title: Direct involvement of the receptor-mediated apoptotic pathways in cisplatin-induced renal tubular cell death.
abstract: BACKGROUND
  Tumor necrosis factor (TNF) receptor family members, such as Fas and TNF receptor 1 (TNFR1), are thought to induce apoptosis in a variety of cells and organs. Although a number of potential scenarios have been postulated for the involvement of these receptors in the pathogenesis of acute renal failure (ARF), direct evidence for their involvement in death of renal tubular cells (RTCs) and renal dysfunction is preliminary.
  
  
  METHODS
  This study examined the roles of these receptors in RTC death in two systems: (1). in vivo murine and rat models of cisplatin-induced ARF, and (2). murine proximal tubular cells (PTCs), which were isolated from C57BL/6 (B6) mice, Fas-mutant B6-lpr/lpr mice and TNFR1-deficient mice, and normal rat kidney (NRK52E) cells in vitro.
  
  
  RESULTS
  Reverse transcription-polymerase chain reaction indicated cisplatin-induced up-regulation of Fas, Fas ligand and TNF-alpha mRNAs in the kidney in vivo and in RTCs in vitro, both in mice and rats. In contrast, the level of TNFR1 mRNA was substantial but did not change in response to cisplatin. TNF-alpha production in cell culture medium determined by enzyme-linked immunosorbent assay (ELISA) and Fas expression determined by fluorescence-activated cell sorter (FACS) analysis increased following incubation with cisplatin in B6 PTCs. In order to examine whether Fas and TNFR1 are directly involved in RTC death and renal dysfunction, we compared cell resistance to cisplatin using a cell viability assay and FACS analysis with fluorescein isothiocyanate-conjugated annexin V and propidium iodide staining. The ratios of cell viability loss and cell death, both from apoptosis and necrosis, were higher in B6 PTCs than in other cells, while the ratios were comparable between Fas-mutant PTCs and TNFR1-deficient PTCs. Caspase-8 activity was increased in B6 PTCs, but not in Fas-mutant PTCs and TNFR1-deficient PTCs. Furthermore, the renal dysfunction and RTC death, both apoptosis and necrosis, induced by cisplatin were more severe in B6 mice in vivo.
  
  
  CONCLUSIONS
  Based on these data, we conclude that the Fas- and TNFR1-mediated apoptotic pathways are directly involved in the pathogenesis of cisplatin-induced RTC death process.
authors.affiliation: Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. tsuruya@intmed2.med.kyushu-u.ac.jp
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Tsuruya
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Ninomiya
authors.forename: Masanori
authors.initials: M
authors.lastname: Tokumoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Hirakawa
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Masutani
authors.forename: Masatomo
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Fukuda
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kanai
authors.forename: Kenji
authors.initials: K
authors.lastname: Kishihara
authors.forename: Hideki
authors.initials: H
authors.lastname: Hirakata
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Iida
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced / Q000401:mortality / Q000473:pathology*; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D002945:Cisplatin / Q000494:pharmacology*; D053222:Fas Ligand Protein; D007684:Kidney Tubules / Q000166:cytology*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D019463:Mice, Inbred MRL lpr; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000954:Antigens, Surface; D000970:Antineoplastic Agents; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; C505662:Faslg protein, rat; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; C505526:Casp8 protein, mouse; C505528:Casp8 protein, rat; D053181:Caspase 8; D020169:Caspases; D002945:Cisplatin