Effect of aristolochic acid on human renal cells in vitro

Objective To investigate the effects of aristolochic acid(AA) on cell proliferation, cytotoxicity and mRNA expression of some cytokines in cultured human renal interstitial fibroblasts (hRIFs) and human renal tubular epithelial cell line (HK-2). Methods (1) The cell proliferation of hRIFs and HK-2 was determined by MTT method. (2) The cytotoxicity of A A to hRIFs and HK-2 was determined by lactate dehydrogenase (LDH) release test. (3) The mRNA expression of type Ⅰ Collagen (Col Ⅰ), transforming growth factor-β(TGF-β), plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TTMP-1) was detected semiquantitatively with reverse transcription-polymerase chain reaction (RT-PCR). Results (1) AA in the concentrations of 10, 20 and 40μg/ml did not significantly stimulate the proliferation of hRIFs and HK-2 ( P 0. 05) and increase LDH release rates of HK-2 and hRIFs (P 0. 05) . (2) AA in the concentrations of 80 and 160μg/ml significantly elevated LDH release rates of HK-2 and hRIFs ( P 0. 01); LDH release rates were increased by 1.88- and 4.86-fold in HK-2 respectively, and by 1.72- and 1.94-fold in hRIFs respectively as compared to control group. (3) When stimulated by AA of 40μg/ml for 16 hours, the mRNA expression of TGF-β, PAI-1 and TIMP-1 in HK-2 was significantly upregulated ( P 0. 05) and the mRNA expression of Col Ⅰ, TGF-β, PAI-1 and TIMP-1 in hRIFs was also significantly upregulated ( P 0. 05) . The mRNA levels of TGF-β, PAI-1 and TIMP-1 in HK-2 were increased by 1. 65-, 1. 44- and 1. 30-fold respectively, and the mRNA levels of Col Ⅰ, TGF-β, PAI-1 and TIMP-1 in hRIFs were increased by 1. 47-,1. 41-,2. 32-and 1.41-fold respectively as compared to control group. No above-mentioned effects were found in the concentrations of 10 and 20μg/ml of AA. Conclusions The cytotoxic effects of AA in the concentrations of 80 and 160μg/ml on HK-2 may be related to pathogenesis of acute AA nephropathy. AA in the concentration of 40μg/rnl can significantly upregulate mRNA expression of TGF-β, PAI-1 and TIMP-1 of hRIFs and HK-2, and also upregulate Col Ⅰ mRNA expression of hRIFs, which may be related to pathogenesis of chronic AA nephropathy.