Profiling of podocyte microparticle-derived miRNAs as a Biomarkers in idiopathic membranous nephropathy

Abstract

Membranous nephropathy (MGN) is a common inflammatory kidney disease associated with podocyte damage and proteinuria. The only accurate diagnostic method of this disease is biopsy, which is an invasive method. The use of specific biomarkers of Microparticles (MPs) isolated from damaged podocytes released in the patient's urine has been proposed as an early, non-invasive and reproducible diagnostic method. Considering the involvement of microRNAs in podocyte damage, the aim of this study is the extraction of podocyte MPs from the urine of patients and characterizing and assay the expression level of miR-30c, miR-135 and miR-186 in the MPs sample isolated from the urine of patients with MGN. Material and methods. Urine samples of 30 patients with membranous nephropathy and 16 healthy individuals were collected to extract podocyte MPs using ultracentrifuge. Characterizing of these particles was determined using the specific protein marker of MPs, TSG-101, and the podocyte-specific marker Nephrin, by western blot method, and SEM was used to check the size and morphology. Evaluation of the expression level of microRNAs extracted from podocyte MPs, miR-30c, miR-135 and miR-186 were also performed by Real time PCR method. Results. The evaluation of the characteristics of MPs showed that there are many particles with a size of more than 100 nm in the urine sample, and there are higher levels of the specific marker TSG-101 and Nephrin in the urine samples of MGN patients compared to the control samples P< 0.001, respectively). The expression level of miR-186 was compared between the three studied groups and based on the results of the expression of this miRNA in the group of membranous nephropathy patients compared to healthy people group, there is a significant increase in expression (P<0.001)