Premium
Thyroid hormone promotes insulin‐induced glucose uptake by enhancing Akt phosphorylation and VAMP2 translocation in 3T3‐L1 adipocytes
Author(s) -
Lin Yi,
Sun Zhongjie
Publication year - 2011
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.22613
Subject(s) - glut4 , glucose transporter , glucose uptake , medicine , protein kinase b , endocrinology , insulin , phosphorylation , biology , insulin receptor , 3t3 l1 , chromosomal translocation , insulin receptor substrate , microbiology and biotechnology , adipocyte , insulin resistance , biochemistry , adipose tissue , gene
The purpose of this study was to test a hypothesis that T3 promotes glucose uptake via enhancing insulin‐induced Akt phosphorylation and VAMP2 translocation in 3T3‐L1 adipocytes. T3 significantly enhanced insulin‐induced phosphorylation of Akt, cytoplasma to cell membrane translocations of vesicle‐associated membrane protein 2 (VAMP2) and glucose transporter 4 (GLUT4), and glucose uptake in adipocytes. Akt inhibitor X abolished the promoting effects of T3, suggesting that Akt activation is essential for T3 to enhance these insulin‐induced events in adipocytes. Knockdown of VAMP2 using siRNA abrogated the effects of T3 on insulin‐induced GLUT4 translocation and glucose uptake, suggesting that VAMP2 is an important mediator of these processes. These data suggest that T3 may promote glucose uptake via enhancing insulin‐induced phosphorylation of Akt and subsequent translocations of VAMP2 and GLUT4 in 3T3‐L1 adipocytes. Akt phosphorylation is necessary for the promoting effects of T3 on insulin‐stimulated VAMP2 translocation. Further, VAMP2 is essential for T3 to increase insulin‐stimulated translocation of GLUT4 and subsequent uptake of glucose in adipocytes. J. Cell. Physiol. 226: 2625–2632, 2011. © 2010 Wiley‐Liss, Inc.