Transcriptome analysis of the response of cultured murine podocytes to puromycin aminonucleoside

Aims: Idiopathic nephrotic syndrome is known as a disease of the renal glomerular epithelial cells (podocytes). Recent advances in podocyte biology showed that podocytopathy is the culprit of nephrotic syndrome. To obtain comprehensive information about the response of podocytes to injury, we investigated the gene expression profile of podocytes in response to puromycin aminonucleoside (PAN)-induced injury. Methods: Differentiated mouse podocyte cell line (MPC5) cells were treated with 25 μg/ml PAN for 24, 48, or 72 h. Gene expression profiles of these cells were analyzed. Real time PCR analysis was used to confirm the findings of microarray. Results: Expression levels of 23 genes (differentially expressed genes, DEGs), including laminin α₁ and MMP3, were significantly different between PAN-treated podocytes and untreated cells. Gene ontology of DEGs indicated that their functional categories were cell adhesion, extracellular matrix (ECM) formation, and ECM degradation. Real-time PCR and indirect immunohistochemistry of PAN-treated and untreated podocytes confirmed the differential expression of DEGs. Conclusion: Using unbiased global gene expression profiling, we found that podocytes respond to PAN-induced injury by down-regulating the expression of genes involved in cell adhesion and extracellular matrix.