Comprehensive search for novel circulating mirnas and axon guidance pathway proteins associated with risk of eskd in diabetes

Background Mechanisms underlying the pro gression of diabetic kidney disease to ESKD are not fully understood. Methods We performed global microRNA (miRNA) analysis on plasma from two cohorts consisting of 375 individualswith type 1 andtype 2 diabeteswith latediabetickidney disease, andtargetedproteomics analysis on plasma from four cohorts consisting of 746 individuals with late and early diabetic kidney disease. We examined structural lesions in kidney biopsy specimens from the 105 individuals with early diabetic kidney disease.Human umbilical vein endothelial cellswere used to assess the effects of miRNAmimics or inhibitors on regulation of candidate proteins. Results In the late diabetic kidney disease cohorts, we identified 17 circulating miRNAs, represented by four exemplars (miR-1287-5p, miR-197-5p, miR-339-5p, and miR-328-3p), that were strongly associated with 10-year risk of ESKD. These miRNAs targeted proteins in the axon guidance pathway. Circulating levels of six of these proteins-most notably, EFNA4 and EPHA2-were strongly associated with 10-year risk of ESKD in all cohorts. Furthermore, circulating levels of these proteins correlated with severity of structural lesions in kidney biopsy specimens. In contrast, expression levels of genes encoding these proteins had no apparent effects on the lesions. In in vitro experiments,mimics ofmiR-1287-5p andmiR-197-5p and inhibitors ofmiR-339-5p andmiR-328-3p upregulated concentrations of EPHA2 in either cell lysate, supernatant, or both. Conclusions This study reveals novel mechanisms involved in progression to ESKD and points to the importance of systemic factors in the development of diabetic kidney disease. Some circulatingmiRNAs and axon guidance pathway proteins represent potential targets for newtherapies to prevent and treat this condition.