Nutritional Intervention as a Complementary Neuroprotective Approach against Propionic Acid-Induced Neurotoxicity and Associated Biochemical Autistic Features in Rat Pups

Vasostatin-1 restores autistic disorders in an idiopathic autism model (BTBR T+ Itpr3tf/J mice) by decreasing hippocampal neuroinflammation

Chromogranin A (CgA), a ∼ 49 kDa acidic secretory protein, is ubiquitously distributed in endocrine and neuroendocrine cells and neurons. As a propeptide, CgA is proteolytically cleaved to generate several peptides of biological importance, including pancreastatin (PST: hCgA250-301), Vasostatin 1 (VS1: hCgA1-76), and catestatin (CST: CgA 352-372). VS1 represents the most conserved fragment of CgA. A 20 amino acid domain within VS1 (CgA 47-66) exhibits potent antimicrobial and anti-inflammatory activities. Autism is known to be associated with inflammation. Therefore, we seek to test the hypothesis that VS1 modulates autism behaviors by reducing inflammation in the hippocampus. Treatment of C57BL/6 (B6) and BTBR (a mouse model of idiopathic autism) mice with VS1 revealed the following: BTBR mice showed a significant decrease in chamber time in the presence of a stranger or a novel object. Treatment with VS1 significantly increased chamber time in both cases, underscoring a crucial role for VS1 in improving behavioral deficits in BTBR mice. In contrast to chamber time, sniffing time in BTBR mice in the presence of a stranger was less compared to B6 control mice. VS1 did not improve this latter parameter. Surprisingly, sniffing time in BTBR mice in the presence of a novel object was comparable with B6 mice. Proinflammatory cytokines such as IL-6 and IL-1b, as well as other inflammatory markers, were elevated in BTBR mice, which were dramatically reduced after supplementation with VS1. Interestingly, even Beclin-1/p62, pAKT/AKT, and p-p70-S6K/p70-S6K ratios were notably reduced by VS1. We conclude that VS1 plays a crucial role in restoring autistic spectrum disorders (ASD) plausibly by attenuating neuroinflammation.

Neuroplasticity of children in autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that encompasses a range of symptoms including difficulties in verbal communication, social interaction, limited interests, and repetitive behaviors. Neuroplasticity refers to the structural and functional changes that occur in the nervous system to adapt and respond to changes in the external environment. In simpler terms, it is the brain's ability to learn and adapt to new environments. However, individuals with ASD exhibit abnormal neuroplasticity, which impacts information processing, sensory processing, and social cognition, leading to the manifestation of corresponding symptoms. This paper aims to review the current research progress on ASD neuroplasticity, focusing on genetics, environment, neural pathways, neuroinflammation, and immunity. The findings will provide a theoretical foundation and insights for intervention and treatment in pediatric fields related to ASD.

Roles of Epigenetics and Glial Cells in Drug-Induced Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by severe deficits in social communication and interaction, repetitive movements, abnormal focusing on objects, or activity that can significantly affect the quality of life of the afflicted. Neuronal and glial cells have been implicated. It has a genetic component but can also be triggered by environmental factors or drugs. For example, prenatal exposure to valproic acid or acetaminophen, or ingestion of propionic acid, can increase the risk of ASD. Recently, epigenetic influences on ASD have come to the forefront of investigations on the etiology, prevention, and treatment of this disorder. Epigenetics refers to DNA modifications that alter gene expression without making any changes to the DNA sequence. Although an increasing number of pharmaceuticals and environmental chemicals are being implicated in the etiology of ASD, here, we specifically focus on the molecular influences of the abovementioned chemicals on epigenetic alterations in neuronal and glial cells and their potential connection to ASD. We conclude that a better understanding of these phenomena can lead to more effective interventions in ASD.

Modulation of gut microbiota with probiotics as a strategy to counteract endogenous and exogenous neurotoxicity

The existing data demonstrate that probiotic supplementation affords protective effects against neurotoxicity of exogenous (e.g., metals, ethanol, propionic acid, aflatoxin B1, organic pollutants) and endogenous (e.g., LPS, glucose, Aβ, phospho-tau, α-synuclein) agents. Although the protective mechanisms of probiotic treatments differ between various neurotoxic agents, several key mechanisms at both the intestinal and brain levels seem inherent to all of them. Specifically, probiotic-induced improvement in gut microbiota diversity and taxonomic characteristics results in modulation of gut-derived metabolite production with increased secretion of SFCA. Moreover, modulation of gut microbiota results in inhibition of intestinal absorption of neurotoxic agents and their deposition in brain. Probiotics also maintain gut wall integrity and inhibit intestinal inflammation, thus reducing systemic levels of LPS. Centrally, probiotics ameliorate neurotoxin-induced neuroinflammation by decreasing LPS-induced TLR4/MyD88/NF-κB signaling and prevention of microglia activation. Neuroprotective mechanisms of probiotics also include inhibition of apoptosis and oxidative stress, at least partially by up-regulation of SIRT1 signaling. Moreover, probiotics reduce inhibitory effect of neurotoxic agents on BDNF expression, on neurogenesis, and on synaptic function. They can also reverse altered neurotransmitter metabolism and exert an antiamyloidogenic effect. The latter may be due to up-regulation of ADAM10 activity and down-regulation of presenilin 1 expression. Therefore, in view of the multiple mechanisms invoked for the neuroprotective effect of probiotics, as well as their high tolerance and safety, the use of probiotics should be considered as a therapeutic strategy for ameliorating adverse brain effects of various endogenous and exogenous agents.

Associations between genetically determined dietary factors and risk of autism spectrum disorder: a Mendelian randomization study

Background

Existing studies confirm the importance of dietary factors in developing autism spectrum disorder (ASD) and disease progression. Still, these studies are primarily observational, and their causal relationship is unknown. Moreover, due to the extensive diversity of food types, the existing research remains somewhat limited in comprehensiveness. The inconsistency of the results of some studies is very disruptive to the clinic. This study infers a causal relationship between dietary factors on the risk of developing ASD from a genetic perspective, which may lead to significant low-cost benefits for children with ASD once the specificity of dietary factors interfering with ASD is confirmed.

Methods

We performed a two-sample Mendelian randomization (MR) analysis by selecting single nucleotide polymorphisms (SNPs) for 18 common dietary factors from the genome-wide association study (GWAS) database as instrumental variables (IVs) and obtaining pooled data for ASD (Sample size = 46,351) from the iPSYCH-PGC institution. Inverse variance weighted (IVW) was used as the primary analytical method to estimate causality, Cochran's Q test to assess heterogeneity, the Egger-intercept test to test for pleiotropy and sensitivity analysis to verify the reliability of causal association results.

Results

The MR analysis identified four dietary factors with potential causal relationships: poultry intake (fixed-effects IVW: OR = 0.245, 95% CI: 0.084-0.718, P < 0.05), beef intake (fixed-effects IVW: OR = 0.380, 95% CI: 0.165-0.874, P < 0.05), cheese intake (random-effects IVW: OR = 1.526, 95% CI: 1.003-2.321, P < 0.05), and dried fruit intake (fixed-effects IVW: OR = 2.167, 95% CI: 1.342-3.501, P < 0.05). There was no causal relationship between the remaining 14 dietary factors and ASD (P > 0.05).

Conclusion

This study revealed potential causal relationships between poultry intake, beef intake, cheese intake, dried fruit intake, and ASD. Poultry and beef intake were associated with a reduced risk of ASD, while cheese and dried fruit intake were associated with an increased risk. Other dietary factors included in this study were not associated with ASD.