Signaling events that control the fate of existing vessels

控制现有船只命运的信号事件

基本信息

批准号：
8120703
负责人：
Andrius Kazlauskas
金额：
$ 45.74万
依托单位：
SCHEPENS EYE RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-08-01 至 2013-07-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Angiogenesis is an essential pathological component of numerous ocular diseases that afflicts a large segment of the world's population. Substantial advances have been made in our understanding of the factors that promote angiogenesis. This has led to effective therapies that prevent the formation of new blood vessels. Since many patients have existing pathological blood vessels, agents that induce regression of vessels would be very useful. The major barrier to developing such therapies is our lack of understanding of how vessel stability and regression is controlled at the molecular level. The long-term goal is to elucidate the molecular mechanisms controlling vessel stability and regression. Our findings will enable the development of next generation therapies that reverse angiogenic-based ocular diseases such as ROP, PDR and the wet form of AMD. By studying what regulates the stability and regression of existing vessels, this grant will make a unique and complementary contribution to the field of angiogenesis, which is largely focused on the formation of vessels. The central hypothesis is that signaling enzymes control the fate of existing vessels. More specifically, the amplitude of phosphoinositide 3 kinase (PI3K) activity governs vessel stability. Once vessels are destabilized, then phospholipase C y (PLCy) triggers regression by inducing the production of a soluble regression factor. We will test this hypothesis in the following set of aims. 1. Investigate the role of PI3K in governing vessel stability. We will test whether the magnitude of the PI3K/Akt output is a key determinant of tube stability. Using both mono- and co-culture models, we will compare PI3K/Akt output in stable and unstable tubes. In addition, we will determine whether forcing a change in the PI3K/Akt output results in a corresponding change in stability. 2. Determine how PLCy triggers vessel regression. We have established assays to detect regression factors and identified an excellent candidate: autotaxin (ATX). We will determine the timing of ATX expression, whether it's necessary and/or sufficient for regression, and its dependence on PLCy. These studies will test our working hypothesis that PLCy triggers regression by promoting the secretion of a soluble regression factor. 3. Determine the importance of PLCy and ATX for stability and regression in vivo (mice). The working hypothesis for this aim is that the regulators of stability and regression in the in vitro setting will also play a role in vivo. This hypothesis will be tested by comparing stability and regression of vessels in several vascular beds within eyes of wild type and mice heterozygous for PLCy or ATX.

描述（由申请人提供）：血管生成是困扰世界大部分人口的众多眼部疾病的重要病理成分。我们对促进血管生成的因素的理解已经取得了实质性进展。这导致了防止新血管形成的有效疗法。由于许多患者已有病理性血管，因此诱导血管退化的药物将非常有用。开发此类疗法的主要障碍是我们对如何在分子水平上控制血管稳定性和退化缺乏了解。长期目标是阐明控制血管稳定性和退化的分子机制。我们的研究结果将有助于开发下一代疗法，逆转基于血管生成的眼部疾病，例如 ROP、PDR 和湿性 AMD。通过研究调节现有血管稳定性和退化的因素，这笔赠款将为血管生成领域做出独特和补充的贡献，该领域主要集中在血管的形成。中心假设是信号酶控制现有血管的命运。更具体地说，磷酸肌醇 3 激酶 (PI3K) 活性的幅度控制血管稳定性。一旦血管不稳定，磷脂酶 C y (PLCy) 就会通过诱导可溶性回归因子的产生来触发回归。我们将在以下目标中检验这一假设。 1. 研究 PI3K 在控制船舶稳定性中的作用。我们将测试 PI3K/Akt 输出的大小是否是管稳定性的关键决定因素。使用单一培养和共培养模型，我们将比较稳定和不稳定管中的 PI3K/Akt 输出。此外，我们将确定强制改变 PI3K/Akt 输出是否会导致稳定性发生相应变化。 2. 确定 PLCy 如何触发血管退化。我们已经建立了检测回归因子的方法，并确定了一个极好的候选者：自分泌运动因子（ATX）。我们将确定 ATX 表达的时间，对于回归是否必要和/或充分，以及它对 PLCy 的依赖性。这些研究将检验我们的工作假设，即 PLCy 通过促进可溶性回归因子的分泌来触发回归。 3. 确定 PLCy 和 ATX 对于体内稳定性和回归（小鼠）的重要性。这一目标的工作假设是，体外环境中稳定性和回归的调节因子也将在体内发挥作用。将通过比较野生型和 PLCy 或 ATX 杂合小鼠眼内几个血管床中血管的稳定性和退化来检验该假设。