Abstract

MicroRNAs as Biomarkers and Therapeutic Targets for Autism

Anitha Ayyappan Pillai, Associate Professor, ICCONS

Autism is a complex polygenic neurodevelopmental disorder characterized by deficits in social interaction and communication and the presence of restricted, repetitive, stereotyped patterns of behavior. According to a recent report, the prevalence of this pervasive developmental disorder has risen to 1 in 68. This will have enormous public health implications in the future and has necessitated the need to discover predictive biomarkers that could index for autism before the onset of symptoms. microRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression at the post-transcriptional level. They have recently emerged as prominent epigenetic regulators of various cellular processes including neurodevelopment. More than 1,000 miRNAs are expressed in the human brain, and their dysfunction has been implicated in a range of neuropathological disorders including autism. miRNAs, previously known to be expressed only in cells and tissues, have also been detected in extracellular body fluids such as serum, plasma, saliva and urine. Altered expression of several cellular and circulating miRNAs have been observed in autistic individuals compared to healthy controls. In fact, aberrant expression of miRNAs has been detected in the post-mortem brain, lymphoblastoid cell lines, serum and whole blood of autistic individuals. Enrichment pathway analysis of the target genes of these aberrantly expressed miRNAs has implicated crucial neurologically relevant pathways. miRNA-based therapeutics hold a great potential because of their ability to silence multiple genes simultaneously. Thus, miRNAs are considered as potential targets for the development of novel therapeutic strategies for genetically complex disorders such as autism.