Poster Sessions

Neu-24

Pablo Moya

P. R. Moya, A. Anavitarte, J. R. Wendland, C. Jensen, D. L. Murphy

Regulation of human serotonin transporter by microRNAs.

Alterations in serotonin transporter (SERT) expression have been shown to have a role in anxiety and depressive disorders as well as autism. Most prior research has focused on polymorphisms in the promoter and coding regions of this gene, while investigations of the 3’-untranslated regulatory region including its messenger RNA is scant. We found a cluster of predicted miRNA binding sites in the 3’untranslated region (UTR) of the human SERT mRNA. Cloning of the SERT 3’UTR into a reporter vector markedly reduced its expression in RN46 and JAR cell lines. Synthetic miRNA precursors comprising four of the predicted miRNAs further decreased gene expression. Transfection of corresponding anti-miRNAs rescued the expression of reporter vector to levels comparable to control. Similar results were obtained when cloning a 75 bp region spanning the predicted miRNA binding site. When evaluating the effect on endogenous SERT expression using plasmid-based overexpression, we found one miRNA able to effectively downregulate SERT expression in the serotonergic cell lines. We are currently developing lentiviral-mediated miRNA overexpression techniques in raphe nuclei of mice to extend these investigations in vivo, to provide evidence of relevance to the many human disorders found to be associated with altered SERT function and expression.