Tripartite separation of glomerular proteomes from reporter-free mice

Renal blood filtration occurs in a functional unit called the glomerulus. The resident cell types comprise the filtration barrier, namely podocytes, mesangial cells and glomerular endothelial cells. Here we introduce a glomerular cell isolation protocol, which enables the separation of these three cell types in sufficient amounts and purity to allow detailed protein-biochemical investigations. We demonstrate that the expression of fluorescent transgenes in glomerular cells can result in proteome artifacts. We show that different mouse strains have different glomerular cell type proteomes. Further, we demonstrate the power of the technique to identify new glomerular cell type-enriched proteins and demonstrate the potential of this globally applicable technique in the dissection of cell-specific disease responses and intra-glomerular cell-type crosstalk.