The role of TGF-β1/SGK1 signaling pathway in diabetic nephropathy / 中国医师杂志

ABSTRACT

Objective To explore the role of transforming growth factor-β1/serum and glucocorticoid induced kinase 1 (TGF-β1/SGK1) signaling pathway in diabetic nephropathy (DN).Methods Totally 60 clean grade healthy male Sprague-Dawley (SD) rats were divided into normal control (Con group,n =20) and diabetic model group (diabetic group,n =40).Type 2 diabetic animal model was induced by intraperitoneal injection of streptozotocin (STZ,45 mg/kg) to SD rats.Half of rats in each group were sacrificed after implemented for 4 weeks and 8 weeks,respectively.Fasting glucose,serum urea and creatinine,as well as urine protein in 24 h were detected.Pathological changes of rats' kidney cortex tissue were examined by hematoxylin-eosin staining.The expression of SGK1 was detected by immunohistochemistry in renal tissue.The mRNA level of SGK1 was analyzed by real-time polymerase chain reaction (PCR).The protein expression of TGF-β1 and SGK1 were determined by Western blotting.Results Compared to the control group,the blood glucose of the diabetic group rats was significantly increased,kidney hypertrophy index,serum urea and creatinine,24 h urine volume and urinary microalbumin as well as kidney index were significantly higher (P ＜0.05).The mRNA expressed of SGK1,protein expression of TGF-β1 and SGK1 were also increased obviously in the renal cortex of diabetic rats (all P ＜ 0.05 vs Control).Conclusions TGF-β1/SGK1 signaling pathway is closely related to the TIF damage of kidney cortex in diabetic rats.