LAUSR

AIMS MicroRNAs (miRNAs) that circulate in biological fluids are frequently enclosed in extracellular vesicles (EVs). However, urinary EVs and their cargo miRNAs have not been systematically studied according to their EV isolation methods. METHODS In type 2 diabetes mellitus persons with diabetic nephropathy (n=4), we compared miRNA species in urine EVs prepared by ultracentrifugation (UC), qEV original size exclusion column (qEV), ExoQuick-TC Plus (ExoQuick), and ultrafiltration using Amicon Ultra centrifugal filter devices (Amicons) 10K and 100K. EV miRNAs were profiled by next-generation sequencing (NGS). Additionally, we evaluated the correlations of EV miRNA expression between the urine and serum samples isolated by UC. RESULTS From each of 100 ml of urine, the UC method yielded the highest number of EV miRNA species (233 ± 37.3), with the ExoQuick yielded the lowest (103 ± 17.4). Urine EV miRNA profiles were highly correlated between UC, qEV, ExoQuick and Amicon 10K methods. EV miRNA profiles between the urine and serum samples showed variable correlations between the patients (paired sample number=3, r =0.39-0.72). CONCLUSIONS UC, qEV, ExoQuick, and Amicon 10K are acceptable for urinary EV isolation to profile miRNAs. Urine- and serum-derived EV miRNA profiles have variable correlations depending on specific patients.