Oxidative stress marker aberrations in children with autism spectrum disorder: a systematic review and meta-analysis of 87 studies (N = 9109)

The interplay between oxidative stress and inflammation supports autistic-related behaviors in Cntnap2 knockout mice

Autism Spectrum Disorder (ASD) is a highly prevalent neurodevelopmental condition characterized by social communication deficits and repetitive/restricted behaviors. Several studies showed that oxidative stress and inflammation may contribute to ASD. Indeed, increased levels of oxygen radicals and pro-inflammatory molecules were described in the brain and peripheral blood of persons with ASD and mouse models. Despite this, a potential direct connection between oxidative stress and inflammation within specific brain areas and ASD-related behaviors has not been investigated in detail yet. Here, we used RT-qPCR, RNA sequencing, metabolomics, immunohistochemistry, and flow cytometry to show that pro-inflammatory molecules were increased in the cerebellum and periphery of mice lacking Cntnap2, a robust model of ASD. In parallel, oxidative stress was present in the cerebellum of mutant animals. Systemic treatment with N-acetyl-cysteine (NAC) rescued cerebellar oxidative stress, inflammation, as well as motor and social impairments in Cntnap2-/- mice, concomitant with enhanced function of microglia cells in NAC-treated mutants. Intriguingly, social deficits, cerebellar inflammation, and microglia dysfunction were induced by NAC in Cntnap2+/+ animals. Our findings suggest that the interplay between oxidative stress and inflammation accompanied by genetic vulnerability may underlie ASD-related behaviors in Cntnap2 mutant mice.

Oxidative stress response and NRF2 signaling pathway in autism spectrum disorder

The prevalence of autism spectrum disorder (ASD), a neurodevelopmental disorder characterized by impairments in social communication and restricted/repetitive behavioral patterns, has increased significantly over the past few decades. The etiology of ASD involves a highly complex interplay of genetic, neurobiological, and environmental factors, contributing to significant heterogeneity in its clinical phenotype. In the evolving landscape of ASD research, increasing evidence suggests that oxidative stress, resulting from both intrinsic and extrinsic factors, may be a crucial pathophysiological driver in ASD, influencing neurodevelopmental processes that underlie behavioral abnormalities. Elevated levels of oxidative stress biomarkers, including lipid peroxides, protein oxidation products, and DNA damage markers, alongside deficient antioxidant enzyme activity, have been consistently linked to ASD. This may be attributed to dysregulated activity of nuclear factor erythroid 2-related factor 2 (NRF2), a pivotal transcription factor that maintains cellular redox homeostasis by orchestrating the expression of genes involved in antioxidant defenses. Here, we summarize the converging evidence that redox imbalance in ASD may result from NRF2 dysregulation, leading to reduced expression of its target genes. We also highlight the most promising antioxidant compounds under investigation, which may restore NRF2 activity and ameliorate ASD behavioral symptoms.

Gut microbiota mediated regulation of vitamin B homeostasis in autism spectrum disorders

The exact cause of autism spectrum disorder (ASD) is yet unknown, although possible causes include early childhood, foetal development, gestation, delivery mode, genetics, and environmental variables. Approximately 1% of children worldwide have ASD, and this percentage is rising. The immunological, endocrine, gut microbiota and brain-gut axis quality influence the intensity of ASD symptoms. Deficits in the composition and diversity of gut microbiota are common in children with ASD, accounting for 9-90% of these illnesses, including elevated inflammatory cytokines, inflammation, leaky gut syndrome, and pathological microflora growth. Dysbiosis can be made worse by eating issues that are prevalent in ASD. B vitamins, such as cobalamin and folate, which are essential methyl donors for DNA epigenetic changes, are usually produced by a healthy gut microbiota. 50% of people with ASD have a vitamin B deficit. This work summarises research on the impact of gut microbiota on DNA methylation and B vitamin synthesis in ASD, as well as etiological variables connected to dysbiosis. Probiotics, postbiotics, and vitamin B therapies in kids with ASD should be investigated in future studies.

Oxidative Stress and Dynamic Thiol/Disulfide Homeostasis in Autism: A Focus on Early Childhood

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with multifactorial etiopathogenesis, where oxidative stress (OS) has been implicated as a key contributing factor. This study aimed to evaluate the plasma dynamic thiol/disulfide homeostasis (DTDH) parameters-a relatively novel OS biomarker-alongside classical OS biomarkers, including total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), glutathione, and glutathione peroxidase (GPx), in preschool children diagnosed with ASD. A total of 49 children with ASD and 31 age- and sex-matched typically developing children between the ages of 2 and 6 years were included. In addition to sociodemographic data collection, the Childhood Autism Rating Scale (CARS) and Clinical Global Impression-Severity Scale (CGI-S) were administered to assess autism severity. Blood samples were analyzed using automated spectrophotometric techniques to determine OS biomarkers. The results demonstrated that DTDH parameters and classical OS markers exhibited parallel changes; however, no statistically significant differences were detected between the ASD and control groups across all OS markers. Furthermore, no significant association was found between OS biomarkers and autism severity. Moreover, we intentionally restricted our sample to a younger age group to enable a focused examination of OS dynamics during early developmental stages. This study underscores the potential impact of age as a critical determinant in OS-related alterations in autism and highlights the need for further age-stratified investigations to elucidate the role of OS in ASD pathophysiology and its potential diagnostic relevance.

Antioxidant-Effective Quercetin Through Modulation of Brain Interleukin-13 Mitigates Autistic-Like Behaviors in the Propionic Acid-Induced Autism Model in Rats

Overproduction of reactive oxygen species occurs when inflammation induces oxidative stress in macrophages and microglia, leading to a self-sustaining cycle of cellular damage and neuroinflammation. Oxidative stress and neuroinflammation are well-established contributors to the pathophysiology of autism spectrum disorders, which are associated with impaired neuronal function, neuronal loss, and behavioral deficits. Damaged cells, through microglial activation, release additional inflammatory mediators under conditions of oxidative stress, exacerbating neuronal damage. Quercetin, a powerful dietary antioxidant, has been shown to scavenge free radicals, reduce oxidative stress, and inhibit inflammatory pathways. Given these properties, we hypothesize that quercetin may improve learning and social skills in individuals with autism spectrum disorders by alleviating oxidative stress and reducing brain levels of inflammatory cytokines. In this study, an autism model was established in 30 rats by intraperitoneal injection of 250 mg/kg/day propionic acid (PPA) for five days. The study groups were as follows: Group 1: Normal ontrol (n = 10); Group 2: PPA + saline (PPAS, n = 10); Group 3: PPA + Quercetin (PPAQ, n = 10). All treatments were administered for 15 days. At the end of the treatment, histological and biochemical analyses of brain tissue and behavioral tests related to autistic-like behaviors were performed. Malondialdehyde, tumor necrosis factor-alpha, and interleukin-13 levels in brain homogenates were significantly higher in the PPAS group compared to the control group, indicating elevated oxidative stress and inflammation following PPA exposure. The PPAQ group significantly reduced oxidative stress parameters and inflammatory biomarkers, demonstrating its antioxidant and anti-inflammatory effects. This biochemical improvement was accompanied by preserving Purkinje cells and neuronal populations, significantly reduced in the PPAS group. Moreover, quercetin-treated rats exhibited improved social behavior and learning, which were severely impaired in the PPAS group. These findings, when interpreted together, suggest that quercetin exerts its neuroprotective effects by targeting oxidative stress and neuroinflammation, thereby preventing neuronal cell loss and alleviating behavioral deficits associated with autism spectrum disorders.

Gut microbiota, vitamin A deficiency and autism spectrum disorder: an interconnected trio - a systematic review

Accumulating evidence proves that children with autism have gastrointestinal problems. However, a significant difference in gut microbiota (GM) exists between autistic and non-autistic children. These changes in the GM may stem from several factors. Recently, researchers focused on nutritional factors, especially vitamin deficiency. Thus, our systematic review investigates the connections among autism, GM alterations, and vitamin A deficiency (VAD), by analyzing studies sourced from PubMed and Embase databases spanning from 2010 to 2022. Adhering to PRISMA guidelines, we meticulously selected 19 pertinent studies that established links between autism and GM changes or between autism and VAD. Our findings uniformly point to significant alterations in the GM of individuals with autism, indicating these changes as promising biomarkers for the disorder. Despite the consistent association of GM alterations with autism, our analysis revealed no notable differences in GM composition between individuals with autism and those experiencing VAD. This suggests that VAD, especially when encountered early in life, might play a role in the onset of autism. Furthermore, our review underscores a distinct correlation between reduced levels of retinoic acid in children with autism, a disparity that could relate to the severity of autism symptoms. The implications of our findings are twofold: they not only reinforce the significance of GM alterations as potential diagnostic markers but also spotlight the critical need for further research into nutritional interventions. Specifically, vitamin A supplementation emerges as a promising avenue for alleviating autism symptoms, warranting deeper investigation into its therapeutic potential.

Analysis of the Association Between the SLC19A1 Genetic Variant (rs1051266) and Autism Spectrum Disorders, Cerebral Folate Deficiency, and Clinical and Laboratory Parameters

Autism spectrum disorders (ASD) are characterized by clinical heterogeneity and may be associated with cerebral folate deficiency (CFD). Among the causes, folate receptor alpha autoantibodies (FRAA) and variants of the SLC19A1 gene are commonly highlighted. The aim of this study was to analyze the rs1051266 variant of the SLC19A1 gene in patients with ASD and CFD and to determine its relationship with clinical and laboratory parameters. The study included 227 children with ASD, 156 of whom had CFD. FRAA detection, genotyping of the rs1051266 variant, and folate metabolism marker measurement (homocysteine, vitamins B9, B12, B6) were performed. FRAA binding was detected in 39.2% of ASD patients, blocking FRAA in 3.5%, and a specific soluble folate receptor in 13.2%. The 80GA genotype was the most common (46.3%), and homocysteine levels tended to be moderately elevated (upper quartile - 7.0). Significant correlations were found between homocysteine levels and vitamins B9, B12, and B6 (p < 0.05) and between verbal impairments and vitamin B12 (p = 0.043). In ASD and CFD patients, the 80GG genotype was more frequent (p = 0.03) and vitamin B12 levels were elevated (p = 0.021). In the ASD group, correlations were found between the 80AA genotype and demyelination (p = 0.020) and between homocysteine levels and demyelination (p = 0.042). In conclusion, the rs1051266 variant of the SLC19A1 gene modifies the clinical course of ASD. Patients with ASD and CFD exhibited high variability in folate metabolism markers. These findings underline the need for further research on folate transport genetics for personalized prevention and treatment strategies for ASD and CFD.

Oxidative Stress Indicated by Nuclear Transcription Factor Nrf2 and Glutathione Status in the Blood of Young Children with Autism Spectrum Disorder: Pilot Study

This pilot study investigated the relationship between nuclear transcription factor Nrf2 and glutathione homeostasis in children with autism spectrum disorder (ASD), addressing the role of oxidative stress in ASD pathophysiology. Oxidative stress, characterized by an imbalance between reactive oxygen species and antioxidant defenses, has been implicated in ASD and may contribute to neuroinflammation and mitochondrial dysfunction. Nrf2, a key regulator of the antioxidant response, influences glutathione synthesis and recycling, making it critical for cellular redox balance. This study included 23 children with ASD and 21 neurotypical healthy controls, and measured levels of Nrf2, Keap1 (Kelch-like ECH-associated protein 1), reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione reductase (GR), and peroxidase (GPx3) in blood samples. Our study reveals altered antioxidant defense in children with autism spectrum disorder, as evidenced by reduced levels of Nrf2, Keap1, GSH, and GR, along with elevated GSSG and a lower GSH/GSSG ratio. These findings indicate an increased oxidative stress burden in this population. Additionally, the observed positive correlation between Nrf2, GSH, and GR levels suggests an important role for Nrf2 in maintaining glutathione homeostasis. Our results underscore the potential involvement of oxidative stress in ASD and emphasize the need for further research into targeted therapeutic approaches to address this imbalance.

Folic acid and autism: updated evidences

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that impairs communication, socialization, and behavior. The association of ASD with folic acid has been investigated due to the importance of this vitamin for neurological health. This study is an update of the publication 'Folic acid and autism: What do we know?' and aims to systematically review studies examining the relationship between folic acid and ASD. The search resulted in 2,389 studies on folic acid and ASD, which were selected by two reviewers based on their titles and abstracts. Studies meeting the inclusion criteria were fully read. The 52 included studies involved 10,429 individuals diagnosed with ASD and assessed the intake of vitamin B6, folic acid, and vitamin B12; serum levels of these vitamins, homocysteine, and methionine; therapeutic interventions using folic acid; and the association between maternal exposure to this vitamin and the risk of ASD. The evidence of insufficient folic acid intake in most individuals with ASD remains consistent in this update. No association was found between maternal exposure to folic acid and the risk of ASD in their children. Despite observed improvements in communication, socialization, and behavior in individuals with ASD following folic acid interventions, it is crucial to consider the individuality and complexity of ASD. Given the relevance of the topic, there remains a need for more high-quality research and clinical trials characterized by rigorous methodological designs.

Selenium metabolism and selenoproteins function in brain and encephalopathy

Selenium (Se) is an essential trace element of the utmost importance to human health. Its deficiency induces various disorders. Se species can be absorbed by organisms and metabolized to hydrogen selenide for the biosynthesis of selenoproteins, selenonucleic acids, or selenosugars. Se in mammals mainly acts as selenoproteins to exert their biological functions. The brain ranks highest in the specific hierarchy of organs to maintain the level of Se and the expression of selenoproteins under the circumstances of Se deficiency. Dyshomeostasis of Se and dysregulation of selenoproteins result in encephalopathy such as Alzheimer's disease, Parkinson's disease, depression, amyotrophic lateral sclerosis, and multiple sclerosis. This review provides a summary and discussion of Se metabolism, selenoprotein function, and their roles in modulating brain diseases based on the most currently published literature. It focuses on how Se is utilized and transported to the brain, how selenoproteins are biosynthesized and function physiologically in the brain, and how selenoproteins are involved in neurodegenerative diseases. At the end of this review, the perspectives and problems are outlined regarding Se and selenoproteins in the regulation of encephalopathy.

Enhancing NADPH to restore redox homeostasis and lysosomal function in G6PD-deficient microglia

Microglia, the immune cells of the central nervous system (CNS), play key roles in neurogenesis, myelination, synaptic transmission, immune surveillance, and neuroinflammation. Inflammatory responses in microglia can lead to oxidative stress and neurodegeneration, contributing to diseases like Parkinson's and Alzheimer's. The enzyme glucose-6-phosphate dehydrogenase (G6PD) is essential for producing nicotinamide adenine dinucleotide phosphate hydrogen (NADPH), which neutralizes oxidative stress. G6PD deficiency has been linked to several disorders, including neurological conditions. Our study shows that G6PD deficiency in microglia reduces NADPH levels, disrupting redox balance and lysosomal function. To address this, we explored alternative metabolic pathways by targeting enzymes like isocitrate dehydrogenase 1 (IDH1) and malic enzyme 1 (ME1), both crucial for NADPH production. Supplementing metabolites such as citric and malic acid improved NADPH levels, while small molecules like dieckol and resveratrol enhanced IDH1 and ME1 expression. The combination of these approaches restored redox homeostasis and lysosomal function, offering potential therapeutic strategies for G6PD deficiency.

Research trends of inflammation in autism spectrum disorders: a bibliometric analysis

Background

Inflammation has been recognized as a significant factor in the pathophysiology of autism spectrum disorders (ASD), which have garnered increasing scholarly attention over the past few decades. This study aims to explore research trends related to inflammation and ASD through bibliometric analysis.

Method

A comprehensive literature search was conducted in the Web of Science Core Collection (WoSCC) on August 28, 2024. This study was restricted to literature published in English. The bibliometric analysis utilized VOSviewer, CiteSpace, and the R package "bibliometrix" to visualize collaborations, keyword co-occurrences, and emerging research trends.

Results

A total of 1,752 articles addressing inflammation and ASD were published, demonstrating a consistent upward trend in research output. The United States emerged as the country with the highest volume of publications. Saleh A. Bakheet was identified as the most prolific authors, significantly contributing to the literature with 54 publications. The University of California System was recognized as the most productive institution in this area of study. The journal of Brain Behavior and Immunity was noted as a prominent venue for publication in this field, exhibiting high citation metrics that reflect its considerable influence. The keyword "children" was the most frequently occurring term, with other significant terms including "oxidative stress" and "brain." The keyword burst analysis revealed notable periods of increased research focus on topics such as "inflammatory bowel disease," "cytokine production," "neurodevelopmental disorders," and "microbiota."

Conclusion

This bibliometric analysis highlights the growing scholarly attention devoted to the relationship between inflammation and ASD. Significant contributions and emerging trends emphasize the pivotal role of neuroinflammation in ASD, indicating a necessity for further exploration in this domain.

Neurodegeneration in Autism: A Study of Clusterin, Very Long-Chain Fatty Acids, and Carnitine

The clinical identification of regression phenomena in ASD lacks specific biological or laboratory criteria and is often based on family history and highly subjective observations by clinicians. The present study aimed to investigate the potential role of plasma clusterin (CLU), very long-chain fatty acids (VLCFA), and carnitine as biomarkers of neurodegeneration in children with autism spectrum disorder (ASD) with and without regression. By exploring these biomarkers, we sought to provide insights into mitochondrial dysfunction, glial activation, and lipid metabolism, which may contribute to the pathophysiology of ASD and aid in the early diagnosis and intervention of regression phenomena in ASD. Ninety children aged 2-6 years were included: 30 with autism spectrum disorder (ASD), 30 with regressive ASD, and 30 healthy controls. Psychiatric assessments were conducted using DSM-5 criteria, CARS, ABC, RBS-R, and ASSQ scales. Regression in ASD was evaluated retrospectively using a modified ADI-R questionnaire. Fasting blood samples were collected, and plasma clusterin (CLU), VLCFA, and carnitine levels were measured. Statistical analyses were performed using MANOVA to assess the effect of group differences on dependent biochemical variables. Serum clusterin and carnitine levels showed no significant differences between groups. However, C22 VLCFA levels were significantly higher in both autism groups compared to controls (p = 0.04), with post hoc analysis indicating the difference between the non-regressive and control groups (p = 0.02). Serum carnitine was positively correlated with stereotypic behaviors subscale scores (r = 0.37, p = 0.004) and total scores (r = 0.35, p = 0.006) of RBS-R. Our study provides insights into the complexities of biomarker research in autism spectrum disorder (ASD), highlighting the challenges in identifying consistent biological markers for regression and non-regression phenotypes. Although no significant findings were observed, further biomarker studies are essential to distinguish possible endophenotypes, improve early diagnosis, and uncover potential therapeutic targets in ASD.

The Role of Oxidative Stress in Autism Spectrum Disorder Pathophysiology, Diagnosis and Treatment

Autism spectrum disorder (ASD) is a significant health problem with no known single cause. There is a vast number of evidence to suggest that oxidative stress plays an important role in this disorder. The author of this article reviewed the current literature in order to summarise the knowledge on the subject. In this paper, the role of oxidative stress is investigated in the context of its influence on pathogenesis, the use of oxidative stress biomarkers as diagnostic tools and the use of antioxidants in ASD treatment. Given the heterogeneity of ASD aetiology and inadequate treatment approaches, the search for common metabolic traits is essential to find more efficient diagnostic tools and treatment methods. There are increasing data to suggest that oxidative stress is involved in the pathogenesis of ASD, both directly and through its interplay with inflammation and mitochondrial dysfunction. Oxidative stress biomarkers appear to have good potential to be used as diagnostic tools to aid early diagnosis of ASD. The results are most promising for glutathione and its derivatives and also for isoprostanses. Probably, complex dedicated multi-parametric metabolic panels may be used in the future. Antioxidants show good potential in ASD-supportive treatment. In all described fields, the data support the importance of oxidative stress but also a need for further research, especially in the context of sample size and, preferably, with a multicentre approach.

The multifaceted role of mitochondria in autism spectrum disorder

Normal brain functioning relies on high aerobic energy production provided by mitochondria. Failure to supply a sufficient amount of energy, seen in different brain disorders, including autism spectrum disorder (ASD), may have a significant negative impact on brain development and support of different brain functions. Mitochondrial dysfunction, manifested in the abnormal activities of the electron transport chain and impaired energy metabolism, greatly contributes to ASD. The aberrant functioning of this organelle is of such high importance that ASD has been proposed as a mitochondrial disease. It should be noted that aerobic energy production is not the only function of the mitochondria. In particular, these organelles are involved in the regulation of Ca2+ homeostasis, different mechanisms of programmed cell death, autophagy, and reactive oxygen and nitrogen species (ROS and RNS) production. Several syndromes originated from mitochondria-related mutations display ASD phenotype. Abnormalities in Ca2+ handling and ATP production in the brain mitochondria affect synaptic transmission, plasticity, and synaptic development, contributing to ASD. ROS and Ca2+ regulate the activity of the mitochondrial permeability transition pore (mPTP). The prolonged opening of this pore affects the redox state of the mitochondria, impairs oxidative phosphorylation, and activates apoptosis, ultimately leading to cell death. A dysregulation between the enhanced mitochondria-related processes of apoptosis and the inhibited autophagy leads to the accumulation of toxic products in the brains of individuals with ASD. Although many mitochondria-related mechanisms still have to be investigated, and whether they are the cause or consequence of this disorder is still unknown, the accumulating data show that the breakdown of any of the mitochondrial functions may contribute to abnormal brain development leading to ASD. In this review, we discuss the multifaceted role of mitochondria in ASD from the various aspects of neuroscience.

Telomere Length and Oxidative Damage in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis

BACKGROUND

Autism spectrum disorder (ASD) has been reported to confer an increased risk of natural premature death. Telomere erosion caused by oxidative stress is a common consequence in age-related diseases. However, whether telomere length (TL) and oxidative indicators are significantly changed in ASD patients compared with controls remains controversial. The aim of this study was to determine the associations of ASD with TL and oxidative indicators by performing a meta-analysis of all published evidence.

METHODS

The PubMed and Embase databases were searched for articles published up to April, 2024. The effect size was expressed as standardized mean difference (SMD) and 95% confidence interval (CI) via Stata 15.0 software.

RESULTS

Thirty-nine studies were included. Pooled results showed that compared with controls, children and adolescents with ASD were associated with significantly shorter TL (SMD = -0.48; 95% CI = -0.66- -0.29; p < 0.001; particularly in males), lower total antioxidant capacity (TAC: SMD = -1.15; 95% CI = -2.01- -0.30; p = 0.008), and higher oxidative DNA (8-hydroxy-2'-deoxyguanosine, 8-OHdG: SMD = 0.63; 95% CI = 0.03-1.23; p = 0.039), lipid (hexanolyl-lysine, HEL: SMD = 0.37; 95% CI = 0.13-0.62; p = 0.003), and protein (3-nitrotyrosine, 3-NT: SMD = 0.86; 95% CI = 0.21-1.51; p = 0.01; dityrosine, DT: SMD = 0.66; 95% CI = 0.521-0.80; p < 0.01) damage. There were no significant differences between ASD and controls in 8-isoprostane and oxidative stress index after publication bias correction, and in N-formylkynurenine during overall meta-analysis.

CONCLUSIONS

TL, 8-OHdG, TAC, HEL, 3-NT, and DT represent potential biomarkers for prediction of ASD in children and adolescents.

The Role of Nutrition, Oxidative Stress, and Trace Elements in the Pathophysiology of Autism Spectrum Disorders

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficits in social communication and interaction, alongside repetitive behaviors, and atypical sensory-motor patterns. The growing prevalence of ASD has driven substantial advancements in research aimed at understanding its etiology, preventing its onset, and mitigating its impact. This ongoing effort necessitates continuous updates to the body of knowledge and the identification of previously unexplored factors. The present study addresses this need by examining the roles of nutrition, oxidative stress, and trace elements in the pathophysiology of ASD. In this review, an overview is provided of the key dietary recommendations for individuals with ASD, including gluten-free and casein-free (GFCF) diets, ketogenic diets (KDs), and other nutritional interventions. Furthermore, it explores the involvement of oxidative stress in ASD and highlights the significance of trace elements in maintaining neuropsychiatric health. The impact of these factors on molecular and cellular mechanisms was discussed, alongside therapeutic strategies and their efficacy in managing ASD.

NEAT1 Promotes Valproic Acid-Induced Autism Spectrum Disorder by Recruiting YY1 to Regulate UBE3A Transcription

Evidence suggests that long non-coding RNAs (lncRNAs) play a significant role in autism. Herein, we explored the functional role and possible molecular mechanisms of NEAT1 in valproic acid (VPA)-induced autism spectrum disorder (ASD). A VPA-induced ASD rat model was constructed, and a series of behavioral tests were performed to examine motor coordination and learning-memory abilities. qRT-PCR and western blot assays were used to evaluate target gene expression levels. Loss-and-gain-of-function assays were conducted to explore the functional role of NEAT1 in ASD development. Furthermore, a combination of mechanistic experiments and bioinformatic tools was used to assess the relationship and regulatory role of the NEAT1-YY1-UBE3A axis in ASD cellular processes. Results showed that VPA exposure induced autism-like developmental delays and behavioral abnormalities in the VPA-induced ASD rat model. We found that NEAT1 was elevated in rat hippocampal tissues after VPA exposure. NEAT1 promoted VPA-induced autism-like behaviors and mitigated apoptosis, oxidative stress, and inflammation in VPA-induced ASD rats. Notably, NEAT1 knockdown improved autism-related behaviors and ameliorated hippocampal neuronal damage. Mechanistically, it was observed that NEAT1 recruited the transcription factor YY1 to regulate UBE3A expression. Additionally, in vitro experiments further confirmed that NEAT1 knockdown mitigated hippocampal neuronal damage, oxidative stress, and inflammation through the YY1/UBE3A axis. In conclusion, our study demonstrates that NEAT1 is highly expressed in ASD, and its inhibition prominently suppresses hippocampal neuronal injury and oxidative stress through the YY1/UBE3A axis, thereby alleviating ASD development. This provides a new direction for ASD-targeted therapy.

Therapeutic Potential of Ocimum basilicum L. Extract in Alleviating Autistic-Like Behaviors Induced by Maternal Separation Stress in Mice: Role of Neuroinflammation and Oxidative Stress

A confluence of genetic, environmental, and epigenetic factors shapes autism spectrum disorder (ASD). Early-life stressors like MS play a contributing role in this multifaceted neurodevelopmental disorder. This research was to explore the efficacy of Ocimum basilicum L. (O.B.) extract in mitigating behaviors reminiscent of autism prompted by maternal separation (MS) stress in male mice, focusing on its impact on neuroinflammation and oxidative stress. MS mice were treated with O.B. extract at varying dosages (20, 40, and 60 mg/kg) from postnatal days (PND) 51-53 to PND 58-60. Behavioral experiments, including the Morris water maze, three-chamber test, shuttle box, and resident-intruder test, were conducted post-treatment. The method of maternal separation involved separating the pups from their mothers for 3 h daily, from PND 2 to PND 14. Molecular analysis of hippocampal tissue was performed to assess gene expression of Toll-like receptor 4 (TLR4), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). Hippocampal and serum malondialdehyde (MDA) levels and total antioxidant capacity (TAC) were measured. O.B. extract administration resulted in the amelioration of autistic-like behaviors in MS mice, as evidenced by improved spatial and passive avoidance memories and social interactions, as well as reduced aggression in behavioral tests. O.B. extract attenuated oxidative stress and neuroinflammation, as indicated by decreased MDA and increased TAC levels, as well as downregulation of TLR4, TNF-α, and IL-1β expression in the hippocampus. O.B. extract may offer a novel therapeutic avenue for ASD, potentially mediated through its anti-inflammatory and antioxidant properties.

RFW captures species-level metagenomic functions by integrating genome annotation information

Functional profiling of whole-metagenome shotgun sequencing (WMS) enables our understanding of microbe-host interactions. We demonstrate microbial functional information loss by current annotation methods at both the taxon and community levels, particularly at lower read depths. To address information loss, we develop a framework, RFW (reference-based functional profile inference on WMS), that utilizes information from genome functional annotations and taxonomic profiles to infer microbial function abundances from WMS. Furthermore, we provide an algorithm for absolute abundance change quantification between groups as part of the RFW framework. By applying RFW to several datasets related to autism spectrum disorder and colorectal cancer, we show that RFW augments downstream analyses, such as differential microbial function identification and association analysis between microbial function and host phenotype. RFW is open source and freely available at https://github.com/Xingyinliu-Lab/RFW.

Plasma vitamin levels and pathway analysis in boys with autism spectrum disorders

Abnormal feeding behaviors and inadequate nutrient intake of children with autism spectrum disorder (ASD) have been reported. This study aimed to examine the plasma vitamin status of boys with autism spectrum disorder (ASD) and to analyze the association between vitamin status and symptoms of ASD. A total of 45 boys with ASD (age = 3.25 ± 0.68 years) and 45 typically developing (TD) boys (age = 3.33 ± 0.66 years) were enrolled. The developmental levels were evaluated using the Gesell Developmental Schedules (GDS), the severity of ASD was evaluated using the Childhood Autism Rating Scale (CARS). The plasma vitamin levels were determined using metabolomics method. The Vitamin B1, nicotinamide, pyridoxamine dihydrochloride and Vitamin E were found to be significantly higher in the boys with ASD compared with those without ASD. In addition, no significant differences in vitamin metabolic pathways were found between the ASD group and the TD group.The nicotinamide and pyridoxamine dihydrochloride concentration were found to be negatively correlated with GDS score. In comparison with TD boys, the plasma vitamin concentration of ASD boys was not insufficient. Further studies are required to investigate whether it is necessary to use vitamin nutritional supplements in children with ASD.

N-Acetylcysteine Counteracts Immune Dysfunction and Autism-Related Behaviors in the Shank3b Mouse Model of Autism Spectrum Disorder

Autism spectrum disorder (ASD) includes a range of neurodevelopmental disabilities characterized by social interaction deficits, communication impairments, and repetitive behaviors. Previous studies have shown that pro-inflammatory conditions play a key role in ASD. Despite this, how oxidative stress and inflammation may contribute to ASD-related behaviors is still poorly understood. Here, we reported that increased levels of molecules related to inflammation are present in the cerebellum and peripheral blood (PB) of mice lacking Shank3b, an established model of syndromic ASD. In parallel, immune dysfunction was documented in the bone marrow (BM) and spleens of mutant mice. N-acetylcysteine (NAC) treatment rescued inflammation in the cerebellum and PB and impaired the production of pro-inflammatory molecules in the BM and spleen. In addition, social impairment was counteracted in NAC-treated Shank3b-/- animals. Taken together, our results provide clear evidence of the key role of cerebellar oxidative stress and inflammation in the establishment of ASD-related behaviors. Furthermore, our findings underscore the importance of considering ASD as a systemic disorder.

Proteomics analysis of extracellular vesicles for biomarkers of autism spectrum disorder

Background

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by symptoms that include social interaction deficits, language difficulties and restricted, repetitive behavior. Early intervention through medication and behavioral therapy can eliminate some ASD-related symptoms and significantly improve the life-quality of the affected individuals. Currently, the diagnosis of ASD is highly limited.

Methods

To investigate the feasibility of early diagnosis of ASD, we tested extracellular vesicles (EVs) proteins obtained from ASD cases. First, plasma EVs were isolated from healthy controls (HCs) and ASD individuals and were analyzed using proximity extension assay (PEA) technology to quantify 1,196 protein expression level. Second, machine learning analysis and bioinformatic approaches were applied to explore how a combination of EV proteins could serve as biomarkers for ASD diagnosis.

Results

No significant differences in the EV morphology and EV size distribution between HCs and ASD were observed, but the EV number was slightly lower in ASD plasma. We identified the top five downregulated proteins in plasma EVs isolated from ASD individuals: WW domain-containing protein 2 (WWP2), Heat shock protein 27 (HSP27), C-type lectin domain family 1 member B (CLEC1B), Cluster of differentiation 40 (CD40), and folate receptor alpha (FRalpha). Machine learning analysis and correlation analysis support the idea that these five EV proteins can be potential biomarkers for ASD.

Conclusion

We identified the top five downregulated proteins in ASD EVs and examined that a combination of EV proteins could serve as biomarkers for ASD diagnosis.

Effects of low-dose ionizing radiation on the molecular pathways linking neurogenesis and autism spectrum disorders in zebrafish embryos

Prenatal exposure to environmental factors may play an important role in the aetiopathogenesis of autism spectrum disorder (ASD). We aim to investigate the potential effects of low-dose x-rays from dental diagnostic x-rays on neurodevelopment and molecular mechanisms associated with ASD in developing zebrafish embryos. Zebrafish embryos were divided into four groups and exposed using a dental x-ray unit: control, 0.08, 0.15 and 0.30 seconds, which are exemplary exposure settings for periapical imaging. These exposure times were measured as 7.17, 23.17 and 63.83 mSv using optical stimulated luminescence dosimeters. At the end of 72 hours post-fertilization, locomotor activity, oxidant-antioxidant status, and acetylcholine esterase (AChE) activity were analyzed. Expression of genes related to apoptosis (bax, bcl2a, p53), neurogenesis (α1-tubulin, syn2a, neurog1, elavl3) and ASD (eif4eb, adsl2a, shank3) was determined by RT-PCR. Even at reduced doses, developmental toxicity was observed in three groups as evidenced by pericardial edema, yolk sac edema and scoliosis. Deleterious effects of dental x-rays on neurogenesis through impaired locomotor activity, oxidative stress, apoptosis and alterations in genes associated with neurogenesis and ASD progression were more pronounced in the 0.30s exposure group. Based on these results we suggest that the associations between ASD and low-dose ionizing radiation need a closer look.

Transmethylation and Oxidative Biomarkers in Children with Autism Spectrum Disorder: A Cross Sectional Study

We aimed to investigate the potential role of biomarkers of transmethylation, oxidative stress, and mitochondrial dysfunction in children with Autism Spectrum Disorder (ASD) by comparing them with that of typically developing children (TDC) controls. We also tried to correlate them with severity of autism, sensory issues, behavioural comorbidities and developmental quotients 119 with ASD and 52 age and sex matched typically developing children (TDC) controls were enrolled excluding those with chronic-illness or on any antioxidant therapy/multivitamins/anti-epileptic drugs. Median levels of biomarkers - serum homocysteine, cysteine, methionine, urine uric acid-to-creatinine ratio, arterial lactate, serum vitamin E, vitamin B12, folate, Nε-carboxymethyllysine, Nω- carboxymethylarginine (CMA), dityrosine and MTHFR C677T polymorphism were calculated. Children with ASD were further characterised using Childhood Autism Rating Scale-2, Childhood behavioural checklist, child sensory profile 2 caregiver questionnaire, Developmental Profile 3 for any correlation with the various biomarker levels. The median level of serum homocysteine in ASD group was 9 μmol/L(Range, 7- 16μmol/L), which was significantly higher than controls 7 μmol/L(Range, 4- 11μmol/L)(p=0.01). The prevalence of hyper-homocystinemia(>15μmol/L) was 13.4% in ASD as compared to 3.8% in controls with a significant difference(p=0.04). Dityrosine level was higher among ASD children when compared to TDC (9.8 vs 2.2 counts per second(cps), p<0.001). No significant correlation was found between prevalence of hyperhomocysteinemia and severity of autism/DQ/behavioural issues. No significant difference was found between the median levels of other biomarkers. Results support possible role of transmethylation defects and oxidative stress in ASD pathogenesis. Further studies are warranted for a better understanding of ASD pathogenesis.

GPR50 regulates neuronal development as a mitophagy receptor

Neurons rely heavily on high mitochondrial metabolism to provide sufficient energy for proper development. However, it remains unclear how neurons maintain high oxidative phosphorylation (OXPHOS) during development. Mitophagy plays a pivotal role in maintaining mitochondrial quality and quantity. We herein describe that G protein-coupled receptor 50 (GPR50) is a novel mitophagy receptor, which harbors the LC3-interacting region (LIR) and is required in mitophagy under stress conditions. Although it does not localize in mitochondria under normal culturing conditions, GPR50 is recruited to the depolarized mitochondrial membrane upon mitophagy stress, which marks the mitochondrial portion and recruits the assembling autophagosomes, eventually facilitating the mitochondrial fragments to be engulfed by the autophagosomes. Mutations Δ502-505 and T532A attenuate GPR50-mediated mitophagy by disrupting the binding of GPR50 to LC3 and the mitochondrial recruitment of GPR50. Deficiency of GPR50 causes the accumulation of damaged mitochondria and disrupts OXPHOS, resulting in insufficient ATP production and excessive ROS generation, eventually impairing neuronal development. GPR50-deficient mice exhibit impaired social recognition, which is rescued by prenatal treatment with mitoQ, a mitochondrially antioxidant. The present study identifies GPR50 as a novel mitophagy receptor that is required to maintain mitochondrial OXPHOS in developing neurons.

Altered leptin level in autism spectrum disorder and meta-analysis of adipokines

BACKGROUND

Increasing evidence suggests that leptin is involved in the pathology of autism spectrum disorder (ASD). In this study, our objective was to investigate the levels of leptin in the blood of children with ASD and to examine the overall profile of adipokine markers in ASD through meta-analysis.

METHODS

Leptin concentrations were measured using an enzyme-linked immunosorbent assay (ELISA) kit, while adipokine profiling, including leptin, was performed via meta-analysis. Original reports that included measurements of peripheral adipokines in ASD patients and healthy controls (HCs) were collected from databases such as Web of Science, PubMed, and Cochrane Library. These studies were collected from September 2022 to September 2023 and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Standardized mean differences were calculated using a random effects model for the meta-analysis. Additionally, we performed meta-regression and explored heterogeneity among studies.

RESULTS

Our findings revealed a significant increase in leptin levels in children with ASD compared to HCs (p = 0.0319). This result was consistent with the findings obtained from the meta-analysis (p < 0.001). Furthermore, progranulin concentrations were significantly reduced in children with ASD. However, for the other five adipokines analyzed, there were no significant differences observed between the children with ASD and HCs children. Heterogeneity was found among the studies, and the meta-regression analysis indicated that publication year and latitude might influence the results of the meta-analysis.

CONCLUSIONS

These findings provide compelling evidence that leptin levels are increased in children with ASD compared to healthy controls, suggesting a potential mechanism involving adipokines, particularly leptin, in the pathogenesis of ASD. These results contribute to a better understanding of the pathology of ASD and provide new insights for future investigations.

Abnormal Porphyrin Metabolism in Autism Spectrum Disorder and Therapeutic Implications

Autism spectrum disorder (ASD) is a mosaic of neurodevelopmental conditions composed of early-onset social interaction and communication deficits, along with repetitive and/or restricted patterns of activities, behavior, and interests. ASD affects around 1% of children worldwide, with a male predominance. Energy, porphyrin, and neurotransmitter homeostasis are the key metabolic pathways affected by heavy metal exposure, potentially implicated in the pathogenesis of ASD. Exposure to heavy metals can lead to an altered porphyrin metabolism due to enzyme inhibition by heavy metals. Heavy metal exposure, inborn genetic susceptibility, and abnormal thiol and selenol metabolism may play a significant role in the urinary porphyrin profile anomalies observed in ASD. Altered porphyrin metabolism in ASD may also be associated with, vitamin B6 deficiency, hyperoxalemia, hyperhomocysteinemia, and hypomagnesemia. The present review considers the abnormal porphyrin metabolism in ASD in relation to the potential pathogenic mechanism and discusses the possible metabolic therapies such as vitamins, minerals, cofactors, and antioxidants that need to be explored in future research. Such targeted therapeutic therapies would bring about favorable outcomes such as improvements in core and co-occurring symptoms.

Newborn Dried Blood Spot Folate in Relation to Maternal Self-reported Folic Acid Intake, Autism Spectrum Disorder, and Developmental Delay

BACKGROUND

Maternal folic acid intake has been associated with decreased risk for neurodevelopmental disorders including autism spectrum disorder (ASD). Genetic differences in folate metabolism could explain some inconsistencies. To our knowledge, newborn folate concentrations remain unexamined.

METHODS

We measured folate in archived newborn dried blood spots of children from the CHARGE (Childhood Autism Risks from Genetics and the Environment) case-control study who were clinically confirmed at 24-60 months to have ASD (n = 380), developmental delay (n = 128), or typical development (n = 247). We quantified monthly folic acid intake from maternally-reported supplements and cereals consumed during pregnancy and 3 months prior. We assessed associations of newborn folate with maternal folic acid intake and with ASD or developmental delay using regression. We stratified estimates across maternal and child MTHFR genotypes.

RESULTS

Among typically developing children, maternal folic acid intake in prepregnancy and each pregnancy month and prepregnancy prenatal vitamin intake were positively associated with newborn folate. Among children with ASD, prenatal vitamin intake in pregnancy months 2-9 was positively associated with newborn folate. Among children with developmental delay, maternal folic acid and prenatal vitamins during the first pregnancy month were positively associated with neonatal folate. Associations differed by MTHFR genotype. Overall, neonatal folate was not associated with ASD or developmental delay, though we observed associations with ASD in children with the MTHFR 677 TT genotype (odds ratio: 1.76, 95% CI = 1.19, 2.62; P for interaction = 0.08).

CONCLUSION

Maternal prenatal folic acid intake was associated with neonatal folate at different times across neurodevelopmental groups. Neonatal folate was not associated with reduced ASD risk. MTHFR genotypes modulated these relationships.

Metabolomic changes in children with autism

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficits in social communication and repetitive behaviors. Metabolomic profiling has emerged as a valuable tool for understanding the underlying metabolic dysregulations associated with ASD.

AIM

To comprehensively explore metabolomic changes in children with ASD, integrating findings from various research articles, reviews, systematic reviews, meta-analyses, case reports, editorials, and a book chapter.

METHODS

A systematic search was conducted in electronic databases, including PubMed, PubMed Central, Cochrane Library, Embase, Web of Science, CINAHL, Scopus, LISA, and NLM catalog up until January 2024. Inclusion criteria encompassed research articles (83), review articles (145), meta-analyses (6), systematic reviews (6), case reports (2), editorials (2), and a book chapter (1) related to metabolomic changes in children with ASD. Exclusion criteria were applied to ensure the relevance and quality of included studies.

RESULTS

The systematic review identified specific metabolites and metabolic pathways showing consistent differences in children with ASD compared to typically developing individuals. These metabolic biomarkers may serve as objective measures to support clinical assessments, improve diagnostic accuracy, and inform personalized treatment approaches. Metabolomic profiling also offers insights into the metabolic alterations associated with comorbid conditions commonly observed in individuals with ASD.

CONCLUSION

Integration of metabolomic changes in children with ASD holds promise for enhancing diagnostic accuracy, guiding personalized treatment approaches, monitoring treatment response, and improving outcomes. Further research is needed to validate findings, establish standardized protocols, and overcome technical challenges in metabolomic analysis. By advancing our understanding of metabolic dysregulations in ASD, clinicians can improve the lives of affected individuals and their families.

Exposure to organophosphate, pyrethroid, and neonicotinoid insecticides and dyslexia: Association with oxidative stress

Organophosphates (OPPs), pyrethroids (PYRs), and neonicotinoids (NNIs) are three major classes of insecticides used worldwide. They might compromise child neurodevelopment. However, few studies have explored the association between exposure to them and dyslexia. The present study aimed to investigate the association between dyslexia and exposure to the three classes of insecticides, as well as explore the potential role of oxidative stress in the association. A total of 355 dyslexic children and 390 controls were included in this study. The exposure biomarkers were determined by liquid chromatography-tandem mass spectrometry. Specifically, the exposure biomarkers included three typical metabolites of OPPs, three of PYRs, and nine of NNIs. Additionally, three typical oxidative stress biomarkers, namely, 8-hydroxy-2'-deoxyguanosine (8-OHdG) for DNA damage, 8-hydroxyguanosine (8-OHG) for RNA damage, and 4-hydroxy-2-nonenal-mercapturic acid (HNEMA) for lipid peroxidation were measured. The detection frequencies of the urinary biomarkers ranged from 83.9% to 100%. Among the target metabolites of the insecticides, a significant association was observed between urinary 3,5,6-trichloro-2-pyridinol (TCPy, the metabolite of chlorpyrifos, an OPP insecticide) and dyslexia. After adjusting for potential confounding variables, children in the highest quartile of TCPy levels had an increased odds of dyslexia (odds ratio [OR], 1.68; 95% confidence interval [CI]: 1.03, 2.75] in comparison to those in the lowest quartile. Among the three oxidative stress biomarkers, urinary HNEMA concentration showed a significant relationship with dyslexia. Children in the highest quartile of HNEMA levels demonstrated an increased dyslexic odds in comparison to those in the lowest quartile after multiple adjustments (OR, 1.64; 95% CI: 1.01, 2.65). Mediation analysis indicated a significant effect of HNEMA in the association between urinary TCPy and dyslexia, with an estimate of 17.2% (P < 0.01). In conclusion, this study suggested the association between urinary TCPy and dyslexia. The association could be attributed to lipid peroxidation partially.

Autism spectrum disorder: pathogenesis, biomarker, and intervention therapy

Autism spectrum disorder (ASD) has become a common neurodevelopmental disorder. The heterogeneity of ASD poses great challenges for its research and clinical translation. On the basis of reviewing the heterogeneity of ASD, this review systematically summarized the current status and progress of pathogenesis, diagnostic markers, and interventions for ASD. We provided an overview of the ASD molecular mechanisms identified by multi-omics studies and convergent mechanism in different genetic backgrounds. The comorbidities, mechanisms associated with important physiological and metabolic abnormalities (i.e., inflammation, immunity, oxidative stress, and mitochondrial dysfunction), and gut microbial disorder in ASD were reviewed. The non-targeted omics and targeting studies of diagnostic markers for ASD were also reviewed. Moreover, we summarized the progress and methods of behavioral and educational interventions, intervention methods related to technological devices, and research on medical interventions and potential drug targets. This review highlighted the application of high-throughput omics methods in ASD research and emphasized the importance of seeking homogeneity from heterogeneity and exploring the convergence of disease mechanisms, biomarkers, and intervention approaches, and proposes that taking into account individuality and commonality may be the key to achieve accurate diagnosis and treatment of ASD.

Exploratory Analysis of MicroRNA Alterations in a Neurodevelopmental Mouse Model for Autism Spectrum Disorder and Schizophrenia

MicroRNAs (miRNAs) play a crucial role in the regulation of gene expression levels and have been implicated in the pathogenesis of autism spectrum disorder (ASD) and schizophrenia (SCZ). In this study, we examined the adult expression profiles of specific miRNAs in the prefrontal cortex (PFC) of a neurodevelopmental mouse model for ASD and SCZ that mimics perinatal pathology, such as NMDA receptor hypofunction, and exhibits behavioral and neurophysiological phenotypes related to these disorders during adulthood. To model the early neuropathogenesis of the disorders, mouse pups were administered subcutaneously with ketamine (30 mg/Kg) at postnatal days 7, 9, and 11. We focused on a set of miRNAs most frequently altered in ASD (miR-451a and miR-486-3p) and in SCZ (miR-132-3p and miR-137-3p) according to human studies. Additionally, we explored miRNAs whose alterations have been identified in both disorders (miR-21-5p, miR-92a-2-5p, miR-144-3p, and miR-146a-5p). We placed particular emphasis on studying the sexual dimorphism in the dynamics of these miRNAs. Our findings revealed significant alterations in the PFC of this ASD- and SCZ-like mouse model. Specifically, we observed upregulated miR-451a and downregulated miR-137-3p. Furthermore, we identified sexual dimorphism in the expression of miR-132-3p, miR-137-3p, and miR-92a-2-5p. From a translational perspective, our results emphasize the potential involvement of miR-92a-2-5p, miR-132-3p, miR-137-3p, and miR-451a in the pathophysiology of ASD and SCZ and strengthen their potential as biomarkers and therapeutic targets of such disorders.

Ascorbate and its transporter SVCT2: The dynamic duo's integrated roles in CNS neurobiology and pathophysiology

Ascorbate is a small antioxidant molecule essential for the proper development and function of the brain. Ascorbate is transported into the brain and between brain cells via the Sodium vitamin C co-transporter 2 (SVCT2). This review provides an in-depth analysis of ascorbate's physiology, including how ascorbate is absorbed from food into the CNS, emphasizing cellular mechanisms of ascorbate recycling and release in different CNS compartments. Additionally, the review delves into the various functions of ascorbate in the CNS, including its impact on epigenetic modulation, synaptic plasticity, and neurotransmission. It also emphasizes ascorbate's role on neuromodulation and its involvement in neurodevelopmental processes and disorders. Furthermore, it analyzes the relationship between the duo ascorbate/SVCT2 in neuroinflammation, particularly its effects on microglial activation, cytokine release, and oxidative stress responses, highlighting its association with neurodegenerative diseases, such as Alzheimer's disease (AD). Overall, this review emphasizes the crucial role of the dynamic duo ascorbate/SVCT2 in CNS physiology and pathology and the need for further research to fully comprehend its significance in a neurobiological context and its potential therapeutic applications.

The role and impact of abnormal vitamin levels in autism spectrum disorders

The prevalence of autism spectrum disorder (ASD), a neurodevelopmental disorder with a predominance of social behavioral disorders, has increased dramatically in various countries in recent decades. The interplay between genetic and environmental factors is believed to underlie ASD pathogenesis. Recent analyses have shown that abnormal vitamin levels in early life are associated with an increased risk of autism. As essential substances for growth and development, vitamins have been shown to have significant benefits for the nervous and immune systems. However, it is unknown whether certain vitamin types influence the emergence or manifestation of ASD symptoms. Several studies have focused on vitamin levels in children with autism, and neurotypical children have provided different insights into the types of vitamins and their intake. Here, we review the mechanisms and significance of several vitamins (A, B, C, D, E, and K) that are closely associated with the development of ASD in order to prevent, mitigate, and treat ASD. Efforts have been made to discover and develop new indicators for nutritional assessment of children with ASD to play a greater role in the early detection of ASD and therapeutic remission after diagnosis.

Genetic evidence for causal effects of immune dysfunction in psychiatric disorders: where are we?

The question of whether immune dysfunction contributes to risk of psychiatric disorders has long been a subject of interest. To assert this hypothesis a plethora of correlative evidence has been accumulated from the past decades; however, a variety of technical and practical obstacles impeded on a cause-effect interpretation of these data. With the advent of large-scale omics technology and advanced statistical models, particularly Mendelian randomization, new studies testing this old hypothesis are accruing. Here we synthesize these new findings from genomics and genetic causal inference studies on the role of immune dysfunction in major psychiatric disorders and reconcile these new data with pre-omics findings. By reconciling these evidences, we aim to identify key gaps and propose directions for future studies in the field.

Rodent Models for ASD Biomarker Development

Advances in molecular biology and genetics are increasingly revealing the complex etiology of autism spectrum disorder (ASD). In parallel, a number of biochemical, anatomical, and electrophysiological measures are emerging as potential disease-relevant biomarkers that could inform the diagnosis and clinical management of ASD. Rodent ASD models play a key role in ASD research as essential experimental tools. Nevertheless, there are challenges and limitations to the validity and translational value of rodent models, including genetic relevance and cognitive performance differences between humans and rodents. In this chapter, we begin with a brief history of autism research, followed by prominent examples of disease-relevant mouse models enabled by current knowledge of genetics, molecular biology, and bioinformatics. These ASD-associated rodent models enable quantifiable biomarker development. Finally, we discuss the prospects of ASD biomarker development.

Glutathione Therapy in Diseases: Challenges and Potential Solutions for Therapeutic Advancement

An endogenous antioxidant, reduced glutathione (GSH), is found at high concentrations in nearly all typical cells. GSH synthesis is a controlled process, and any disruption in the process of GSH synthesis could result in GSH depletion. Cellular oxidative damage results from GSH depletion. Various pathological conditions such as aging, cardiovascular disease (CVD), psychiatric disorders, neurological disorders, liver disorders, and diabetes mellitus are more affected by this stress. There are various reasons for GSH reduction, but replenishing it can help to improve this condition. However, there are challenges in this field. Low bioavailability and poor stability of GSH limit its delivery to tissues, mainly brain tissue. Today, new approaches are used for the optimal amount and efficiency of drugs and alternative substances such as GSH. The use of nano-materials and liposomes are effective methods for improving the treatment effects of GSH. The difficulties of GSH decrease and its connection to the most important associated disorders are reviewed for the first time in this essay. The other major concerns are the molecular mechanisms involved in them; the impact of treatment with replacement GSH; the signaling pathways impacted; and the issues with alternative therapies. The utilization of nano-materials and liposomes as potential new approaches to solving these issues is being considered.

Advances in the Treatment of Autism Spectrum Disorder: Current and Promising Strategies

Autism spectrum disorder (ASD) is an umbrella term for developmental disorders characterized by social and communication impairments, language difficulties, restricted interests, and repetitive behaviors. Current management approaches for ASD aim to resolve its clinical manifestations based on the type and severity of the disability. Although some medications like risperidone show potential in regulating ASD-associated symptoms, a comprehensive treatment strategy for ASD is yet to be discovered. To date, identifying appropriate therapeutic targets and treatment strategies remains challenging due to the complex pathogenesis associated with ASD. Therefore, a comprehensive approach must be tailored to target the numerous pathogenetic pathways of ASD. From currently viable and basic treatment strategies, this review explores the entire field of advancements in ASD management up to cutting-edge modern scientific research. A novel systematic and personalized treatment approach is suggested, combining the available medications and targeting each symptom accordingly. Herein, summarize and categorize the most appropriate ways of modern ASD management into three distinct categories: current, promising, and prospective strategies.

Transcriptome Analysis and Epigenetics Regulation in the Hippocampus and the Prefrontal Cortex of VPA-Induced Rat Model

Autism spectrum disorders (ASD) are a highly heterogeneous group of neurodevelopmental disorders caused by complex interaction between various genes and environmental factors. As the hippocampus and prefrontal cortex are involved in social recognition, they are the regions of the brain implicated in autism. The effects of prenatal exposure to valproic acid (VPA) can induce an ASD phenotype in both humans and rats; this tool is commonly used to model the complexity of ASD symptoms in the laboratory. However, researchers rarely undertake epigenetic regulation of the brain regions using this model. The present study has addressed this gap by examining gene expression abnormalities in the hippocampus and prefrontal cortex in the VPA rat model of ASD. mRNA and miRNA sequencing was performed on samples from the hippocampus and prefrontal cortex of the VPA model of autism. According to the analysis, 3000 mRNAs in the hippocampus and 2187 mRNAs in the prefrontal cortex showed a significant difference in expression between the VPA and saline groups. In addition, there were 115 DE miRNAs in the hippocampus and 14 DE miRNAs in the prefrontal cortex. Further, the predicted and validated target mRNA of DE miRNA enriched pathways involved neurotransmitter uptake, long-term synaptic depression, and AMPA receptor complex (anti-GluA2-b) in the hippocampus; as well as the neuroactive ligand-receptor interaction and regulation of postsynaptic membrane potential in the prefrontal cortex. This revealed the negative regulation network of miRNAs-mRNAs in the hippocampus and prefrontal cortex, while filtering out key genes (miR-10a-5p and Grm3). Finally, the significant variable miR-10a-5p and its negative regulated genes (Grm3) were verified in both brain regions by QPCR. Importantly, the fact that miR-10a-5p downregulated Grm3 in both the hippocampus and the prefrontal cortex may play a potentially significant role in the occurrence and development of autism. This study suggests that the VPA model has the potential to reproduce ASD-related hippocampus and prefrontal cortex abnormalities, at the epigenetic and transcriptional levels. Furthermore, the network of miRNAs-mRNAs was confirmed; this negative regulatory relationship may play a key role in determining the occurrence and development of autism. The study of this topic help better understand the pathogenesis of ASD.

Correlation between Vitamin B12 and Mental Health in Children and Adolescents: A Systematic Review and Meta-analysis

To conduct the association between vitamin B12 and mental health in children and adolescents. Five databases were searched for observational studies in any language reporting on mental health and vitamin B12 levels or intake in children and adolescents from inception to March 18, 2022. Two authors independently extracted data and assessed study quality. Qualitative and quantitative analysis of data were performed. The review was registered in the PROSPERO database (CRD42022345476). Fifty six studies containing 37,932 participants were identified in the review. Vitamin B12 levels were lower in participants with autism spectrum disorders (ASD) (standardized mean difference [SMD], -1.61; 95% confidence interval [95% CI], -2.44 to -0.79; p ＜ 0.001), attention deficit hyperactivity disorders (SMD, -0.39; 95% CI, -0.78 to -0.00; p = 0.049) compared with control group. Vitamin B12 intake were lower in participants with ASDs (SMD, -0.86; 95% CI, -1.48 to -0.24; p = 0.006) compared with control group, but showed no difference between depression group (SMD, -0.06; 95% CI, -0.15 to 0.03; p = 0.17) and the control group. Higher vitamin B12 intake were associated with lower risk of depression (odds ratio [OR], 0.79; 95% CI, 0.63-0.98; p = 0.034) and behavioral problems (OR, 0.83; 95% CI, 0.69-0.99; p = 0.04). The vast majority of included studies supported potential positive influence of vitamin B12 on mental health, and vitamin B12 deficiency may be a reversible cause for some mental health disorders in children and adolescents.

(R)-ketamine attenuates neurodevelopmental disease-related phenotypes in a mouse model of maternal immune activation

Infections during pregnancy are associated with an increased risk of neuropsychiatric disorders with developmental etiologies, such as schizophrenia and autism spectrum disorders (ASD). Studies have shown that the animal model of maternal immune activation (MIA) reproduces a wide range of phenotypes relevant to the study of neurodevelopmental disorders. Emerging evidence shows that (R)-ketamine attenuates behavioral, cellular, and molecular changes observed in animal models of neuropsychiatric disorders. Here, we investigate whether (R)-ketamine administration during adolescence attenuates some of the phenotypes related to neurodevelopmental disorders in an animal model of MIA. For MIA, pregnant Swiss mice received intraperitoneally (i.p.) lipopolysaccharide (LPS; 100 µg/kg/day) or saline on gestational days 15 and 16. The two MIA-based groups of male offspring received (R)-ketamine (20 mg/kg/day; i.p.) or saline from postnatal day (PND) 36 to 50. At PND 62, the animals were examined for anxiety-like behavior and locomotor activity in the open-field test (OFT), as well as in the social interaction test (SIT). At PND 63, the prefrontal cortex (PFC) was collected for analysis of oxidative balance and gene expression of the cytokines IL-1β, IL-6, and TGF-β1. We show that (R)-ketamine abolishes anxiety-related behavior and social interaction deficits induced by MIA. Additionally, (R)-ketamine attenuated the increase in lipid peroxidation and the cytokines in the PFC of the offspring exposed to MIA. The present work suggests that (R)-ketamine administration may have a long-lasting attenuation in deficits in emotional behavior induced by MIA, and that these effects may be attributed to its antioxidant and anti-inflammatory activity in the PFC.

Saffron and crocin ameliorate prenatal valproic acid-induced autistic-like behaviors and brain oxidative stress in the male offspring rats

Autism is a neurobehavioral disease that induces cognitive and behavioral alterations, usually accompanied by oxidative stress in the brain. Crocus sativus (saffron) and its active ingredient, crocin, have potent antioxidative effects that may benefit autistic behaviors. This study aimed to determine the effects of saffron extract and crocin against brain oxidative stress and behavioral, motor, and cognitive deficits in an animal model of autism in male offspring rats. 14 female rats were randomly divided into the saline and valproic acid (VPA) groups. Then, they were placed with mature male rats to mate and produce offspring. VPA (500 mg/kg, i.p.) was injected on day 12.5 of pregnancy (gestational day, GD 12.5) to induce an experimental model of autism. 48 male pups were left undisturbed for 29 days. First-round behavioral tests (before treatments) were performed on 30-33 post-natal days (PND), followed by 28 days of treatment (PND 34-61) with saffron (30 mg/kg, IP), crocin (15 or 30 mg/kg, i.p.), or saline (2 ml/kg, i.p.). The second round of behavioral tests (after treatments) was performed on PND 62-65 to assess the effects of the treatments on behavioral and cognitive features. In the end, animals were sacrificed under deep anesthesia, and their brains were dissected to evaluate the brain oxidative stress parameters, including malondialdehyde (MDA), glutathione (GSH), and catalase (CAT). VPA injection into female rats increased anxiety-like behaviors, enhanced pain threshold, impaired motor functions, disturbed balance power, increased MDA, and decreased GSH and CAT in their male offspring. 28 days of treatment with saffron or crocin significantly ameliorated behavioral abnormalities, reduced MDA, and increased GSH and CAT levels. Brain oxidative stress has been implicated in the pathophysiology of autistic-like behaviors. Saffron and crocin ameliorate anxiety-like behaviors, pain responses, motor functions, and brain oxidative stress parameters in an experimental model of autism. Saffron and crocin may hold promise as herbal-based pharmacological treatments for individuals with autism. However, further histological evidence is needed to confirm their efficacy.

Mass spectrometry-based analysis of gut microbial metabolites of aromatic amino acids

Small molecules derived from gut microbiota have been increasingly investigated to better understand the functional roles of the human gut microbiome. Microbial metabolites of aromatic amino acids (AAA) have been linked to many diseases, such as metabolic disorders, chronic kidney diseases, inflammatory bowel disease, diabetes, and cancer. Important microbial AAA metabolites are often discovered via global metabolite profiling of biological specimens collected from humans or animal models. Subsequent metabolite identity confirmation and absolute quantification using targeted analysis enable comparisons across different studies, which can lead to the establishment of threshold concentrations of potential metabolite biomarkers. Owing to their excellent selectivity and sensitivity, hyphenated mass spectrometry (MS) techniques are often employed to identify and quantify AAA metabolites in various biological matrices. Here, we summarize the developments over the past five years in MS-based methodology for analyzing gut microbiota-derived AAA. Sample preparation, method validation, analytical performance, and statistical methods for correlation analysis are discussed, along with future perspectives.

Does Lead Have a Connection to Autism? A Systematic Review and Meta-Analysis

Environmental pollutants, particularly toxic trace metals with neurotoxic potential, have been related to the genesis of autism. One of these metals that stands out, in particular, is lead (Pb). We conducted an in-depth systematic review and meta-analysis of peer-reviewed studies on Pb levels in biological materials retrieved from autistic children (cases) and neurotypical children (controls) in this work. A systematic review was conducted after the careful selection of published studies according to established criteria to gain a broad insight into the higher or lower levels of Pb in the biological materials of cases and controls, and the findings were then strengthened by a meta-analysis. The meta-analysis included 17 studies (hair), 13 studies (whole blood), and 8 studies (urine). The overall number of controls/cases was 869/915 (hair), 670/755 (whole blood), and 344/373 (urine). This meta-analysis showed significantly higher Pb levels in all three types of biological material in cases than in controls, suggesting a higher body Pb burden in autistic children. Thus, environmental Pb exposure could be related to the genesis of autism. Since no level of Pb can be considered safe, the data from this study undoubtedly point to the importance of regularly monitoring Pb levels in autistic children.

N-acetylcysteine improves autism-like behavior by recovering autophagic deficiency and decreasing Notch-1/Hes-1 pathway activity

N-acetylcysteine (NAC) has been reported to improve social interaction behavior, irritability, self-injury, and anxiety-like behavior in autism. However, the molecular mechanism underlying the therapeutic roles of NAC in autism remains unknown. This study mainly aimed to investigate the therapeutic effect of NAC on valproic acid (VPA)-induced autism model and the underlying mechanisms. Our results showed that NAC ameliorated the deficits in sociability and the anxiety- and repetitive-like behaviors displayed by VPA-exposed rats. In addition, VPA exposure induced autophagic deficiency and enhanced Notch-1/Hes-1 pathway activity based on lowered Beclin-1 and LC3B levels, while increased expression of p62, Notch-1, and Hes-1 expression at the protein level. However, NAC recovered VPA-induced autophagic deficiency and reduced Notch-1/Hes-1 pathway activity in a VPA-exposed autism rat model and SH-SY5Y neural cells. The present results demonstrated that NAC improves autism-like behavioral abnormalities by inactivating Notch-1/Hes-1 signaling pathway and recovering autophagic deficiency. Taken together, this study helps to elucidate a novel molecular mechanism that underlies the therapeutic actions of NAC in autism and suggests its potential to ameliorate behavioral abnormalities in neurodevelopmental disorders.

Candidate biomarkers in psychiatric disorders: state of the field

The field of psychiatry is hampered by a lack of robust, reliable and valid biomarkers that can aid in objectively diagnosing patients and providing individualized treatment recommendations. Here we review and critically evaluate the evidence for the most promising biomarkers in the psychiatric neuroscience literature for autism spectrum disorder, schizophrenia, anxiety disorders and post-traumatic stress disorder, major depression and bipolar disorder, and substance use disorders. Candidate biomarkers reviewed include various neuroimaging, genetic, molecular and peripheral assays, for the purposes of determining susceptibility or presence of illness, and predicting treatment response or safety. This review highlights a critical gap in the biomarker validation process. An enormous societal investment over the past 50 years has identified numerous candidate biomarkers. However, to date, the overwhelming majority of these measures have not been proven sufficiently reliable, valid and useful to be adopted clinically. It is time to consider whether strategic investments might break this impasse, focusing on a limited number of promising candidates to advance through a process of definitive testing for a specific indication. Some promising candidates for definitive testing include the N170 signal, an event-related brain potential measured using electroencephalography, for subgroup identification within autism spectrum disorder; striatal resting-state functional magnetic resonance imaging (fMRI) measures, such as the striatal connectivity index (SCI) and the functional striatal abnormalities (FSA) index, for prediction of treatment response in schizophrenia; error-related negativity (ERN), an electrophysiological index, for prediction of first onset of generalized anxiety disorder, and resting-state and structural brain connectomic measures for prediction of treatment response in social anxiety disorder. Alternate forms of classification may be useful for conceptualizing and testing potential biomarkers. Collaborative efforts allowing the inclusion of biosystems beyond genetics and neuroimaging are needed, and online remote acquisition of selected measures in a naturalistic setting using mobile health tools may significantly advance the field. Setting specific benchmarks for well-defined target application, along with development of appropriate funding and partnership mechanisms, would also be crucial. Finally, it should never be forgotten that, for a biomarker to be actionable, it will need to be clinically predictive at the individual level and viable in clinical settings.

Amelioration of Hepatotoxic and Neurotoxic Effect of Cartap by Aloe vera in Wistar Rats

Pesticide exposure can pose a serious risk to nontarget animals. Cartap is being broadly used in agricultural fields. The toxic effects of cartap on the levels of hepatotoxicity and neurotoxicity have not been properly studied in mammalian systems. Therefore, the present work focused on the effect of cartap on the liver and brain of Wistar rats and made an assessment of the ameliorating potential of A. vera. The experimental animals were divided into 4 groups, comprising six rats in each: Group 1-Control; Group 2-A. vera; Group 3-Cartap; and Group 4-A. vera + Cartap. The animals orally given cartap and A. vera were sacrificed after 24 h of the final treatment and histological and biochemical investigations were conducted in liver and brain of Wistar rats. Cartap at sublethal concentrations caused substantial decreases in CAT, SOD, and GST levels in the experimental rats. The activity levels of transaminases and phosphatases in cartap group were also found to be substantially altered. The AChE activity was recorded as decreasing in RBC membrane and brain of the cartap-treated animals. The TNF-α and IL-6 level in serum were increased expressively in the cartap challenged groups. Histological investigation of liver showed disorganized hepatic cords and severely congested central veins due to cartap. However, the A. vera extract was observed to significantly protect against the effects of cartap toxicity. The protective impact of A. vera against cartap toxicity may be due to the existence of antioxidants in it. These findings suggest that A. vera may be developed as a potential supplement to the appropriate medication in the treatment of cartap toxicity.

The use of data independent acquisition based proteomic analysis and machine learning to reveal potential biomarkers for autism spectrum disorder

Autism spectrum disorder (ASD) is a complex neurological developmental disorder in children, and is associated with social isolation and restricted interests. The etiology of this disorder is still unknown. There is neither any confirmed laboratory test nor any effective therapeutic strategy to diagnose or cure it. We performed data independent acquisition (DIA) and multiple reaction monitoring (MRM) analysis of plasma from children with ASD and controls. The result showed that 45 differentially expressed proteins (DEPs) were identified between autistic subjects and controls. Among these, only one DEP was down-regulated in ASD; other DEPs were up-regulated in ASD children's plasma. These proteins are found associated with complement and coagulation cascades, vitamin digestion and absorption, cholesterol metabolism, platelet degranulation, selenium micronutrient network, extracellular matrix organization and inflammatory pathway, which have been reported to be related to ASD. After MRM verification, five key proteins in complement pathway (PLG, SERPINC1, and A2M) and inflammatory pathway (CD5L, ATRN, SERPINC1, and A2M) were confirmed to be significantly up-regulated in ASD group. Through the screening of machine learning model and MRM verification, we found that two proteins (biotinidase and carbonic anhydrase 1) can be used as early diagnostic markers of ASD (AUC = 0.8, p = 0.0001). SIGNIFICANCE: ASD is the fastest growing neurodevelopmental disorder in the world and has become a major public health problem worldwide. Its prevalence has been steadily increasing, with a global prevalence rate of 1%. Early diagnosis and intervention can achieve better prognosis. In this study, data independent acquisition (DIA) and multiple reaction monitoring (MRM) analysis was applied to analyze the plasma proteome of ASD patients (31 (±5) months old), and 378 proteins were quantified. 45 differentially expressed proteins (DEPs) were identified between the ASD group and the control group. They mainly were associated with platelet degranulation, ECM proteoglycar, complement and coagulation cascades, selenium micronutrient network, regulation of insulin-like growth factor (IGF) transport and uptake by insulin-like growth factor binding proteins (IGFBPs), cholesterol metabolism, vitamin metabolism, and inflammatory pathway. Through the integrated machine learning methods and the MRM verification of independent samples, it is considered that biotinidase and carbon anhydrase 1 have the potential to become biomarkers for the early diagnosis of ASD. These results complement proteomics database of the ASD patients, broaden our understanding of ASD, and provide a panel of biomarkers for the early diagnosis of ASD.

Thiol disulfide homeostasis in psychiatric disorders: A comprehensive review

Thiol-disulfide couple maintains an intracellular redox status. Dynamic thiol-disulfide homeostasis acts crucial parts in metabolic processes involving signal mechanisms, inflammation, antioxidant defense. Thiol-disulfide homeostasis have been implicated in numerous diseases. In this comprehensive review we identified the studies that examined the thiol-disulfide homeostasis in psychiatric disorders. Most cases demonstrated alterations in thiol-disulfide homeostasis and in most of them the thiol-disulfide balance tended to change direction to the disulfide side, that is, to the oxidative side. Currently, the fact that N-acetylcysteine, a thiol-containing compound, is of great interest as a new treatment approach in psychiatric disorders and the role of glutathione, the most abundant thiol, in the brain highlights the importance of evaluating the thiol-disulfide balance in psychiatric disorders.