Abstract
Peritoneal dialysis (PD) is a renal replacement therapy but deteriorates the peritoneal membrane (PM), reducing efficacy. Crosstalk between peritoneal cells contributes to this damage, yet no model exists to study these interactions closely. This study developed a co-culture model to investigate cell-to-cell communication via proteome and secretome analysis.Mesothelial and endothelial cells were co-cultured in transwell plates under optimized non-starving conditions (5% FCS) and exposed to PD-fluids in co- or single-culture conditions. To enable secretomics analysis in non-starvation conditions, an equalizer approach was used to deplete high-abundant proteins, combined with SILAC to trace cell origins.
Co-cultured cells displayed distinct responses to PD-fluid exposure compared to single cultures, with secretome analysis revealing cell-specific secretion patterns and low correlation with intracellular protein abundances. Proteome and secretome integration identified unique ligand-receptor pairs and 11 functional clusters of secreted proteins interacting with cell surface receptors. Identified secreted proteins overlapped with clinical PD patient samples and correlated with clinical parameters. Further analysis yielded novel candidate pathways, validated in a chronic mouse model and patient samples.
Deep secretomics analysis revealed a complex modulation of crosstalk, providing novel insights into PM pathophysiology and potential therapeutic targets to improve PD outcomes.