RT Journal Article
SR Electronic
T1 Insights into Insulin-mediated Regulation of CYP2E1: miR 132/212 Targeting of CYP2E1 and Role of PI3-K, Akt, mTOR Signaling in Regulating miR132/212 and miR 122/181a Expression in Primary Cultured Rat Hepatocytes
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP dmd.113.052860
DO 10.1124/dmd.113.052860
A1 Upasana Shukla
A1 Nithin Tumma
A1 Theresa Gratsch
A1 Alan Dombkowski
A1 Raymond F Novak
YR 2013
UL http://dmd.aspetjournals.org/content/early/2013/08/08/dmd.113.052860.abstract
AB Several microRNAs (miRs) were selected for characterization of their response to insulin signaling based on in silico predictions of targeting Cytochrome (P450) 2E1 (CYP2E1) mRNA and previous reports implicating their role in hepatic metabolism and disease. CYP2E1 expression decreases with increasing insulin concentration and has been shown to be regulated by the phosphatidylinositol 3-kinase (PI3-K) / Akt / mammalian target of rapamycin (mTOR) signaling pathway. In primary cultured rat hepatocytes, insulin at 0.1, 1.0, 10 nM elevated miRNA 132 and 212 expression ~2- and 1.8-fold respectively, whereas expression of miRNAs181a and 122 increased ~1.6- and 1.4-fold, respectively. In contrast, insulin failed to significantly alter the expression of miRNA let-7a. Mechanistic studies employing inhibitors of PI3-K, Akt, and mTOR, were used to examine the role of the insulin signaling pathway on miR expression and resulted in significant suppression of the insulin-mediated elevation of miR-132, miR-212 and miR-122 levels, with a lesser effect observed for miR-181a. Targeting of the rat CYP2E1 3' untranslated region (UTR) by miR-132 and 212 was demonstrated with an in vitro luciferase reporter assay. These data show that insulin, which regulates CYP2E1 through the PI3-K, Akt, mTOR signaling pathway, also regulates the expression of miRs which target the 3'-UTR of CYP 2E1 mRNA and are involved in regulation of hepatic metabolism, and disease.