A Molecular Approach to Prevent Pulmonary Dysfunction in the Intrauterine Growth

描述（由申请人提供）：宫内生长限制（IUGR）改变肺部发育，增加整个出生后呼吸系统损害的风险。这种呼吸损害背后的细胞-分子机制的垂直整合为了解IUGR后代慢性肺部疾病的发病机制提供了一种强大的功能基因组方法。由于肺发育是由时空特异性的肺泡上皮-间质相互作用决定的，我们假设IUGR改变了正常肺发育所必需的关键肺泡上皮-间质信号通路。我们建议使用一个完善的啮齿类动物模型，从妊娠第10天到足月，直到出生后21天，母体食物限制（MFR）为50%。该模型先前已被证明在MFR后代中出现成人发病的肥胖、糖尿病和高血压。现在我们的初步数据为MFR后代肺泡化失败和肺功能障碍提供了明确的证据。利用该模型和成熟的分子技术，如肺形态测定、Real-Time-PCR、Western分析、免疫组织化学、激光捕获显微解剖、反义和过表达研究以及体内肺功能检测，我们将1)确定MFR对子代出生后1和21天、3和9个月时肺结构和功能的影响；2)专门研究MFR如何影响肺泡甲状旁腺激素相关蛋白/过氧化物酶体增殖物激活受体3信号，这是已知的正常肺发育所必需的；3)评估受MFR影响的关键肺泡上皮-间质信号通路的改变，以及随后的肺结构和功能改变，是否可以通过相关关键调控基因的过表达或沉默而正常化。根据我们的初步数据，我们预计，在MFR后代的肺部，我们将发现对肺泡化至关重要的分子通路被破坏，这解释了后代肺部编程的改变，因此提供了通过特定的分子干预来预防和/或逆转这种变化的可能性。通过利用功能基因组方法，本文提出的研究将转化为新的和创新的分子预防和治疗方法，用于IUGR后代继发于MFR和其他原因的肺功能障碍。

DESCRIPTION (provided by applicant): Intrauterine growth restriction (IUGR) alters lung development, increasing the risk of respiratory compromise throughout postnatal life. Vertical integration of the cell-molecular mechanism(s) underlying this respiratory compromise offers a powerful functional genomic approach to understand the pathogenesis of chronic lung disease in the IUGR offspring. Since lung development is determined by spatio-temporally specific alveolar epithelial-mesenchymal interactions, we hypothesize that IUGR alters the key alveolar epithelial-mesenchymal signaling pathways that are essential for normal lung development. We propose utilizing a well established rodent model of 50% maternal food restriction (MFR) from day 10 of gestation to term and through postnatal day 21. This model has previously been shown to demonstrate adult-onset obesity, diabetes, and hypertension in the MFR offspring. Now our preliminary data provide clear evidence for failed alveolarization and pulmonary dysfunction in the MFR offspring. Using this model and well established molecular techniques such as lung morphometry, Real-Time-PCR, Western analysis, immunohistochemistry, laser capture microdissection, anti-sense and overexpression studies, and in vivo pulmonary function testing, we will 1) determine the effect of MFR on lung structure and function in the offspring at postnatal days 1 and 21, and months 3 and 9; 2) specifically examine how MFR affects alveolar Parathyroid Hormone-related Protein/Peroxisome Proliferator-Activated Receptor 3 signaling that is known to be essential for normal lung development; and 3) evaluate if alterations in key alveolar epithelial-mesenchymal signaling pathways affected by MFR, and the subsequent lung structural and functional changes, can be normalized by either over-expression or silencing of the key regulatory genes involved. Based on our preliminary data, we expect that, in the lung of the MFR offspring, we will find disruption in molecular pathways that are essential for alveolarization, accounting for the altered lung programming seen in the offspring, hence offering the possibility of prevention and/or reversal of such changes with specific molecular interventions. By exploiting the functional genomic approach, the studies proposed herein will translate into novel and innovative molecular preventive and therapeutic approaches for pulmonary dysfunction seen in IUGR offspring secondary to not only MFR, but also to other causes. PUBLIC HEALTH RELEVANCE: There is accumulating evidence to show that infants who are delivered following growth restriction during the fetal period have significant lung morbidity during their postnatal life. Further, since the mechanism of this lung morbidity is not known, there is no specific intervention to prevent it. Using a well established rat model of intrauterine growth restriction and the state-of-the-art technology, we propose studies that will unravel the fundamental molecular mechanism (s) of pulmonary dysfunction in the growth restricted offspring, allowing us to design novel intervention strategies that may not only prevent, but also reverse intrauterine growth restriction associated lung damage during postnatal life.