title: Triptolide alters barrier function in renal proximal tubular cells in rats.
abstract: Alteration of the tight junction complex in renal epithelial cells can affect renal barrier function and perturb normal kidney homeostasis. The objective of the present study was to determine whether triptolide could affect tight junctions in the proximal tubule epithelial cells both in vivo and in vitro. Wistar rats were gavaged with triptolide at 0, 100, 200 or 400 μg/kg/day for 28 days. Pathologic examination of the kidney showed that triptolide primarily affected the proximal tubules. The nephrotoxicity of triptolide is morphologically characterized by the detachment of the proximal tubular epithelial cells from each other. Immunohistochemical analysis showed that there was marked alteration in the localization of Zonula Occludens 1 protein (ZO-1) in the proximal tubule epithelium. Additionally, the uptake of FITC-dextran, a marker of fluid phase endocytosis in the proximal tubule, was considerably lower in triptolide-treated animals than in normal rats. Supported by these results, we detected significant increases in blood urea nitrogen (BUN) but not of creatinine (Cr) in rats treated with triptolide, indicating damage to the proximal tubules. Furthermore, triptolide treatment caused an alteration of the tight junction complex, resulting in changes in paracellular permeability in NRK-52E cells in vitro. Taken together, these results suggest that triptolide induced renal toxicity in rats and that the mechanism of toxicity was related to the disruption of cell-cell junctions and alterations of the paracellular permeability in the proximal tubule.
authors.affiliation: Jiangsu Center for Drug Screening, China Pharmaceutical University, Nanjing 210009, China. Electronic address: slxcpu@126.com.
authors.forename: Lixin
authors.initials: L
authors.lastname: Sun
authors.forename: Han
authors.initials: H
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Shan
authors.initials: S
authors.lastname: Huang
authors.forename: Huifang
authors.initials: H
authors.lastname: Mei
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Jiang
authors.forename: Luyong
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001806:Blood Urea Nitrogen; D015153:Blotting, Western; D002460:Cell Line; D003404:Creatinine / Q000097:blood; D003911:Dextrans / Q000378:metabolism; D004224:Diterpenes / Q000633:toxicity*; D004852:Epoxy Compounds / Q000633:toxicity; D005260:Female; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000378:metabolism; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000633:toxicity*; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D010616:Phenanthrenes / Q000633:toxicity*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019108:Tight Junctions / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D062826:Zonula Occludens-1 Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D003911:Dextrans; D004224:Diterpenes; D004852:Epoxy Compounds; D007166:Immunosuppressive Agents; D010616:Phenanthrenes; D012333:RNA, Messenger; D062826:Zonula Occludens-1 Protein; C015219:fluorescein isothiocyanate dextran; C001899:triptolide; D003404:Creatinine; D016650:Fluorescein-5-isothiocyanate
keywords: BUN; Cr; FBS; FITC; HE; Nephrotoxicity; Proximal tubule; TER; TJ; Tight junctions; Triptolide; blood urea nitrogen; creatinine; fetal bovine serum; fluorescein isothiocyanate; hematoxylin and eosin; tight junction; transepithelial resistance