No abstract

Endothelial inflammation and dysfunction are critical to the process of atherosclerosis. Emerging evidence demonstrates that upregulation of miR-200a reduces VCAM-1 expression and prevents monocytic cell adhesion onto the aortic endothelium. However, limited information is available about the role of in facilitating atherosclerotic lesion formation. We investigated the anti-inflammatory and anti-atherosclerotic actions of miR-200a. Human umbilical vein endothelial cells (HUVECs) were cultured in the presence of oxidized low-density lipoprotein (ox-LDL), and their viability and apoptosis were evaluated using CCK-8 assays and flow cytometric analysis. The enhancer of zeste homolog 2 (EZH2) promoter activity was evaluated in the presence of miR-200a by dual luciferase reporter gene assay. EZH2-mediated methylation of signal transducer and activator of transcription 3 (STAT3) was validated by ChIP and IP assays. ApoE −/− mice were given a 12-week high-fat diet and developed as in vivo atherosclerotic models. miR-200a was downregulated but EZH2 and HMGB1 were upregulated in ox-LDL-treated HUVECs and the aorta tissues of atherosclerotic mouse models. Elevated miR-200a was shown to protect HUVECs against ox-LDL-induced apoptosis and inflammation. EZH2 was verified as a target of miR-200a. The protective effects of miR-200a were abrogated upon an elevation of EZH2. EZH2 methylated STAT3 and enhanced STAT3 activity by increased tyrosine phosphorylation of STAT3, thereby increasing apoptosis and release of pro-inflammatory cytokines in ox-LDL-treated HUVECs. An anti-atherosclerotic role of miR-200a was also demonstrated in atherosclerotic mouse models. Our study demonstrates that miR-200a has anti-inflammatory and anti-atherosclerotic activities dependent on the EZH2/STAT3 signaling cascade.

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The implication of different dietary n-3/n-6 polyunsaturated fatty acids (PUFAs) ratios has been investigated in some neurodevelopmental disorders (including autism and depression). However, the mechanisms underlying the effects of different PUFAs ratios on the autism are still poorly understood. In the present study, a valproic acid (VPA) rat model of autism was used to study the effects of diet with different n-3/n-6 PUFA ratios on the autism, and the underlying mechanisms explored. Our results showed that rats with prenatal administration of VPA took less response time to sniff three odorants in the olfactory habituation/dishabituation tests, had lower frequency of pinning and following patterns, and had decreased hippocampal 5-hydroxytryptamine (5-HT), increased serum 5-HT and downregulated expression of tight junction protein (occludin and claudin-1) in the colon. However, supplementation of n-3/n-6 PUFAs (1:5) in the VPA treated rats ameliorated the autistic behaviors, increased hippocampal 5-HT and tight junction expression in the colon, and decreased serum 5-HT. In conclusion, dietary supplementation of n-3/n-6 PUFAs (1:5) significantly improves VPA-induced autism-like behaviors in rats, which may be, at least partially, related to the increased hippocampal 5-HT. Furthermore, this diet can increase the expression of tight junction proteins to improve intestinal barrier impairment.

Autism spectrum disorder (ASD) is a developmental disability which may cause significant social, communication, and behavioral challenges. Besides certain essential symptoms, a lot of ASD individuals also suffer the comorbidity of gut microbiota dysbiosis, which possibly causes a variety of gastrointestinal (GI) difficulties. Interestingly, evidence has indicated that behavioral output may be modulated through the communication between the central nervous system and gut microbiota via the gut-brain axis. Polyunsaturated fatty acids (PUFAs) and n-3 fatty acids (n-3 PUFA) are structurally and functionally crucial components for the brain, and the state of n-3 PUFAs also affects the gut microbiota. However, how varying intake ratios of n-3/n6 PUFAs affect the gut microbiota composition in ASDs is not well-understood. Pregnant female Wistar rats with intraperitoneal administration of valproate acid (VPA) at embryonic day (E) 12.5 and their male offspring were grouped and fed three diets: a control chow (VPA group), omega-3 deficient (A group), and n-3/n6 (1:5) diet (B group). The diet of pregnant female Wistar rats with intraperitoneal administration of saline and their male offspring was a control chow (normal group). Microbial composition and species abundance were investigated accordingly by the 16S rRNA gene-based metagenomics analysis on the fecal samples. Results showed that fecal microbial abundance was decreased because of VPA administration in the period of pregnancy, and the changing pattern of gut microbiota was similar to that reported in ASD patients. Furthermore, the n-3/n6 (1:5) diet increased the fecal microbial abundance and decreased the elevated Firmicutes. In conclusion, n-3/n6 PUFAs (1:5) diet supplementation may alter gut microbiota composition in VPA-exposed rats. This study put forward a new strategy for the intervention and treatment of autism by n-3/n-6 PUFAs ratio supplementation intakes.