Federica Barutta 1 , * , Marinella Tricarico 1 , Alessandro Corbelli 2 , 3 , Laura Annaratone 4 , Silvia Pinach 1 , Serena Grimaldi 1 , Graziella Bruno 1 , Daniela Cimino 5 , Daniela Taverna 5 , Maria Chiara Deregibus 6 , Maria Pia Rastaldi 2 , Paolo Cavallo Perin 1 , Gabriella Gruden 1
4 November 2013
MicroRNAs (miRNAs), a class of small non-protein-encoding RNAs, regulate gene expression via suppression of target mRNAs. MiRNAs are present in body fluids in a remarkable stable form as packaged in microvesicles of endocytic origin, named exosomes. In the present study, we have assessed miRNA expression in urinary exosomes from type 1 diabetic patients with and without incipient diabetic nephropathy. Results showed that miR-130a and miR-145 were enriched, while miR-155 and miR-424 reduced in urinary exosomes from patients with microalbuminuria. Similarly, in an animal model of early experimental diabetic nephropathy, urinary exosomal miR-145 levels were increased and this was paralleled by miR-145 overexpression within the glomeruli. Exposure of cultured mesangial cells to high glucose increased miR-145 content in both mesangial cells and mesangial cells-derived exosomes, providing a potential mechanism for diabetes-induced miR-145 overexpression. In conclusion, urinary exosomal miRNA content is altered in type 1 diabetic patients with incipient diabetic nephropathy and miR-145 may represent a novel candidate biomarker/player in the complication.