A Molecular Approach to Prevent Pulmonary Dysfunction in the Intrauterine Growth

描述（由申请人提供）：宫内生长受限（IUGR）改变肺发育，增加整个出生后呼吸系统损害的风险。这种呼吸系统损害的细胞分子机制的垂直整合提供了一种强大的功能基因组方法来了解IUGR后代慢性肺部疾病的发病机制。由于肺发育是由时空特异性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。我们建议利用一个完善的啮齿动物模型的50%产妇限食（MFR），从妊娠第10天到足月，并通过出生后第21天。该模型先前已被证明在MFR后代中显示成人发病的肥胖症、糖尿病和高血压。现在，我们的初步数据提供了明确的证据，失败的肺泡化和肺功能障碍的MFR后代。使用该模型和成熟的分子技术，例如肺形态测量、实时-PCR、Western分析、免疫组织化学、激光捕获显微切割、反义和过表达研究以及体内肺功能测试，我们将1）确定MFR对出生后第1天和第21天以及第3和第9个月的后代的肺结构和功能的影响; 2）具体检查MFR如何影响肺泡甲状旁腺激素相关蛋白/过氧化物酶体激活受体3信号传导，这是已知的正常肺发育所必需的;和3）评估受MFR影响的关键肺泡上皮-间充质信号传导途径的改变，以及随后的肺结构和功能变化，可以通过过表达或沉默所涉及的关键调控基因来正常化。基于我们的初步数据，我们预计，在MFR后代的肺中，我们将发现肺泡化所必需的分子途径的破坏，解释了后代中观察到的改变的肺编程，因此提供了用特定分子干预预防和/或逆转这种变化的可能性。通过利用功能基因组学方法，本文提出的研究将转化为用于IUGR后代中不仅继发于MFR而且继发于其他原因的肺功能障碍的新颖和创新的分子预防和治疗方法。 公共卫生相关性：越来越多的证据表明，在胎儿期生长受限后分娩的婴儿在其出生后的生活中具有显著的肺部发病率。此外，由于这种肺部发病的机制尚不清楚，因此没有具体的干预措施来预防它。使用一个成熟的宫内生长受限大鼠模型和最先进的技术，我们提出了一些研究，这些研究将揭示生长受限后代肺功能障碍的基本分子机制，使我们能够设计新的干预策略，不仅可以预防，而且逆转出生后生命期间与宫内生长受限相关的肺损伤。

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.