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Exp Clin Endocrinol Diabetes 2012; 120(09): 553-559
DOI: 10.1055/s-0032-1311644
Article
© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

MiRNA-21 Reverses High Glucose and High Insulin Induced Insulin Resistance in 3T3-L1 Adipocytes through Targeting Phosphatase and Tensin Homologue

Authors

  • H.-y. Ling

    1   Department of Physiology, School of Medicine, University of South China, Hengyang, China
    2   Center for basic medical post-doctoral studies, University of South China, Hengyang, China

  • B. Hu

    1   Department of Physiology, School of Medicine, University of South China, Hengyang, China

  • X.-b. Hu

    3   Department of Biochemistry and Molecular Biology, School of life sciences and Technology, University of South China, Hengyang, China

  • J. Zhong

    4   Institute of Clinical Research/First Affiliated Hospital, University of South China, Hengyang, China

  • S.-d. Feng

    5   Department of Epidemiology, School of Public Health, University of South China, Hengyang, China

  • L. Qin

    6   Key Laboratory for Pharmacoproteomics of Hunan Province/Institute of Pharmacy and Pharmacology, University of South China, Hengyang, China

  • G. Liu

    6   Key Laboratory for Pharmacoproteomics of Hunan Province/Institute of Pharmacy and Pharmacology, University of South China, Hengyang, China

  • G.-b. Wen

    4   Institute of Clinical Research/First Affiliated Hospital, University of South China, Hengyang, China

  • D.-f. Liao

    7   Division of Stem Cell Regulation and Application, State Key Laboratory of Chinese Medicine Powder and Medicine Innovation in Hunan (incubation), Hunan University of Chinese Medicine, Changsha Hunan, China.
Further Information

Publication History

received 20 November 2011
first decision 01 April 2012

accepted 02 April 2012

Publication Date:
06 September 2012 (online)

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Abstract

Aims/hypothesis:

Our previous study showed there was a change of microRNA (miRNA) expression profile, and miR-21 was significantly down regulated in insulin-resistant adipocytes (IR-adipocytes). Phosphatase and tensin homologs deleted on chromosome 10 (PTEN), a negative regulator of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, was identified to be a target gene of miR-21, which suggested miR-21 might be associated with insulin resistance (IR) or diabetes. However, it is not known whether miR-21 play any role in the development of IR in 3T3-L1 adipocytes.

Methods:

Normal adipocytes and adipocytes transfected with pre-miR-21(pmiR-21) or negative control (pNeg) were treated with high glucose and high insulin for 24 h, insulin-stimulated glucose uptake was determined by 2-Deoxyglucose transport assay, miR-21 expression level was measured by using quantitative real-time RT-PCR (qRT-PCR). The protein expression levels of PTEN, Akt, phospho-Akt (Ser473), IRβ, GSK3β, phospho-GSK3β (Ser9) and GLUT4 were detected by western blotting assay.

Results:

We further confirmed that miR-21 was down regulated in IR-adipocytes by qRT-PCR. Over-expression of miR-21 significantly increased insulin-induced glucose uptake and decreased PTEN protein expression, while it had no significant effect on PTEN mRNA expression in IR-adipocytes. Moreover, over-expressing miR-21 significantly increased insulin-induced phosphorylation of AKT (Ser473), GSK3β (Ser9) and the translocation of glucose transporter 4 (GLUT4) in IR-adipocytes.

Conclusions:

In this study, our data demonstrate that miR-21 reverses high glucose and high insulin induced IR in 3T3-L1 adipocytes, possibly through modulating the PTEN-AKT pathway, and miR-21 may be a new therapeutic target for metabolic diseases such as T2DM and obesity.

Key words

miR-21 - insulin resistance - PTEN - AKT