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

项目摘要/摘要 在鸟类、斑马鱼和哺乳动物胚胎中，毛细神经丛的形成机制已经得到了很好的研究， 这些过程的准确时间被发现在形成一个 高效而强健的血管系统。然而，由于体内发育模型的限制，没有结果 修改初始条件或临时修改流体的启动和增加粘度的重要性 血细胞何时进入循环是未知的。最近的报告利用了可用的精确控制 在微流控体外设备中，以阐明新的血管生成机制。这项提议的目标是 研究是要确定如何在时间上调节切应力、介质粘度和增加皮质 肌动蛋白通过非规范的Notch途径组装影响新生毛细血管床向血管床的转变 排列的静态血管网络，并确定导致从稳定的 从静止的网络到高度动态的表型。实验将在体外双通道中进行 微流控装置，用于精确控制活体模型中无法实现的实验条件。整体而言 这一建议的假设是，剪切力和流体粘度的变化在 原始神经丛的形成，使血管能够快速有效地重塑，这是由 皮质强化的非典型切迹通路。我们将解决这一假设，并实现 建议的目标首先确定如何精确地定时剪切力、动态粘度变化，以及添加 新生血管上外源蛋白的表达影响皮质强化、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作用的皮质- 网络适配中的陷波信令，以适应改变的流配置文件。应用于改变的力的分支 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建， 并确定部分皮质-Notch通路的抑制是否允许网络从 稳定静止到高度动态和增殖，而不影响规范- 缺口表达式。更全面地了解这一过程具有重要的生物学和临床意义。 因为它将允许对高度流行和致命的血管疾病，如外周血管疾病进行新的恢复性治疗 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).