Morphogenesis of the pulmonary artery smooth muscle layer

血管平滑肌细胞(VSMCs)去分化、增殖和运动能力增强 在许多血管疾病的发病机制中起关键作用。因此，要详细了解 正常血管的VSMC层的发展有望提供对血管的关键洞察 疾病。然而，任何特定血管或血管床的形态发生的潜在过程是 不是很清楚。这项提议的中心目标是阐明关键的分子和细胞事件 左肺动脉平滑肌细胞(SMC)层的形态发生 小鼠肺发育的最初四天。这一目标是迈向以下长期目标的第一步 描述了在整个发育过程中，在构建肺动脉的所有层中发生的关键事件。 实现这些目标的一个基本要素是确定特定信号通路所扮演的角色 在肺动脉发育中发挥作用。血小板衍生生长因子(PDGF)诱导的信号转导 与肺动脉高压和冠状动脉再狭窄的发病机制有关 血管成形术；然而，PDGF信号在这些疾病或在大血管形成中的特殊作用 船只仍然难以捉摸。我推测，通过PDGF途径的信号对 多点早期肺间充质细胞群的维持、增殖和/或招募 有能力分化为左肺动脉的SMC层。 该提案有三个具体目标：1)建立分子标记和细胞事件的时间表 识别小鼠肺间充质细胞向分化左肺转变过程中的特定阶段 肺动脉SMC及其与内皮细胞和非血管组织发育的关系； 识别左肺PDGF受体介导的信号通路的激活模式和作用 动脉SMC发育；3)决定早期PDGF受体-β阳性患者肺组织的去向 对间充质细胞进行谱系分析。为了实现这些目标，将从野生型中解剖肺 和转基因小鼠胚胎，进行整体免疫染色、原位杂交或X-Gal 染色。在选定的实验中，胚胎肺将在分析之前进行培养。共焦显微镜 将被用来在细胞水平上分析荧光染色。 总之，拟议的工作将使左肺动脉成为最好的理解的例子。 特定血管的形态发生。这些研究将对这些机制产生关键的见解。 潜在的普遍的血管疾病，如冠状动脉粥样硬化。此外，这项工作 承诺推进对严重缺乏研究的平滑肌细胞生理学疾病的研究 肺，如肺动脉高压和淋巴管肌瘤病。

Dedifferentiation and enhanced proliferation and motility of vascular smooth muscle cells (VSMCs) are key elements in the pathogenesis of many vascular diseases. Thus, a detailed understanding of the development of the VSMC layer of normal blood vessels promises to provide critical insights into vascular disease. However, the processes underlying the morphogenesis of any specific vessel or vascular bed are not well understood. The central goal of this proposal is to elucidate the key molecular and cellular events encompassing the morphogenesis of the smooth muscle cell (SMC) layer of the left pulmonary artery during the initial four days of murine lung development. This goal is the first step towards the long term objective of delineating the critical events in the building of all layers of the pulmonary artery throughout development. An essential element of achieving these goals is to characterize the roles specific signaling pathways play in pulmonary artery development. Platelet derived growth factor (PDGF)-induced signaling has been implicated in the pathogenesis of pulmonary artery hypertension and restenosis following coronary artery angioplasty; yet, the specific effects of PDGF signaling in these diseases or in the morphogenesis of large vessels remain elusive. I hypothesize that signaling through the PDGF pathway is critical for the maintenance, proliferation and/or recruitment of a multipoint early lung mesenchymal cell population that has the capacity to differentiate into the SMC layer of the left pulmonary artery. The proposal has three specific aims: 1) establish a timeline of molecular markers and cellular events that identify specific stages during the transition of a murine lung mesenchymal cell into a differentiated left pulmonary artery SMC and relate this timeline to'endothelial cell and non-vascular tissue development; 2) identify the pattern and effects of activation of PDGF receptor-mediated signaling pathways in left pulmonary artery SMC development; 3) determine the fate in the lung of early PDGF receptor-beta-positive mesenchymal cells through lineage analysis. To achieve these aims, lungs will be dissected from wildtype and transgenic mouse embryos and subjected to whole mount immunostaining, in situ hybridization or X-gal staining. In selected experiments, embryonic lungs will be cultured prior to analysis. Confocal microscopy will be used to analyze fluorescent stains on a cellular level. In sum, the proposed work will make the left pulmonary artery the best understood example of morphogenesis of a specific blood vessel. These studies will yield critical insights into the mechanisms underlying prevalent vascular diseases such as coronary artery atherosclerosis. In addition, this work promises to advance the investigation of critically understudied disorders of smooth muscle cell physiology in the lung, such as pulmonary artery hypertension and lymphangioleiomyomatosis.