Effect of voluntary exercise on expression of miRNA-192, TGF-β (transforming growth factor) and SIP1 (Smad-interacting protein) levels of kidney tissue in type 2 diabetic male rats

Abstract

Nephropathy has been reported as an important complication of diabetes. Since physical activity and exercise can reduce metabolic syndrome and prevent the development of type 2 diabetes; in this study, we aimed to investigate the effect of exercise on nephropathy process by evaluating miRNA-192 expression pathway and TGF-β and SIP1 proteins in kidney tissue of type 2 diabetic rats. Methods: Forty male wistar rats (180-220 g) were divided into 4 groups: 1) control group, 2) diabetic group, 3) voluntary exercise group, 4) diabetic and voluntary exercise group. Type 2 diabetes was induced by high-fat diet followed by an intraperitoneal injection of streptozotocin (35 mg/kg). Voluntary exercise was also performed for 10 weeks through a rotating wheel. At the end of the protocols and after deep anesthesia, the right kidney was isolated and frozen to determine the expression level of miRNA-192 by qPCR, and the levels of TGF-β and SIP1 proteins by western blot method. Results: An increase in TGF-β protein expression and miRNA-192 levels and a decrease in SIP1 protein expression were observed in the kidney tissue of the diabetic group compared to the control group. In addition, voluntary exercise caused a significant decrease in miRNA-192 and an increase in SIP1 protein expression compared to the control group. Diabetic and voluntary exercise group showed reduced TGF-β protein expression and miRNA-192 levels, and increased SIP1 protein expression as compared to the diabetic group.