Stress kinase cascades in an in vitro model of peritoneal dialysis

Peritoneal dialysis (PD) is the most frequent chronic renal replacement therapy in end stage renal disease in childhood. Successful long term PD is dependent on the integrity and function of the peritoneal membrane. But persistent exposure of the mesothelium to peritoneal dialysis fluid (PDF) results in peritoneal injury. Understanding the mechanism of mesothelial cell damage in response to PDF is therefore a major goal on the way to improve mesothelial cell viability in long-term PD. Stress sensitive protein kinase cascades are among the earliest indicators and sensors of cellular stress. In this proposal, we therefore wish to analyze stress activated protein kinase cascades in human mesothelial cells exposed to PDF, both commercially available forms and to solutions with defined alterations with respect to their physico-chemical properties. Focus will be placed upon the early events that lead to activation of distinct subsets of stress kinase cascades, as with their role in the mesothelial cell`s response to PDF. We specifically wish to address the following three aims. First to unravel and analyze stress kinase pathways that are specifically activated upon PDF exposure in human mesothelial cells. Second aim is to delineate downstream targets of these pathways and analyze their significance in the cellular response to PDF. An the third aim is to analyze whether defined modulation of the kinase pathways by pharmacological or genetic manipulation would alter the cellular response to PDF. Analysis of stress kinase pathways will be valuable for the study of mesothelial repair mechanisms with respect to future in vivo studies. This proposal therefore represents an essential step on the way to elucidate the molecular mechanisms that lead to membrane failure in PD. The ability to understand and modify the cellular stress response might offer promising new therapeutic approaches to prevent or diminish peritoneal damage during PD.