Table of Contents Author Guidelines Submit a Manuscript
Journal of Diabetes Research
Volume 2017, Article ID 2654520, 9 pages
https://doi.org/10.1155/2017/2654520
Research Article

Liver-Specific Overexpression of Gamma-Glutamyltransferase Ameliorates Insulin Sensitivity of Male C57BL/6 Mice

1Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu 610041, China
2Laboratory of Endocrinology, Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
3Division of General Practice, West China Hospital of Sichuan University, Chengdu 610041, China
4Department of Stomatology, Hebei Medical University Affiliated North China Petroleum Bureau General Hospital, Renqiu 062552, China
5Health Examination Management Center, Sichuan Province People’s Hospital, Chengdu 610072, China

Correspondence should be addressed to Haoming Tian; moc.621@999naitmh and Tao Chen; moc.qq@oatnehc.rd

Received 8 February 2017; Revised 18 April 2017; Accepted 4 May 2017; Published 4 June 2017

Academic Editor: Joseph F. Ndisang

Copyright © 2017 Yang Long et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In the current study, we developed a liver-specific GGT-overexpressing mice model by rapid injection pLIVE-GGT vector through tail vein and investigated the effects of GGT elevation on glucose metabolism and insulin sensitivity. The serum GGT activity was significantly increased after 7 days of pLIVE-GGT1 vector delivery and lasted for about 3 weeks. GGT overexpression reduced the levels of GSSG and GSH in the liver and serum and had no effects on total antioxidative capacity in the liver, kidney, and skeletal muscle except for the pancreas. Increased GGT activity had no effect on the glucose tolerance but could facilitate blood glucose lowering after intraperitoneal insulin administration. The results of Western blotting showed that increased GGT activity enhanced insulin-induced AKT phosphorylation at Ser473. Furthermore, GGT inhibitor could attenuate the changes of insulin-induced blood glucose uptake and AKT phosphorylation in the liver. In summary, the present study developed a liver-specific GGT-overexpressing mice model and found that GGT elevation in short term had no effects on glucose metabolism but could increase insulin sensitivity through enhancing the activity of insulin signaling pathway.