title: miR-200b targets Ets-1 and is down-regulated by hypoxia to induce angiogenic response of endothelial cells.
abstract: The miR-200 family plays a crucial role in epithelial to mesenchymal transition via controlling cell migration and polarity. We hypothesized that miR-200b, one miR-200 family member, could regulate angiogenic responses via modulating endothelial cell migration. Delivery of the miR-200b mimic in human microvascular endothelial cells (HMECs) suppressed the angiogenic response, whereas miR-200b-depleted HMECs exhibited elevated angiogenesis in vitro, as evidenced by Matrigel® tube formation and cell migration. Using in silico studies, miR target reporter assay, and Western blot analysis revealed that v-ets erythroblastosis virus E26 oncogene homolog 1 (Ets-1), a crucial angiogenesis-related transcription factor, serves as a novel direct target of miR-200b. Knocking down endogenous Ets-1 simulated an anti-angiogenic response of the miR-200b mimic-transfected cells. Certain Ets-1-associated genes, namely matrix metalloproteinase 1 and vascular endothelial growth factor receptor 2, were negatively regulated by miR-200b. Overexpression of Ets-1 rescued miR-200b-dependent impairment in angiogenic response and suppression of Ets-1-associated gene expression. Both hypoxia as well as HIF-1α stabilization inhibited miR-200b expression and elevated Ets-1 expression. Experiments to identify how miR-200b modulates angiogenesis under a low oxygen environment illustrated that hypoxia-induced miR-200b down-regulation de-repressed Ets-1 expression to promote angiogenesis. This study provides the first evidence that hypoxia-sensitive miR-200b is involved in induction of angiogenesis via directly targeting Ets-1 in HMECs.
authors.affiliation: Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, Ohio 43210, USA.
authors.forename: Yuk Cheung
authors.initials: YC
authors.lastname: Chan
authors.forename: Savita
authors.initials: S
authors.lastname: Khanna
authors.forename: Sashwati
authors.initials: S
authors.lastname: Roy
authors.forename: Chandan K
authors.initials: CK
authors.lastname: Sen
mesh_terms: D015687:Cell Hypoxia / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D015536:Down-Regulation / Q000502:physiology*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D050784:Proto-Oncogene Protein c-ets-1 / Q000096:biosynthesis* / Q000235:genetics; D015682:Retroviridae Proteins, Oncogenic / Q000096:biosynthesis / Q000235:genetics
chemical_list: C494041:ETS1 protein, human; C533896:MIRN200 microRNA, human; D035683:MicroRNAs; D050784:Proto-Oncogene Protein c-ets-1; D015682:Retroviridae Proteins, Oncogenic; C050379:oncogene proteins v-ets