Project description:Ultimately, autism is classified as an early neurodevelopmental disorder, highly heterogeneous and with a heritability of between 40% and 90%. Transcriptome studies have already been done in subjects with autism, but we decided to perform such a study on our own cohort of Sicilian subjects with autism. the results obtained show the involvement of differentially expressed genes involving inflammatory mechanisms and the mitochondrilae system.
Project description:In order to unveil the molecular mechanisms at play during the development of autistic brains, we studied cells that are representative of the very early stages of ontogenesis, namely stem cells. We used nasal olfactory stem cells that are readily accessible and can be biopsied safely. We recruited a relatively homogeneous cohort of nine adults with severe autism and low to very low developmental disabilities, and included two more adults with either Asperger syndrome or high-functioning autism, to enlarge the spectrum. The cohort was then paired with 11 age- and gender-matched control individuals. Stem cells were purified, banked and used for a transcriptomic study. Two-colors experiment. The cohort was then paired with 11 age- and gender-matched control individuals. Stem cells were purified, banked and used for a transcriptomic study. Validation by reverse transcription design.
Project description:Individualized outcome prediction classifiers were successfully constructed through expression profiling of 91 up-regulated and 67 down-regulated miRNAs in 5 autism spectrum disorder (ASD) cases and 5 controls. In the study presented here, a well-defined cohort of 5 autism spectrum disorder cases and 5 controls was used to acquire expression profiles of 91 up-regulated and 67 down-regulated miRNAs, leading to the first global miRNA expression profile of ASD in China.
Project description:In order to unveil the molecular mechanisms at play during the development of autistic brains, we studied cells that are representative of the very early stages of ontogenesis, namely stem cells. We used nasal olfactory stem cells that are readily accessible and can be biopsied safely. We recruited a relatively homogeneous cohort of nine adults with severe autism and low to very low developmental disabilities, and included two more adults with either Asperger syndrome or high-functioning autism, to enlarge the spectrum. The cohort was then paired with 11 age- and gender-matched control individuals. Stem cells were purified, banked and used for a transcriptomic study.
Project description:Background: Fetal alcohol spectrum disorder (FASD) is a developmental disorder that manifests through a range of cognitive, adaptive, physiological, and neurobiological deficits resulting from prenatal alcohol exposure. Although the North American prevalence is currently estimated at 2-5%, FASD has proven difficult to identify in the absence of the overt physical features characteristic of fetal alcohol syndrome. As interventions may have the greatest impact at an early age, accurate biomarkers are needed to identify children at risk for FASD. Building on our previous work identifying distinct DNA methylation patterns in children and adolescents with FASD, we have attempted to validate these associations in a different clinical cohort and to use our DNA methylation signature to develop a possible epigenetic predictor of FASD. Methods: Genome-wide DNA methylation patterns were analyzed using the Illumina HumanMethylation450 array in the buccal epithelial cells of a cohort of 48 individuals aged 3.5-18 (24 FASD cases, 24 controls). The DNA methylation predictor of FASD was built using a stochastic gradient boosting model on our previously published dataset FASD cases and controls (GSE80261). The predictor was tested on the current dataset and an independent dataset of 48 autism spectrum disorder cases and 48 controls (GSE50759). Results: We validated findings from our previous study that identified a DNA methylation signature of FASD, replicating the altered DNA methylation levels of 161/648 CpGs in this independent cohort, which may represent a robust signature of FASD in the epigenome. We also generated a predictive model of FASD using machine learning in a subset of our previously published cohort of 179 samples (83 FASD cases, 96 controls), which was tested in this novel cohort of 48 samples and resulted in a moderately accurate predictor of FASD status. Upon testing the algorithm in an independent cohort of individuals with autism spectrum disorder, we did not detect any bias towards autism, sex, age, or ethnicity. Conclusion: These findings further support the association of FASD with distinct DNA methylation patterns, while providing a possible entry point towards the development of epigenetic biomarkers of FASD.
Project description:We performed aCGH analysis using a custom Agilent oligonucleotide array to analyze 288 probands with idiopathic autism spectrum disorder (ASD) from the Simons Simplex Collection (SSC) of autism samples. The array is customized to high resolution coverage of exons for genes identified as encoding proteins included in a detailed protein interaction network for autism.
Project description:Rare DNA copy-number variation (CNV) plays an important role in the underlying genetic etiology of autism and intellectual disability. Although large numbers of copy-number variants (CNVs) have been recently implicated in autism, most are large affecting many genes and specificity of these lesions with respect to classically defined autism as opposed to more broadly defined developmental delay is unclear. We exploited the repeat architecture of the genome to target smaller regions (n=1340 hotspots, median size 15 kbp) flanked by repetitive sequence among 2,240 autism simplex patients and a subset of unaffected parents.
Project description:Purpose: We aimed to detected the circRNA expression profile and constructed a circRNA-based competing endogenous RNA (ceRNA) network in autism. Methods:Valproate acid was used to establish an in vivo model of autism in mice. circRNAs in autism group was identified by RNA sequencing. The expression of circRNAs were detected by real-time PCR. Module analysis was conducted followed by GO and KEGG pathway enrichment analysis. Results: A total of 1059 differentially expressed circRNAs (477 upregulated and 582 downregulated) in autism group. The expression of novel_circ_015779 and novel_circ_035247 were detected by real-time PCR. A ceRNA network based on altered circRNAs was established, with 9715 nodes and 150408 edges. The top three modules were all correlated with autism-related pathways involving ‘TGF-beta signaling pathway’, ‘Notch signaling pathway’, ‘MAPK signaling pathway’, ‘long term depression’, ‘thyroid hormone signaling pathway’, etc. Conclusions: The present study reveals a novel circRNA involved mechanisms in the pathogenesis of autism.
Project description:To identify the regulation of gene expression change in autism, we sequenced small RNAs in autism and control samples using miRNA-seq. We found a significant enrichment of binding sites in the 3'UTR regions of one cluster of genes with expression change in autism. Furthermore, expression of 18 miRNAs showing significant binding site enrichment in this cluster, correlated significantly with the expression of their predicted targets.