title: miR-146a-Mediated extracellular matrix protein production in chronic diabetes complications.
abstract: OBJECTIVE
  MicroRNAs (miRNAs), through transcriptional regulation, modulate several cellular processes. In diabetes, increased extracellular matrix protein fibronectin (FN) production is known to occur through histone acetylator p300. Here, we investigated the role of miR-146a, an FN-targeting miRNA, on FN production in diabetes and its relationship with p300.
  
  
  METHODS
  miR-146a expressions were measured in endothelial cells from large vessels and retinal microvessels in various glucose levels. FN messenger RNA expression and protein levels with or without miR-146a mimic or antagomir transfection were examined. A luciferase assay was performed to detect miR-146a's binding to FN 3'-untranslated region (UTR). Likewise, retinas from type 1 diabetic rats were studied with or without an intravitreal injection of miR-146a mimic. In situ hybridization was used to localize retinal miR-146a. Cardiac and renal tissues were analyzed from type 1 and type 2 diabetic animals.
  
  
  RESULTS
  A total of 25 mmol/L glucose decreased miR-146a expression and increased FN expression compared with 5 mmol/L glucose in both cell types. miR-146a mimic transfection prevented such change, whereas miR-146a antagomir transfection in the cells in 5 mmol/L glucose caused FN upregulation. A luciferase assay confirmed miR-146a's binding to FN 3'-UTR. miR-146a was localized in the retinal endothelial cells and was decreased in diabetes. Intravitreal miR-146a mimic injection restored retinal miR-146a and decreased FN in diabetes. Additional experiments showed that p300 regulates miR-146a. Similar changes were seen in the retinas, kidneys, and hearts in type 1 and type 2 diabetic animals.
  
  
  CONCLUSIONS
  These studies showed a novel, glucose-induced molecular mechanism in which miR-146a participates in the transcriptional circuitry regulating extracellular matrix protein production in diabetes.
authors: Department of Pathology, Schulich School of Medicine and Dentistry and the University of Western Ontario, London, Ontario, Canada.
authors: Biao
authors: B
authors: Feng
authors: Shali
authors: S
authors: Chen
authors: Kara
authors: K
authors: McArthur
authors: Yuexiu
authors: Y
authors: Wu
authors: Subhrojit
authors: S
authors: Sen
authors: Qingming
authors: Q
authors: Ding
authors: Ross D
authors: RD
authors: Feldman
authors: Subrata
authors: S
authors: Chakrabarti
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D048909:Diabetes Complications / Q000188:drug therapy / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009928:Organ Specificity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012171:Retinal Vessels / Q000166:cytology / Q000378:metabolism; D050880:p300-CBP Transcription Factors / Q000378:metabolism; D000099224:p300-CBP-Associated Factor
chemical_list: D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D035683:MicroRNAs; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C542542:MIRN146 microRNA, human