Evaluation of the role of blood stem cells with c-kit marker on TGF-β1 / SMAD signaling pathway and expression of collagen I, fibronectin and α-SMA in the process of kidney fibrosis of type 2 diabetic male rats

Abstract

Nephropathy has been reported as an important complication of diabetes. Since stem cell therapy can treat and reduce progression of diabetic complications; in this study, we aimed to evaluate the role of blood stem cells with c-kit marker on TGF-β1/Smad signaling pathway and expression of collagen I, fibronectin and α-SMA in the process of kidney fibrosis of type 2 diabetic male rats. Methods: Fifty male wistar rats (200-250 g) were divided into 4 groups: 1) control group, 2) diabetic group, 3) Diabetic+ C-Kit+ 4) diabetic and C-Kit_. Type 2 diabetes was induced by high-fat diet followed by an intraperitoneal injection of streptozotocin (35 mg/kg). group 3, intravenously received 50 μl phosphatebuffered saline (PBS) containing 3×105 c-kit+ cells and group 4 receive the same amount of C-Kit- solution. At the end of the protocols and after deep anesthesia, the right kidney was isolated and frozen to determine the expression level of TGF-β, collagen I, fibronectin and α-SMA and SMADs proteins by western blot method. Results: Diabetes increased the level of TGF-β1, collagen I, α-SMA, fibronectin, SMAD 2/3 and SMAD 7 in kidney tissues of male rats compared to the control group. Injection of C-Kit positive cells decreased the level of these factors in diabetic rats. C-Kit negative cells also had no effect in these markers, except for fibronectin which had a significant reducing effect. In all markers, except for fibronectin, there was no significant difference between C-Kit positive and C-kit negative cells. The decreasing effect of C-Kit positive cells on fibronectin was very significant compared to C-Kit negative cells. Histological results also confirmed these results.