title: Estrogen receptor-mediated regulation of microRNA inhibits proliferation of vascular smooth muscle cells.
abstract: OBJECTIVE
  Estradiol (E2) regulates gene transcription by activating estrogen receptor-α and estrogen receptor-β. Many of the genes regulated by E2 via estrogen receptors are repressed, yet the molecular mechanisms that mediate E2-induced gene repression are currently unknown. We hypothesized that E2, acting through estrogen receptors, regulates expression of microRNAs (miRs) leading to repression of expression of specific target genes.
  
  
  RESULTS
  Here, we report that E2 significantly upregulates the expression of 26 miRs and downregulates the expression of 6 miRs in mouse aorta. E2-mediated upregulation of one of these miRs, miR-203, was chosen for further study. In cultured vascular smooth muscle cells (VSMC), E2-mediated upregulation of miR-203 is mediated by estrogen receptor-α (but not estrogen receptor-β) via transcriptional upregulation of the primary miR. We demonstrate that the transcription factors Zeb-1 and AP-1 play critical roles in mediating E2-induced upregulation of miR-203 transcription. We show further that miR-203 mediates E2-induced repression of Abl1, and p63 protein abundance in VSMC. Finally, knocking-down miR-203 abolishes E2-mediated inhibition of VSMC proliferation, and overexpression of miR-203 inhibits cultured VSMC proliferation, but not vascular endothelial cell proliferation.
  
  
  CONCLUSIONS
  Our findings demonstrate that E2 regulates expression of miRs in the vasculature and support the estrogen receptors-dependent induction of miRs as a mechanism for E2-mediated gene repression. Furthermore, our findings demonstrate that miR-203 contributes to E2-induced inhibition of VSMC proliferation and highlight the potential of miR-203 as a therapeutic agent in the treatment of proliferative cardiovascular diseases.
authors.affiliation: Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA 02111, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhao
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Imbrie
authors.forename: Wendy E
authors.initials: WE
authors.lastname: Baur
authors.forename: Lakshmanan K
authors.initials: LK
authors.lastname: Iyer
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Aronovitz
authors.forename: Tanya B
authors.initials: TB
authors.lastname: Kershaw
authors.forename: Greta M
authors.initials: GM
authors.lastname: Haselmann
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.forename: Richard H
authors.initials: RH
authors.lastname: Karas
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000473:pathology; D001665:Binding Sites; D049109:Cell Proliferation; D002478:Cells, Cultured; D004958:Estradiol / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology; D010052:Ovariectomy; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism; D034622:RNA Interference; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D000071799:Zinc Finger E-box-Binding Homeobox 1
chemical_list: D047628:Estrogen Receptor alpha; D018398:Homeodomain Proteins; D051741:Kruppel-Like Transcription Factors; C575934:MIRN203 microRNA, mouse; D035683:MicroRNAs; D010750:Phosphoproteins; D015534:Trans-Activators; D018808:Transcription Factor AP-1; C486419:Trp63 protein, mouse; C519422:ZEB1 protein, mouse; D000071799:Zinc Finger E-box-Binding Homeobox 1; D004958:Estradiol; D016315:Proto-Oncogene Proteins c-abl