Transcriptional profiling of human neural precursors post alcohol exposure reveals impaired neurogenesis via dysregulation of ERK signaling and miR-145

Gestational alcohol exposure causes a range of neuropsychological disorders by modulating neurodevelopmental genes and proteins. The extent of damage depends on the stage of the embryo, as well as dosage, duration, and frequency of exposure. Here, we investigated the neurotoxic effects of alcohol using Human Embryonic Stem Cells (hESC). Multiple read-outs were engaged to assess the proliferation and differentiation capacity of neural precursor cells (NPC) upon exposure to 100 mM ethanol for 48 hrs corresponding to the blood alcohol levels for binge drinkers. Whole genome analysis revealed a spatiotemporal dysregulation of neuronal and glial specific gene expression that play critical roles in Central Nervous System (CNS) development. Alterations observed in the transcriptome may be attributed to epigenetic constitution witnessed by differential histone H3 Lys-4/Lys-27 modifications and acetylation status. In-depth mRNA and protein expression studies revealed abrogated ERK signaling in alcohol- treated cells. Consistent with this finding, Ingenuity Pathway Analysis (IPA) and microRNA profiling demonstrated upregulation of miR-145 by targeting the neural specifier Sox-2. We also show that the neurite branching complexity of TUJ1+ neurons was greatly reduced in response to alcohol. Lastly, in vivo studies using zebrafish embryos reconfirmed the in vitro findings. Employing molecular endpoints in a human model, this report indicates for the first time that acute alcohol exposure could lead to impaired brain development via perturbation of ERK pathway and miR-145. However, it still needs to be addressed whether these modulations sustain throughout development, compromising the ability of the individual during adulthood and aging. This article is protected by copyright. All rights reserved.