title: Reprint of: miRNA-1 regulates endothelin-1 in diabetes.
abstract: OBJECTIVE
  MicroRNAs (miRNAs) play important roles in several biological processes. In this study, we investigated the role of miR-1, an endothelin-1 (ET-1) targeting miRNA, in endothelial cells (ECs) and tissues of diabetic animals. ET-1 is known to be of pathogenetic significance in several chronic diabetic complications.
  
  
  METHODS
  PCR array was used to identify alterations of miRNA expression in ECs exposed to glucose. miR-1 expression was validated by TaqMan real-time PCR assay. Human retinal ECs (HRECs) and human umbilical vein ECs (HUVECs) exposed to various glucose levels with or without miR-1 mimic transfection, and tissues from streptozotocin-induced diabetic animals after two months of follow-up, were examined for miR-1 expression, as well as ET-1 and fibronectin (FN) mRNA and protein levels.
  
  
  RESULTS
  Array analyses showed glucose-induced alterations of 125 miRNAs (out of 381) in ECs exposed to 25 mM glucose compared to 5 mM glucose. Fifty-one miRNAs were upregulated and 74 were downregulated. 25 mM glucose decreased miR-1 expression and increased ET-1 mRNA and protein levels. miR-1 mimic transfection prevented HG-induced ET-1 upregulation. Furthermore, glucose induced upregulation of FN, which is mediated partly by ET-1, was also prevented by such transfection. Diabetic animals showed decreased miR-1 expression in the retina, heart and kidneys. In parallel, ET-1 mRNA expressions were increased in these tissues of diabetic animals, in association with upregulation of FN.
  
  
  CONCLUSIONS
  These results indicate a novel glucose-induced mechanism of tissue damage, in which miR-1 regulates ET-1 expressions in diabetes. Identifying such mechanisms may lead to RNA based treatment for diabetic complications.
authors.affiliation: Department of Pathology, Western University, London, ON, Canada.
authors.forename: Biao
authors.initials: B
authors.lastname: Feng
authors.affiliation: Department of Pathology, Western University, London, ON, Canada; Mudanjiang Medical University, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Pathology, Western University, London, ON, Canada.
authors.forename: Shali
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Pathology, Western University, London, ON, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Ruiz
authors.affiliation: Department of Pathology, Western University, London, ON, Canada. Electronic address: Subrata.Chakrabarti@schulich.uwo.ca.
authors.forename: Subrata
authors.initials: S
authors.lastname: Chakrabarti
keywords: Endothelial cells; Glucose; MicroRNA