Identification of microRNAs and their target genes in Alport syndrome using deep sequencing of iPSCs samples

MicroRNAs (miRNAs) are a class of small RNA molecules that are implicated in post-transcriptional regulation of gene expression during development. The discovery and understanding of miRNAs has revolutionized the traditional view of gene expression. Alport syndrome (AS) is an inherited disorder of type IV collagen, which most commonly leads to glomerulonephritis and kidney failure. Patients with AS inevitably reach end-stage renal disease and require renal replacement therapy, starting in young adulthood. In this study, Solexa sequencing was used to identify and quantitatively profile small RNAs from an AS family. We identified 30 known miRNAs that showed a significant change in expression between two individuals. Nineteen miRNAs were up-regulated and eleven were down-regulated. Forty-nine novel miRNAs showed significantly different levels of expression between two individuals. Gene target predictions for the miRNAs revealed that high ranking target genes were implicated in cell, cell part and cellular process categories. The purine metabolism pathway and mitogen-activated protein kinase (MAPK) signaling pathway were enriched by the largest number of target genes. These results strengthen the notion that miRNAs and their target genes are involved in AS and the data advance our understanding of miRNA function in the pathogenesis of AS.