Gene expression analysis of rat glomerular parietal epithelial cells

Very little is known about the function of glomerular parietal epithelial cells (PECs). In this study, we performed genome-wide expression analysis on PEC-enriched capsulated vs. PEC-deprived decapsulated rat glomeruli to determine the transcriptional state of PECs under normal conditions. We identified hundreds of differentially expressed genes that mapped to distinct biologic modules including development, tight junction, ion transport, and metabolic processes. Since developmental programs were highly enriched in PECs, we characterized several of their candidate members at the protein level. Collectively, our findings confirm that PECs are multifaceted cells and help define their diverse functional repertoire. We developed a sequential sieving methodology to selectively isolate capsulated (PEC-enriched) glomeruli from un-capsulated (PEC-deprived) glomeruli in rats. Three samples were obtained for each preparation. Total RNA was isolated and its integrity confirmed via Bioanalyzer 2100. Each sample (n =6) was hybridized to an Affymetrix Rat GeneChip 1.0ST microarray.