Format

Send to

Choose Destination
See comment in PubMed Commons below
PLoS One. 2011 Mar 25;6(3):e17343. doi: 10.1371/journal.pone.0017343.

The induction of microRNA targeting IRS-1 is involved in the development of insulin resistance under conditions of mitochondrial dysfunction in hepatocytes.

Author information

1
Department of Biochemistry, Dongguk University College of Medicine, Kyungju, Korea.

Erratum in

  • PLoS One. 2011;6(5). doi: 10.1371/annotation/2faafaa7-e359-4711-af5b-3597c705388d.

Abstract

BACKGROUND:

Mitochondrial dysfunction induces insulin resistance in myocytes via a reduction of insulin receptor substrate-1 (IRS-1) expression. However, the effect of mitochondrial dysfunction on insulin sensitivity is not understood well in hepatocytes. Although research has implicated the translational repression of target genes by endogenous non-coding microRNAs (miRNA) in the pathogenesis of various diseases, the identity and role of the miRNAs that are involved in the development of insulin resistance also remain largely unknown.

METHODOLOGY:

To determine whether mitochondrial dysfunction induced by genetic or metabolic inhibition causes insulin resistance in hepatocytes, we analyzed the expression and insulin-stimulated phosphorylation of insulin signaling intermediates in SK-Hep1 hepatocytes. We used qRT-PCR to measure cellular levels of selected miRNAs that are thought to target IRS-1 3' untranslated regions (3'UTR). Using overexpression of miR-126, we determined whether IRS-1-targeting miRNA causes insulin resistance in hepatocytes.

PRINCIPAL FINDINGS:

Mitochondrial dysfunction resulting from genetic (mitochondrial DNA depletion) or metabolic inhibition (Rotenone or Antimycin A) induced insulin resistance in hepatocytes via a reduction in the expression of IRS-1 protein. In addition, we observed a significant up-regulation of several miRNAs presumed to target IRS-1 3'UTR in hepatocytes with mitochondrial dysfunction. Using reporter gene assay we confirmed that miR-126 directly targeted to IRS-1 3'UTR. Furthermore, the overexpression of miR-126 in hepatocytes caused a substantial reduction in IRS-1 protein expression, and a consequent impairment in insulin signaling.

CONCLUSIONS/SIGNIFICANCE:

We demonstrated that miR-126 was actively involved in the development of insulin resistance induced by mitochondrial dysfunction. These data provide novel insights into the molecular basis of insulin resistance, and implicate miRNA in the development of metabolic disease.

PMID:
21464990
PMCID:
PMC3064581
DOI:
10.1371/journal.pone.0017343
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Public Library of Science Icon for PubMed Central
    Loading ...
    Support Center