLC-Q-TOF/MS. C57BL/6 J mice were used as a control group. A total of 14 differential metabolites were identified. Compared with the control group, the intensities of PI(16:0/22:5(4Z,7Z,10Z,13Z,16Z)), PC(22:6(4Z,7Z,10Z,13Z,16Z,19Z)/18:1(9Z)), PA(16:0/18:1(11Z)), 17-beta-estradiol-3-glucuronide, and N6,N6,N6-trimethyl-L-lysine decreased significantly (p < 0.01) and the intensities of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, LysoPC(20:4(5Z,8Z,11Z,14Z)/0:0), adenosine monophosphate, adenosine-5'-phosphosulfate, LacCer(d18:1/12:0),3-dehydro-L-gulonate, N-(1-deoxy-1-fructosyl)tryptophan, homovanillic acid, and LPA(0:0/18:1(9Z)) increased significantly (p < 0.01) in the BTBR group. These changes in metabolites were closely related to perturbations in lipid metabolism, energy metabolism, purine metabolism, sulfur metabolism, amino acid metabolism, and carnitine biosynthesis. Notably, exacerbation of the oxidative stress response caused by differential prooxidant metabolites led to alteration of antioxidative systems in the cerebral cortex and resulted in mitochondrial dysfunction, further leading to abnormal energy metabolism as an etiological mechanism of autism. A central role of abnormal metabolites in neurological functions associated with behavioral outcomes and disturbance of sulfur metabolism and carnitine biosynthesis were found in the cerebral cortex of BTBR mice, which helped increase our understanding for exploring the pathological mechanism of autism.

An insight into sex-specific neurotoxicity and molecular mechanisms of DEHP: A critical review

Di-2-Ethylhexyl Phthalate (DEHP) is often used as an additive in polyvinyl chloride (PVC) to give plastics flexibility, which makes DEHP widely used in food packaging, daily necessities, medical equipment, and other products. However, due to the unstable combination of DEHP and polymer, it will migrate to the environment in the materials and eventually contact the human body. It has been recorded that low-dose DEHP will increase neurotoxicity in the nervous system, and the human health effects of DEHP have been paid attention to because of the extensive exposure to DEHP and its high absorption during brain development. In this study, we review the evidence that DEHP exposure is associated with neurodevelopmental abnormalities and neurological diseases based on human epidemiological and animal behavioral studies. Besides, we also summarized the oxidative damage, apoptosis, and signal transduction disorder related to neurobehavioral abnormalities and nerve injury, and described the potential mechanisms of neurotoxicity caused by DEHP. Overall, we found exposure to DEHP during the critical developmental period will increase the risk of neurobehavioral abnormalities, depression, and autism spectrum disorders. This effect is sex-specific and will continue to adulthood and even have an intergenerational effect. However, the research results on the sex-dependence of DEHP neurotoxicity are inconsistent, and there is a lack of systematic mechanisms research as theoretical support. Future investigations need to be carried out in a large-scale population and model organisms to produce more consistent and convincing results. And we emphasize the importance of mechanism research, which can enhance the understanding of the environmental and human health risks of DEHP exposure.

Unique Features of the Immune Response in BTBR Mice

Inflammation plays a considerable role in the pathogenesis of many diseases, including neurodegenerative and psychiatric ones. Elucidation of the specific features of an immune response in various model organisms, and studying the relation of these features with the behavioral phenotype, can improve the understanding of the molecular mechanisms of many psychopathologies. In this work, we focused on BTBR mice, which have a pronounced autism-like behavioral phenotype, elevated levels of oxidative-stress markers, an abnormal immune response, several structural aberrations in the brain, and other unique traits. Although some studies have already shown an abnormal immune response in BTBR mice, the existing literature data are still fragmentary. Here, we used inflammation induced by low-dose lipopolysaccharide, polyinosinic:polycytidylic acid, or their combinations, in mice of strains BTBR T+Itpr3tf/J (BTBR) and C57BL6/J. Peripheral inflammation was assessed by means of a complete blood count, lymphocyte immunophenotyping, and expression levels of cytokines in the spleen. Neuroinflammation was evaluated in the hypothalamus and prefrontal cortex by analysis of mRNA levels of proinflammatory cytokines (tumor necrosis factor, Tnf), (interleukin-1 beta, Il-1β), and (interleukin-6, Il-6) and of markers of microglia activation (allograft inflammatory factor 1, Aif1) and astroglia activation (glial fibrillary acidic protein, Gfap). We found that in both strains of mice, the most severe inflammatory response was caused by the administration of polyinosinic:polycytidylic acid, whereas the combined administration of the two toll-like receptor (TLR) agonists did not enhance this response. Nonetheless, BTBR mice showed a more pronounced response to low-dose lipopolysaccharide, an altered lymphocytosis ratio due to an increase in the number of CD4+ lymphocytes, and high expression of markers of activated microglia (Aif1) and astroglia (Gfap) in various brain regions as compared to C57BL6/J mice. Thus, in addition to research into mechanisms of autism-like behavior, BTBR mice can be used as a model of TLR3/TLR4-induced neuroinflammation and a unique model for finding and evaluating the effectiveness of various TLR antagonists aimed at reducing neuroinflammation.

Deficits in Cerebellum-Dependent Learning and Cerebellar Morphology in Male and Female BTBR Autism Model Mice

Recently, there has been increased interest in the role of the cerebellum in autism spectrum disorder (ASD). To better understand the pathophysiological role of the cerebellum in ASD, it is necessary to have a variety of mouse models that have face validity for cerebellar disruption in humans. Here, we add to the literature on the cerebellum in mouse models of autism with the characterization of the cerebellum in the idiopathic BTBR T + Itpr3tf/J (BTBR) inbred mouse strain, which has behavioral phenotypes that are reminiscent of ASD in patients. When we examined both male and female BTBR mice in comparison to C57BL/6J (C57) controls, we noted that both sexes of BTBR mice showed motor coordination deficits characteristic of cerebellar dysfunction, but only the male mice showed differences in delay eyeblink conditioning, a cerebellum-dependent learning task that is known to be disrupted in ASD patients. Both male and female BTBR mice showed considerable expansion of, and abnormal foliation in, the cerebellum vermis—including a significant expansion of specific lobules in the anterior cerebellum. In addition, we found a slight but significant decrease in Purkinje cell density in both male and female BTBR mice, irrespective of the lobule. Finally, there was a marked reduction of Purkinje cell dendritic spine density in both male and female BTBR mice. These findings suggest that, for the most part, the BTBR mouse model phenocopies many of the characteristics of the subpopulation of ASD patients that have a hypertrophic cerebellum. We discuss the significance of strain differences in the cerebellum as well as the importance of this first effort to identify both similarities and differences between male and female BTBR mice with regard to the cerebellum.

The live biotherapeutic Blautia stercoris MRx0006 attenuates social deficits, repetitive behaviour, and anxiety-like behaviour in a mouse model relevant to autism

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by deficits in social behaviour, increased repetitive behaviour, anxiety and gastrointestinal symptoms. The aetiology of ASD is complex and involves an interplay of genetic and environmental factors. Emerging pre-clinical and clinical studies have documented a potential role for the gut microbiome in ASD, and consequently, the microbiota represents a potential target in the development of novel therapeutics for this neurodevelopmental disorder. In this study, we investigate the efficacy of the live biotherapeutic strain, Blautia stercoris MRx0006, in attenuating some of the behavioural deficits in the autism-relevant, genetic mouse model, BTBR T+ Itpr3tf/J (BTBR). We demonstrate that daily oral administration with MRx0006 attenuates social deficits while also decreasing repetitive and anxiety-like behaviour. MRx0006 administration increases the gene expression of oxytocin and its receptor in hypothalamic cells in vitro and increases the expression of hypothalamic arginine vasopressin and oxytocin mRNA in BTBR mice. Additionally at the microbiome level, we observed that MRx0006 administration decreases the abundance of Alistipes putredinis, and modulates the faecal microbial metabolite profile. This alteration in the metabolite profile possibly underlies the observed increase in expression of oxytocin, arginine vasopressin and its receptors, and the consequent improvements in behavioural outcomes. Taken together, these findings suggest that the live biotherapeutic MRx0006 may represent a viable and efficacious treatment option for the management of physiological and behavioural deficits associated with ASD.

Protective role of IGF-1 and GLP-1 signaling activation in neurological dysfunctions

Insulin-like growth factor-1 (IGF-1), a pleiotropic polypeptide, plays an essential role in CNS development and maturation. Glucagon-like peptide-1 (GLP-1) is an endogenous incretin hormone that regulates blood glucose levels and fatty acid oxidation in the brain. GLP-1 also exhibits similar functions and growth factor-like properties to IGF-1, which is likely how it exerts its neuroprotective effects. Recent preclinical and clinical evidence indicate that IGF-1 and GLP-1, apart from regulating growth and development, prevent neuronal death mediated by amyloidogenesis, cerebral glucose deprivation, neuroinflammation and apoptosis through modulation of PI3/Akt kinase, mammalian target of rapamycin (mTOR) and mitogen-activated protein kinase (MAPK/ERK). IGF-1 resistance and GLP-1 deficiency impair protective cellular signaling mechanisms, contributing to the progression of neurodegenerative diseases. Over the past decades, IGF-1 and GLP-1 have emerged as an essential component of the neuronal system and as potential therapeutic targets for several neurodegenerative and neuropsychiatric dysfunctions. There is substantial evidence that IGF-1 and GLP-1 analogues penetrate the blood-brain barrier (BBB) and exhibit neuroprotective functions, including synaptic formation, neuronal plasticity, protein synthesis, and autophagy. Conclusively, this review represents the therapeutic potential of IGF-1 and GLP-1 signaling target activators in ameliorating neurological disorders.

Neuroprotective effect of the standardised extract of Bacopa monnieri (BacoMind) in valproic acid model of autism spectrum disorder in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bacopa monnieri (BM) is commonly employed in the Indian traditional system of medicines, i.e. Ayurveda as a memory booster, antioxidant, anti-inflammatory, antipyretic, analgesic, sedative and anti-epileptic for decades.

AIM OF THE STUDY

To evaluate the neuroprotective effect of Bacopa monnieri (BM) in experimental model of autism spectrum disorder (ASD) in Wistar rats and explore its mechanism of action.

MATERIALS AND METHODS

BacoMind, was evaluated for its neuroprotective effect in valproic acid (VPA) model of ASD. For in-vivo study, the pregnant female Wistar rats were divided in two groups; normal control (NC) and VPA group who received single dose of normal saline (0.9%) or 600 mg/kg dose of VPA respectively on gestation day (G.D) 12.5. After the birth, all pups were segregated according to the sex. All the male pups from the dams were divided into six groups: Group 1 (NC, treated with only 0.9% normal saline, group 2 (VPA, treated 600 mg/kg on G.D12.5 and normal saline from post natal day (PND) 23 to 43), group 3 (risperidone 2.5 mg/kg, PND 23 to 43) and groups 4, 5 and 6 (BM 20, 40, 80 mg/kg, PND 23 to 43). All experimental groups were subjected to batteries of behavior parameters (three chamber sociability test, Morris Water Maze, elevated plus maze, open field and rota rod test), biochemical parameters such as oxidative stress (GSH, SOD, Catalase, MDA), inflammatory cytokines (Il-1β, IL-6, IL-10, TNF-α), histopathological examination (cresyl violet staining) of hippocampus (HC) and prefrontal cortex (PFC) regions. Further, the mRNA as well as protein expression of AMPA receptor was evaluated using RT-PCR and western blot respectively to study the mechanism of neuroprotective effect of BM. The in-silico analysis followed evaluating the binding profile of different constituents of BacoMind with AMPA receptor.

RESULTS

The results of the in-vivo study indicated BM at 80 mg/kg ameliorated abnormal behavioral paradigms such as social deficits, repetitive behavior, learning and memory impairments, and motor coordination exhibited by the VPA model of ASD in rats. Furthermore, BM was found to have a significant anti-oxidant (increasing GSH, SOD, and catalase and decreasing MDA levels) and anti-inflammatory properties (decreasing IL-1β, 6, TNF- α). The histopathological score was also found to be significantly improved by BM in a dose dependent manner in both HC and PFC. In addition to this, the up-regulated mRNA as well as protein expression of AMPA receptor was significantly reduced by 80 mg/kg dose of BM in both HC and PFC. Further, the in-silico analysis of different constituents of BacoMind with AMPA receptor demonstrated that luteolin and apigenin showed good binding to both the competitive antagonist binding site, non-competitive antagonist binding site and allosteric modulator site while Bacosaponin C showed good binding to the non-competitive antagonist binding site.

CONCLUSION

The present study concluded that BM can be a potential candidate for ameliorating the ASD symptoms in rats and acts via modulating the up-regulated AMPA receptor expression.

Renoprotective and hepatoprotective activity of Lepidium draba L. extracts on oxymetholone-induced oxidative stress in rat

Misuse and abuse of anabolic androgenic steroids (AAS) such as oxymetholone (OM) cause side effects such as male infertility, cardiovascular disorders, musculoskeletal, and hepato-renal dysfunctions in athletes. The aim of this study was to evaluate the protective effects of Lepidium draba L. (L. draba) extract on OM-induced hepato-renal toxicity. Thirty adult male Wistar rats into six groups (n = 5) were randomly divided as follows: control (normal saline), OM (5 mg/kg/day), L. draba-treated (100, 200, and 400 mg/kg/d) plus 5 mg/kg/day OM, and L. draba (400 mg/kg/d) groups. Normal saline, OM and L. draba extract were orally administered for 30 days. On day 31 of the study, hepatic and renal biochemical parameters were measured. Serum cytokines (IL-1β, IL-10, IL-6) tumor necrosis factor- α (TNF-α) and nitric oxide, levels alongside catalase, glutathione peroxidase, and superoxide dismutase activity were evaluated. Also, changes in liver and kidney histopathology were evaluated. Finally, the anti-oxidant properties of the extract were determined. The results of this study showed that in the groups treated with the L. draba extract, hepatic-renal biochemical parameters improved and also the level of nitric oxide and inflammatory cytokines decreased and the activity of anti-oxidant enzymes increased compared with the OM group. These findings revealed that L. draba, due to its high anti-oxidant properties and high content of polyphenols (especially flavonoids), can improve OM-induced hepato-renal oxidative damages. PRACTICAL APPLICATIONS: L. draba due to its remarkable anti-oxidant and anti-inflammatory properties can protects the kidney and liver injuries against oxymetholone. These features are attributed to the presence of phenolic and flavonoid components. This fidings would be helpful to desgin new therapeutic agents for treating and preventing liver/kidney injuries.

Altered Blood Brain Barrier Permeability and Oxidative Stress in Cntnap2 Knockout Rat Model

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by three core symptoms, specifically impaired social behavior, stereotypic/repetitive behaviors, and sensory/communication deficits. Although the exact pathophysiology of ASD is still unknown, host genetics, oxidative stress, and compromised blood brain barrier (BBB) have been implicated in predisposition to ASD. With regards to genetics, mutations in the genes such as CNTNAP2 have been associated with increased susceptibility of developing ASD. Although some studies observed conflicting results suggesting no association of CNTNAP2 with ASD, other investigations correlated this gene with autism. In addition, CNTNAP2 mediated signaling is generally considered to play a role in neurological disorders due to its critical role in neurodevelopment, neurotransmission, and synaptic plasticity. In this investigation, we studied BBB integrity and oxidative stress in Cntnap2^−/− rats. We observed that the BBB permeability was significantly increased in Cntnap2^−/− rats compared to littermate wild-type (WT) animals as determined by FITC-dextran and Evans blue assay. High levels of thiobarbituric acid reactive substances and lower amounts of reduced glutathione were observed in brain homogenates of Cntnap2^−/− rats, suggesting oxidative stress. Brain sections from Cntnap2^−/− rats showed intense inducible nitric oxide synthase immunostaining, which was undetectable in WT animals. Quantification of nitric oxide in brain homogenates revealed significantly high levels in Cntnap2^−/− rats compared to the control group. As increased permeability of the BBB and oxidative stress have been observed in ASD individuals, our results suggest that Cntnap2^−/− rats have a high construct and face validity and can be explored to develop effective therapeutic modalities.

Repetitive Restricted Behaviors in Autism Spectrum Disorder: From Mechanism to Development of Therapeutics

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by deficits in social communication, social interaction, and repetitive restricted behaviors (RRBs). It is usually detected in early childhood. RRBs are behavioral patterns characterized by repetition, inflexibility, invariance, inappropriateness, and frequent lack of obvious function or specific purpose. To date, the classification of RRBs is contentious. Understanding the potential mechanisms of RRBs in children with ASD, such as neural connectivity disorders and abnormal immune functions, will contribute to finding new therapeutic targets. Although behavioral intervention remains the most effective and safe strategy for RRBs treatment, some promising drugs and new treatment options (e.g., supplementary and cell therapy) have shown positive effects on RRBs in recent studies. In this review, we summarize the latest advances of RRBs from mechanistic to therapeutic approaches and propose potential future directions in research on RRBs.

Role of melatonin in autism spectrum disorders in a male murine transgenic model: Study in the prefrontal cortex

Autism spectrum disorders (ASDs) are a group of clinically heterogeneous neurodevelopmental disorders sharing common features related to impaired social and communication abilities in addition to stereotyped behaviors. ASD patients present encephalic morphological, physiological, and biomolecular alterations with low levels of melatonin due to alterations in its pathways. Therefore, even if ASDs have traditionally been framed as behavioral disorders, several lines of evidence are accumulating that ASDs are characterized by certain anatomical and physiological abnormalities, including oxidative stress and inflammation in peripheral biomarkers, but likewise present in human brain tissue also characterized by alterations in synaptic remodeling and neuromodulation. Melatonin has also protective and antioxidant properties, so we can therefore hypothesize that alterations in melatonin's pathways may be one of the causes of the symptomatology of autism. The aim of the present study was to analyze the beneficial effect induced by melatonin administration and its possible mechanism of action in a transgenic mouse model of autism, immediately after weaning. The male mice were daily treated per os with melatonin (10 mg/Kg/day) or vehicle for 8 weeks starting from the sixth week of life. The antioxidant modulation, the GABAergic/glutamatergic impairment, and the synaptic remodeling in the prefrontal cortex have been evaluated. Social and repetitive behaviors were also evaluated. The behavioral results showed no statistical evidences, instead the immunohistochemical results indicated the ability of melatonin to promote the activity of antioxidant system, the GABAergic/glutamatergic equilibrium, and the synaptic remodeling. The results show that melatonin may be a possible adjuvant therapeutic strategy in ASDs.

MicroRNA-Messenger RNA Regulatory Network Mediates Disrupted TH17 Cell Differentiation in Depression

Accumulating evidence indicates an important role for microRNA (miRNA)-messenger RNA (mRNA) regulatory networks in human depression. However, the mechanisms by which these networks act are complex and remain poorly understood. We used data mining to identify differentially expressed miRNAs from GSE81152 and GSE152267 datasets, and differentially expressed mRNAs were identified from the Netherlands Study of Depression and Anxiety, the GlaxoSmithKline-High-Throughput Disease-specific target Identification Program, and the Janssen-Brain Resource Company study. We constructed a miRNA-mRNA regulatory network based on differentially expressed mRNAs that intersected with target genes of differentially expressed miRNAs, and then performed bioinformatics analysis of the network. The key candidate genes were assessed in the prefrontal cortex of chronic social defeat stress (CSDS) depression mice by quantitative real-time polymerase chain reaction (qRT-PCR). Three differentially expressed miRNAs were commonly identified across the two datasets, and 119 intersecting differentially expressed mRNAs were identified. A miRNA-mRNA regulatory network including these three key differentially expressed miRNAs and 119 intersecting differentially expressed mRNAs was constructed. Functional analysis of the intersecting differentially expressed mRNAs revealed that an abnormal inflammatory response characterized by disturbed T-helper cell 17 (Th17) differentiation was the primary altered biological function. qRT-PCR validated the decreased expression of Th17 cell differentiation-related genes, including interleukin (IL)17A, IL21, IL22, and IL1β, and the increased expression of retinoic acid receptor-related orphan receptor gamma-t (RORγt) in CSDS mice, which showed significant depressive- and anxiety-like behaviors. This study indicates that an abnormal inflammatory response characterized by disturbed Th17 cell differentiation is the primary altered biological process in major depressive disorder. Our findings indicate possible biomarkers and treatment targets and provide novel clues to understand the pathogenesis of major depressive disorder.

Leaky gut biomarkers in casein- and gluten-rich diet fed rat model of autism

It is proposed that gluten- and casein-rich diets (GRD and CRD) can synergistically exacerbate dysbiosis as comorbidity in autism by worsening leaky gut that affects the brain through the gut–brain axis. In this study, 35 young male rats were divided into 7 groups, Group 1 serves as control; Group 2, clindamycin (CL)-treated; and Group 3, propionic acid (PPA)-induced rodent model of autism. These three groups were fed standard diet until the end of the experiment. Groups 4–7 are rats treated similarly with CL and PPA, then fed on CRD or GRD until the end of the experiment. Serum zonulin, glutathione (GSH), lipid peroxides, and gut microbial composition were measured in the seven studied groups. Data demonstrate the significant increase in serum zonulin as marker of leaky gut in the CL-treated groups fed on CRD or GRD. Lipid peroxides were significantly higher in the serum of GRD-fed rats compared to CRD-fed or normal diet-fed rats. GSH was much lower in CL-treated groups fed on CRD or GRD compared to PPA-treated rats fed on both diets. Both diets differentially affected the diversity of the gut microbiota. This study demonstrates that CRD and GRD exacerbates leaky gut, according to serum zonulin, which was used as marker for increased gut permeability.

Behavioral aspects and neurobiological properties underlying medical cannabis treatment in Shank3 mouse model of autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disease with a wide spectrum of manifestation. The core symptoms of ASD are persistent deficits in social communication, and restricted and repetitive patterns of behavior, interests, or activities. These are often accompanied by intellectual disabilities. At present, there is no designated effective treatment for the core symptoms and co-morbidities of ASD. Recently, interest is rising in medical cannabis as a treatment for ASD, with promising clinical data. However, there is a notable absence of basic pre-clinical research in this field. In this study, we investigate the behavioral and biochemical effects of long-term oral treatment with CBD-enriched medical cannabis oil in a human mutation-based Shank3 mouse model of ASD. Our findings show that this treatment alleviates anxiety and decreases repetitive grooming behavior by over 70% in treated mutant mice compared to non-treated mutant mice. Furthermore, we were able to uncover the involvement of CB1 receptor (CB1R) signaling in the Avidekel oil mechanism, alongside a mitigation of cerebrospinal fluid (CSF) glutamate concentrations. Subsequently, RNA sequencing (RNA seq) of cerebellar brain samples revealed changes in mRNA expression of several neurotransmission-related genes post-treatment. Finally, our results question the relevancy of CBD enrichment of medical cannabis for treating the core symptoms of ASD, and emphasize the importance of the THC component for alleviating deficits in repetitive and social behaviors in ASD.

Lead (Pb)-induced oxidative stress mediates sex-specific autistic-like behaviour in Drosophila melanogaster

Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder characterised by three main behavioural symptoms: abnormal social interaction, verbal and non-verbal communication impairments, and repetitive and restricted activities or interests. Even though the exact aetiology of ASD remains unknown, studies have shown a link between genetics and environmental pollutants. Heavy metal lead (Pb), the environmental pollutant, is associated with ASD. Pb may also exhibit sex-specific ASD behaviour, as has been demonstrated in the global human populations. Drosophila melanogaster as a model has been used in the present study to understand the involvement of Pb-induced oxidative stress in developing ASD behaviour. The larval feeding technique has been employed to administer different Pb concentrations (0.2-0.8 mM) to Oregon-R (ORR), superoxide dismutase (Sod), or catalase (Cat) antioxidants overexpressed or knockdown flies. Adult Drosophila (5-day old) were used for Pb content, biochemical, and behavioural analysis.Pb accumulated in the Drosophila brain induces oxidative stress and exhibited a human autistic-like behaviour such as reduced climbing, increased grooming, increased social spacing, and decreased learning and memory in a sex-specific manner.Pb-induced autistic-like behaviour was intensified in Sod or Cat-knockdown flies, whereas Sod or Cat-overexpressed flies overcome that behavioural alterations. These results unequivocally proved that Pb-induced oxidative stress causes ASD behaviour of humans in Drosophila. Thus, Drosophila is used as a model organism to analyse ASD-like human behaviour and underlines the importance of using antioxidant therapy in alleviating ASD symptoms in children.

Glutathione S-Transferase Polymorphisms and Clinical Characteristics in Autism Spectrum Disorders

Background: Autism spectrum disorders (ASD) are a heterogeneous group of developmental disorders, with different levels of symptoms, functioning, and comorbidities. Recent findings suggested that oxidative stress and genetic variability in glutathione S-transferases (GSTs) might increase the risk of ASD development. We aimed to determine whether GST polymorphisms influence the severity of symptoms as well as the cognitive and adaptive abilities in children with ASD. Methods: The sample included 113 ASD cases. All participants were genotyped for GSTA1, GSTM1, GSTT1, and GSTP1 polymorphisms. The clinical characteristics were determined with Autism Diagnostic Interview-Revised (ADI-R) in all of the participants. In non-verbal participants, we explored the adaptive functioning using the Vineland Adaptive Behavior Scale II, while in verbal participants, we used the Wechsler Abbreviated Scale of Intelligence (WASI). Results: It was shown that the GSTA1 * CC genotype was a predictor of a lower non-verbal communication impairment as well as of a lower chance of having seizures during life. GSTM1-active genotype predicted a higher adaptive functioning. The predictive effect of GSTA1, GSTM1, and GSTT1 genotype was moderated by exposure during pregnancy (maternal smoking and medication). The GSTP1 * IleIle genotype was significantly associated to a better cognitive functioning in children with ASD. Conclusion: Besides the complex gene-environment interaction for the specific risk of developing ASD, there is also a possible complexity of interactions between genetic and environmental factors influencing the level of symptoms and impairment in people with ASD. Detoxification and antioxidant enzymes, such as GSTA1, might contribute to the core of this complexity.

How Robust is the Evidence for a Role of Oxidative Stress in Autism Spectrum Disorders and Intellectual Disabilities?

Growing interest in the pathogenesis of autism spectrum disorders (ASDs) and other intellectual and developmental disabilities (IDD) has led to emerging evidence implicating a role for oxidative stress. However, understanding the strength of this association is made challenging by the use of a variety of purported biomarkers of oxidative stress, many of which have either uncertain specificity or flawed methods of analysis. This review aims to address this issue, which is widespread in the ASD and IDD literature, by providing readers with information concerning the strengths and limitations of the choice and analysis of biomarkers of oxidative stress. We highlight that biomarkers and assays should be specific, sensitive, reproducible, precise, robust, and chosen with careful consideration. Future studies should be sufficiently powered and address sample collection, processing, and storage which are, additionally, poorly considered, sources of bad practice, and potential errors. Only with these issues considered, will the data lead to conclusions as to the precise role of oxidative stress in ASDs and IDD.

The histamine H3R and dopamine D2R/D3R antagonist ST-713 ameliorates autism-like behavioral features in BTBR T+tf/J mice by multiple actions

Several brain neurotransmitters, including histamine (HA), acetylcholine (ACh), and dopamine (DA) are suggested to be involved in several brain disorders including cognitive deficits, depression, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with Autism spectrum disorder (ASD). Therefore, the ameliorative effects of the novel multiple-active compound ST-713 with high binding affinities at histamine H3 receptor (H3R), dopamine D2sR and D3R on ASD-like behaviors in male BTBR T+tf/J mice model were assessed. ST-713 (3-(2-chloro-10H-phenothiazin-10-yl)-N-methyl-N-(4-(3-(piperidin-1-yl)propoxy)benzyl)propan-1-amine; 2.5, 5, and 10 mg/kg, i.p.) ameliorated dose-dependently social deficits, and significantly alleviated the repetitive/compulsive behaviors of BTBR mice (all P < 0.05). Moreover, ST-713 modulated disturbed anxiety levels, but failed to obliterate increased hyperactivity of tested mice. Furthermore, ST-713 (5 mg/kg) attenuated the increased levels of hippocampal and cerebellar protein expressions of NF-κB p65, COX-2, and iNOS in BTBR mice (all P < 0.05). The ameliorative effects of ST-713 on social parameters were entirely reversed by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. The obtained results demonstrate the potential of multiple-active compounds for the therapeutic management of neuropsychiatric disorders, e.g. ASD.

Folic acid ameliorates neonatal isolation-induced autistic like behaviors in rats: epigenetic modifications of BDNF and GFAP promotors

The current study investigated the role of epigenetic dysregulation of brain derived neurotrophic factor (BDNF) and glial fibrillary acidic protein (GFAP) genes and oxidative stress as possible mechanisms of autistic-like behaviors in neonatal isolation model in rats and the impact of folic acid administration on these parameters. Forty Wistar albino pups were used as follows: control, folic acid administered, isolated, and isolated folic acid treated groups. Isolated pups were separated from their mothers for 90 min daily from postnatal day (PND) 1 to 11. Pups (isolated or control) received either the vehicle or folic acid (4 mg/kg/day) orally from PND 1 to 29. Behavioral tests were done from PND 30 to 35. Oxidative stress markers and antioxidant defense in the frontal cortex homogenate were determined. DNA methylation of BDNF and GFAP genes was determined by qPCR. Histopathological examination was carried out. Neonatal isolation produced autistic-like behaviors that were associated with BDNF and GFAP hypomethylation, increased oxidative stress, increased inflammatory cell infiltration, and structural changes in the frontal cortex. Folic acid administration concurrently with isolation reduced neonatal isolation-induced autistic-like behaviors, decreased oxidative stress, regained BDNF and GFAP gene methylation, and ameliorated structural changes in the frontal cortices of isolated folic acid treated rats. Novelty: Neonatal isolation induces "autistic-like" behavior and these behaviors are reversed by folic acid supplementation. Neonatal isolation induces DNA hypomethylation of BDNF and GFAP, increased oxidative stress markers, and neuroinflammation. All of these changes were reversed by daily folic acid supplementation.

The Multi-Targeting Ligand ST-2223 with Histamine H3 Receptor and Dopamine D2/D3 Receptor Antagonist Properties Mitigates Autism-Like Repetitive Behaviors and Brain Oxidative Stress in Mice

Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder characterized by social and communicative impairments, as well as repetitive and restricted behaviors (RRBs). With the limited effectiveness of current pharmacotherapies in treating repetitive behaviors, the present study determined the effects of acute systemic treatment of the novel multi-targeting ligand ST-2223, with incorporated histamine H₃ receptor (H₃R) and dopamine D₂/D₃ receptor affinity properties, on ASD-related RRBs in a male Black and Tan BRachyury (BTBR) mouse model of ASD. ST-2223 (2.5, 5, and 10 mg/kg, i.p.) significantly mitigated the increase in marble burying and self-grooming, and improved reduced spontaneous alternation in BTBR mice (all p < 0.05). Similarly, reference drugs memantine (MEM, 5 mg/kg, i.p.) and aripiprazole (ARP, 1 mg/kg, i.p.), reversed abnormally high levels of several RRBs in BTBR (p < 0.05). Moreover, ST-2223 palliated the disturbed anxiety levels observed in an open field test (all p < 0.05), but did not restore the hyperactivity parameters, whereas MEM failed to restore mouse anxiety and hyperactivity. In addition, ST-2223 (5 mg/kg, i.p.) mitigated oxidative stress status by decreasing the elevated levels of malondialdehyde (MDA), and increasing the levels of decreased glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) in different brain parts of treated BTBR mice (all p < 0.05). These preliminary in vivo findings demonstrate the ameliorative effects of ST-2223 on RRBs in a mouse model of ASD, suggesting its pharmacological prospective to rescue core ASD-related behaviors. Further confirmatory investigations on its effects on various brain neurotransmitters, e.g., dopamine and histamine, in different brain regions are still warranted to corroborate and expand these initial data.

Aggravation of autism-like behavior in BTBR T+tf/J mice by environmental pollutant, di-(2-ethylhexyl) phthalate: Role of nuclear factor erythroid 2-related factor 2 and oxidative enzymes in innate immune cells and cerebellum

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder which manifests itself in early childhood and is distinguished by recurring behavioral patterns, and dysfunction in social/communication skills. Ubiquitous environmental pollutant, di-2-ethylhexyl phthalate (DEHP) is one of the most frequently used plasticizers in various industrial products, e.g. vinyl flooring, plastic toys, and medical appliances. DEHP gets easily released into the environment and leads to human exposure through various routes. DEHP has been described to be linked with oxidative stress in various organs in animal/human studies. Increased concentration of DEHP has also been detected in ASD children which indicates an association between phthalates exposure and ASD. However, effect of DEHP on autism-like behavior has not been investigated previously. Therefore, this study probed the effect of DEHP on autism-like behavior (marble burying, self-grooming and sociability) and innate immune cells (dendritic cells/neutrophils)/cerebellar oxidant-antioxidant balance (NFkB, iNOS, NADPH oxidase, nitrotyrosine, lipid peroxides, Nrf2, SOD, GPx) in BTBR and C57 mice. Our data show that DEHP treatment causes worsening of autism-like behavior in BTBR mice which is associated with enhancement of oxidative stress in innate immune cells and cerebellum with concomitant lack of antioxidant protection. DEHP also causes oxidative stress in C57 mice in both innate immune cells and cerebellar compartment, however there is Nrf2-mediated induction of enzymatic antioxidants which protects them from upregulated oxidative stress. This proposes the notion that ubiquitous environmental pollutants such as DEHP may be involved in the pathogenesis/progression of ASD through dysregulation of antioxidant-antioxidant balance in innate immune cells and cerebellum.

NOX1/NADPH oxidase affects the development of autism-like behaviors in a maternal immune activation model

Autism spectrum disorder (ASD) is a neurodevelopmental disorder caused by genetic and environmental factors. Among the environmental factors, maternal infection is known as one of the principal risk factors for ASD. On the other hand, postmortem studies suggested the relationship of oxidative stress with ASD etiology. However, the role of oxidative stress in the development of ASD remains unclear. Here, we report the involvement of NOX1/NADPH oxidase, an enzyme generating reactive oxygen species (ROS), in behavioral and anatomical abnormalities in a maternal immune activation (MIA) model. In the MIA model of gestational polyinosinic-polycytidylic acid (poly(I:C)) exposure, increased serum levels of IL-6 were observed in both wild-type (WT) and Nox1-deficient mice (Nox1KO). Following the comparable induction of MIA in the two genotypes, impairment of social preference and defects in motor coordination were observed in WT offspring but not in offspring deficient in Nox1. MIA up-regulated NOX1 mRNA in the cerebral cortex and cerebellum of the fetus but not in the adult offspring. Although the development of cortical neurons was unaffected by MIA in either genotype, the dropout of Purkinje cells in lobule VII of MIA-affected offspring was significantly ameliorated in Nox1KO. Taken together, these results suggested that NOX1/NADPH oxidase plays an essential role in some behavioral phenotypes observed in ASD, possibly by promoting the loss of Purkinje cells in the cerebellum.

The role of glutathione redox imbalance in autism spectrum disorder: A review

The role of glutathione in autism spectrum disorder (ASD) is emerging as a major topic, due to its role in the maintenance of the intracellular redox balance. Several studies have implicated glutathione redox imbalance as a leading factor in ASD, and both ASD and many other neurodevelopmental disorders involve low levels of reduced glutathione (GSH), high levels of oxidized glutathione (GSSG), and abnormalities in the expressions of glutathione-related enzymes in the blood or brain. Glutathione metabolism, through its impact on redox environment or redox-independent mechanisms, interferes with multiple mechanisms involved in ASD pathogenesis. Glutathione-mediated regulation of glutamate receptors [e.g., N-methyl-d-aspartate (NMDA) receptor], as well as the role of glutamate as a substrate for glutathione synthesis, may be involved in the regulation of glutamate excitotoxicity. However, the interaction between glutathione and glutamate in the pathogenesis of brain diseases may vary from synergism to antagonism. Modulation of glutathione is also associated with regulation of redox-sensitive transcription factors nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1) and downstream signaling (proinflammatory cytokines and inducible enzymes), thus providing a significant impact on neuroinflammation. Mitochondrial dysfunction, as well as neuronal apoptosis, may also provide a significant link between glutathione metabolism and ASD. Furthermore, it has been recently highlighted that glutathione can affect and modulate DNA methylation and epigenetics. Review analysis including research studies meeting the required criteria for analysis showed statistically significant differences between the plasma GSH and GSSG levels as well as GSH:GSSG ratio in autistic patients compared with healthy individuals (P = 0.0145, P = 0.0150 and P = 0.0202, respectively). Therefore, the existing data provide a strong background on the role of the glutathione system in ASD pathogenesis. Future research is necessary to investigate the role of glutathione redox signaling in ASD, which could potentially also lead to promising therapeutics.

3-Aminobenzamide alleviates elevated DNA damage and DNA methylation in a BTBR T+Itpr3tf/J mouse model of autism by enhancing repair gene expression

Little is known about genetic and epigenetic alterations in autism spectrum disorder. Moreover, the efficiency of DNA repair in autism must be improved to correct these alterations. We examined whether 3-aminobenzamide (3-AB) could reverse these alterations. We conducted experiments to clarify the molecular mechanism underlying these ameliorations. An assessment of genetic and epigenetic alterations by a modified comet assay showed elevated levels of oxidative DNA strand breaks and DNA hypermethylation in BTBR T⁺Itpr3^tf/J (BTBR) mice used as a model of autism. Oxidative DNA strand breaks and DNA methylation were further quantified fluorometrically, and the results showed similar changes. Conversely, 3-AB treated BTBR mice showed a significant reduction in these alterations compared with untreated mice. The expressions of 43 genes involved in DNA repair were altered in BTBR mice. RT² Profiler PCR Array revealed significantly altered expression of seven genes, which was confirmed by RT-PCR analyses. 3-AB treatment relieved these disturbances and significantly improved Ogg1 and Rad1 up-regulation. Moreover, autism-like behaviors were also mitigated in BTBR animals by 3-AB treatment without alterations in locomotor activities. The simultaneous effects of reduced DNA damage and DNA methylation levels as well as the regulation of repair gene expression indicate the potential of 3-AB as a therapeutic agent to decrease the levels of DNA damage and DNA methylation in autistic patients. The current data may help in the development of therapies that ultimately provide a better quality of life for individuals suffering from autism.

Simultaneous Blockade of Histamine H3 Receptors and Inhibition of Acetylcholine Esterase Alleviate Autistic-Like Behaviors in BTBR T+ tf/J Mouse Model of Autism

Autism spectrum disorder (ASD) is a heterogenous neurodevelopmental disorder defined by persistent deficits in social interaction and the presence of patterns of repetitive and restricted behaviors. The central neurotransmitters histamine (HA) and acetylcholine (ACh) play pleiotropic roles in physiological brain functions that include the maintenance of wakefulness, depression, schizophrenia, epilepsy, anxiety and narcolepsy, all of which are found to be comorbid with ASD. Therefore, the palliative effects of subchronic systemic treatment using the multiple-active test compound E100 with high H₃R antagonist affinity and AChE inhibitory effect on ASD-like behaviors in male BTBR T+tf/J (BTBR) mice as an idiopathic ASD model were assessed. E100 (5, 10 and 15 mg/kg, i.p.) dose-dependently palliated social deficits of BTBR mice and significantly alleviated the repetitive/compulsive behaviors of tested animals. Moreover, E100 modulated disturbed anxiety levels, but failed to modulate hyperactivity parameters, whereas the reference AChE inhibitor donepezil (DOZ, one milligram per kilogram) significantly obliterated the increased hyperactivity measures of tested mice. Furthermore, E100 mitigated the increased levels of AChE activity in BTBR mice with observed effects comparable to that of DOZ and significantly reduced the number of activated microglial cells compared to the saline-treated BTBR mice. In addition, the E100-provided effects on ASD-like parameters, AChE activity, and activated microglial cells were entirely reversed by co-administration of the H₃R agonist (R)-α-methylhistamine (RAM). These initial overall results observed in an idiopathic ASD mice model show that E100 (5 mg/kg) alleviated the assessed behavioral deficits and demonstrate that simultaneous targeting of brain histaminergic and cholinergic neurotransmissions is crucial for palliation of ASD-like features, albeit further in vivo assessments on its effects on brain levels of ACh as well as HA are still needed.

Dietary Flavonoids in p53-Mediated Immune Dysfunctions Linking to Cancer Prevention

The p53 protein plays a central role in mediating immune functioning and determines the fate of the cells. Its role as a tumor suppressor, and in transcriptional regulation and cytokine activity under stress conditions, is well defined. The wild type (WT) p53 functions as a guardian for the genome, while the mutant p53 has oncogenic roles. One of the ways that p53 combats carcinogenesis is by reducing inflammation. WT p53 functions as an anti-inflammatory molecule via cross-talk activity with multiple immunological pathways, such as the major histocompatibility complex I (MHCI) associated pathway, toll-like receptors (TLRs), and immune checkpoints. Due to the multifarious roles of p53 in cancer, it is a potent target for cancer immunotherapy. Plant flavonoids have been gaining recognition over the last two decades to use as a potential therapeutic regimen in ameliorating diseases. Recent studies have shown the ability of flavonoids to suppress chronic inflammation, specifically by modulating p53 responses. Further, the anti-oxidant Keap1/Nrf2/ARE pathway could play a crucial role in mitigating oxidative stress, leading to a reduction of chronic inflammation linked to the prevention of cancer. This review aims to discuss the pharmacological properties of plant flavonoids in response to various oxidative stresses and immune dysfunctions and analyzes the cross-talk between flavonoid-rich dietary intake for potential disease prevention.

Oxidative Stress and Immune System Dysfunction in Autism Spectrum Disorders

Autism Spectrum Disorders (ASDs) represent a group of neurodevelopmental disorders associated with social and behavioral impairments. Although dysfunctions in several signaling pathways have been associated with ASDs, very few molecules have been identified as potentially effective drug targets in the clinic. Classically, research in the ASD field has focused on the characterization of pathways involved in neural development and synaptic plasticity, which support the pathogenesis of this group of diseases. More recently, immune system dysfunctions have been observed in ASD. In addition, high levels of reactive oxygen species (ROS), which cause oxidative stress, are present in ASD patients. In this review, we will describe the major alterations in the expression of genes coding for enzymes involved in the ROS scavenging system, in both ASD patients and ASD mouse models. In addition, we will discuss, in the context of the most recent literature, the possibility that oxidative stress, inflammation and immune system dysfunction may be connected to, and altogether support, the pathogenesis and/or severity of ASD. Finally, we will discuss the possibility of novel treatments aimed at counteracting the interplay between ROS and inflammation in people with ASD.

Early Celastrol Administration Prevents Ketamine-Induced Psychotic-Like Behavioral Dysfunctions, Oxidative Stress and IL-10 Reduction in The Cerebellum of Adult Mice

Administration of subanesthetic doses of ketamine during brain maturation represents a tool to mimic an early insult to the central nervous system (CNS). The cerebellum is a key player in psychosis pathogenesis, to which oxidative stress also contributes. Here, we investigated the impact of early celastrol administration on behavioral dysfunctions in adult mice that had received ketamine (30 mg/kg i.p.) at postnatal days (PNDs) 7, 9, and 11. Cerebellar levels of 8-hydroxydeoxyguanosine (8-OHdG), NADPH oxidase (NOX) 1 and NOX2, as well as of the calcium-binding protein parvalbumin (PV), were also assessed. Furthermore, celastrol effects on ketamine-induced alterations of proinflammatory (TNF-α, IL-6 and IL-1β) and anti-inflammatory (IL-10) cytokines in this brain region were evaluated. Early celastrol administration prevented ketamine-induced discrimination index decrease at adulthood. The same was found for locomotor activity elevations and increased close following and allogrooming, whereas no beneficial effects on sniffing impairment were detected. Ketamine increased 8-OHdG in the cerebellum of adult mice, which was also prevented by early celastrol injection. Cerebellar NOX1 levels were enhanced at adulthood following postnatal ketamine exposure. Celastrol per se induced NOX1 decrease in the cerebellum. This effect was more significant in animals that were early administered with ketamine. NOX2 levels did not change. Ketamine administration did not affect PV amount in the cerebellum. TNF-α levels were enhanced in ketamine-treated animals; however, this was not prevented by early celastrol administration. While no changes were observed for IL-6 and IL-1β levels, ketamine determined a reduction of cerebellar IL-10 expression, which was prevented by early celastrol treatment. Our results suggest that NOX inhibition during brain maturation prevents the development of psychotic-like behavioral dysfunctions, as well as the increased cerebellar oxidative stress and the reduction of IL-10 in the same brain region following ketamine exposure in postnatal life. This opens novel neuroprotective opportunities against early detrimental insults occurring during brain development.

Assessment of DNA repair efficiency in the inbred BTBR T+tf/J autism spectrum disorder mouse model exposed to gamma rays and treated with JNJ7777120

Information regarding DNA repair in autism is limited to a few studies, which have reported inconsistent results. Therefore, we designed a study to determine whether DNA repair efficiency is altered in autism and to investigate whether the H₄ ligand JNJ7777120 can enhance DNA repair efficiency in BTBR T⁺tf/J (BTBR) mice; we also attempted to elucidate the mechanism(s) underlying this amelioration. Evaluation of DNA damage using the comet assay on bone marrow cells showed increased levels of DNA damage in BTBR mice compared with age-matched control C57BL/6J mice. Conversely, BTBR animals pretreated with 20 mg/kg JNJ7777120 for five days exhibited significant decreases in DNA damage compared with that of control BTBR mice. Our results also indicated higher sensitivity of BTBR mice exposed to gamma rays to DNA damage generation. A marked difference was observed between BTBR and C57BL/6J mice at different sampling times after irradiation, with BTBR mice showing a higher percentage of DNA damage and slower repair rate than that of C57BL/6J mice. JNJ7777120 led to enhanced repair of the DNA damage induced by radiation when administered to BTBR mice five days prior to radiation. Additionally, oxidative stress in BTBR mice was significantly elevated with a reduced GSH/GSSG ratio; significant amelioration was subsequently observed in JNJ7777120-pretreated BTBR mice. Furthermore, repetitive behaviors were also attenuated in BTBR mice by JNJ7777120 treatment without altering locomotor activity. Our results suggest that JNJ7777120 can be developed for use as a therapeutic agent to enhance DNA repair efficiency in autism spectrum disorder.