Expression and Function of TR3/nur77 in angiogenesis

描述(申请人提供)：病理性血管生成是癌症和各种缺血性和炎症性疾病的标志。血管内皮生长因子/血管内皮生长因子是目前最重要的血管生成因子，因其对血管内皮细胞的活性和选择性而成为最重要的血管生成因子。血管内皮生长因子/血管内皮生长因子不仅参与血管生成的几个步骤，而且是目前发现的唯一使微血管对循环大分子具有高通透性的因素。血管内皮细胞生长因子/血管内皮生长因子广泛地重新编程基因表达，刺激内皮细胞迁移和分裂，保护内皮细胞免于凋亡和衰老。以VPF/VEGF刺激培养的人脐静脉内皮细胞(HUVEC)的RNA为模板，进行DNA微阵列分析，以了解VPF/VEGF诱导的基因表达谱。核受体TR3是一种转录因子，是高度上调的基因之一。此外，在VPF/VEGF治疗的小鼠肠系膜上，TR3的小鼠同源基因Nur77表达上调，只有EC表达VPF/VEGF受体。进一步的实验表明，TR3是VPF/VEGF刺激的HUVEC增殖所必需的。然而，正义TR3的过表达抑制了VPF/VEGF刺激的HUVEC迁移，但通过反义方法阻断内源性TR3的表达，在没有VPF/VEGF的情况下触发了HUVEC迁移。已知TR3/Nur77在发育、动态平衡和疾病中起重要作用。然而，TR3/Nur77是否在血管生成中发挥作用尚不清楚。 本应用的总体目标是研究核受体TR3/Nur77在VPF/VEGF诱导的血管生成中的作用以及调节VPF/VEGF诱导的TR3表达的信号通路。该应用的具体目的是：(1)研究TR3/Nur77在VPF/VEGF、肿瘤和创伤诱导的病理性血管生成中的表达。(2)确定TR3/Nur77在血管生成中的作用。(3)明确调控TR3/Nur77基因表达的分子机制。

DESCRIPTION (provided by applicant): Pathological angiogenesis is a hallmark of cancer and various ischaemic and inflammatory diseases. VPF/VEGF is the most important angiogenic factor because of its potency and selectivity for vascular endothelium. VPF/VEGF is not only involved in several steps of angiogenesis, but also the only potent factor rendering microvessels hyperpermeable to circulating macromolecules identified so far. VPF/VEGF extensively reprograms gene expression, stimulates endothelial cell migration and division, and protects endothelial cells from apoptosis and senescence. In order to profile the genes induced by VPF/VEGF, DNA microarray assay was conducted with RNA obtained from cultured HUVEC stimulated with VPF/VEGF. Nuclear receptor TR3, a transcription factor, is one of the highly upregulated genes. In addition, Nur77, the mouse homologue of TR3, is upregulated in the mesentery of VPF/VEGF-treated mouse, where only EC express VPF/VEGF receptors. Further experiments indicated that TR3 is required for VPF/VEGF-stimulated HUVEC proliferation. However, overexpression of sense TR3 inhibits VPF/VEGF-stimulated HUVEC migration, but blocking the expression of the endogenous TR3 by an antisense approach triggers HUVEC migration in the absence of VPF/VEGF. It is known that TR3/nur77 plays crucial roles in development, homeostasis and diseases. However, whether TR3/nur77 plays a role in angiogenesis is not known. The overall goal of this application is to study the function of the nuclear receptor TR3/nur77 in VPF/VEGF-induced angiogenesis and the signaling pathways that regulate VPF/VEGF-induced TR3 expression. The specific aims of this application are: (1) Investigate TR3/nur77 expression in the pathological angiogenesis induced by VPF/VEGF, tumors and wounding. (2) Determine the function of TR3/nur77 in angiogenesis. (3) Define the molecular mechanisms regulating TR3/Nur77 expression.