Pulmonary Blood Flow in Lung Development and Congenital Diaphragmatic Hernia

描述（由申请人提供）：这是一份申请K08职业发展奖的申请，研究胚胎肺血流在正常肺发育和先天性膈疝（CDH）肺异常发展中的作用。CDH是一种出生缺陷，大约每2500个活产婴儿中就有1个。在CDH中，膈膜存在缺陷，使得胎儿发育期间腹腔脏器持续存在于胸腔中。CDH与不同程度的肺发育不全、气道分支减少和肺血管的特异性发育缺陷（包括肺内动脉肌肉化增加）有关。继发于肺血管异常的肺动脉高压，再加上肺发育不全，通常会导致CDH新生儿严重的呼吸窘迫，导致高达40%的婴儿死亡率。此外，相当大比例的CDH幸存者患有严重的长期发病率。胚胎肺血流在调节气道分支形态发生和肺血管发育中的潜在作用尚未得到研究。此外，CDH中肺发育不全和肺血管异常的分子机制尚不完全清楚。该建议的主要假设是，正常的肺气道和血管发育特别依赖于充足的胚胎肺血流，而胚胎肺血流不足会导致CDH的肺发育缺陷。为了解决这一假设，一种新的超声引导下的子宫胚胎小鼠心脏内注射技术将利用一个描述良好的小鼠CDH模型来实现以下具体目标：1)证明气道分支形态发生对发育中的胚胎肺血流的依赖性；2)确定肺动脉壁成熟是否依赖于成熟血管内的胚胎肺血流；3)测量CDH胚胎肺血流不足的模式，确定CDH肺发育过程中气道分支形态发生和血管成熟的缺陷是否与胚胎肺血流不足有关。在宽型小鼠和小鼠CDH模型中，研究气道分支形态发生和肺动脉壁成熟与早期胚胎肺血流和组织氧合的关系。候选人是一名儿科外科医生，自成为全职教师以来一直与导师密切合作。候选人将受益于一个成熟而成功的导师和一个非常支持性的研究和实践环境。此外，候选人将定期与该机构内由肺发育和肺血管生物学专家组成的科学咨询委员会会面。候选人的直接目标是在先进的实验发育生物学概念和技术方面获得更多的知识和熟练程度，并能够设计和进行越来越复杂的实验来解决假设驱动的问题。候选人的长期目标是成为一名富有成效的独立研究者，能够在发育生物学和儿科外科领域做出重大贡献，并最终将基础科学发现转化为临床领域。为了实现这些目标，在奖励期间制定了一项结构化的职业发展计划，包括：获得更多的先进实验技术经验；当然工作;参加会议、专题讨论会和全国性会议；经常与导师会面寻求指导；并在奖励期间逐渐增加独立性。

DESCRIPTION (provided by applicant): This is an application for a K08 Career Development Award studying the role of embryonic pulmonary blood flow in normal lung development and the development of lung abnormalities seen in congenital diaphragmatic hernia (CDH). CDH is a birth defect occurring in approximately 1 out of 2,500 live-born infants. In CDH, there is a defect in the diaphragm allowing persistence of abdominal viscera in the chest cavity during fetal development. CDH is associated with varying degrees of lung hypoplasia, with decreased airway branching, and specific developmental defects of the pulmonary vasculature, including increased muscularization of intrapulmonary arteries. The combination of pulmonary hypertension, secondary to the underlying abnormal pulmonary vasculature, along with pulmonary hypoplasia results in often severe respiratory distress in neonates with CDH resulting in high infant mortality of up to 40%. Furthermore, a significant proportion of CDH survivors suffer from significant long-term morbidity. The potential role of embryonic pulmonary blood flow in modulating airway branching morphogenesis and pulmonary vascular development has not been examined. Also, the molecular mechanisms responsible for the development of pulmonary hypoplasia and pulmonary vascular abnormalities in CDH are incompletely understood. The overriding hypothesis for this proposal is that normal lung airway and vascular development is specifically dependent upon adequate embryonic pulmonary blood flow and that deficiencies in embryonic pulmonary blood flow contribute to lung developmental defects in CDH. To address this hypothesis, a novel technique of ultrasound-guided in utero embryonic mouse intracardiac injection utilizing a well-described murine model of CDH will be employed to pursue the following specific aims: 1) to demonstrate the dependence of airway branching morphogenesis on embryonic pulmonary blood flow in the developing lung; 2) to determine whether pulmonary arterial wall maturation is dependent upon embryonic pulmonary blood flow within the maturing vessel; and 3) to measure patterns of deficient embryonic pulmonary blood flow in CDH and determine whether defects in airway branching morphogenesis and vessel maturation in developing CDH lung are related to deficient embryonic pulmonary blood flow. Airway branching morphogenesis and pulmonary arterial wall maturation will be examined in relation to early embryonic pulmonary blood flow and tissue oxygenation in wide-type mice and in a murine model of CDH. The candidate is a pediatric surgeon who has been working closely with the mentor since becoming full-time faculty. The candidate benefits from a well-established and successful mentor and a very supportive research and practice environment. In addition, the candidate will have regular meetings with a scientific advisory committee compromised of experts in lung development and pulmonary vascular biology within the institution. The candidate's immediate goals are to obtain increased knowledge and proficiency in advanced experimental developmental biology concepts and techniques and to be able to design and conduct increasingly sophisticated experiments to address hypothesis-driven questions. The candidate's long-term goals are to become a productive independent investigator who is able to contribute significantly to the fields of developmental biology and pediatric surgery and eventually translate basic science findings back to the clinical realm. To achieve these goals a structured career development plan over the award period has been developed consisting of: gaining increased experience with advanced experimental techniques; course work; participation in conferences, symposia, and national meetings; frequent meetings with the mentor for guidance; and a gradual increase in independence over the award period.