title: Mechanisms of endothelial to mesenchymal transition in the retina in diabetes.
abstract: OBJECTIVE
  Hyperglycemia-induced endothelial damage is a key pathogenetic factor in diabetic retinopathy. Endothelial damage may lead to phenotypic changes in the cells manifested by reduced expression of endothelial markers and increased expression of mesenchymal markers, termed endothelial to mesenchymal transition (EndMT). We investigated mechanisms of such changes in the retinal endothelial cells and in the retina of diabetic animals.
  
  
  METHODS
  Human retinal microvascular endothelial cells were grown in medium containing 5 mM glucose or 25 mM glucose with or without TGFβ1 peptide or TGFβ1 inhibitor or miR-200b mimic transfection. Messenger RNA levels of endothelial markers, mesenchymal markers, and specific signaling molecules of TGFβ pathway were quantified. Expression of miR-200b and histone acetylator p300 was quantified. Retinal tissues from mice with endothelial-specific overexpression of miR-200b, with or without streptozotocin-induced diabetes, were similarly examined.
  
  
  RESULTS
  Glucose caused decreased expression of mRNA and protein levels of endothelial markers and increased expression of mesenchymal markers with reduced miR-200b. A glucose-like effect was seen using TGFβ1 peptide. Such changes were mediated by miR-200b and p300. In the retinas of wild-type diabetic mice, EndMT was observed, which was prevented in miR-200b transgenic mice with diabetes.
  
  
  CONCLUSIONS
  These data indicate glucose-induced EndMT in vitro and in vivo is possibly mediated through TGFβ and regulated by miR-200b and p300.
authors.affiliation: Department of Pathology, Western University, London, Ontario, Canada Medical Research Center, Mudanjiang Medical University, Mudanjiang, Heilongjiang, People's Republic of China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Pathology, Western University, London, Ontario, Canada.
authors.forename: Biao
authors.initials: B
authors.lastname: Feng
authors.affiliation: Department of Pathology, Western University, London, Ontario, Canada.
authors.forename: Shali
authors.initials: S
authors.lastname: Chen
authors.affiliation: Medical Research Center, Mudanjiang Medical University, Mudanjiang, Heilongjiang, People's Republic of China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Chu
authors.affiliation: Department of Pathology, Western University, London, Ontario, Canada.
authors.forename: Subrata
authors.initials: S
authors.lastname: Chakrabarti
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental; D003930:Diabetic Retinopathy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D015536:Down-Regulation; D050881:E1A-Associated p300 Protein / Q000096:biosynthesis / Q000235:genetics*; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D012165:Retinal Ganglion Cells / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D035683:MicroRNAs; C543719:Mirn200 microRNA, mouse; D012333:RNA, Messenger; D050881:E1A-Associated p300 Protein; C494361:Ep300 protein, mouse
keywords: TGFβ; diabetes; endothelial mesenchymal transition; miR-200b; p300; retina