Mechanistic Studies of Hedgehog Signaling in the Lung

 描述(申请人提供)：成人肺部疾病的实质性疤痕，如特发性肺纤维化(IPF)，导致显著的发病率和死亡率。目前的IPF治疗并不能延长生存期。在IPF中，肺成纤维细胞聚集在疤痕中，产生细胞外基质，最终破坏正常的肺结构。发育信号通路，如Sonic Hedgehog(SHH)信号，与IPF有关，与它们在肺生长过程中调节成纤维细胞的作用一致。我们揭示了在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研究肺纤维化在病理生理学相关小鼠模型中的特征来更好地了解肺纤维化的分子特征，以阐明新的机制和改进治疗方案。这项拟议的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，以了解SHH信号在肺纤维化中可能的病理作用。我们假设SHH信号调节肺成纤维细胞的功能，在出生后肺泡隔壁成熟和肺纤维化持续状态期间。在目标1中，我们将在出生后肺发育过程中将SHH信号的时空变化与肺成纤维细胞中的细胞和分子事件相关联。我们将使用遗传记者来评估增殖、凋亡、衰老，并使用电子显微镜评估隔壁成熟。我们将确定在出生后肺发育的特定阶段(肺泡化和成熟)SHH信号的药物和遗传增强和减少对肺成纤维细胞和肺结构的影响。在肺泡化阶段的关键时间点分离的FACS分选的HH反应成纤维细胞的转录组图谱将被RNAseq检测，以揭示可以作为靶点的候选基因，以减少成人纤维化中的成纤维细胞。在目标2中，我们将在一个特征明确的实验模型中探讨SHH信号是延缓还是促进纤维化的解决，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，器官发育、HH信号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，以及纽约大学核心机构在特定技术方面的专业知识，为我过渡到独立教员职位后，为发展技术和方法方面的专业知识提供了最佳环境，这些专业知识是我未来在肺纤维化研究领域取得成功所需的。

 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.