Effect of rhein on expression of thrombospondin-1 and transforming growth factor β1 in renal tubular cells

Objective:To investigate the effect of rhein on expression of thrombospondin-1 and transforming growth factor β1 (TGF-β1) in renal tubular cells. Methodology:HK-2 cells were stimulated by different concentrations of rhein (10,20,40 μg/ml) in the presence of angiotensin-Ⅱ (AngⅡ,10-7 mol/L),untreated HK-2 cells were acted as normal control group,HK-2 cells treated by AngⅡ (10-7 mol/L) were acted as positive group. Real Time PCR was used to detect the expression of TSP-1 mRNA and TGF-β1 mRNA. Western blot analysis was used to detect the expression of TSP-1 and TGF-β1 protein. ELISA was used to detect the levels of total and active TGF-β1. Results:The expression of TSP-1 mRNA (3.84±0.48 vs 1.32±0.19,P0.05) and TGF-β1 mRNA (3.68±0.46 vs 1.18±0.13,P0.05) was up-regulated obviously when stimulated by AngⅡ (10-7 mol/L). The protein expression of TSP-1 (0.5246±0.0936 vs 0.1015±0.0768,P0.01)and TGF-β1(0.5948±0.0624 vs 0.1264±0.0811,P0.01)were also up-regulated simultaneously when stimulated by AngⅡ (10-7 mol/L). The expression of TSP-1 and TGF-β1 induced by AngⅡ was down-regulated markedly with 20 μg/ml and 40 μg/ml of rhein in mRNA and protein levels(P0.05,P0.01). And rhein (20 μg/ml and 40 μg/ml) could reduce the levels of total and active TGF-β1(P0.05,P0.01). Conclusion:Rhein can inhibit the expression of TSP-1 and TGF-β1 in mRNA and protein levels and down-regulate the levels of total and active TGF-β1.