Based On TGF-β/Smads Signaling Pathway To Study The Effect And Mechanism Of Oxytropis Falcata Bunge Extract On Renal Interstitial Fibrosis

Objective: Through studying the effect of extract of Oxytropis Falcate Bunge on transdifferentiation of human renal tubular epithelial cells HK-2 induced with transforming growth factor-β1( TGF-β1), to explore the mechanism of it on renal fibrosis.Methods: Rats were given extract of Oxytropis Falcate Bunge(300mg/kg)orally, 2 times a day for three days. Three days later, rat femoral artery blood serum was separated, that was the extract of Oxytropis Falcate Bunge containing serum. The HK-2 cells were cultured in DMEM /F12(1:1)with 10% fetal bovine serum. Cells were divided into control group, rat serum control group( TGF-β110ng/ml +10% rat serum), therapy group(TGF-β110ng/ml + 10%extract of Oxytropis Falcate Bunge-containing rat serum), TGF-β1 group(TGF-β110ng/ml). After 24 h,α-SMA and E-cadherin expression were observed by immunohistochemistry assay, the mRNA expression of TβRI and TβRII were tested by fluorescence quantitatiye PCR, and the protein expression of Smad 2 and smad 3 by Western-blot. And after 24 h, 48 h and 72 h, the concentration of type Ⅰ collagen, type Ⅲ collagen and FN in culture medium supernatant were detected by ELISA assay.Results: Normal HK-2 cell express E-cadherin, only do not express α-SMA,but after TGF-β1induction the expression of E-cadherin was decreased and α-SMA increased. Through treating with extract of Oxytropis Falcate Bunge, the α-SMA markedly decrease and E-cadherin increase.Compared with control group, the secretion of type Ⅰ collagen, type Ⅲ collagen and FN were markedly increased in TGF-β1 group. Compared with TGF-β1 group, the secretion of type Ⅰcollagen, type Ⅲ collagen and FN were markedly inhibited in therapy group, at 72 h the effect was the most significantly. The expression of TβRI、TβRII mRNA and Smad 2、smad 3protein in TGF-β1 group were increased compared with control group, and significantly decreased in therapy group TβRI、TβRII mRNA、Smad2 and smad3, compared with TGF-β1 group. Rat serum had no such effect.Conclusion: The results showed that Oxytropis falcate extract could inhibit transdifferentiation of renal tubular epithelial cells, and reduce the secretion of extracellular matrixcomponents, and regulate Smads signaling pathway, so it had the effect of prevention of renal interstitial fibrosis to some extent.