Heat shock response protects human peritoneal mesothelial cells from dialysate-induced oxidative stress and mitochondrial injury.
BACKGROUND
Chronic peritoneal dialysis (PD) is one of the major therapies for uremic patients. However, the peritoneal mesothelial cells (PMCs) are subject to the injury by bioincompatible dialysates. The aim of this study is to investigate the protective roles and mechanisms of heat shock response in PMCs.


METHODS
Primary cultured human PMCs (HPMCs) were subjected to commercial peritoneal dialysates. The cell viability was assayed by MTT test and Annexin V assay. The expression of HSPs was detected by Western blots analysis. Intracellular hydrogen peroxide and superoxide anion were detected using H(2)DCFDA and dHE probe, respectively, with flow cytometry. The mitochondrial membrane potential (DeltaPsim) of HPMCs was evaluated using JC1 probe with flow-cytometry.


RESULTS
Exposure of HPMCs to 1.5%, 2.5%, and 4.25% dextrose, and 7.5% icodextrin dialysates, respectively, for 60 min resulted in significantly accumulation of intracellular reactive oxygen species (ROS), DeltaPsim loss, and cell death in HPMCs. Amino acid dialysates exhibited no significant cytotoxicity. Adjusting the acidity in 1.5% dextrose and icodextrin dialysate significantly attenuated the dialysate-induced ROS generation and cell death in HPMCs. Heat pretreatment (41 degrees C, 30 minutes), which induced HSP 27 and 72 syntheses, significantly attenuated the dialysate-induced intracellular ROS accumulation, Dym loss, and cell death in HPMCs.


CONCLUSIONS
In conclusion, the acidic bioincompatible dialysates induce oxidative stress, DeltaPsim loss, and subsequent cell death in HPMCs. Amino acid dialysates is more biocompatible than glucose and icodextrin dialysates to HPMCs. Heat shock response protects HPMCs from the bioincompatible dialysates-induced cellular damage.
Kuo
Hung-Tien
HT
Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Faculty of Renal Care, Kaohsiung Medical University, Kaohsiung, Taiwan.
Chen
Hsiang-Wen
HW
Hsiao
Hui-Hsu
HH
Chen
Hung-Chun
HC
D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D015314:Dialysis Solutions / Q000009:adverse effects* / Q000737:chemistry; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D050884:HSP72 Heat-Shock Proteins / Q000096:biosynthesis; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D018869:Heat-Shock Response / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010530:Peritoneal Dialysis / Q000009:adverse effects; D010537:Peritoneum / Q000293:injuries* / Q000378:metabolism* / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism
D015314:Dialysis Solutions; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D017382:Reactive Oxygen Species