The Antiapoptotic Effects on NO in Pulmonary Endothelium

描述(申请人提供)：肺内皮细胞是高氧性肺损伤早期结构和功能改变的部位。部分还原的氧物种的产生和消除之间的不平衡似乎是导致这种病理的发生和/或维持的原因，而且有证据表明，部分还原的氮物种可能会加剧这种伤害。尽管如此，近年来很明显，在许多情况下，一氧化氮(NO)实际上可以限制内皮细胞的损伤，并发挥抗炎细胞保护分子的作用。根据最近的报道和初步数据，我们推测诱导型一氧化氮合酶产生的NO可能通过翻译后S-亚硝化机制发挥潜在的抗细胞凋亡作用，从而对肺内皮细胞具有保护作用。因此，本奖学金申请的特定目的是确定：(1)iNOS衍生的NO在高氧条件下对iNOS-/-小鼠或在其肺内皮细胞中过度表达iNOS的小鼠的肺内皮细胞结构和功能的影响；(2)利用PECAM抗体靶向的含人iNOS的cDNA的聚乙烯亚胺载体进行体细胞基因转移；(2)用共聚焦和多光子激光扫描显微镜观察培养的小鼠肺内皮细胞和体外灌流肺组织中NO信号通路中锌的释放。

DESCRIPTION (provided by applicant): Pulmonary endothelium is the locus of early structural and functional changes in hyperoxic lung injury. An imbalance between the production of partially reduced oxygen species and their elimination appears to account for the genesis and/or maintenance of such pathology and evidence exists to suggest that such injury may be exacerbated by partially reduced nitrogen species. Nonetheless, in recent years, it is apparent that in many conditions, nitric oxide (NO) may actually limit endothelial cell injury and act as an anti-inflammatory cytoprotective molecule. From recent reports and preliminary data, we hypothesize that iNOS derived NO may be protective to lung endothelium by its potential antiapoptotic effect via posttranslational mechanisms involving S-nitrosylation. Accordingly, the specific aims of this fellowship application are to determine the role of: (1) iNOS-derived NO in affecting pulmonary endothelial cell structure and function in hyperoxia in iNOS-/- mice or in mice that overexpress iNOS in their pulmonary endothelium via somatic gene transfer using a PECAM antibody targeted polyethlyenimine vector containing cDNA to human iNOS; (2) zinc release in NO signaling in the pulmonary endothelium of cultured murine lung endothelial cells and isolated perfused lung using confocal and multiphoton laser scanning microscopy.