The role of protein kinase C activity in the proliferation of peritoneal fibroblasts.
OBJECTIVE
To clarify the effect of glucose on peritoneal sclerosis, we performed several experiments to determine how glucose influences the proliferation of, and the production of extracellular matrix proteins by, peritoneal fibroblasts. The effect of heparin on these phenomena was also studied.


METHODS
Using rat peritoneal fibroblasts, cells were cultured in four separate media: M199 with 5% fetal bovine serum (FBS) (control medium), control medium with 4% glucose (glucose medium), glucose medium with H7 [an inhibitor of protein kinase C (PKC)] 50 micromol, and glucose medium with heparin 50 microg/mL. Cell proliferation and concentrations of procollagen 3 peptide (P3P) and hyaluronic acid (HA) in the supernatants were evaluated at 24 hours, 72 hours, and 120 hours after culture. PKC activity in cytosolic and cell membrane fractions were measured 30 minutes after incubation in control medium and in glucose medium with and without heparin.


RESULTS
Glucose accelerated cell proliferation 24 hours after culture, but inhibited it 120 hours after culture. Glucose stimulated the production of HA from these cells 72 hours and 120 hours after culture, but it did not stimulate the production of P3P at any time. Heparin and H7 inhibited cell proliferation by glucose 24 hours after culture. Heparin and H7 also inhibited the production of HA in the peritoneal fibroblasts after culture, but did not affect the production of P3P. Glucose accelerated PKC activity in cell membrane, but not in cytosol. Heparin inhibited the elevated PKC activity of the membrane fraction by glucose.


CONCLUSIONS
Glucose may accelerate the proliferation of, and HA production in, peritoneal fibroblasts by stimulation of cellular PKC activity. Heparin suppresses these phenomena by inhibiting PKC activity.
Department of Medicine, Kidney Center, Tokyo Women's Medical University, Japan.
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Higuchi
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Nihei
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D006493:Heparin / Q000494:pharmacology; D006820:Hyaluronic Acid / Q000096:biosynthesis; D010446:Peptide Fragments / Q000096:biosynthesis; D010537:Peritoneum / Q000166:cytology*; D011347:Procollagen / Q000096:biosynthesis; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D011347:Procollagen; C041876:procollagen Type III-N-terminal peptide; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D006820:Hyaluronic Acid; D006493:Heparin; D011493:Protein Kinase C; D005947:Glucose