Regulation of Angiogenesis During Wound Healing

描述(申请人提供)：伤口愈合需要形成 在一个复杂的过程中新的血管形成依赖于稳定性和 不稳定信号。内皮细胞特异性受体酪氨酸 Tie2在其主要配体血管生成素-1(Ang1)的刺激下， 通过刺激细胞活性促进血管稳定性，基底 膜的完整性和血管周围细胞的募集。ANG2，一位 Tie2受体通过竞争Ang1结合来阻断这些信号，并 对于与血管生成相关的局部血管不稳定是必要的。 因此，血管紧张素转换酶1和血管紧张素转换酶2的比率是调节 血管新生；改变Ang1或Ang2的表达可导致 血管缺陷。这项研究的重点是有证据表明Ang2的表达是 转录后调控；内皮细胞和平滑肌细胞培养 模型显示Ang2 mRNA半衰期发生了深刻的变化 某些增长因素。这种引起的消息稳定性变化依赖于 关于新的转录，可能是与受调控的mRNA相关的因子 营业额。据推测，这种事后的法规是 在组织修复过程中维持适当的Ang2水平至关重要。 为了测试这一点，假定的信使核糖核酸控制元件在人，老鼠，和 调控诱导的消息稳定性/不稳定性的大鼠Ang2 mRNAs 翻译将被识别和表征。它们在调节血管紧张素转换酶2中的作用 然后通过将这些元素引入体内来测试表达 记者构建；然后将被用于开发转基因小鼠。这个 这些信使核糖核酸调控元件的生物学作用将在 这些元素被条件性同源基因消融的小鼠 重组。这些小鼠模型将被用来测试 功能失调的Ang2转录后调控对伤口愈合的影响。这些 研究将表明转录后基因的相对重要性 血管紧张素转换酶2的调节，以及是否消除细胞的调节能力 血管生长因子2基因的稳定性或平移影响创伤过程中的血管结构 治愈的过程。

Description (provided by applicant): Wound healing requires the formation of new vasculature in a complex process that is dependent on stabilization and destabilization signals. The endothelial cell-specific receptor tyrosine kinase, Tie2, when stimulated by its primary ligand, angiopoietin-1 (Ang1), promotes blood vessel stability by stimulating cell viability, basement membrane integrity, and perivascular cell recruitment. Ang2, an antagonist of the Tie2 receptor, blocks these signals by competing for Ang1 binding, and is necessary for the locaiized vessel instability associated with angiogenesis. Thus, the ratio of Ang1 to Ang2 is a critical factor in the regulation of neovascularization; altering Ang1 or Ang2 expression can lead to profound vascular defects. This study focuses on evidence that Ang2 expression is regulated post-transcriptionally; endothelial and smooth muscle cell culture models demonstrate profound changes in Ang2 mRNA half-life in response to certain growth factors. This induced change in message stability is dependent on new transcription, presumably of factors associated with regulated mRNA turnover. It is hypothesized that such post-traiascriptional regulation is critical for the maintenance of appropriate Ang2 levels during tissue repair. To test this, the putative mRNA control elements within the human, mouse, and rat Ang2 MRNAs that regulate induced message stability/instability or translation will be identified and characterized. Their role in regulating Ang2 expression will then be tested in vivo by introducing these elements into reporter constructs; which will then be used to develop transgenic mice. The biological roles of these mRNA control elements will be further analyzed in mice in which these elements are ablated by conditional homologous recombination. These mouse models will be used to test the effects of dysfunctional Ang2 post-transcriptional regulation on wound healing. These studies will indicate the relative importance of post-transcriptional regulation of Ang2, and whether eliminating the ability of cells to regulate Ang2 mRNA stability or translation impacts vessel structure during the wound healing process.