Peritoneal dialysate fluid composition determines heat shock protein expression patterns in human mesothelial cells.
BACKGROUND
Low biocompatibility of peritoneal dialysis fluids (PDF) contributes to mesothelial injury. We investigated whether the heat shock proteins (HSP)-27, HSP-72, and HSP-90 are differentially induced upon exposure of mesothelial cells to PDF and whether this was affected by selective modulation of the physicochemical properties of PDF.


METHODS
Human mesothelial cells (Met5A and primary human mesothelial cells) were exposed to acidic lactate and glucose-monomer based PDF (CAPD2 and CAPD3), to control culture media, or to a neutral lactate and glucose-monomer-based PDF with reduced levels of glucose degradation products (BALANCE). Expression of HSP-27, HSP-72, and HSP-90 and cellular distribution of HSP-72 were assessed by Western blotting and immunocytochemistry.


RESULTS
Mesothelial cells exhibited strong constitutive expression of HSP-27 and to a lesser extent HSP-72 and HSP-90. Exposure of the cells to CAPD2 and CAPD3 resulted in strong up-regulation of HSP-72. HSP-27 levels were slightly increased, but HSP-90 levels were unchanged upon exposure to CAPD2 or CAPD3. In contrast, exposure of the cells to BALANCE did not affect HSP-27 or HSP-72 expression. The acidic pH and glucose degradation products were found to be principal in mediating increased HSP-72 expression upon exposure to PDF.


CONCLUSIONS
Analysis of HSP expression represents a novel tool to assess biocompatibility of PDF. Among the HSP investigated, HSP-72 is the most predictive and accurate parameter to assess mesothelial cell injury in the early phase of exposure to PDF.
Arbeiter
K
K
Kinderdialyse, Department of Pediatrics, Universitätsklinik für Kinder und Jugendheilkunde, AKH Wien, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
Bidmon
B
B
Endemann
M
M
Bender
T O
TO
Eickelberg
O
O
Ruffingshofer
D
D
Mueller
T
T
Regele
H
H
Herkner
K
K
Aufricht
C
C
D002478:Cells, Cultured; D015314:Dialysis Solutions / Q000737:chemistry*; D004847:Epithelial Cells / Q000378:metabolism; D050884:HSP72 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins / Q000096:biosynthesis; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006801:Humans; D010530:Peritoneal Dialysis
D015314:Dialysis Solutions; D050884:HSP72 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins