title: Altered tight junctions and fence function in NRK-52E cells induced by aristolochic acid.
abstract: Aristolochic acid (AA) can accumulate in the tubulointerstitium and cause kidney-specific injuries. However, the mechanism by which AA induces nephropathy remains largely unknown. This study explored the effect of AA-I on tight junctions (TJs), and the fence function in a renal epithelial cell (REC). NRK-52E cells were exposed to different concentrations of AA-I for 4 h or 25 μM AA-I for different time. Cell viability was detected by MTT, cell apoptosis by flow cytometric analysis, the expression of zonula occludens-1 (ZO-1), E-cadherin and polarity scaffold (Par3) by western blot and immunofluorescence, cell membrane permeability by transepithelial electrical resistance (TEER). It was found that AA-I reduced the expression of ZO-1, E-cadherin, and Par3 in a concentration- and time-dependent fashion, and altered the distribution of ZO-1 and Par3 from cell membrane to cell plasma. In parallel to the reduced expression of TJ proteins, TEER exhibited a significant reduction in response to AA-I treatment in a time- and concentration-dependent manner. Meanwhile, α-SMA expression in cells was increased following AA-I treatment. In contrast, cell viability and apoptosis were unaltered with the doses of AA-I tested. Our findings show for the first time that AA-I treatment in cultured RECs induced a rapid disruption of TJ and the fence function preceding apoptosis, which indicated that aberrant expression of TJ proteins within RECs may be involved in initiating the renal tubulointerstitial disorders.
authors.affiliation: Department of Nephrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.forename: Jinjin
authors.initials: J
authors.lastname: Fan
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Youjia
authors.initials: Y
authors.lastname: Zeng
authors.forename: Jing
authors.initials: J
authors.lastname: Nie
authors.forename: Xueqing
authors.initials: X
authors.lastname: Yu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D034341:Aristolochic Acids / Q000633:toxicity*; D015820:Cadherins / Q000378:metabolism; D002352:Carrier Proteins; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D019108:Tight Junctions / Q000187:drug effects* / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
chemical_list: D034341:Aristolochic Acids; D015820:Cadherins; D002352:Carrier Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C472451:Pard3 protein, rat; D010750:Phosphoproteins; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; C000228:aristolochic acid I