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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

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.
› Author Affiliations
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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