NITRIC OXIDE SYNTHASES IN LUNG DEVELOPMENT AND BRONCHOPULMONARY DYSPLASIA

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 信号分子一氧化氮（NO）在发育中的肺中与气道和血管功能密切相关。 NO由三种NO合酶（NOS）亚型产生，即神经元NOS（nNOS）、内皮NOS（eNOS）和诱导型NOS（iNOS）。 我们在正常狒狒胎儿的初步工作表明，所有三种亚型在气道上皮细胞中表达，并且nNOS和eNOS在妊娠晚期上调，以优化围产期的NO产生。 支气管肺发育不良（BPD）是一种破坏早产儿肺发育的炎症性疾病，其特征是气道和肺血管功能障碍。 我们在狒狒BPD模型中的初步研究表明，在BPD的发生过程中，肺NO的产生和肺nNOS和eNOS的表达显着减弱，并且吸入NO替代（iNO）导致氧合指数的持续改善。 该建议的总体目标是研究狒狒模型中BPD病理生理学中NOS表达改变的作用。 主要假设是在BPD的发展过程中肺nNOS和eNOS表达下调，导致NO产生减少以及气道和血管结构和功能异常。 次要假设是iNO逆转这些异常。 目的1是确定正常个体发育和早期BPD中NOS蛋白和mRNA表达的变化，使用包括激光捕获显微切割的方法来评估从冷冻切片中收获的特定细胞类型的NOS mRNA水平。目的2是确定每个NOS异构体在完整动物的NOS拮抗研究中在气道和血管功能中的作用。 目的3是揭示呼出NO水平的变化与胎儿发育和BPD，以及每个NOS亚型呼出NO的贡献。目的4是确定iNO对气道和血管功能的影响，对早期BPD的肺过程中，肺组织学。 目的5：探讨狒狒气道上皮细胞组成型nNOS和eNOS基因表达下调的机制，以及细胞因子在其下调中的作用。 所获得的结果将增加我们的知识的作用，NO在正常成功的出生后肺适应和BPD的病理生理，从而可能导致新的治疗这种毁灭性的疾病。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The signaling molecule nitric oxide (NO) is critically involved in airway and vascular function in the developing lung. NO is produced by three isoforms of NO synthase (NOS), neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). Our preliminary work in normal baboon fetuses indicates that all three isoforms are expressed in airway epithelium, and that nNOS and eNOS are upregulated during late gestation to optimize No production in the perinatal period. Bronchopulmonary dysplasia (BPD) is an inflammatory condition which disrupts the development of the preterm human lung, and it is characterized by airway and pulmonary vascular dysfunction. Our initial studies in the baboon BPD model indicate that lung NO production and lung nNOS and eNOS expression are markedly attenuated during the genesis of BPD, and that NO replacement by inhalation (iNO) results in a sustained improvement in oxygenation index. The overall objective of this proposal is to investigate the role of alterations in NOS expression in the pathopysiology of BPD in the baboon model. The primary hypothesis is that pulmonary nNOS and eNOS expression are downregulated during the development of BPD, leading to diminished NO production and abnormal airway and vascular structure and function. The secondary hypothesis is that iNO reverses these abnormalities. Aim 1 is to define the normal ontogeny and changes in NOS protein and mRNA expression in early BPD, using approaches including laser capture microdissection to evaluate NOS mRNA levels in specific cell types harvested from frozen sections Aim 2 is to determine the role of each NOS isoform in airway and vascular function in studies of NOS antagonism in intact animals. Aim 3 is to reveal the changes in exhaled NO levels with fetal development and BPD, as well as the contribution of each NOS isoform to exhaled NO. Aim 4 is to determine the effects of iNO on airway and vascular function, on the pulmonary course of early BPD, and on lung histology. Aim 5 is to determine the mechanisms underlying constitutive nNOS and eNOS gene expression in cultured in baboon airway epithelium, and the role of cytokines in their downregulation. The results obtained will increase our knowledge of the role of NO in normally successful postnatal pulmonary adaptation and in the pathophysiology of BPD, thereby possibly leading to novel therapies for this devastating disorder.