Mechanistic Studies of Hedgehog Signaling in the Lung

 描述（由申请人提供）： 伴有实质瘢痕形成的成人肺部疾病，如特发性肺纤维化（IPF），会导致显著的发病率和死亡率。目前的IPF治疗不能延长生存期。在IPF中，肺成纤维细胞在瘢痕中积聚，产生细胞外基质，最终破坏正常的肺结构。发育信号传导途径（如Sonic Hedgehog（SHH）信号传导）与IPF有关，这与其在肺生长期间调节成纤维细胞的作用一致。我们揭示了出生后肺发育和实验性IPF模型中肺成纤维细胞中的SHH信号。该项目的长期目标是通过在病理生理学相关的小鼠模型中研究其特征来更好地了解肺纤维化的分子特征，以阐明新的机制并改善治疗方案。 这项研究将使用我们的出生后模型来确定SHH对肺成纤维细胞的生理作用，以告知SHH信号在肺纤维化中可能的病理作用。我们假设SHH信号调节出生后肺中肺泡间隔壁成熟过程中和肺纤维化持续状态期间的肺成纤维细胞功能。在目的1中，我们将SHH信号的时空变化与出生后肺发育过程中肺成纤维细胞的细胞和分子事件相关联。我们将采用遗传报告评估增殖，凋亡，衰老，和电子显微镜评估室间隔壁成熟。我们将确定在出生后肺发育的特定阶段（肺泡化和成熟）对肺成纤维细胞和肺结构的药理学和遗传增强和减少SHH信号传导的影响。将通过RNAseq检查在肺泡化阶段的关键时间点分离的FACS分选的HH应答成纤维细胞的转录组谱，以揭示可用作减少成人纤维化中成纤维细胞的靶点的候选基因。在目标2中，我们将在一个充分表征的实验模型中讨论SHH信号是否延缓纤维化的消退或促进纤维化的持续，并阐明SHH信号影响成纤维细胞和肌成纤维细胞的重要机制。 这些研究将在基质生物学专家丹尼尔里夫金博士的指导下进行，并由器官发育、HH信号传导和小鼠遗传学专家亚历山德拉乔伊纳博士和肺发育和肺纤维化专家约翰芒格博士共同指导。导师和他们的实验室，再加上纽约大学核心设施在特定技术方面的专业知识，为我过渡到独立教师职位后在肺纤维化研究领域取得未来成功所需的技术和方法方面的专业知识提供了最佳环境。

 DESCRIPTION (provided by applicant): Adult lung diseases with parenchymal scarring, such as idiopathic pulmonary fibrosis (IPF), cause significant morbidity and mortality. Current IPF treatment does not prolong survival. In IPF, lung fibroblasts accumulate in scars, producing extracellular matrix that ultimately destroys normal lung structure. Developmental signaling pathways, such as Sonic Hedgehog (SHH) signaling, have been implicated in IPF, consistent with their roles in regulating fibroblasts during lung growth. We revealed SHH signaling in lung fibroblasts during postnatal lung development and in an experimental IPF model. The long-term goals of this project are to better understand the molecular signatures of pulmonary fibrosis by studying their characteristics in pathophysiologically relevant mouse models to elucidate novel mechanisms and improve treatment options. The proposed study will use our postnatal model to define the physiologic effect of SHH on lung fibroblasts, in order to inform the likely pathological effects of SHH signaling in lung fibrosis. We hypothesize that SHH signaling regulates lung fibroblast function during alveolar septal wall maturation in postnatal lung and during the persistent state of pulmonary fibrosis. In Aim 1 we will correlate spatiotemporal changes in SHH signaling with cellular and molecular events in lung fibroblasts during postnatal lung development. We will employ genetic reporters to assess proliferation, apoptosis, senescence, and electron microscopy to assess septal wall maturation. We will determine the effects of pharmacological and genetic augmentation and reduction of SHH signaling during specific phases of postnatal lung development (alveolarization and maturation) on lung fibroblasts and lung structure. Transcriptome profiles of FACS-sorted HH-responding fibroblasts isolated at critical time points of the alveolarization phase will be examined by RNAseq to reveal candidate genes that could be used as targets to decrease fibroblasts in adult fibrosis. In Aim 2 we will address whether SHH signaling retards resolution or promotes persistence of fibrosis in a well-characterized experimental model, and elucidate the involvement of important mechanisms by which SHH signaling affects fibroblasts and myofibroblasts. These studies will be performed under the mentorship of Dr. Daniel Rifkin, an expert in matrix biology, and the co-mentorship of Dr. Alexandra Joyner, an expert in organ development, HH signaling and mouse genetics, and Dr. John Munger, expert in lung development and pulmonary fibrosis. The mentors and their laboratories, together with the expertise of NYU core facilities on specific techniques, provide the optimal setting for developing expertise in the techniques and methodologies required for future success in the field of pulmonary fibrosis research after my transition to an independent faculty position.