Urinary Exosomal microRNA-451-5p Is a Potential Early Biomarker of Diabetic Nephropathy in Rats

• Published in: PloS one 2016-04, Vol.11 (4), p.e0154055
• Main Authors: Mohan, Aradhana, Singh, Ravi Shankar, Kumari, Manju, Garg, Devika, Upadhyay, Aditya, Ecelbarger, Carolyn M, Tripathy, Sucheta, Tiwari, Swasti
• Format: Article
• Language: English
• Subjects: Albumin; Animals; Biochemistry; Bioindicators; Biological markers; Biology; Biology and Life Sciences; Biomarkers; Biomarkers - urine; Biotechnology; Body weight; Cancer; Cytokines; Diabetes; Diabetes mellitus; Diabetic nephropathies; Diabetic Nephropathies - diagnosis; Diabetic Nephropathies - urine; Diabetic nephropathy; Diagnosis; Disease; Disease Models, Animal; Early Diagnosis; Exosomes - metabolism; Fibrosis; Fuel consumption; Gene expression; Gene sequencing; Genetic aspects; Insulin; Kidney - metabolism; Kidney - pathology; Male; Medicine; Medicine and Health Sciences; MicroRNA; MicroRNAs; MicroRNAs - urine; miRNA; Nephropathy; Pathology; Physiological aspects; Physiology; Polymerase chain reaction; Rats; Rats, Wistar; Research and analysis methods; Ribonucleic acid; RNA; Rodents; Streptozocin; Studies; Urine
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0154055

Non-invasive renal signatures can help in serial monitoring of diabetic patients. We tested whether urinary exosomal (UE) microRNA (miR) analysis could non-invasively predict renal pathology in diabetic rats during the course of diabetes. Diabetes mellitus (DM) was induced in male Wistar rats by a single intraperitoneal injection of streptozotocin (STZ, 50 mg/kg body weight). Non-diabetic control (CTRL) rats were injected with vehicle. Insulin (INS) treatment (5U/d, s.c.) was provided to 50% of the DM rats. Urine samples were collected at weeks 3, 6, and 9 following injections and UE prepared. An increase in miR-451-5p and miR-16, observed by pilot small RNA sequencing of UE RNA, was confirmed by quantitative real-time polymerase chain reaction (qPCR) and selected for further study. Subsets of rats were euthanized after 3, 6, and 9 weeks of diabetes for renal pathology analysis, including determination of the tubulointerstitial fibrotic index (TFI) and glomerulosclerotic index (GI) scores. qPCR showed a substantial rise in miR-451-5p in UE from DM rats during the course of diabetes, with a significant rise (median fold change >1000) between 3 and 6 weeks. Moreover, UE miR-451-5p at 6 weeks predicted urine albumin at 9 weeks (r = 0.76). A delayed but significant rise was also observed for miR-16. In contrast, mean urine albumin only increased 21% between 3 and 6 weeks (non-significant rise), and renal TFI and GI were unchanged till 9 weeks. Renal expression of miR-451-5p and miR-16 (at 10 weeks) did not correlate with urine levels, and moreover, was negatively associated with indices of renal pathology (r≥-0.70, p = 0.005 for TFI and r≥-0.6, p≤0.02 for GI). Overall, a relative elevation in renal miR-451-5p and miR-16 in diabetes appeared protective against diabetes-induced kidney fibrosis; while UE miR-451-5p may hold prognostic value as an early and sensitive non-invasive indicator of renal disease.