Elucidating Mechanisms for Rapid Vascularization by Modeling Vascular Islands in Early Embryogenesis

项目概要/摘要 毛细血管丛形成的机制已经在鸟类、斑马鱼和哺乳动物胚胎中得到了很好的研究， 这些过程的精确时间被发现在形成一个 高效和强健的脉管系统。然而，由于体内发育模型的限制，没有结果表明， 改变初始条件或暂时改变流动的开始和增加粘度的重要性 血细胞何时进入血液循环尚不清楚。最近的报告利用了现有的精确控制 在微流体体外装置中，以阐明新的血管生成机制。建议的目标 研究的目的是确定如何在时间上调节剪切应力、介质粘度和增加皮质 肌动蛋白通过非经典Notch途径的组装影响新生毛细血管床转变为 对齐静止的血管网络，并确定导致从稳定的血管网络转变的分子线索。 静态网络到高度动态表型。实验将在体外双通道 微流控装置，以精确控制实验条件，在体内模型中不可用。整体 这一建议的假设是，剪切力和流体粘度的变化是在剪切力和流体粘度变化之后立即开始的。 原始神经丛的形成，使快速和有效的血管重塑，这是稳定的， 一种皮质强化非经典Notch通路我们将解决这一假设，并实现 提出的目标，首先确定如何精确定时剪切力，动态粘度的变化，并添加 新生血管系统上的外源性蛋白表达影响皮质强化、网络动力学和 形态学其次，我们将阐明主要的分子和机械转导介导的作用，皮质- 在网络适应改变的流简档中的陷波信令。施加在 将确定血管岛和新生血管系统以及它如何允许血管网络重塑， 并确定抑制部分皮质-Notch通路是否会使网络从 稳定静止到高度动态和增殖，而不损害典型的， Notch表情。更全面地了解这一过程具有重要的生物学和临床意义 因为它将为高度流行和致命的血管疾病，如外周血管疾病， 动脉疾病（PAD）和缺血性心脏病（IHD）。

Project Summary/Abstract Mechanisms of capillary plexus formation have been well studied in avian, zebrafish, and mammalian embryos, with the precise timing of these processes being found to have profound importance in the formation of an efficient and robust vasculature. However, due to the limitations of in vivo developmental models, no results of modifying initial conditions or temporally modifying the initiation of flow and the importance of increased viscosity when blood cells enter circulation are unknown. Recent reports have leveraged the precise control available within microfluidic in vitro devices to elucidate novel angiogenic mechanisms. The objective of this proposed research is to determine how temporally modulating the shear stress, media viscosity, and increasing cortical actin assembly through a non-canonical Notch pathway affect the transition of a nascent capillary bed into an aligned quiescent vascular network, and determine the molecular cues that cause a transition from a stable quiescent network to a highly dynamic phenotype. Experiments will be carried out in an in vitro dual-channel microfluidic device to precisely control experimental conditions that are unavailable in in vivo models. The overall hypothesis of this proposal is that changes in shear force and fluid viscosity initiated immediately after formation of the primitive plexus, enable rapid and efficient vascular remodeling, which is stabilized by a cortical reinforcing non-canonical Notch pathway. We will address this hypothesis and achieve the proposed goals by first determining how precisely timed shear force, dynamic viscosity changes, and addition of exogenous protein expression on nascent vasculature affects cortical reinforcement, network dynamics, and morphology. Secondly, we will elucidate the main molecular and mechanotransduction mediated role of cortical- Notch signaling in network adaptation to altered flow profiles. The ramifications of altered force applied to vascular islands and a nascent vasculature and how it allows vascular network remodeling will be determined, and ascertain whether inhibition of parts of the cortical-Notch pathway allows the network to revert from being stably quiescent to highly dynamic and proliferative without compromising the overall expression of canonical- Notch expression. More complete understanding of this process is of significant biological and clinical importance as it will allow novel restorative therapies for highly prevalent and deadly vascular diseases such as Peripheral Arterial Disease (PAD) and Ischemic Heart Disease (IHD).