Randomized Controlled Trial
Copyright ©2014 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 28, 2014; 20(40): 14950-14957
Published online Oct 28, 2014. doi: 10.3748/wjg.v20.i40.14950
Therapeutic effects of globular adiponectin in diabetic rats with nonalcoholic fatty liver disease
Hong Ma, Fan Cui, Jing-Jing Dong, Guo-Ping You, Xiang-Jiu Yang, Hua-Dong Lu, Yan-Ling Huang
Hong Ma, Fan Cui, Xiang-Jiu Yang, Yan-Ling Huang, Department of Endocrinology, Zhongshan Hospital Xiamen University, Xiamen 361004, Fujian Province, China
Hong Ma, Jing-Jing Dong, Guo-Ping You, Department of Endocrinology, Xiamen Zhongshan Teaching Hospital of Fujian Medical University, Xiamen 361004, Fujian Province, China
Hua-Dong Lu, Department of Pathology, Zhongshan Hospital Xiamen University, Xiamen 361004, Fujian Province, China
Author contributions: Ma H designed the study; Ma H and Cui F performed the data analyses and wrote the manuscript; Yang XJ and Huang YL participated in the data collection; Dong JJ, You GP and Lu HD performed the research; all the authors participated in the critical review and final approval of the manuscript.
Supported by Science and Technology Project of Xiamen, China, No. 3502Z20114016
Correspondence to: Hong Ma, MD, PhD, Associate Professor, Department of Endocrinology, Zhongshan Hospital Xiamen University, 209 Hubin South Road, Xiamen 361004, Fujian Province, China. mah-169@163.com
Telephone: +86-592-2590251 Fax: +86-592-2212328
Received: December 15, 2013
Revised: February 14, 2014
Accepted: June 13, 2014
Published online: October 28, 2014
Processing time: 318 Days and 8.1 Hours
Abstract

AIM: To explore the therapeutic role of globular adiponectin (gAd) in high-fat diet/streptozotocin (STZ)-induced type 2 diabetic rats with nonalcoholic fatty liver disease (NAFLD).

METHODS: Seven rats were fed a basic diet (normal control group; NC) during the experiment. Experimental rats (14 rats) were given a high-fat diet for 4 wk and were then injected with STZ to induce type 2 diabetes mellitus (T2DM) and NAFLD. Half of the T2DM/NAFLD rats were randomly injected intraperitoneally with gAd for 7 d (gAd-treated group), while the other 7 rats (T2DM/NAFLD group) received 0.9% saline. Plasma biochemical parameters and insulin concentrations were measured. Liver histopathology was examined by hematoxylin-eosin staining. Insulin receptor expression in the liver was analyzed by immunohistochemical staining, Western blot and quantitative real-time reverse transcription polymerase chain reaction analysis.

RESULTS: Compared to the control group, the T2DM/NAFLD group had increased levels of glucolipid and decreased levels of insulin. Plasma glucose and lipid levels were decreased in the gAd-treated group, while serum insulin levels increased. The expression of insulin receptor in the T2DM/NAFLD group increased compared with the NC group, and gAd downregulated insulin receptor expression in the livers of T2DM/NAFLD rats. Steatosis of the liver was alleviated in the gAd-treated group compared to the T2DM/NAFLD group (NAS 1.39 ± 0.51 vs 1.92 ± 0.51, P < 0.05).

CONCLUSION: Globular adiponectin exerts beneficial effects in T2DM rats with NAFLD by promoting insulin secretion, mediating glucolipid metabolism, regulating insulin receptor expression and alleviating hepatic steatosis.

Keywords: Adiponectin; Insulin secretion; Insulin receptor; Steatosis

Core tip: Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and is closely associated with obesity and type 2 diabetes mellitus (T2DM). Adiponectin is a fat-derived hormone with anti-diabetic properties, and evidence indicates that adiponectin plays a protective role in NAFLD. Our study focused on the beneficial roles of adiponectin in T2DM rats with NAFLD as a potential therapeutic target. The findings demonstrated that adiponectin exerts its beneficial effects in T2DM rats with NAFLD by promoting insulin secretion, mediating glucolipid metabolism, regulating insulin receptor expression and alleviating hepatic steatosis.