Protein kinase C α inhibition prevents peritoneal damage in a mouse model of chronic peritoneal exposure to high-glucose dialysate

Abstract

Chronic exposure to commercial glucose-based peritoneal dialysis fluids during peritoneal dialysis induces peritoneal membrane damage leading to ultrafiltration failure. In this study the role of protein kinase C (PKC) α in peritoneal membrane damage was investigated in a mouse model of peritoneal dialysis. We used 2 different approaches: blockade of biological activity of PKCα by intraperitoneal application of the conventional PKC inhibitor Go6976 in C57BL/6 wild-type mice and PKCα-deficient mice on a 129/Sv genetic background. Daily administration of peritoneal dialysis fluid for 5 weeks induced peritoneal upregulation and activation of PKCα accompanied by epithelial-to-mesenchymal transition of peritoneal mesothelial cells, peritoneal membrane fibrosis, neoangiogenesis, and macrophage and T cell infiltration, paralleled by reduced ultrafiltration capacity. All pathological changes were prevented by PKCα blockade or deficiency. Moreover, treatment with Go6976 and PKCα deficiency resulted in strong reduction of proinflammatory, profibrotic, and proangiogenic mediators. In cell culture experiments, both treatment with Go6976 and PKCα deficiency prevented peritoneal dialysis fluid-induced release of MCP-1 from mouse peritoneal mesothelial cells and ameliorated transforming growth factor-β1-induced epithelial-to-mesenchymal transition and peritoneal dialysis fluid-induced MCP-1 release in human peritoneal mesothelial cells. Thus, PKCα plays a crucial role in the pathophysiology of peritoneal membrane dysfunction induced by peritoneal dialysis fluids, and we suggest that its therapeutic inhibition might be a valuable treatment option for peritoneal dialysis patients.

Activation of General Control Nonderepressible-2 Kinase Ameliorates Glucotoxicity in Human Peritoneal Mesothelial Cells, Preserves Their Integrity, and Prevents Mesothelial to Mesenchymal Transition

“…DAG, an intermediate product of this pathway, activates PKC [23,24], which, in turn, by activating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), can upregulate the expression of the profibrotic TGF-β1, as well as various proinflammatory cytokines [36][37][38]. Interestingly, previous studies have shown that high glucose induces PKC activation in peritoneal mesothelial cells, resulting in TGF-β1 and fibronectin production [39], whereas inhibition of PKC-α prevents peritoneal injury in a mouse model of chronic peritoneal exposure to high-glucose dialysate [40]. Our experiments confirmed that, in mesothelial cells cultured under high-glucose conditions, the PKC activity increases, whereas both halofuginone and tryptophanol prevent this to a significant extent.…”

Urokinase receptor associates with TLR4 interactome to promote LPS response

“…Immortalized mouse peritoneal mesothelial cell line was generated in our lab by limited dilution cultures of primary cells obtained from omentum tissue of Immorto mice harboring the tsSV40T gene as previously described 35 Construction of vector for Gaussia luciferase expression under control of NFκB promoter was described elsewhere 17 . Activity was measured using GeneCopoeia kits and Tecan Genios multiplate reader.…”

PKC-α Triggers EGFR Ubiquitination, Endocytosis and ERK Activation in Podocytes Stimulated with High Glucose

“…Cells were then subjected to subcellular organelle isolation, immunoprecipitation, cell surface biotinylation, internalization and Western blot analyses. The well-accepted PKC-α inhibitor Gö6976 [19, 20] was purchased from Tocris Bioscience (Cat. No.…”