Role of rat organic anion transporter 1 in renal cellular uptake of aristolochic acid Ⅰ and the induction of cellular toxicity / 中华肾脏病杂志

ABSTRACT

Objective To investigate the role of rat organic anion transporter 1 (OAT1, SLC22A6) in the renal cellular uptake of AA Ⅰ and its impact on cellular toxicity. Methods HEK-293 cells were transfeeted with rat OAT1 cDNA or empty vectors. The over-expression of rOAT1 was confirmed by Western blot analysis and its activity was validated by using para-aminohippurate (PAH) as a probe. Cellular apoptosis was examined by flow cytometery using propodium iodode (PI) and annexin V-FITC staining. Results Concentration-and time-dependent intracellular accumulation of AA Ⅰ was observed in rOATl-transfected HEK-293 cells. After treatment with AA Ⅰ at the concentrations of 40 mg/L, 80 mg/L, 120 mg/L and 160 mg/L,respectively, for 45 min, the intracellular concentrations of AA Ⅰ in rOAT1-transfected HEK-293 cells were higher than those in controls (P<0.05). After treatment with AA Ⅰ (120 mg/L for 30 min, 60 min, 90 min and 120 min, respectively, the intracellular concentrations of AA Ⅰ in rOAT1-transfected HEK-293 cells were higher than those in controls (P<0.05). PAH significantly reduced the intracellular accumulations of AA Ⅰ in rOAT1-transfected HEK-293 cells. After treatment with AA Ⅰ at the concentrations of 40 mg/L, 80 mg/L, 120 mg/L and 160 mg/L respectively for 35 min, the intracellular accumulations of AA Ⅰ in rOAT1-transfected HEK-293 cells that treated with PAH were lower than those that were not treated by PAH. Cellular apoptosis and caspase-3 expression in rOAT1-transfeeted HEK-293 cells were significantly up-regnlated as compared to controls (P<0.05). Conclusion rOAT1 is involved in the cellular uptake of AA Ⅰ which leads to increased epithelial apoptosis. Further studies are suggested to investigate the role of human OAT in the disposition of AA and its toxicological consequences.