Endothelial Regeneration Following Lung Vascular Injury

项目总结/摘要 肺血管损伤导致富含蛋白质的水肿形成是ALI和呼吸系统疾病的标志。 重症患者的失败。肺血管内皮细胞损伤的机制尚不清楚， 血管损伤后的再生。然而，随着人们对 内皮祖细胞（EPCs）和我们的能力，以识别和获得他们在足够的 来自诱导的多能干细胞衍生的内皮祖细胞（iPSC）或 通过体细胞（成纤维细胞）的直接重编程， EPCs在促进血管再生中的作用及其机制 再生此外，我们还开发了一种采用他莫昔芬的小鼠报告基因模型- 可诱导的内皮特异性Scl-Cre（End-Scl-Cre-ER），其能够严格追踪 内皮细胞损伤后的内皮细胞谱系。使用这种方法，我们也处于 探讨内源性内皮再生和肺血管重建的机制 完整该建议的重点是通过内源性的肺血管内皮细胞修复受损的肺内皮细胞。 细胞以及移植外源性再生EPCs。在目标1中，我们将研究 移植的iPSC-EPCs（诱导多能干细胞衍生的 内皮祖细胞）。我们将检验这个假设 iPSC-EPC移植可预防肺水肿并提高肺移植后的存活率， 通过急性恢复屏障功能以及通过植入到肺中而损伤 微血管，从而恢复肺液体平衡。在目标2中，我们将研究肺 小鼠成纤维细胞的血管再生潜力， 转化为内皮细胞（Fib-EPCs）。我们将检验成年人 使用新的microRNA策略将成纤维细胞直接转化为功能性增殖性EPCs 恢复肺内皮屏障功能和体液平衡，预防肺水肿。在 目的3：通过内皮细胞谱系示踪， 修复细胞，并确定它们的激活是否促进肺血管 再生和恢复肺液体平衡。我们将检验这个假设， 内源性修复内皮细胞的活化和增殖恢复肺内皮细胞 血管损伤后的屏障和液体平衡。上述研究将提供必要的 开发新的内皮再生和恢复疗法所需的框架， 肺血管损伤

Project Summary / Abstract Lung vascular injury leading to protein-rich edema formation is a hallmark of ALI and respiratory failure in critically ill patients. Little is known about the mechanisms of lung vascular endothelial regeneration following vascular injury. However, with an ever-growing understanding of Endothelial Progenitor Cells (EPCs) and our ability to identify and obtain them in sufficient numbers from induced Pluripotent Stem Cell-derived Endothelial Progenitor Cells (iPSC) or through direct reprogramming of somatic cells (fibroblasts), it is feasible to address the role EPCs in promoting vascular regeneration and to define the mechanism of vascular regeneration. In addition, we have developed a mouse reporter model employing the tamoxifen- inducible endothelial specific Scl-Cre (End-Scl-Cre-ER) which enables the rigorous tracing of endothelial lineage following endothelial injury. Using this approach we are also in the position of addressing mechanisms of intrinsic endothelial regeneration and restoration of lung vascular integrity. This proposal focuses on restoration of the injured lung endothelium by endogenous cells as well as transplantation of exogenous regenerative EPCs. In Aim 1 we will investigate the efficacy and fate of transplanted iPSC-EPCs (induced pluripotent stem cells-derived endothelial progenitor cells) following lung vascular injury. We will test the hypothesis that iPSC-EPC transplantation prevents pulmonary edema and improves survival after lung injury by acutely restoring barrier function as well as through engraftment into the lung microvasculature, and thus restores lung fluid balance. In Aim 2 we will study the lung vascular regenerative potential of mouse fibroblasts that have undergone lineage conversion into endothelial cells (Fib-EPCs). We will test the hypothesis that adult fibroblasts converted directly into functional proliferative EPCs using a novel microRNA strategy restore lung endothelial barrier function and fluid balance and prevent pulmonary edema. In Aim 3 we will identify through endothelial lineage tracing populations of endogenous reparative cells and determine whether their activation promotes lung vascular regeneration and restoration of lung fluid balance. We will test the hypothesis that activation and proliferation of endogenous reparative endothelial cells restores lung endothelial barrier and fluid balance following vascular injury. The above studies will provide the essential frame-work needed to develop novel therapies for endothelial regeneration and recovery after lung vascular injury.