MicroRNAs as markers to monitor Endothelin-1 signaling and potential treatment in renal disease: Carcinoma - proteinuric damage - toxicity. (review).

This review highlights new developments in miRNA as diagnostic and surveillance tools in diseases damaging the renal proximal tubule mediated by endothelin in the field of renal carcinoma, proteinuric kidney disease and tubulotoxicity. A new mechanism in the miRNA regulation of proteins leads to the binding of the miRNA directly to the DNA with premature transcriptional termination and hence the formation of truncated protein isoforms (Mxi2, Vim3). These isoforms are mediated through miRNA15a or miRNA 498, respectively. ET-1 can activate a cytoplasmic complex consisting of NF-κB p65, MAPK p38α, and PKCα. Consequently, PKCα does not transmigrate into the nucleus, which leads to the: loss of suppression of a primiRNA15a, maturation of this miRNA in the cytoplasm, tubular secretion, and detectability in the urine. This mechanism has been shown in renal cell carcinoma and in proteinuric disease as a biomarker for the activation of the signaling pathway. Similarly, ET-1 induced miRNA 498 transmigrates into the nucleus to form the truncated protein Vim3, which is a biomarker for the benign renal cell tumor, oncocytoma. In tubulotoxicity, ET-1 induced miRNa133a downregulating multiple-drug-resistant related protein-2, relevant for proteinuric and cisplatin/cyclosporine A toxicitiy. Current advantages and limitationsof miRNAs as urinary biomarkers are discussed. This article is protected by copyright. All rights reserved.