Defining the molecular determinants of mesenchymal lineage allocation in lung development and disease

项目摘要 肺是一个结构复杂的器官，由特化的上皮细胞组成，周围有致密的 间充质网络。我们实验室和其他实验室最近的研究表明，在空间上是谨慎的 上皮到间充质壁龛信号对肺和成人组织的正常发育是必需的。 静止和再生。这些研究促使我们开发一种体内途径报告系统来 监测间充质信号通路的活性。使用这个记者系统，我们解构了 使用创新方法的间充质和分类谱系；单细胞和谱系序列转录组 侧写，三维空间定位，体内对损伤的反应和体外生态位支持能力。 我们已经鉴定了一种间充质肺泡巢细胞(MANC)，它具有WNT反应，表达血小板- 衍生生长因子受体α(PDGFRA)，对肺泡上皮细胞生长和自身生长至关重要。 更新。相比之下，Axin2肌纤维生成前体(AMP)细胞在病理上产生有害的 损伤后的肌成纤维细胞。这些研究为定义细胞和分子框架提供了一个平台 肺间充质壁龛。下一步，在本提案的目标1中，我将研究谱系个体发育 并阐明PDGFRA信号通路在控制血统分配和细胞分化中的作用。 出生后肺泡发育时期的肺泡龛的发育。在独立阶段 在目标2中，我将定义控制促再生与肌纤维生成反应的机制 急性肺损伤后的间质。基于使用多细胞比对的生物信息学分析 来自肺泡龛的配体和同源受体对，我将定义Notch和CXCR4通路的影响 在体内引发AMP谱系的肌纤维形成反应。重要的是，这项提案概述了 严格的培训计划将为我在生物医学研究方面的职业发展奠定基础。

PROJECT ABSTRACT The lung is an architecturally complex organ, comprised of specialized epithelial cells surrounded by a dense network of mesenchyme. Recent work from our lab as well as others has shown that spatially discreet epithelial to mesenchymal niche signaling is required for proper lung development as well as adult tissue quiescence and regeneration. These studies prompted us to develop an in vivo pathway reporter system to monitor mesenchymal signaling pathway activity. Using this reporter system, we have deconstructed the mesenchyme and classified lineages using innovative methods; Single-Cell and Lineage-Seq transcriptome profiling, three-dimensional spatial orientation, in vivo response to injury and ex vivo niche support capacity. We have characterized a mesenchymal alveolar niche cell (MANC) as Wnt responsive, expresses platelet- derived growth factor receptor alpha (PDGFRa), and is critical for alveolar epithelial cell growth and self- renewal. In contrast, the Axin2+ myofibrogenic progenitor (AMP) cell generates pathologically deleterious myofibroblasts after injury. These studies provide a platform for defining the cellular and molecular framework of the lung mesenchymal niches. Moving forward, in Aim 1 of this proposal, I will examine the lineage ontogeny of Axin2-positive mesenchyme and elucidate the role of PDGFRa-signaling in controlling lineage allocation and development of the alveolar niche during the postnatal period of alveologenesis. In the independent phase outlined in Aim 2, I will define mechanisms controlling the pro-regenerative versus myofibrogenic responses in the mesenchyme after acute lung injury. Based on bioinformatic analyses using multicellular alignment of ligand and cognate receptor pairs from the alveolar niche, I will define the impact of Notch and Cxcr4 pathways in provoking the myofibrogenic response from the AMP lineage, in vivo. Importantly, this proposal outlines a rigorous training plan that will establish the foundation to advance my career in biomedical research.