MiRNA expression profile and miRNA-mRNA integrated analysis (MMIA) during podocyte differentiation

The podocyte is a prominent cell type, which encases the capillaries of glomerulus. Podocyte-selective deletion of Dicer or Drosha was reported to induce proteinuria and glomerulosclerosis, suggesting the essential role of microRNA (miRNA) in podocytes for renal function. However, no comprehensive miRNA expression or miRNA-mRNA integrated analysis (MMIA) can be found during podocyte differentiation. Herein, miRNA and mRNA microarrays are presented, which were carried out in differentiated and undifferentiated mouse podocyte cell lines (MPC5). A total of 50 abnormal miRNAs (26 down-regulated and 24 up-regulated) were identified in differentiated and undifferentiated podocytes. Using MMIA, 80 of the 743 mRNAs (>twofold change) were predicted for potential crosstalk with 30 miRNAs of the 50 abnormal miRNAs. In addition, the gene ontology of mRNAs and the pathway analysis of miRNAs revealed a new potential-regulated network during podocyte differentiation. The expressions of three remarkably changed miRNAs (miR-34c, miR-200a and miR-467e) and four mRNAs (Runx1t1, Atp2a2, Glrp1, and Mmp15), were randomly chosen for further validation by the quantitative real-time polymerase chain reaction, and their expression trends were consistent with the microarray data. Reference searching was also conducted to confirm our data and to find potential new molecules and miRNA-target pairs involved in the podocyte differentiation. The dual luciferase reporter assay for miR-200a/GLRX and let-7b/ARL4D confirmed the prediction of MMIA. The results of this study provide a detailed integration of mRNA and miRNA during podocyte differentiation. The molecular integration mode will open up new perspectives for a better understanding of the mechanism during podocyte differentiation.