Centrosome Mis-Regulation and Blood Vessel Function

描述(申请人提供)：中心体使细胞中的微管成核，并在间期通过微管组织中心(MTOC)组织它们，在有丝分裂时通过纺锤体组织它们。中心体复制通常受到严格的调控，每个细胞周期只发生一次，这种调控的缺失会导致中心体过剩、遗传不稳定性和肿瘤细胞的非整倍体。我们最近首次发现，暴露于高水平的血管内皮生长因子-A信号的血管内皮细胞有过多的中心体，这是通过Akt、mek/erk和cdk2/周期蛋白E介导的。中心体过多预计会扰乱细胞骨架并导致细胞行为的改变，尽管这种联系尚未在细胞或组织中建立；它还被预测会导致染色体不稳定和非整倍体，导致 到EC，从规范到深刻的变化。这项工作将检验这一假说，即EC中过多的中心体通过有丝分裂和非有丝分裂扰动来扰乱血管功能，并检查导致中心体对血管生成因子刺激的错误调节的机制。这一高度创新的假说将以三个目标进行检验，以解决以下问题：1)导致EC中心体失控的输入和机制是什么？2)中心体过多对EC行为和萌发有什么后果？3)体内血管内皮细胞中心体过多的结果是什么？我们将利用基于细胞的血管形成模型和体内小鼠发育和疾病模型来解决这些问题。这项工作的意义将是揭示中心体介导的EC功能障碍和遗传不稳定性在血管发育中的易感性，预计这将以新的方式导致血管功能障碍，并导致新的和独特的治疗靶点。

DESCRIPTION (provided by applicant): Centrosomes nucleate microtubules in cells, and organize them via a microtubule organizing center (MTOC) during interphase and via spindles during mitosis. Centrosome duplication is normally tightly regulated to occur once and only once per cell cycle, and loss of this regulation leads to excess centrosomes, genetic instability, and aneuploidy in tumor cells. We recently showed, for the first time, that endothelial cells (EC) in blood vessels exposed to elevated VEGF-A signaling have excess centrosomes, mediated through Akt, MEK/ERK, and Cdk2/cyclin E. Centrosome excess is predicted to perturb the cytoskeleton and result in alterations in cellular behaviors, although this link has not been made in cells or tissues; it also is predicted to produce chromosome instability and aneuploidy, leading to EC with profound changes from the norm. This work will test the hypothesis that excess centrosomes in EC perturb vessel function via both mitotic and non-mitotic perturbations, and examine the mechanisms that lead to centrosome mis-regulation upon angiogenic factor stimulation. This highly innovative hypothesis will be tested with three aims that address the questions: 1) What are the inputs and mechanisms that lead to EC centrosome mis- regulation? 2) What are the consequences of excess centrosomes to EC behaviors and sprouting? and 3) what are the outcomes of excess centrosomes in EC of vessels in vivo? We will utilize cell- based models of blood vessel formation and in vivo mouse developmental and disease models to address the questions. The significance of this work will be to reveal susceptibility in developing vessels for centrosome-mediated EC dysfunction and genetic instability, which is predicted to contribute to blood vessel dysfunction in novel ways, and lead to new and distinct therapeutic targets.