Correlation between HSP-72 expression and IL-8 secretion in human mesothelial cells.
BACKGROUND
Cytotoxicity of peritoneal dialysis fluid (PDF) and peritoneal inflammation are currently regarded as the two major culprits for chronic mesothelial injury and peritoneal membrane failure. In this study, we correlated induction of HSP-72, as a marker of the cellular stress response, to secretion of IL-8, as a marker for pro-inflammatory cytokines, in mesothelial cells upon sublethal PDF exposure.


METHODS
Primary omental cell cultures of human mesothelial cells were subjected to sublethal PDF exposure times (CAPD2, Fresenius, Germany). At the end of a 24 hour recovery period, induction of HSP-72 in the cell homogenate and IL-8 secretion in the supernatant was assessed by immunodensitometry and ELISA, respectively.


RESULTS
PDF exposure times from 15 min to 60 min resulted in progressively increased HSP-72 expression levels (267 vs 320 vs 419% of controls, p<0.05 vs controls) as well as increased IL-8 secretion (323 vs 528 vs 549% of controls, p<0.05 vs controls) with full cell viability (MTT unchanged to control). HSP-72 expression was statistically significantly correlated with IL-8 secretion.


CONCLUSIONS
The significant correlation between HSP-72 expression and IL-8 secretion suggests that the regulation of pro-inflammatory pathways in mesothelial cells exposed to PDF may represent an integral part of their stress response. Future studies to investigate the cellular regulatory mechanism involved are warranted.
Bender
T O
TO
Department of Nephrology and Medical Intensive Care, Universitätsklinikum Charité, Campus Virchow-Klinikum, Berlin, Germany.
Riesenhuber
A
A
Endemann
M
M
Herkner
K
K
Witowski
J
J
Jörres
A
A
Aufricht
C
C
D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D015314:Dialysis Solutions / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism*; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D009852:Omentum / Q000166:cytology; D010530:Peritoneal Dialysis
D015314:Dialysis Solutions; D050884:HSP72 Heat-Shock Proteins; D016209:Interleukin-8