Spleen-Kidney Supplementing Formula Alleviates Renal Fibrosis in Diabetic Rats via TGF-β1-miR-21-PTEN Signaling Pathway

Background. Spleen-Kidney Supplementing Formula (SKSF), composed of 6 raw Chinese herbs and proposed based on the therapeutic principle of supplementing spleen-kidney and clearing the extra heat of stomach-lung, is effective in the treatment of type 2 diabetes mellitus (T2DM). Aim. This study aims to investigate the mechanism of SKSF to alleviate renal fibrosis in diabetic rats. Methods. T2DM model was induced by high-fat diet and multiple injections of low-dose streptozotocin. After 8-week intervention, samples were collected for detection. Results. SKSF decreased fasting blood glucose, glycosylated hemoglobin A1c, blood urea nitrogen, uric acid, urea, 24-hour urine protein, and KW/BW ratio, while it increased creatinine clearance rate of T2DM rats. Meanwhile, SKSF attenuated the renal fibrosis and improved the morphology and structure of renal tissue. Furthermore, SKSF significantly reduced the expression level of plasma miR-21 and TGF-β1 protein level and increased PTEN protein level. Conclusion. SKSF could attenuate the renal damage and renal fibrosis induced in T2DM, which may be related to its regulation on the expressions of TGF-β1, PTEN, and miR-21