Microtranscriptome regulation by gonadotropin-releasing hormone

Gonadotropin-releasing hormone (GnRH) regulates biosynthesis in the pituitary gonadotrope via a complex signaling and gene network. Small non-coding microRNAs (miRNA) can play important roles in gene expression. We investigated the microtranscriptome in the mouse L beta T2 gonadotrope cell line using microarray, single molecule coincidence detection assays, hairpin real time PCR and LNA (locked nucleic acid) primer-extension PCR. Expression of nearly 200 miRNAs were detected by array and a panel of 101 hairpin real time PCR assays. Within this broad family of expressed miRNAs. GnRH induced upregulation of two miRNA products of the same primary transcript. miR-132 and miR-212, a result confirmed by single molecule, hairpin and LNA assays. Induction peaked 6 h after GnRH exposure and showed no significant frequency sensitivity. Bioinformatics analysis was used to predict potential targets of each of these GnRH-regulated miRNAs. These findings suggest the importance of the microtranscriptome in gene control in the gonadotrope and implicate miR-132 and miR-212 in the regulation of GnRH-stimulated biosynthetic response. (C) 2009 Elsevier Ireland Ltd. All rights reserved.