Aberrant NF-kappaB expression in autism spectrum condition: a mechanism for neuroinflammation

Targeting Microglia in Neuroinflammation: H3 Receptor Antagonists as a Novel Therapeutic Approach for Alzheimer's Disease, Parkinson's Disease, and Autism Spectrum Disorder

Histamine performs dual roles as an immune regulator and a neurotransmitter in the mammalian brain. The histaminergic system plays a vital role in the regulation of wakefulness, cognition, neuroinflammation, and neurogenesis that are substantially disrupted in various neurodegenerative and neurodevelopmental disorders. Histamine H3 receptor (H3R) antagonists and inverse agonists potentiate the endogenous release of brain histamine and have been shown to enhance cognitive abilities in animal models of several brain disorders. Microglial activation and subsequent neuroinflammation are implicated in impacting embryonic and adult neurogenesis, contributing to the development of Alzheimer's disease (AD), Parkinson's disease (PD), and autism spectrum disorder (ASD). Acknowledging the importance of microglia in both neuroinflammation and neurodevelopment, as well as their regulation by histamine, offers an intriguing therapeutic target for these disorders. The inhibition of brain H3Rs has been found to facilitate a shift from a proinflammatory M1 state to an anti-inflammatory M2 state, leading to a reduction in the activity of microglial cells. Also, pharmacological studies have demonstrated that H3R antagonists showed positive effects by reducing the proinflammatory biomarkers, suggesting their potential role in simultaneously modulating crucial brain neurotransmissions and signaling cascades such as the PI3K/AKT/GSK-3β pathway. In this review, we highlight the potential therapeutic role of the H3R antagonists in addressing the pathology and cognitive decline in brain disorders, e.g., AD, PD, and ASD, with an inflammatory component.

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.

Innate Immune Dysfunction and Neuroinflammation in Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by communication and social behavior deficits. The presence of restricted and repetitive behaviors often accompanies these deficits, and these characteristics can range from mild to severe. The past several decades have seen a significant rise in the prevalence of ASD. The etiology of ASD remains unknown; however, genetic and environmental risk factors play a role. Multiple hypotheses converge to suggest that neuroinflammation, or at least the interaction between immune and neural systems, may be involved in the etiology of some ASD cases or groups. Repeated evidence of innate immune dysfunction has been seen in ASD, often associated with worsening behaviors. This evidence includes data from circulating myeloid cells and brain resident macrophages/microglia in both human and animal models. This comprehensive review presents recent findings of innate immune dysfunction in ASD, including aberrant innate cellular function, evidence of neuroinflammation, and microglia activation. Appeared originally in Brain Behav Immun 2023; 108:245-254.

Microglia and Microbiome-Gut-Brain Axis

The mammalian gut contains a community of microorganisms called gut microbiome. The gut microbiome is integrated into mammalian physiology, contributing to metabolism, production of metabolites, and promoting immunomodulatory actions. Microglia, the brain's resident innate immune cells, play an essential role in homeostatic neurogenesis, synaptic remodeling, and glial maturation. Microglial dysfunction has been implicated in the pathogenesis of several neuropsychiatric disorders. Recent findings indicate that microglia are influenced by the gut microbiome and their derived metabolites throughout life. The pathways by which microbiota regulate microglia have only started to be understood, but this discovery has the potential to provide valuable insights into the pathogenesis of brain disorders associated with an altered microbiome. Here, we discuss the recent literature on the role of the gut microbiome in modulating microglia during development and adulthood and summarize the key findings on this bidirectional crosstalk in selected examples of neuropsychiatric and neurodegenerative disorders. We also highlight some current caveats and perspectives for the field.

Taurine as a potential therapeutic agent interacting with multiple signaling pathways implicated in autism spectrum disorder (ASD): An in-silico analysis

Autism spectrum disorders (ASD) are a complex sequelae of neurodevelopmental disorders which manifest in the form of communication and social deficits. Currently, only two agents, namely risperidone and aripiprazole have been approved for the treatment of ASD, and there is a dearth of more drugs for the disorder. The exact pathophysiology of autism is not understood clearly, but research has implicated multiple pathways at different points in the neuronal circuitry, suggesting their role in ASD. Among these, the role played by neuroinflammatory cascades like the NF-KB and Nrf2 pathways, and the excitotoxic glutamatergic system, are said to have a bearing on the development of ASD. Similarly, the GPR40 receptor, present in both the gut and the blood brain barrier, has also been said to be involved in the disorder. Consequently, molecules which can act by interacting with one or multiple of these targets might have a potential in the therapy of the disorder, and for this reason, this study was designed to assess the binding affinity of taurine, a naturally-occurring amino acid, with these target molecules. The same was scored against these targets using in-silico docking studies, with Risperidone and Aripiprazole being used as standard comparators. Encouraging docking scores were obtained for taurine across all the selected targets, indicating promising target interaction. But the affinity for targets actually varied in the order NRF-KEAP > NF-κB > NMDA > Calcium channel > GPR 40. Given the potential implication of these targets in the pathogenesis of ASD, the drug might show promising results in the therapy of the disorder if subjected to further evaluations.

Preclinical Evidence for the Role of the Yin/Yang Angiotensin System Components in Autism Spectrum Disorder: A Therapeutic Target of Astaxanthin

Autism spectrum disorder (ASD) prevalence is emerging with an unclear etiology, hindering effective therapeutic interventions. Recent studies suggest potential renin-angiotensin system (RAS) alterations in different neurological pathologies. However, its implications in ASD are unexplored. This research fulfills the critical gap by investigating dual arms of RAS and their interplay with Notch signaling in ASD, using a valproic acid (VPA) model and assessing astaxanthin's (AST) modulatory impacts. Experimentally, male pups from pregnant rats receiving either saline or VPA on gestation day 12.5 were divided into control and VPA groups, with subsequent AST treatment in a subset (postnatal days 34-58). Behavioral analyses, histopathological investigations, and electron microscopy provided insights into the neurobehavioral and structural changes induced by AST. Molecular investigations of male pups' cortices revealed that AST outweighs the protective RAS elements with the inhibition of the detrimental arm. This established the neuroprotective and anti-inflammatory axes of RAS (ACE2/Ang1-7/MasR) in the ASD context. The results showed that AST's normalization of RAS components and Notch signaling underscore a novel therapeutic avenue in ASD, impacting neuronal integrity and behavioral outcomes. These findings affirm the integral role of RAS in ASD and highlight AST's potential as a promising treatment intervention, inviting further neurological research implications.

Microbiota-indole 3-propionic acid-brain axis mediates abnormal synaptic pruning of hippocampal microglia and susceptibility to ASD in IUGR offspring

BACKGROUND

Autism spectrum disorder (ASD) has been associated with intrauterine growth restriction (IUGR), but the underlying mechanisms are unclear.

RESULTS

We found that the IUGR rat model induced by prenatal caffeine exposure (PCE) showed ASD-like symptoms, accompanied by altered gut microbiota and reduced production of indole 3-propionic acid (IPA), a microbiota-specific metabolite and a ligand of aryl hydrocarbon receptor (AHR). IUGR children also had a reduced serum IPA level consistent with the animal model. We demonstrated that the dysregulated IPA/AHR/NF-κB signaling caused by disturbed gut microbiota mediated the hippocampal microglia hyperactivation and neuronal synapse over-pruning in the PCE-induced IUGR rats. Moreover, postnatal IPA supplementation restored the ASD-like symptoms and the underlying hippocampal lesions in the IUGR rats.

CONCLUSIONS

This study suggests that the microbiota-IPA-brain axis regulates ASD susceptibility in PCE-induced IUGR offspring, and supplementation of microbiota-derived IPA might be a promising interventional strategy for ASD with a fetal origin. Video Abstract.

Mouse Model of Fragile X Syndrome Analyzed by Quantitative Proteomics: A Comparison of Methods

Multiple methods for quantitative proteomics are available for proteome profiling. It is unclear which methods are most useful in situations involving deep proteome profiling and the detection of subtle distortions in the proteome. Here, we compared the performance of seven different strategies in the analysis of a mouse model of Fragile X Syndrome, involving the knockout of the fmr1 gene that is the leading cause of autism spectrum disorder. Focusing on the cerebellum, we show that data-independent acquisition (DIA) and the tandem mass tag (TMT)-based real-time search method (RTS) generated the most informative profiles, generating 334 and 329 significantly altered proteins, respectively, although the latter still suffered from ratio compression. Label-free methods such as BoxCar and a conventional data-dependent acquisition were too noisy to generate a reliable profile, while TMT methods that do not invoke RTS showed a suppressed dynamic range. The TMT method using the TMTpro reagents together with complementary ion quantification (ProC) overcomes ratio compression, but current limitations in ion detection reduce sensitivity. Overall, both DIA and RTS uncovered known regulators of the syndrome and detected alterations in calcium signaling pathways that are consistent with calcium deregulation recently observed in imaging studies. Data are available via ProteomeXchange with the identifier PXD039885.

Autistic spectrum disorder (ASD) - Gene, molecular and pathway signatures linking systemic inflammation, mitochondrial dysfunction, transsynaptic signalling, and neurodevelopment

Background

Despite advances in autism spectrum disorder (ASD) research and the vast genomic, transcriptomic, and proteomic data available, there are still controversies regarding the pathways and molecular signatures underlying the neurodevelopmental disorders leading to ASD.

Purpose

To delineate these underpinning signatures, we examined the two largest gene expression meta-analysis datasets obtained from the brain and peripheral blood mononuclear cells (PBMCs) of 1355 ASD patients and 1110 controls.

Methods

We performed network, enrichment, and annotation analyses using the differentially expressed genes, transcripts, and proteins identified in ASD patients.

Results

Transcription factor network analyses in up- and down-regulated genes in brain tissue and PBMCs in ASD showed eight main transcription factors, namely: BCL3, CEBPB, IRF1, IRF8, KAT2A, NELFE, RELA, and TRIM28. The upregulated gene networks in PBMCs of ASD patients are strongly associated with activated immune-inflammatory pathways, including interferon-α signaling, and cellular responses to DNA repair. Enrichment analyses of the upregulated CNS gene networks indicate involvement of immune-inflammatory pathways, cytokine production, Toll-Like Receptor signalling, with a major involvement of the PI3K-Akt pathway. Analyses of the downregulated CNS genes suggest electron transport chain dysfunctions at multiple levels. Network topological analyses revealed that the consequent aberrations in axonogenesis, neurogenesis, synaptic transmission, and regulation of transsynaptic signalling affect neurodevelopment with subsequent impairments in social behaviours and neurocognition. The results suggest a defense response against viral infection.

Conclusions

Peripheral activation of immune-inflammatory pathways, most likely induced by viral infections, may result in CNS neuroinflammation and mitochondrial dysfunction, leading to abnormalities in transsynaptic transmission, and brain neurodevelopment.

Deletion of Cryab increases the vulnerability of mice to the addiction-like effects of the cannabinoid JWH-018 via upregulation of striatal NF-κB expression

Synthetic cannabinoids have exhibited unpredictable abuse liabilities, especially self-administration (SA) responses in normal rodent models, despite seemingly inducing addiction-like effects in humans. Thus, an efficient pre-clinical model must be developed to determine cannabinoid abuse potential in animals and describe the mechanism that may mediate cannabinoid sensitivity. The Cryab knockout (KO) mice were recently discovered to be potentially sensitive to the addictive effects of psychoactive drugs. Herein, we examined the responses of Cryab KO mice to JWH-018 using SA, conditioned place preference, and electroencephalography. Additionally, the effects of repeated JWH-018 exposure on endocannabinoid- and dopamine-related genes in various addiction-associated brain regions were examined, along with protein expressions involving neuroinflammation and synaptic plasticity. Cryab KO mice exhibited greater cannabinoid-induced SA responses and place preference, along with divergent gamma wave alterations, compared to wild-type (WT) mice, implying their higher sensitivity to cannabinoids. Endocannabinoid- or dopamine-related mRNA expressions and accumbal dopamine concentrations after repeated JWH-018 exposure were not significantly different between the WT and Cryab KO mice. Further analyses revealed that repeated JWH-018 administration led to possibly greater neuroinflammation in Cryab KO mice, which may arise from upregulated NF-κB, accompanied by higher expressions of synaptic plasticity markers, which might have contributed to the development of cannabinoid addiction-related behavior in Cryab KO mice. These findings signify that increased neuroinflammation via NF-κB may mediate the enhanced addiction-like responses of Cryab KO mice to cannabinoids. Altogether, Cryab KO mice may be a potential model for cannabinoid abuse susceptibility.

Proteome profiling of the prefrontal cortex of Fmr1 knockout mouse reveals enhancement of complement and coagulation cascades

Fragile X mental retardation protein (FMRP) deficit resulted from mutations in its encoded fragile X mental retardation 1 (Fmr1) gene is a common inherited cause of Fragile X syndrome (FXS) characterized by intellectual disability and autism spectrum disorder (ASD). The FMRP absence-induced altered gene expression in prefrontal cortex (PFC) are associated with autistic behaviors. However, there lacks a large-scale protein profiling in the PFC upon loss of FMRP. This study used a TMT-labeled proteomic analysis to identify a protein profile of the PFC in the Fmr1 knockout mouse. A total of 5886 proteins were identified in the PFC with 100 differentially abundant proteins (DAPs) in response to FMRP deficiency. Bioinformatical analyses showed that these DAPs were mostly enriched in immune system, extracellular part and complement and coagulation cascades. The complement and coagulation cascades include 6 upregulated proteins (SERPING1, C1QA, C3, FGA, FGB and FGG), which are associated with fibrin degradation, cell lysis, degranulation chemotaxis and phagocytosis linked to activation of immune and inflammatory responses. Thus, our data provide an altered protein profile upon loss of FMRP in the PFC, and suggest that the enhancement of complement and coagulation cascades might contribute to etiological and pathogenic roles of ASD in FXS. SIGNIFICANCE: The etiology of autism spectrum disorder (ASD), a group of neurobiological disorders characterized by deficits in social interaction barriers and other abnormal behaviors, is still elusive. Autistic-like phenotypes are present in both Fragile X syndrome (FXS) patients and FMRP-deficiency FXS models. Given that prefrontal cortex is a critical brain area for social interaction, the FMRP absence induced-changes of a subset of proteins might contribute to ASD in FXS. Using a comprehensive proteomic analysis, this study provides a prefrontal protein profile of the FMRP-absent mouse with a total of 100 differentially abundant proteins (DAPs). Bioinformatic analyses suggest that these DAPs are mainly involved in the regulations of immune system and complement and coagulation cascades. We also show that 6 upregulated proteins (SERPING1, C1QA, C3, FGA, FGB and FGG) in the complement and coagulation cascades are associated with fibrin degradation, cell lysis, degranulation chemotaxis and phagocytosis regarding dysregulation of immune and inflammatory responses in the prefrontal cortex. Therefore, this study suggests that these FMRP-deficient DAPs in the prefrontal cortex might contribute to the etiology and pathogenesis of ASD in FXS.

A potent and selective CXCR2 antagonist improves neuroimmune dysregulation through the inhibition of NF-κB and notch inflammatory signaling in the BTBR mouse model of autism

Autism comprises a broad range of neurodevelopmental disorders characterized by social communication deficits and repetitive and stereotyped behaviors. Chemokine receptor CXCR2 is expressed on neurons and is upregulated in neurological disorders. BTBR T+ Itpr3tf/J (BTBR) mice, a model for autism that shows the core features of ASD. Here, we studied the anti-inflammatory effect of a potent and selective CXCR2 antagonist SB332235 in the BTBR mice. The CXCR2 antagonist represents a promising therapeutic agent for several neuroinflammatory disorders. In this study, we investigated the effects of SB332235 administration on NF-κB-, Notch-1-, Notch-3-, GM-CSF-, MCP-1-, IL-6-, and IL-2- and TGF-β1-expressing CD40+ cells in BTBR and C57BL/6 (C57) mice in the spleen cells by flow cytometry. We further assessed the effect of SB332235 treatment on NF-κB, Notch-1, GM-CSF, MCP-1, IL-6, and IL-2 mRNA expression levels in the brain tissue by RT-PCR. We also explored the effect of SB332235 administration on NF-κB, GM-CSF, IL-6, and TGF-β1 protein expression levels in the brain tissue by western blotting. The SB332235-treated BTBR mice significantly decreases in CD40 + NF-κB+, CD40 + Notch-1+, CD40 + Notch-3+, CD40 + GM-CSF+, CD40 + MCP-1+, CD40 + IL-6+, and CD40 + IL-2+, and increases in CD40 + TGF-β1+ in the spleen cells. Our results further demonstrated that BTBR mice treated with SB332235 effectively decreased NF-κB, Notch-1, GM-CSF, MCP-1, IL-6, and IL-2, increasing TGF-β1 mRNA and protein expression levels in the brain tissue. In conclusion, these results indicate that SB332235 elicits an anti-inflammatory response by downregulating the inflammatory mediators and NF-κB/Notch inflammatory signaling in BTBR mice. This could represent a promising novel therapeutic target for autism treatment.

Innate immune dysfunction and neuroinflammation in autism spectrum disorder (ASD)

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by communication and social behavior deficits. The presence of restricted and repetitive behaviors often accompanies these deficits, and these characteristics can range from mild to severe. The past several decades have seen a significant rise in the prevalence of ASD. The etiology of ASD remains unknown; however, genetic and environmental risk factors play a role. Multiple hypotheses converge to suggest that neuroinflammation, or at least the interaction between immune and neural systems, may be involved in the etiology of some ASD cases or groups. Repeated evidence of innate immune dysfunction has been seen in ASD, often associated with worsening behaviors. This evidence includes data from circulating myeloid cells and brain resident macrophages/microglia in both human and animal models. This comprehensive review presents recent findings of innate immune dysfunction in ASD, including aberrant innate cellular function, evidence of neuroinflammation, and microglia activation.

Sex hormone receptor expression in children with autism spectrum disorder.. [DOI: 10.21203/rs.3.rs-2345028/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Sex hormones, especially estrogen, which binds to estrogen receptor β (ERβ), play a vital role in the pathogenesis of mental disorders such as autism spectrum disorder (ASD). The purpose of this study was to analyze the serum levels of hormone receptors, including ERβ, progesterone receptor (PGR) and androgen receptor (AR), and compare these levels between children with ASD and typically developing (TD) children. We also investigated the relationships of ERβ mRNA levels with ASD core symptoms, sleep, and developmental quotients (DQs) from the Gesell Developmental Schedules (GDS) among children with ASD. Methods We compared the mRNA levels of ERβ, AR, and PGR between 56 children with ASD and 37 TD children by using quantitative real-time PCR. Then, a correlation analysis was performed to determine the correlations of ERβ mRNA levels with Childhood Autism Rating Scale (CARS), Autism Behavior Checklist (ABC), and Children’s Sleep Habits Questionnaire (CHSQ) scores as well as DQs among ASD children. Results We found that serum mRNA levels of ERβ in ASD children were significantly lower than those in the TD group. However, we found no correlations of the ERβ mRNA level with CARS, ABC, and CHSQ scores as well as DQs on each GDS domain among ASD children. Conclusions Elevated ERβ mRNA levels in peripheral blood may be related to ASD but this association needs to be validated with a larger sample size.

The molecular basis of p21-activated kinase-associated neurodevelopmental disorders: From genotype to phenotype

Although the identification of numerous genes involved in neurodevelopmental disorders (NDDs) has reshaped our understanding of their etiology, there are still major obstacles in the way of developing therapeutic solutions for intellectual disability (ID) and other NDDs. These include extensive clinical and genetic heterogeneity, rarity of recurrent pathogenic variants, and comorbidity with other psychiatric traits. Moreover, a large intragenic mutational landscape is at play in some NDDs, leading to a broad range of clinical symptoms. Such diversity of symptoms is due to the different effects DNA variations have on protein functions and their impacts on downstream biological processes. The type of functional alterations, such as loss or gain of function, and interference with signaling pathways, has yet to be correlated with clinical symptoms for most genes. This review aims at discussing our current understanding of how the molecular changes of group I p21-activated kinases (PAK1, 2 and 3), which are essential actors of brain development and function; contribute to a broad clinical spectrum of NDDs. Identifying differences in PAK structure, regulation and spatio-temporal expression may help understanding the specific functions of each group I PAK. Deciphering how each variation type affects these parameters will help uncover the mechanisms underlying mutation pathogenicity. This is a prerequisite for the development of personalized therapeutic approaches.

Toll-Like Receptor 4 Gene Polymorphisms and Susceptibility to Schizophrenia: A Case-Control Study

Schizophrenia is a common psychiatric disorder that exhibits a variety of symptoms. The exact etiology and pathogenesis are still doubtful. However, genetic and environmental factors seem to have a role. Years ago, the role of the immune system was focused on auto-antibodies, cytokines, different types of immune cells and immune genes. The Toll-like receptors (TLR) are a cornerstone of the innate immune system, particularly TLR4. TLR4 primarily recognises gram-negative lipopolysaccharides bacteria. This case-control study, for the first time to our knowledge, examined the role of TLR4 gene polymorphisms in 142 Egyptian schizophrenic patients and 175 healthy controls. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), four single nucleotide polymorphisms (SNPs) were investigated in the TLR4 gene rs11536889, rs10759931, rs1927911, and rs1927914. The Positive and Negative Syndrome Scale (PANSS) was used in diagnosis and assessment. A statistically significant association was observed between rs11536889, rs1927911 and rs1927914, but no association was found between rs10759931. There was no association between the different SNP genotypes and PANSS, except between rs1927914 and general psychopathologic symptoms. This study shows a strong association between TLR4 rs11356889 and rs1927911 minor alleles and schizophrenia. These findings could be additional evidence for the immune system's role in schizophrenia development. However, more studies with a more significant sample number, TLR4 protein assessment, and a larger number of SNPs are recommended.

Lead (Pb) exposure exacerbates behavioral and immune abnormalities by upregulating Th17 and NF-κB-related signaling in BTBR T+ Itpr3tf/J autistic mouse model

Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder that are characterized by abnormal social interaction impairments in communication and repetitive and restricted activities or interests. Even though the exact etiology of ASD remains unknown. Lead (Pb) is a toxin known to harm many organs in the body, it is one of the most ubiquitous metal exposures which is associated with neurological deficits. Previous studies have shown that the exposure to Pb may play a role in ASD. BTBR T⁺ Itpr3^tf/J (BTBR) mouse model is commonly used as a preclinical model for ASD. In this study, we investigated the effects of Pb exposure on sociability, self-grooming and marble burying behaviors tests in BTBR mice. We further examined the effects of Pb on IL-17A- RORγT-, STAT3-, NF-κB p65-, iNOS-, TLR-2- and TLR-4-producing CD45⁺ cells in spleen using flow cytometry. We also explored the effects of Pb on IL-17A, RORγT, STAT3, NF-κB p65, and TLR-2 mRNA expression in the brain tissue using RT-PCR analysis. Our results demonstrated that Pb exposure substantially increased repetitive behavior, marble burying and decrease social interactions in BTBR mice. In addition, in spleen cells, Pb exposure exaggerated CD45⁺IL-17A⁺, CD45⁺RORγT⁺, CD45⁺STAT3⁺, CD45⁺NF-κB p65⁺, CD45⁺iNOS⁺, CD45⁺TLR-2⁺ and CD45⁺TLR-4⁺ in BTBR mice. We also found that Pb significantly increased IL-17A, RORγT, STAT3, NF-κB p65, and TLR-2 mRNA in the brain tissue. Therefore, Pb exposure exacerbates behavioral and neuroimmune function in BTBR mice, suggesting a potentially strong role for Pb in ASD.

Microglial Inflammatory-Metabolic Pathways and Their Potential Therapeutic Implication in Major Depressive Disorder

Increasing evidence supports the notion that neuroinflammation plays a critical role in the etiology of major depressive disorder (MDD), at least in a subset of patients. By virtue of their capacity to transform into reactive states in response to inflammatory insults, microglia, the brain's resident immune cells, play a pivotal role in the induction of neuroinflammation. Experimental studies have demonstrated the ability of microglia to recognize pathogens or damaged cells, leading to the activation of a cytotoxic response that exacerbates damage to brain cells. However, microglia display a wide range of responses to injury and may also promote resolution stages of inflammation and tissue regeneration. MDD has been associated with chronic priming of microglia. Recent studies suggest that altered microglial morphology and function, caused either by intense inflammatory activation or by senescence, may contribute to depression and associated impairments in neuroplasticity. In this context, modifying microglia phenotype by tuning inflammatory pathways might have important translational relevance to harness neuroinflammation in MDD. Interestingly, it was recently shown that different microglial phenotypes are associated with distinct metabolic pathways and analysis of the underlying molecular mechanisms points to an instrumental role for energy metabolism in shaping microglial functions. Here, we review various canonical pro-inflammatory, anti-inflammatory and metabolic pathways in microglia that may provide new therapeutic opportunities to control neuroinflammation in brain disorders, with a strong focus on MDD.

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.

Proteomic profiling of postmortem prefrontal cortex tissue of suicide completers

Suicide is a leading cause of death worldwide, presenting a serious public health problem. We aimed to investigate the biological basis of suicide completion using proteomics on postmortem brain tissue. Thirty-six postmortem brain samples (23 suicide completers and 13 controls) were collected. We evaluated the proteomic profile in the prefrontal cortex (Broadmann area 9, 10) using tandem mass tag-based quantification with liquid chromatography-tandem mass spectrometry. Bioinformatics tools were used to elucidate the biological mechanisms related to suicide. Subgroup analysis was conducted to identify common differentially expressed proteins among clinically different groups. Of 9801 proteins identified, 295 were differentially expressed between groups. Suicide completion samples were mostly enriched in the endocannabinoid and apoptotic pathways (CAPNS1, CSNK2B, PTP4A2). Among the differentially expressed proteins, GSTT1 was identified as a potential biomarker among suicide completers with psychiatric disorders. Our findings suggest that the previously under-recognized endocannabinoid system and apoptotic processes are highly involved in suicide.

Dysregulated gene expression associated with inflammatory and translation pathways in activated monocytes from children with autism spectrum disorder

Autism spectrum disorder (ASD) is a complex developmental disorder characterized by deficits in social interactions, communication, and stereotypical behaviors. Immune dysfunction is a common co-morbidity seen in ASD, with innate immune activation seen both in the brain and periphery. We previously identified significant differences in peripheral monocyte cytokine responses after stimulation with lipoteichoic acid (LTA) and lipopolysaccharide (LPS), which activate toll-like receptors (TLR)-2 and 4 respectively. However, an unbiased examination of monocyte gene expression in response to these stimulants had not yet been performed. To identify how TLR activation impacts gene expression in ASD monocytes, we isolated peripheral blood monocytes from 26 children diagnosed with autistic disorder (AD) or pervasive developmental disorder-not otherwise specified (PDDNOS) and 22 typically developing (TD) children and cultured them with LTA or LPS for 24 h, then performed RNA sequencing. Activation of both TLR2 and TLR4 induced expression of immune genes, with a subset that were differentially regulated in AD compared to TD samples. In response to LPS, monocytes from AD children showed a unique increase in KEGG pathways and GO terms that include key immune regulator genes. In contrast, monocytes from TD children showed a consistent decrease in expression of genes associated with translation in response to TLR stimulation. This decrease was not observed in AD or PDDNOS monocytes, suggesting a failure to properly downregulate a prolonged immune response in monocytes from children with ASD. As monocytes are involved in early orchestration of the immune response, our findings will help elucidate the mechanisms regulating immune dysfunction in ASD.

CTRP3 as a novel biomarker in the plasma of Saudi children with autism

BACKGROUND

C1q/tumor necrosis factor-related protein-3 (CTRP3) has diverse functions: anti-inflammation, metabolic regulation, and protection against endothelial dysfunction.

METHODS

The plasma level of CTRP3 in autistic patients (n = 32) was compared to that in controls (n = 37) using ELISA.

RESULTS

CTRP3 was higher (24.7% with P < 0.05) in autistic patients than in controls. No association was observed between CTRP3 and the severity of the disorder using the Childhood Autism Rating Scale (CARS). A positive correlation between CARs and the age of patients was reported. Receiver operating characteristic (ROC) analysis demonstrated a low area under the curve (AUC) for all patients (0.636). Low AUCs were also found in the case of severe patients (0.659) compared to controls, but both values were statistically significant (P ≤ 0.05). Despite the small sample size, we are the first to find an association between CTRP3 and autism spectrum disorder (ASD).

Psychobiotics improve propionic acid-induced neuroinflammation in juvenile rats, rodent model of autism

This study aimed to evaluate the protective and therapeutic potency of bee pollen and probiotic mixture on brain intoxication caused by propionic acid (PPA) in juvenile rats. Five groups of six animals each, were used: the control group only receiving phosphate-buffered saline; the bee pollen and probiotic-treated group receiving a combination of an equal quantity of bee pollen and probiotic (0.2 kg/kg body weight); the PPA group being treated for 3 days with an oral neurotoxic dose of PPA (0.25 kg/kg body weight); the protective and therapeutic groups receiving bee pollen and probiotic mixture treatment right before and after the neurotoxic dose of PPA, respectively. The levels of interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor α, and interferon γ (IFN-γ) were investigated to evaluate the neuroinflammatory responses in brain tissues from different animal groups. The much higher IL-1β, IL-8, and IFN-γ, as pro-inflammatory cytokines (P < 0.001), together with much lower IL-10, as anti-inflammatory cytokine (P < 0.001) compared to controls clearly demonstrated the neurotoxic effects of PPA. Interestingly, the mixture of bee pollen and probiotics was effective in alleviating PPA neurotoxic effects in both therapeutic and protective groups demonstrating highly significant changes in IL-1β, IL-8, IL-10, and IFN-γ levels together with non-significant reduction in IL-6 levels compared to PPA-treated rats. Overall, our findings demonstrated a new approach to the beneficial use of psychobiotics presenting as bee pollen and probiotic combination in neuroinflammation through cytokine changes as a possible role of glial cells in gut–brain axis.

Autoimmune Encephalitis and Autism Spectrum Disorder

The concept of "acquired autism" refers to the hypothesis that amongst the massive heterogeneity that encompasses autism spectrum disorder (ASD) there may be several phenotypes that are neither syndromic nor innate. Strong and consistent evidence has linked exposure to various pharmacological and infective agents with an elevated risk of a diagnosis of ASD including maternal valproate use, rubella and herpes encephalitis. Autoimmune encephalitis (AE) describes a group of conditions characterised by the body's immune system mounting an attack on healthy brain cells causing brain inflammation. The resultant cognitive, psychiatric and neurological symptoms that follow AE have also included ASD or autism-like traits and states. We review the current literature on AE and ASD. Drawing also on associated literature on autoimmune psychosis (AP) and preliminary evidence of a psychosis-linked subtype of ASD, we conclude that AE may either act as a potentially causative agent for ASD, and/or produce symptoms that could easily be mistaken for or misdiagnosed as autism. Further studies are required to discern the connection between AE and autism. Where autism is accompanied by regression and atypical onset patterns, it may be prudent to investigate whether a differential diagnosis of AE would be more appropriate.

Effects of catechin on a rodent model of autism spectrum disorder: implications for the role of nitric oxide in neuroinflammatory pathway

AIM

The present research work aims at deciphering the involvement of nitric oxide pathway and its modulation by ( ±)catechin hydrate in experimental paradigm of autism spectrum disorders (ASD).

METHOD

An intracerebroventricular infusion of 4 μl of 1 M propanoic acid was given in the anterior region of the lateral ventricle to induce autism-like phenotype in male rats. Oral administration of ( ±)catechin hydrate (25, 50, and 100 mg/kg) was initiated from the 3rd day lasting till the 28th day. L-NAME (50 mg/kg) and L-arginine (800 mg/kg) were also given individually as well as in combination to explore the ability of ( ±)catechin hydrate to act via nitric oxide pathway. Behavior test for sociability, stereotypy, anxiety, depression, and novelty, repetitive, and perseverative behavior was carried out between the 14th and 28th day. On the 29th day, animals were sacrificed, and levels of mitochondrial complexes and oxidative stress parameters were evaluated. We also estimated the levels of neuroinflammatory and apoptotic markers such as TNF-α, IL-6, NF-κB, IFN-γ, HSP-70, and caspase-3. To evaluate the involvement of nitric oxide pathway, the levels of iNOS and homocysteine were estimated.

RESULTS

Treatment with ( ±)catechin hydrate significantly ameliorated behavioral, biochemical, neurological, and molecular deficits. Hence, ( ±)catechin hydrate has potential to be used as neurotherapeutic agent in ASD targeting nitric oxide pathway-mediated oxidative and nitrosative stress responsible for behavioral, biochemical, and molecular alterations via modulating nitric oxide pathway.

CONCLUSION

The evaluation of the levels of iNOS and homocysteine conclusively establishes the role of nitric oxide pathway in causing behavioral, biochemical, and molecular deficits and the beneficial effect of ( ±)catechin hydrate in restoring these alterations.

Dysregulation of NF-κB-Associated LncRNAs in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a long-standing neurodevelopmental condition with prominent effects on social behavior of affected children. This disorder has been linked with neuroinflammatory responses. NF-κB has been shown to affect these responses in the orbitofrontal cortex of patients with ASD, thus being implicated in the pathogenesis of ASD. We measured expression of some NF-κB-associated lncRNAs and mRNAs (DILC, ANRIL, PACER, CHAST, ADINR, DICER1-AS1, HNF1A-AS1, NKILA, ATG5 and CEBPA) in the peripheral blood of ASD kids vs. healthy children. Expression quantities of ADINR, ANRIL, DILC, NKILA and CHAST were meaningfully higher in ASD cases compared with healthy kids (Posterior Beta = 1.402, P value < 0.0001; Posterior Beta = 2.959, P value < 0.0001; Posterior Beta = 0.882, P value = 0.012; Posterior Beta = 1.461, P value < 0.0001; Posterior Beta = 0.541, P value = 0.043, respectively). The Bonferroni corrected P values for these lncRNAs remained significant except for CHAST and DILC. Expression levels of other genes were not considerably different between cases and controls. Expressions of ATG5, DICER-AS1 and DILC were correlated with age of ASD patients (P < 0.0001). Among ASD cases, the most robust correlation has been detected between ADINR and NKILA (r = 0.87, P < 0.0001). Expression of none of genes has been correlated with age of healthy children. Among this group of children, expression levels of ADINR and CHAST were robustly correlated (r = 0.83, P < 0.0001). ANRIL had the greatest AUC value (AUC = 0.857), thus the best diagnostic power among the assessed genes. NKILA ranked the second position in this regard (AUC = 0.757). Thus, NF-κB-associated lncRNAs might partake in the pathogenesis of ASD.

Reduced false positives in autism screening via digital biomarkers inferred from deep comorbidity patterns

Here, we develop digital biomarkers for autism spectrum disorder (ASD), computed from patterns of past medical encounters, identifying children at high risk with an area under the receiver operating characteristic exceeding 80% from shortly after 2 years of age for either sex, and across two independent patient databases. We leverage uncharted ASD comorbidities, with no requirement of additional blood work, or procedures, to estimate the autism comorbid risk score (ACoR), during the earliest years when interventions are the most effective. ACoR has superior predictive performance to common questionnaire-based screenings and can reduce their current socioeconomic, ethnic, and demographic biases. In addition, we can condition on current screening scores to either halve the state-of-the-art false-positive rate or boost sensitivity to over 60%, while maintaining specificity above 95%. Thus, ACoR can significantly reduce the median diagnostic age, reducing diagnostic delays and accelerating access to evidence-based interventions.

Lycopene ameliorates propionic acid-induced autism spectrum disorders by inhibiting inflammation and oxidative stress in rats

This study was conducted to study lycopene efficacy in brain-behavior, pro-inflammatory and apoptotic markers, and antioxidant levels in a rodent model. Rats were administered with propionic acid (PPA) (500 mg/kg BW) to induce autism-like disorders, then treated with different lycopene (L) concentrations (5, 10, 20 mg kg^-1  day^-1 ) for 35 days. The groups were: (i);control, (ii);PPA, (iii);PPA + L5, (iv);PPA + L10, and (v);PPA + L20. In this study, serum and brain malondialdehyde (MDA) levels decreased with lycopene supplements compared to the PPA group, similarly to the brain levels of inflammatory factors (IL-1α, IL-8, NF-κB, TNF-α; p < .05). Besides, brain levels of anti-apoptotic Bcl-2 decreased, whereas pro-apoptotic Bax, antioxidant Nrf2, and HO-1 levels in brain increased compared with PPA (p < .05). This study showed that lycopene might have therapeutic value to improve the dysfunctions in learning and memory in a dose-dependent way, along with the antioxidant, anti-inflammatory, and antiapoptotic molecular responses in a rat model of ASD-like disorders. PRACTICAL APPLICATIONS: This study suggested that lycopene can reduce propionic acid (PPA)-induced learning and memory impairment and oxidative damage by participating in multiple biological activities such as antioxidant, and anti-inflammatory effects. Lycopene protects serum and brain tissues against PPA induced oxidative damage in rats. These effects may be realized through up-regulation of the brain Nrf2/HO-1 pathway and down-regulation of the IL-1α, IL-8, TNF-α, and NF-κB levels. Lycopene may also contribute to memory and learning function, apoptotic/antiapoptotic modulation, and antioxidant and possible therapeutic efficacy in PPA-induced- Autism spectrum disorder cases.

Autism Spectrum Disorder: Signaling Pathways and Prospective Therapeutic Targets

The Autism Spectrum Disorder (ASD) consists of a prevalent and heterogeneous group of neurodevelopmental diseases representing a severe burden to affected individuals and their caretakers. Despite substantial improvement towards understanding of ASD etiology and pathogenesis, as well as increased social awareness and more intensive research, no effective drugs have been successfully developed to resolve the main and most cumbersome ASD symptoms. Hence, finding better treatments, which may act as "disease-modifying" agents, and novel biomarkers for earlier ASD diagnosis and disease stage determination are needed. Diverse mutations of core components and consequent malfunctions of several cell signaling pathways have already been found in ASD by a series of experimental platforms, including genetic associations analyses and studies utilizing pre-clinical animal models and patient samples. These signaling cascades govern a broad range of neurological features such as neuronal development, neurotransmission, metabolism, and homeostasis, as well as immune regulation and inflammation. Here, we review the current knowledge on signaling pathways which are commonly disrupted in ASD and autism-related conditions. As such, we further propose ways to translate these findings into the development of genetic and biochemical clinical tests for early autism detection. Moreover, we highlight some putative druggable targets along these pathways, which, upon further research efforts, may evolve into novel therapeutic interventions for certain ASD conditions. Lastly, we also refer to the crosstalk among these major signaling cascades as well as their putative implications in therapeutics. Based on this collective information, we believe that a timely and accurate modulation of these prominent pathways may shape the neurodevelopment and neuro-immune regulation of homeostatic patterns and, hopefully, rescue some (if not all) ASD phenotypes.

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.

A Ketogenic Diet and the Treatment of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is characterized by stereotyped behavior and deficits in communication and social interaction. There are no curative treatments for children with ASD. The ketogenic diet (KD) is a high-fat, appropriate-protein, and low-carbohydrate diet that mimics the fasting state of the body and is proven beneficial in drug-resistant epilepsy and some other brain diseases. An increasing number of studies demonstrated that a KD improved autistic behavior, but the underlying mechanisms are not known. We reviewed the neuroprotective role of a KD in ASD, which is likely mediated via improvements in energy metabolism, reductions in antioxidative stress levels, control of neurotransmitters, inhibition of the mammalian target of rapamycin (mTOR) signaling pathway, and modulation of the gut microbiota. A KD is likely a safe and effective treatment for ASD.

Whole Exome Sequencing Identifies Novel De Novo Variants Interacting with Six Gene Networks in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a highly heritable condition caused by a combination of environmental and genetic factors such as de novo and inherited variants, as well as rare or common variants among hundreds of related genes. Previous genome-wide association studies have identified susceptibility genes; however, most ASD-associated genes remain undiscovered. This study aimed to examine rare de novo variants to identify genetic risk factors of ASD using whole exome sequencing (WES), functional characterization, and genetic network analyses of identified variants using Korean familial dataset. We recruited children with ASD and their biological parents. The clinical best estimate diagnosis of ASD was made according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5^TM), using comprehensive diagnostic instruments. The final analyses included a total of 151 individuals from 51 families. Variants were identified and filtered using the GATK Best Practices for bioinformatics analysis, followed by genome alignments and annotation to the reference genome assembly GRCh37 (liftover to GRCh38), and further annotated using dbSNP 154 build databases. To evaluate allele frequencies of de novo variants, we used the dbSNP, gnomAD exome v2.1.1, and genome v3.0. We used Ingenuity Pathway Analysis (IPA, Qiagen) software to construct networks using all identified de novo variants with known autism-related genes to find probable relationships. We identified 36 de novo variants with potential relations to ASD; 27 missense, two silent, one nonsense, one splice region, one splice site, one 5′ UTR, and one intronic SNV and two frameshift deletions. We identified six networks with functional relationships. Among the interactions between de novo variants, the IPA assay found that the NF-κB signaling pathway and its interacting genes were commonly observed at two networks. The relatively small cohort size may affect the results of novel ASD genes with de novo variants described in our findings. We did not conduct functional experiments in this study. Because of the diversity and heterogeneity of ASD, the primary purpose of this study was to investigate probable causative relationships between novel de novo variants and known autism genes. Additionally, we based functional relationships with known genes on network analysis rather than on statistical analysis. We identified new variants that may underlie genetic factors contributing to ASD in Korean families using WES and genetic network analyses. We observed novel de novo variants that might be functionally linked to ASD, of which the variants interact with six genetic networks.

An Anthocyanin-Rich Extract Obtained from Portuguese Blueberries Maintains Its Efficacy in Reducing Microglia-Driven Neuroinflammation after Simulated Digestion

Dietary polyphenols are multi-target compounds that have been considered promising candidates in strategies for the mitigation of neurological diseases, acting particularly through reduction of microglia-driven neuroinflammation. In this study, an anthocyanin-rich extract obtained from Portuguese blueberries was subjected to a simulated gastrointestinal digestion; after chemical characterisation, the potential of both non-digested and digested extracts to combat neuroinflammation was evaluated using a microglia N9 cell line. Although the extracts have markedly different chemical composition, both were efficient in reducing the production of either key inflammatory markers or reactive oxygen species and in enhancing reduced glutathione levels in activated cells. Furthermore, this protection was shown to be related to the suppression of nuclear factor kappa B (NF-kB) activation, and to a signal transducer and activator of transcription 1 (STAT1)-independent mechanism. These results demonstrate that the anthocyanin extract, after simulated digestion, maintains its efficacy against neuroinflammation, and can, therefore, assume a relevant role in prevention of neuroinflammation-related neurological disorders.

Methylmercury chloride exposure aggravates proinflammatory mediators and Notch-1 signaling in CD14+ and CD40+ cells and is associated with imbalance of neuroimmune function in BTBR T+ Itpr3tf/J mice

Autism spectrum disorder (ASD) is a severe neurodevelopmental disorder characterized by deficits in social interaction, communication, and repetitive behaviors. A key role for immune dysfunction has been suggested in ASD. Recent studies have indicated that inflammatory mediators and Notch-1 signaling may contribute to the development of ASD. Methylmercury chloride (MeHgCl) is an environmental pollutant that primarily affects the central nervous system, causing neurological alterations. Its effects on immunological responses have not been fully investigated in ASD. In this study, we examined the influence of MeHgCl exposure on inflammatory mediators and Notch-1 signaling in BTBR T⁺ Itpr3tf/J (BTBR) mice, a model of ASD. We examined the effects of MeHgCl on the IL-6-, GM-CSF-, NF-κB p65-, Notch-1-, and IL-27-producing CD14⁺ and CD40⁺ cells in the spleen. We assessed the effect of MeHgCl on IL-6, GM-CSF, NF-κB p65, Notch-1, and IL-27 mRNA levels in brain tissue. We also measured IL-6, GM-CSF, and NF-κB p65 protein expression levels in brain tissue. MeHgCl exposure of BTBR mice significantly increased IL-6-, GM-CSF-, NF-κB p65-, and Notch-1-, and decreased IL-27-producing CD14⁺, and CD40⁺ cells in the spleen. MeHgCl exposure of BTBR mice upregulated IL-6, GM-CSF, NF-κB p65, and Notch-1, and decreased IL-27 mRNA expression levels in brain tissue. Moreover, MeHgCl resulted in elevated expression of the IL-6, GM-CSF, and NF-κB p65 proteins in brain tissue. Taken together, these results indicate that MeHgCl exposure aggravates proinflammatory mediators and Notch-1 signaling which are associated with imbalance of neuroimmune function in BTBR mice.

GABA-mediated activated microglia induce neuroinflammation in the hippocampus of mice following cold exposure through the NLRP3 inflammasome and NF-κB signaling pathways

Chronic cold stress has long-term dramatic effects on the animal immune and neuroendocrine systems. As one of the important regions of the brain, the hippocampus is the main region involved in response to stressors. Nevertheless, the impact to the hippocampus following cold exposure and the underlying mechanism involved are not clear. To evaluate the response of the hippocampus during chronic cold stress, male C57BL/6 mice were exposed to 4 °C, 3 h per day for 1 week, after which neuroinflammation and the molecular and signaling pathways in the hippocampus response to cold stress were investigated. To confirm the potential mechanism, BV2 cells were treated with γ-aminobutyric acid (GABA) and BAY 11-7082 and MCC950, then the activation of microglia and key proteins involved in the regulation of inflammation were measured. We demonstrated that chronic cold stress induced the activation of microglia, the emergence of neuroinflammation, and the impairment of neurons in the hippocampus, which might be the result of GABA-mediated activation of nod-like receptor protein 3 (NLRP3) inflammasome and the nuclear factor kappa B (NF-κB) signaling pathway.

Upregulation of interleukin (IL)-31, a cytokine producing CXCR1 peripheral immune cells, contributes to the immune abnormalities of autism spectrum disorder

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by communication deficits, impaired social interactions, and restricted stereotypical behaviors. Several immune cells are associated with immune dysfunction in ASD; however, IL-31 has not been explored in ASD. This study aims to investigate the role of inflammatory cytokines and transcription factors of the CXCR1 cells in children with ASD. In the current study, we investigated the cytokines and transcription factors produced by CXCR1⁺ cells (IL-31, IL-9, IL-21R, IL-21, NF-κB p65, RORγT, STAT1, and FoxP3) in peripheral blood mononuclear cells (PBMCs), from children with ASD and typically developing (TD) control children, using flow cytometric analysis. In addition, we measured mRNA and protein expression levels of IL-31 using quantitative real-time PCR and western blot analyses in PBMCs. In our study, children with ASD had increased CXCR1⁺IL-31⁺, CXCR1⁺IL-9⁺, CXCR1⁺IL-21R⁺, CXCR1⁺IL-21⁺, CXCR1⁺NF-κB⁺ p65, CXCR1⁺RORγT⁺, and CXCR1⁺STAT1⁺, and decreased CXCR1⁺FoxP3⁺ cells as compared with cells from the TD control samples. Similarly, children with ASD showed increased IL-31 mRNA and protein expression levels as compared to those of TD control samples. Our results suggest that upregulated production of inflammatory cytokines and transcription factors in CXCR1⁺ cells cause immunological imbalance in children with ASD. Therefore, attenuation of inflammatory cytokines/mediators and transcription factors could have a therapeutic potential in the treatment of ASD.

Analyzing the Potential Biological Determinants of Autism Spectrum Disorder: From Neuroinflammation to the Kynurenine Pathway

Autism Spectrum Disorder (ASD) etiopathogenesis is still unclear and no effective preventive and treatment measures have been identified. Research has focused on the potential role of neuroinflammation and the Kynurenine pathway; here we review the nature of these interactions. Pre-natal or neonatal infections would induce microglial activation, with secondary consequences on behavior, cognition and neurotransmitter networks. Peripherally, higher levels of pro-inflammatory cytokines and anti-brain antibodies have been identified. Increased frequency of autoimmune diseases, allergies, and recurring infections have been demonstrated both in autistic patients and in their relatives. Genetic studies have also identified some important polymorphisms in chromosome loci related to the human leukocyte antigen (HLA) system. The persistence of immune-inflammatory deregulation would lead to mitochondrial dysfunction and oxidative stress, creating a self-sustaining cytotoxic loop. Chronic inflammation activates the Kynurenine pathway with an increase in neurotoxic metabolites and excitotoxicity, causing long-term changes in the glutamatergic system, trophic support and synaptic function. Furthermore, overactivation of the Kynurenine branch induces depletion of melatonin and serotonin, worsening ASD symptoms. Thus, in genetically predisposed subjects, aberrant neurodevelopment may derive from a complex interplay between inflammatory processes, mitochondrial dysfunction, oxidative stress and Kynurenine pathway overexpression. To validate this hypothesis a new translational research approach is necessary.

Association Analysis of ANRIL Polymorphisms and Haplotypes with Autism Spectrum Disorders

Autism spectrum disorder (ASD) has been shown to have a complex inheritance. Several single-nucleotide polymorphisms (SNPs) have been shown to be associated with risk of this neurodevelopmental disorder. In the current study, we genotyped four SNPs in a genomic hotspot for human disorders. The selected SNPs were located in adjacency of the antisense noncoding RNA in the INK4 locus (ANRIL) and have been shown to be associated with a number of human disorders. Genotyping was performed in 420 ASD cases and 420 normally developed children. After correction of P values for multiple comparisons, there was no significant difference in frequencies of rs1333045, rs1333048, rs4977574, and rs10757278 alleles, genotypes, or haplotypes between ASD children and children with normal development. However, one estimated haplotype (T A A A haplotype corresponding to rs1333045, rs1333048, rs4977574, and rs10757278 SNPs, respectively) tended to be more prevalent among cases compared with controls (OR (95% CI) = 1.77 (1.19-2.64), adjusted P value = 0.07). Besides, the T A G G tended to be less common among ASD cases compared with controls (OR (95% CI) = 0.64 (0.47-0.87), adjusted P value = 0.07). Although we could not detect significant difference in alleles, genotypes, or haplotypes frequencies between cases and controls, the trend toward association between two haplotypes and ASD risk implies that there might be a putative causative variant in the mentioned haplotypes whose association with ASD could be determined in larger cohorts of patients.

Bridging the Gap Between Physical Health and Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a highly complex and heterogeneous developmental disorder that affects how individuals communicate with other people and relate to the world around them. Research and clinical focus on the behavioural and cognitive manifestations of ASD, whilst important, have obscured the recognition that ASD is also commonly associated with a range of physical and mental health conditions. Many physical conditions appear with greater frequency in individuals with ASD compared to non-ASD populations. These can contribute to a worsening of social communication and behaviour, lower quality of life, higher morbidity and premature mortality. We highlight some of the key physical comorbidities affecting the immune and the gastrointestinal systems, metabolism and brain function in ASD. We discuss how healthcare professionals working with individuals with ASD and parents/carers have a duty to recognise their needs in order to improve their overall health and wellbeing, deliver equality in their healthcare experiences and reduce the likelihood of morbidity and early mortality associated with the condition.

Targeted Biomedical Treatment for Autism Spectrum Disorders

BACKGROUND

A diagnosis of autism spectrum disorders (ASD) represents presentations with impairment in communication and behaviour that vary considerably in their clinical manifestations and etiology as well as in their likely pathophysiology. A growing body of data indicates that the deleterious effect of oxidative stress, mitochondrial dysfunction, immune dysregulation and neuroinflammation, as well as their interconnections are important aspects of the pathophysiology of ASD. Glutathione deficiency decreases the mitochondrial protection against oxidants and tumor necrosis factor (TNF)-α; immune dysregulation and inflammation inhibit mitochondrial function through TNF-α; autoantibodies against the folate receptors underpin cerebral folate deficiency, resulting in disturbed methylation, and mitochondrial dysfunction. Such pathophysiological processes can arise from environmental and epigenetic factors as well as their combined interactions, such as environmental toxicant exposures in individuals with (epi)genetically impaired detoxification. The emerging evidence on biochemical alterations in ASD is forming the basis for treatments aimed to target its biological underpinnings, which is of some importance, given the uncertain and slow effects of the various educational interventions most commonly used.

METHODS

Literature-based review of the biomedical treatment options for ASD that are derived from established pathophysiological processes.

RESULTS

Most proposed biomedical treatments show significant clinical utility only in ASD subgroups, with specified pre-treatment biomarkers that are ameliorated by the specified treatment. For example, folinic acid supplementation has positive effects in ASD patients with identified folate receptor autoantibodies, whilst the clinical utility of methylcobalamine is apparent in ASD patients with impaired methylation capacity. Mitochondrial modulating cofactors should be considered when mitochondrial dysfunction is evident, although further research is required to identify the most appropriate single or combined treatment. Multivitamins/multiminerals formulas, as well as biotin, seem appropriate following the identification of metabolic abnormalities, with doses tapered to individual requirements. A promising area, requiring further investigations, is the utilization of antipurinergic therapies, such as low dose suramin.

CONCLUSION

The assessment and identification of relevant physiological alterations and targeted intervention are more likely to produce positive treatment outcomes. As such, current evidence indicates the utility of an approach based on personalized and evidence-based medicine, rather than treatment targeted to all that may not always be beneficial (primum non nocere).

Maternal blood folate status during early pregnancy and occurrence of autism spectrum disorder in offspring: a study of 62 serum biomarkers

BACKGROUND

Autism spectrum disorder (ASD) evolves from an interplay between genetic and environmental factors during prenatal development. Since identifying maternal biomarkers associated with ASD risk in offspring during early pregnancy might result in new strategies for intervention, we investigated maternal metabolic biomarkers in relation to occurrence of ASD in offspring using both univariate logistic regression and multivariate network analysis.

METHODS

Serum samples from 100 women with an offspring diagnosed with ASD and 100 matched control women with typically developing offspring were collected at week 14 of pregnancy. Concentrations of 62 metabolic biomarkers were determined, including amino acids, vitamins (A, B, D, E, and K), and biomarkers related to folate (vitamin B₉) metabolism, lifestyle factors, as well as C-reactive protein (CRP), the kynurenine-tryptophan ratio (KTR), and neopterin as markers of inflammation and immune activation.

RESULTS

We found weak evidence for a positive association between higher maternal serum concentrations of folate and increased occurrence of ASD (OR per 1 SD increase: 1.70, 95% CI 1.22-2.37, FDR adjusted P = 0.07). Multivariate network analysis confirmed expected internal biochemical relations between the biomarkers. Neither inflammation markers nor vitamin D₃ levels, all hypothesized to be involved in ASD etiology, displayed associations with ASD occurrence in the offspring.

CONCLUSIONS

Our findings suggest that high maternal serum folate status during early pregnancy may be associated with the occurrence of ASD in offspring. No inference about physiological mechanisms behind this observation can be made at the present time because blood folate levels may have complex relations with nutritional intake, the cellular folate status and status of other B-vitamins. Therefore, further investigations, which may clarify the potential role and mechanisms of maternal blood folate status in ASD risk and the interplay with other potential risk factors, in larger materials are warranted.

The rs12826786 in HOTAIR lncRNA Is Associated with Risk of Autism Spectrum Disorder

Autism spectrum disorder (ASD) encompasses a group of neurodevelopmental disorders with complex pattern of inheritance. Several single nucleotide polymorphisms (SNPs) within coding or non-coding regions of genome have been associated with risk of this disorder. In the current study, we genotyped rs12826786, rs1899663, and rs4759314 SNPs within HOX transcript antisense RNA (HOTAIR) in 427 ASD cases and 430 normally developed children. The rs12826786 was associated with ASD in allelic (T vs. C: OR (95% CI) = 1.29 (1.07-1.57), adjusted P value = 0.03) and recessive (TT vs. TC + CC: OR (95% CI) = 1.60 (1.10-2.32), adjusted P value = 0.04) models. However, the other SNPs were not associated with ASD in any inheritance model. No estimated haplotype within HOTAIR was associated with risk of ASD in the assessed population. Based on the results of the current investigation, the rs12826786 can be regarded as a risk locus for ASD in Iranian population.

Associations between autistic-like traits and polymorphisms in NFKBIL1

OBJECTIVE

The immune system has been suggested to be associated with neuropsychiatric disorders; for example, elevated levels of cytokines and the inflammation-related transcription factor nuclear factor kappa-B (NF-κB) have been reported in individuals with autism spectrum disorder (ASD). The aim of this study was to investigate possible associations between autistic-like traits (ALTs) and single nucleotide polymorphisms (SNPs) in NFKB1 (encoding a subunit of the NF-κB protein complex) and NF-κB inhibitor-like protein 1 (NFKBIL1).

METHODS

The study was conducted in a cohort from the general population: The Child and Adolescent Twin Study in Sweden (CATSS, n = 12 319, 9-12 years old). The subjects were assessed by the Autism-Tics, ADHD, and Other Comorbidities Inventory. Five SNPs within the two genes were genotyped (NFKBIL1: rs2857605, rs2239707, rs2230365 and rs2071592; NFKB1: rs4648022).

RESULTS

We found significant associations for two SNPs in NFKBIL1: rs2239707 showed a significant distribution of genotype frequencies in the case-control analysis both for all individuals combined and in boys only, and rs2230365 was significantly associated with the ALTs-module language impairment in boys only. Furthermore, we found nominal association in the case-control study for rs2230365, replicating earlier association between this SNP and ASD in an independent genome-wide association study.

CONCLUSION

The shown associations between polymorphisms in NFKBIL1 and ALTs are supporting an influence of the immune system on neuropsychiatric symptoms.

Human amniotic epithelial cell transplantation promotes neurogenesis and ameliorates social deficits in BTBR mice

Background

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interactions and communication and stereotypical patterns of behaviors, interests, or activities. Even with the increased prevalence of ASD, there is no defined standard drug treatment for ASD patients. Currently, stem cells, including human amniotic epithelial cell (hAEC) transplantation, seem to be a promising treatment for ASD, but the effectiveness needs to be verified, and the mechanism has not been clarified.

Methods

We intraventricularly transplanted hAECs into a 2-month-old BTBR T+tf/J (BTBR) mouse model of ASD. Behavior tests were detected 1 month later; hippocampal neurogenesis, neuroprogenitor cell (NPC) pool, and microglia activation were analyzed with immunohistochemistry and immunofluorescence; the levels of pro-inflammatory cytokines, brain-derived neurotrophic factor (BDNF), and TrkB in the hippocampus were determined by real-time PCR or western blotting.

Results

After intraventricular injection of hAECs into adult males, social deficits in BTBR mice were significantly ameliorated. In addition, hAEC transplantation restored the decline of neurogenesis and NPCs in the hippocampus of BTBR mice by expanding the stem cell pool, and the decreased levels of BDNF and TrkB were also rescued in the hippocampus of the hAEC-injected BTBR mice. Meanwhile, the transplantation of hAECs did not induce microglial overactivation or excessive production of pro-inflammatory cytokines in the hippocampus of BTBR mice.

Conclusions

Based on these results, we found that hAEC transplantation ameliorated social deficits and promoted hippocampal neurogenesis in BTBR mice. Our study indicates a promising therapeutic option that could be applied to ASD patients in the future.

Fluoride Exposure Induces Inhibition of Sodium-and Potassium-Activated Adenosine Triphosphatase (Na+, K+-ATPase) Enzyme Activity: Molecular Mechanisms and Implications for Public Health

In this study, several lines of evidence are provided to show that Na + , K + -ATPase activity exerts vital roles in normal brain development and function and that loss of enzyme activity is implicated in neurodevelopmental, neuropsychiatric and neurodegenerative disorders, as well as increased risk of cancer, metabolic, pulmonary and cardiovascular disease. Evidence is presented to show that fluoride (F) inhibits Na + , K + -ATPase activity by altering biological pathways through modifying the expression of genes and the activity of glycolytic enzymes, metalloenzymes, hormones, proteins, neuropeptides and cytokines, as well as biological interface interactions that rely on the bioavailability of chemical elements magnesium and manganese to modulate ATP and Na + , K + -ATPase enzyme activity. Taken together, the findings of this study provide unprecedented insights into the molecular mechanisms and biological pathways by which F inhibits Na + , K + -ATPase activity and contributes to the etiology and pathophysiology of diseases associated with impairment of this essential enzyme. Moreover, the findings of this study further suggest that there are windows of susceptibility over the life course where chronic F exposure in pregnancy and early infancy may impair Na + , K + -ATPase activity with both short- and long-term implications for disease and inequalities in health. These findings would warrant considerable attention and potential intervention, not to mention additional research on the potential effects of F intake in contributing to chronic disease.

Cathepsin B inhibition ameliorates leukocyte-endothelial adhesion in the BTBR mouse model of autism

AIMS

Autism spectrum disorder (ASD) is a wide range of neurodevelopmental disorders involving deficits in social interaction and communication. Unfortunately, autism remains a scientific and clinical challenge owing to the lack of understanding the cellular and molecular mechanisms underlying it. This study aimed to investigate the pathophysiological mechanism underlying leukocyte-endothelial adhesion in autism-related neurovascular inflammation.

METHODS

Male BTBR T+tf/J mice were used as an autism model. The dynamic pattern of leukocyte-endothelial adhesion in mouse cerebral vessels was detected by two-photon laser scanning microscopy (TPLSM). Using FACS, RT-PCR, and Western blotting, we explored the expression of cell adhesion molecules, the mRNA expression of endothelial chemokine, the protein levels of cathepsin B, and inflammatory mediators.

RESULTS

We found a significant increase in leukocyte-endothelial adhesion in BTBR mice, accompanied by elevated expression of the adhesion molecule neutrophils CD11b and endothelial ICAM-1. Our data further indicate that elevated neutrophil cathepsin B levels contribute to elevated endothelial chemokine CXCL7 levels in BTBR mice. The pharmacological inhibition of cathepsin B reverses the enhanced leukocyte-endothelial adhesion in the cerebral vessels of autistic mice.

CONCLUSION

Our results revealed the prominent role of cathepsin B in modulating leukocyte-endothelial adhesion during autism-related neurovascular inflammation and identified a promising novel approach for autism treatment.

Proteomics Study of Peripheral Blood Mononuclear Cells (PBMCs) in Autistic Children

Autism is one of the most common neurological developmental disorder associated with social isolation and restricted interests in children. 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. To search for biomarkers for early detection and exploration of the disease mechanisms, here, we investigated the protein expression signatures of peripheral blood mononuclear cells (PBMCs) in autistic children compared with healthy controls by using isobaric tags for relative and absolute quantitation (iTRAQ) proteomics approach. The results showed a total of 41 proteins as differentially expressed in autistic group as compared to control. These proteins are found associated with metabolic pathways, endoplasmic reticulum (ER) stress and protein folding, endocytosis, immune and inflammatory response, plasma lipoprotein particle organization, and cell adhesion. Among these, 17 proteins (13 up-regulated and four down-regulated) are found to be linked with mitochondria. Eight proteins including three already reported proteins in our previous studies were selected to be verified. Five already reported autism associated pro-inflammatory cytokines [interferon-γ (IFN-γ), interleukin-1β (IL-1β), IL-6, IL-12, and tumor necrosis factor-α (TNF-α)] were detected in plasma by enzyme-linked immunosorbent assay (ELISA) analysis. The results were consistent with proteomic results and reports from previous literature. These results proposed that PBMCs from autistic children might be activated, and ER stress, unfolded protein response (UPR), acute-phase response (APR), inflammatory response, and endocytosis may be involved in autism occurrence. These reported proteins may serve as potential biomarkers for early diagnosis of autism. More specifically, simultaneous detection of three proteins [complement C3 (C3), calreticulin (CALR), and SERPINA1] in the plasma and PBMCs could increase the authenticity of detection.