F32 Fellowship for Study of Hedgehog Signaling in Postnatal Lung

描述（由申请人提供）：这是一份为期两年的F32奖学金申请。在研究期间，申请人将致力于阐明Hedgehog （Hh）信号在出生后肺部发育中的作用。Hh信号是由三种类似的蛋白（Sonic， Indian和Desert Hh）作用于细胞受体Patched介导的，通常影响间充质细胞的功能。众所周知，一段时间以来，Hedgehog信号在胚胎发育过程中起着至关重要的作用，但直到最近，人们才认识到Hh信号影响癌症和纤维化等疾病过程。刺猬信号在胚胎肺发育的分支形态发生中起重要作用，但目前尚不清楚该途径在肺发育的最后阶段起什么作用。出生后肺发育的最后阶段包括继发性间隔的形成，以及间隔壁的成熟，这一过程涉及间质细胞的损失，但人们对这一过程知之甚少。也假设发育通路如Hh在肺纤维化中被重新激活。本研究计划旨在验证Hh信号下调的适当时机对于室间隔壁的适当成熟至关重要的假设。该假说认为，出生后早期肺发育中的Hh信号传导支持间充质细胞的大力扩张，而肺泡化末期信号传导的退出导致间充质细胞的相对损失，这是由于增殖减少和细胞凋亡增加的某种组合。为了验证这一点，首先，详细分析Hh信号在此期间的精确计时，使用读取Hh信号的报告小鼠进行测量，通过qRT-PCR测量Hh信号的下游转录靶点，如Gli1，并直接测量Shh蛋白水平。此外，在第二个Aim中，将确定在这两个阶段中增强或抑制Hh信号的影响，并与基于假设的预测进行比较。为了进行这项工作和培训，申请人将在纽约大学细胞生物学代理主席Dan Rifkin博士的基础科学实验室工作，他有很强的指导记录和广泛的研究兴趣（癌症，纤维化，肺，心脏和骨骼的发育），以细胞外基质生物学为共同主线。他还将攻读细胞生物学、发育系统和干细胞生物学的研究生课程，以及与拨款写作、演讲技巧和研究伦理行为相关的重点工作。这项研究经验和相关培训旨在增强他之前在肺纤维化方面的广泛研究经验，使他能够研究肺发育，肺纤维化和损伤以及成人肺过程和疾病中发育信号通路的参与。

DESCRIPTION (provided by applicant): This is an application for F32 fellowship support for two years. During the fellowship period, the applicant will work on elucidating the role of Hedgehog (Hh) signaling in postnatal lung development. Hh signaling is mediated by three similar proteins (Sonic, Indian and Desert Hh) acting on the cell receptor Patched, and typically affects function of mesenchymal cells. Hedgehog signaling has been known for some time to be critical during embryonic development, but only recently has it come to be appreciated that Hh signaling affects disease processes such as cancer and fibrosis. Hedgehog signaling plays a major in branching morphogenesis in embryonic lung development but it is currently unknown what role this pathway plays during the final developmental steps of the lung. This final, postnatal phase of lung development involves creation of secondary septa, and maturation of these septal walls in a poorly understood process involving loss of interstitial cells. It is also postulated that developmental pathways such as Hh are reactivated in pulmonary fibrosis. The research plan is designed to test the hypothesis that proper timing of Hh signaling down-regulation is critical for the proper maturation of septal walls. The hypothesis states that Hh signaling in early postnatal lung development supports vigorous expansion of mesenchymal cells, whereas withdrawal of signaling at the end of the alveolarization phase contributes to a relative loss of mesenchymal cells due to some combination of reduced proliferation and increased apoptosis. The Aims to test this consist of, first, detailed analysis of the precise timig of Hh signaling during this period, measured using reporter mice that read-out Hh signaling, measurement by qRT-PCR of downstream transcriptional targets of Hh signaling such as Gli1, and direct measurement of Shh protein levels. In addition, in the second Aim, the effects of augmenting or inhibiting Hh signaling during the two phases will be determined and compared with predictions based on the hypothesis. To pursue this work and training, the applicant will work in the basic science lab of Dr. Dan Rifkin, acting chair of Cell Biology at NYU, who has a strong mentoring record and a wide range of research interests (cancer, fibrosis, and development of lung, heart and bone) that have extracellular matrix biology as a common thread. He will also pursue graduate level course work in Cell Biology, developmental systems, and stem cell biology, along with focused work related to grant writing, presentation skills and the ethical conduct of research. This research experience and related training are designed to augment his prior extensive research experience in pulmonary fibrosis and leave him poised to investigate questions of lung development, lung fibrosis and injury, and the involvement of developmental signaling pathways in adult lung processes and disease.