title: MicroRNA-29c is a signature microRNA under high glucose conditions that targets Sprouty homolog 1, and its in vivo knockdown prevents progression of diabetic nephropathy.
abstract: Although several recent publications have suggested that microRNAs contribute to the pathogenesis of diabetic nephropathy, the role of miRNAs in vivo still remains poorly understood. Using an integrated in vitro and in vivo comparative miRNA expression array, we identified miR-29c as a signature miRNA in the diabetic environment. We validated our profiling array data by examining miR-29c expression in the kidney glomeruli obtained from db/db mice in vivo and in kidney microvascular endothelial cells and podocytes treated with high glucose in vitro. Functionally, we found that miR-29c induces cell apoptosis and increases extracellular matrix protein accumulation. Indeed, forced expression of miR-29c strongly induced podocyte apoptosis. Conversely, knockdown of miR-29c prevented high glucose-induced cell apoptosis. We also identified Sprouty homolog 1 (Spry1) as a direct target of miR-29c with a nearly perfect complementarity between miR-29c and the 3'-untranslated region (UTR) of mouse Spry1. Expression of miR-29c decreased the luciferase activity of Spry1 when co-transfected with the mouse Spry1 3'-UTR reporter construct. Overexpression of miR-29c decreased the levels of Spry1 protein and promoted activation of Rho kinase. Importantly, knockdown of miR-29c by a specific antisense oligonucleotide significantly reduced albuminuria and kidney mesangial matrix accumulation in the db/db mice model in vivo. These findings identify miR-29c as a novel target in diabetic nephropathy and provide new insights into the role of miR-29c in a previously unrecognized signaling cascade involving Spry1 and Rho kinase activation.
authors.affiliation: Division of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Jianyin
authors.initials: J
authors.lastname: Long
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.forename: Wenjian
authors.initials: W
authors.lastname: Wang
authors.forename: Benny H J
authors.initials: BH
authors.lastname: Chang
authors.forename: Farhad R
authors.initials: FR
authors.lastname: Danesh
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002461:Cell Line, Transformed; D003928:Diabetic Nephropathies / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D005947:Glucose / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D050199:Podocytes / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D054460:rho-Associated Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D048868:Adaptor Proteins, Signal Transducing; D016326:Extracellular Matrix Proteins; C547014:MIRN29 microRNA, mouse; D008565:Membrane Proteins; D035683:MicroRNAs; D020319:Oligodeoxyribonucleotides, Antisense; D010750:Phosphoproteins; C425468:Spry1 protein, mouse; D054460:rho-Associated Kinases; D005947:Glucose