Regulation of Angiogenesis During Wound Healing

描述（由申请人提供）：伤口愈合需要形成 在一个复杂的过程中，新的血管系统依赖于稳定和 不稳定信号内皮细胞特异性受体酪氨酸 激酶Tie 2在其主要配体血管生成素-1（Ang 1）刺激下， 通过刺激细胞活力、基底膜、血管内皮细胞和血管内皮细胞来促进血管稳定性 膜完整性和血管周围细胞募集。Ang 2，一种拮抗剂， Tie 2受体通过竞争Ang 1结合阻断这些信号， 这是与血管生成相关的局部血管不稳定性所必需的。 因此，Ang 1与Ang 2的比例是调节Ang 1与Ang 2的比例的关键因素。 新血管形成;改变Ang 1或Ang 2表达可导致严重的 血管缺陷。这项研究的重点是证据表明，血管生成素2表达是 转录后调节;内皮细胞和平滑肌细胞培养 模型显示Ang 2 mRNA半衰期响应于 某些增长因素。这种信息稳定性的变化依赖于 新的转录，可能是与调节mRNA相关的因子 周转据推测，这种创伤后调节是 这对于在组织修复期间维持适当的Ang 2水平至关重要。 为了测试这一点，在人类、小鼠和哺乳动物中假定的mRNA控制元件被检测到。 调节诱导的信息稳定性/不稳定性的大鼠Ang 2 MRNA，或 翻译将被识别和表征。它们在调节Ang 2中的作用 然后通过将这些元件引入到 报告构建体;然后将其用于开发转基因小鼠。的 这些mRNA控制元件的生物学作用将进一步分析， 小鼠，其中这些元件被条件性同源 重组这些小鼠模型将用于测试 Ang 2对伤口愈合的转录后调节功能失调。这些 研究将表明转录后的相对重要性， Ang 2的调节，以及是否消除了细胞调节Ang 2的能力， Ang 2 mRNA的稳定性或翻译在创伤期间影响血管结构 愈合过程

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.