Anti-angiogenic activity of neurokinin B

描述(申请人提供)：神经激肽B(NK-B)是速激肽家族的一员。传统上，NK-B的表达和功能是在神经系统的背景下研究的。然而，NK-B的过度表达与妊娠相关疾病先兆子痫有关，该疾病的特征是胎盘血管重构缺陷和全身血管调节失调。我们证明了NK-B在体外可逆地抑制内皮细胞在Matrigel上的血管网络组装，并在体内反对血管生成。机制分析表明，NK-B信号抑制血管生成信号诱导的血管内皮生长因子受体1(VEGFR1)和VEGFR2的表达，并减少内皮细胞的迁移。本研究的目的是确定NK-B抑制血管生成信号诱导的VEGFR1和VEGFR2诱导以及内皮细胞迁移的调控机制。我们将制定两个具体目标来解决这一问题。在第一个具体目标中，我们将确定神经激动素B如何抑制血管生成信号依赖的VEGFR诱导。转录因子Ets1和HIF-2α参与了VEGFR1和VEGFR2的转录调控。我们将在体外和体内测试Ets1和HIF-2α是否直接激活VEGFR1和VEGFR2的转录，以响应血管生成信号，以及NK-B信号是否通过阻断Ets1/HIF-2α染色质占据或关键功能占据后抑制转录。在第二个特定目标中，我们将确定NK-B介导的抑制内皮细胞迁移的机制。我们假设，在内皮细胞中，NK-B信号调节介导细胞定向迁移的关键信号通路。为了验证这一假说，我们将记录被刺激进行迁移的内皮细胞中的信号转导事件以及NK-B对这些事件的影响，包括粘着斑激酶、Paxlin、p130Cas的磷酸化，这些分子形成焦点粘连的时空关联，以及Rho家族GTPase rac1和CDc42的激活。公共卫生相关性：血管生成，即从现有的血管系统发展出新的血管，是许多生理过程中的关键事件，如器官生长和发育、伤口愈合和生殖。血管生成在某些病理疾病中也是至关重要的，包括肿瘤的生长/转移。从这些研究中收集的信息将有助于我们理解血管生成的分子机制，并有望导致新的治疗方式。

DESCRIPTION (provided by applicant): Neurokinin B (NK-B) is a member of tachykinin family of peptides. Classically, NK-B expression and function was studied in the context of the nervous system. However overexpression of NK-B has been implicated in the pregnancy-associated disorder preeclampsia, which is characterized by defective remodeling of the placental vasculature and systemic vascular deregulation. We demonstrated that NK-B reversibly inhibits endothelial cell vascular network assembly in vitro on Matrigel and opposes angiogenesis in vivo. Mechanistic analyses revealed that NK-B signaling inhibited angiogenic signal-induced expression of vascular endothelial growth factor receptor1 (VEGFR1) and VEGFR2, and reduced endothelial cell migration. The objective of this proposal is to determine the regulatory mechanisms, by which NK-B inhibits angiogenic signal-induced VEGFR1 and VEGFR2 induction, and endothelial cell migration. We will institute two specific aims to address this. In the first Specific Aim we will determine how neurokinin B represses angiogenic signal-dependent VEGFR induction. Transcription factors Ets1 and HIF-2alpha have been implicated in the transcriptional regulation of VEGFR1 and VEGFR2. We will test whether Ets1 and HIF-2alpha directly activate transcription of VEGFR1 and VEGFR2 in response to angiogenic signals in vitro and in vivo, and whether NK-B signaling represses transcription by blocking Ets1/HIF-2alpha chromatin occupancy or a critical function post-occupancy. In the second Specific Aim we will determine the mechanism of NK-B-mediated inhibition of endothelial cell migration. We hypothesize that, in endothelial cells, NK-B signaling modulates critical signaling pathways that mediate directed cell migration. To test this hypothesis we will document signal transduction events in endothelial cells stimulated to undergo migration and the effect of NK-B on those events, including phosphorylation of focal adhesion kinase, paxillin, p130Cas, spatial and temporal association of these molecules to form focal adhesions, and activation of Rho family of GTPases Rac1 and CDC42. PUBLIC HEALTH RELEVANCE: Angiogenesis, the development of new blood vessels from existing vasculature, is a key event in many physiological processes, like organ growth and development, wound healing, and reproduction. Angiogenesis is also critical for certain pathological disorders including tumor growth/metastasis. Information gleaned from these studies will contribute to our understanding of the molecular mechanisms of angiogenesis and hopefully will lead to novel therapeutic modalities.