title: HSP induction in mesothelial cells by peritoneal dialysis fluid depends on biocompatibility test system.
abstract: BACKGROUND
  We have previously shown that exposure of mesothelial cells (MC) to peritoneal dialysis fluids (PDF) not only caused toxic injury, but also induced cytoprotective heat shock proteins (HSP). This study was performed in order to compare HSP expression in MC upon PDF exposure in three currently used biocompatibility test systems.
  
  
  METHODS
  Omentum-derived human peritoneal MC underwent 3 modalities of exposure to heat- or filter-sterilized PDF: (A) pure PDF for 60 minutes followed by a recovery-period in pure culture medium for 24 hours; (B) 1:1 mixture of PDF and culture medium for 24 hours or (C) pure PDF for 60 minutes followed by a recovery-period in a 1:1 mixture of PDF and culture medium for 24 hours. Biocompatibility was assessed by LDH-release into the supernatant and HSP-72 expression in MC lysates.
  
  
  RESULTS
  Short-term exposure of MC to pure PDF (Modality A) resulted in concordant LDH release and upregulation of HSP-72, regardless of heat or filter sterilization. In contrast, both test systems that exposed MC to heat-sterilized PDF during the recovery period (Modalities B and C) resulted in severe cellular lethality but low HSP-72 expression.
  
  
  CONCLUSIONS
  This study clearly shows that HSP expression in MC upon PDF exposure depends on the biocompatibility test system. The presence of heat-sterilized PDF during recovery resulted in significant downregulation of Hsp-72 despite severe cell injury. Therefore, Hsp-72 expression reflects adequate cellular stress responses rather than PDF cytotoxicity.
authors.affiliation: Department of Nephrology and Medical Intensive Care, Charité Universitätsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Thorsten O
authors.initials: TO
authors.lastname: Bender
authors.forename: Klaus
authors.initials: K
authors.lastname: Kratochwill
authors.forename: Michael
authors.initials: M
authors.lastname: Böhm
authors.forename: Achim
authors.initials: A
authors.lastname: Jörres
authors.forename: Christoph
authors.initials: C
authors.lastname: Aufricht
mesh_terms: D001672:Biocompatible Materials; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D019610:Cytoprotection; D015314:Dialysis Solutions / Q000494:pharmacology* / Q000633:toxicity; D004848:Epithelium / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005374:Filtration; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009852:Omentum / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D010530:Peritoneal Dialysis; D013242:Sterilization / Q000379:methods; D013312:Stress, Physiological; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D001672:Biocompatible Materials; D015314:Dialysis Solutions; D050884:HSP72 Heat-Shock Proteins; D007770:L-Lactate Dehydrogenase