Pyridoxamine alleviates high glucose induced fibrosis in renal tubular epithelial cell by inhibiting the activity of TGF-β1/Smad3 signaling pathway

Abstract Background Renal fibrosis is one of the main characteristics of diabetic nephropathy. TGF-β1/Smad3 pathway is expected to reveal the pathogenesis of renal fibrosis in diabetic nephropathy (DN). Pyridoxamine (PM), a natural form of vitamin B6, is a powerful inhibitor of advanced glycation end products (AGEs). PM plays an anti-apoptotic, anti-oxidative stress, and fibrosis role in DN. The purpose of this study was to assess whether PM has a protective effect in renal tubular epithelial and to investigate its possible mechanism. Methods The effects of PM were investigated in HK-2 cells induced by high glucose. HK-2 cells were administered with PM at a dose of 1 mmol/L. Western blot and Realtime PCR were used to detect the expression levels of renal fibrosis related proteins. The possible mechanism of PM was examined by expression of transforming growth factor-β1 (TGF-β1)/Smad3 pathway. Results PM could reduce the expression of Fibronectin (FN) and α-smooth muscle actin (α-SMA) induced by high glucose. PM could also affect the activity of TGF-β1/Smad3 pathway in HK-2 cells. FN and α-SMA were up-regulated by overexpression of Smad3 for 48 h. After adding PM, the levels of FN and α-SMA are significantly decreased. Conclusion Our findings indicate that PM showed a protective effect in HK-2 cells through the inhibition of TGF-β1/Smad3 pathway.