title: Inhibition of aquaporin-1 expression by RNAi protects against aristolochic acid I-induced apoptosis in human proximal tubular epithelial (HK-2) cells.
abstract: The aim of this study was to investigate the protective effect of inhibition of aquaporin-1 (AQP1) expression against aristolochic acid I (AA-I)-induced apoptosis. HK-2 cells impaired by AA-I were used in this study as the cell model of aristolochic acid nephropathy. Apoptosis was studied by different methods, including 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assays, flow cytometry, and caspase 3 activity assays. We compared AA-I-mediated apoptosis in HK-2 cells with or without knockdown of AQP1 expression by RNA interference. MTT assays showed that AA-I inhibited the viability of HK-2 cells in a time- and concentration-dependent manner. Apoptosis was evidenced by the results of the Annexin V/propidium iodide assay and the occurrence of a sub-G1 peak in cell-cycle analysis. The activity of caspase 3 was found to have been increased by AA-I in a concentration-dependent manner. However, AQP1 RNA interference provided protection against injury in cells treated with AA-I (40 μM) for 24 h and attenuated the number of apoptotic cells. These results suggested that AQP1 plays an important role in AA-I-induced apoptosis and that inhibition of AQP1 expression may protect HK-2 cells from AA-I-induced apoptotic damage.
authors.affiliation: Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.forename: ZhenZhou
authors.initials: Z
authors.lastname: Jiang
authors.forename: LiXin
authors.initials: L
authors.lastname: Sun
authors.forename: Xue
authors.initials: X
authors.lastname: Mei
authors.forename: Bian
authors.initials: B
authors.lastname: Yong
authors.forename: LuYong
authors.initials: L
authors.lastname: Zhang
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D051398:Aquaporin 1 / Q000235:genetics*; D034341:Aristolochic Acids / Q000633:toxicity*; D002460:Cell Line; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D006801:Humans; D007674:Kidney Diseases / Q000139:chemically induced* / Q000473:pathology; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000473:pathology; D008954:Models, Biological; D034622:RNA Interference
chemical_list: D034341:Aristolochic Acids; D051398:Aquaporin 1; C000228:aristolochic acid I