IL-4/IL-13 mediated competing endogenous RNA regulation of prostate fibrosis

Abstract Interleukin-4 and − 13 induced JAK/STAT signaling in fibroblasts can stimulate collagen expression, contributing to organ fibrosis and, in the prostate, aging-associated lower urinary tract dysfunction. These interleukins also influence the expression of several species of regulatory RNAs, including microRNA (miRNA) and circular RNA (circRNA). In the studies described here, complementary nucleotide binding interactions between these RNA species were used to develop a competing endogenous RNA (ceRNA) network to elucidate their role(s) in prostate tissue fibrosis. RNA was extracted from prostate stromal fibroblasts induced by IL-4 or IL-13 and subjected to sequencing or microarray analysis to identify differentially expressed mRNAs, miRNAs and circRNAs. Further analysis identified likely binding interactions between these RNAs that formed a novel ceRNA network of pro-fibrotic genes transcripts and their associations with circRNAs and miRNA. In particular, miR-140-3p was prioritized from the integrated ceRNA network as it showed directionally concordant cytokine-associated regulation and was predicted to interact with the 3′ UTR of the mRNA encoding the pro-fibrotic Cell Migration Inducing Hyaluronidase 1 (CEMIP) protein. Knockdown of miR-140-3p in IL-4 and IL-13 treated cells resulted in a significant increase in CEMIP protein levels, while overexpression of miR-140-3p produced the opposite effect. RNA bead pulldown assays confirmed the direct binding of the CEMIP transcript with miR-140-3p. This suggested that miR-140-3p binding to the 3’UTR of CEMIP negatively regulates CEMIP protein expression. These studies demonstrate that miRNA-mediated post-transcriptional mechanisms can modulate the levels of pro-fibrotic proteins, and suggest that these mechanisms may provide novel therapeutic targets for treating fibrosis.