title: Orphan nuclear receptor TR3/Nur77 regulates VEGF-A-induced angiogenesis through its transcriptional activity.
abstract: Vascular endothelial growth factor (VEGF)-A has essential roles in vasculogenesis and angiogenesis, but the downstream steps and mechanisms by which human VEGF-A acts are incompletely understood. We report here that human VEGF-A exerts much of its angiogenic activity by up-regulating the expression of TR3 (mouse homologue Nur77), an immediate-early response gene and orphan nuclear receptor transcription factor previously implicated in tumor cell, lymphocyte, and neuronal growth and apoptosis. Overexpression of TR3 in human umbilical vein endothelial cells (HUVECs) resulted in VEGF-A-independent proliferation, survival, and induction of several cell cycle genes, whereas expression of antisense TR3 abrogated the response to VEGF-A in these assays and also inhibited tube formation. Nur77 was highly expressed in several types of VEGF-A-dependent pathological angiogenesis in vivo. Also, using a novel endothelial cell-selective retroviral targeting system, overexpression of Nur77 DNA potently induced angiogenesis in the absence of exogenous VEGF-A, whereas Nur77 antisense strongly inhibited VEGF-A-induced angiogenesis. B16F1 melanoma growth and angiogenesis were greatly inhibited in Nur77-/- mice. Mechanistic studies with TR3/Nur77 mutants revealed that TR3/Nur77 exerted most of its effects on cultured HUVECs and its pro-angiogenic effects in vivo, through its transactivation and DNA binding domains (i.e., through transcriptional activity).
authors.affiliation: Department of Pathology, Gastroenterology Division, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA. hzeng@bidmc.harvard.edu
authors.forename: Huiyan
authors.initials: H
authors.lastname: Zeng
authors.forename: Liuliang
authors.initials: L
authors.lastname: Qin
authors.forename: Dezheng
authors.initials: D
authors.lastname: Zhao
authors.forename: Xiaolian
authors.initials: X
authors.lastname: Tan
authors.forename: Eleanor J
authors.initials: EJ
authors.lastname: Manseau
authors.forename: Mien
authors.initials: M
authors.lastname: Van Hoang
authors.forename: Donald R
authors.initials: DR
authors.lastname: Senger
authors.forename: Lawrence F
authors.initials: LF
authors.lastname: Brown
authors.forename: Janice A
authors.initials: JA
authors.lastname: Nagy
authors.forename: Harold F
authors.initials: HF
authors.lastname: Dvorak
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008819:Mice, Nude; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D017434:Protein Structure, Tertiary / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism*; D012190:Retroviridae; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014161:Transduction, Genetic / Q000379:methods; D042461:Vascular Endothelial Growth Factor A / Q000008:administration & dosage
chemical_list: D004268:DNA-Binding Proteins; C539821:NR4A1 protein, human; C539818:Nr4a1 protein, mouse; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D014157:Transcription Factors; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A