ZINC HOMEOSTASIS AND PULMONARY ENDOTHELIAL CELL INJURY

描述(改编自申请人的摘要)：锌是一个整体 大量基因产物的组成部分，包括酶、转录 因子和结构蛋白。细胞内锌的游离浓度 通过各种锌的作用将其维持在极低的水平 其转运体、囊泡储存部位和金属结合蛋白 金属硫蛋白(MT)是主要贡献者。人们对此知之甚少 血管内皮细胞锌稳态的机制。内皮细胞一直是 多种促氧化物质早期结构和功能改变的基因座 其中许多条件受到同时产生NO的影响。这个 申请人假设MT中硫酸锌簇合物的S-亚硝化反应为 细胞氧化还原敏感性的关键成分，将NO与锌联系在一起 内皮细胞的动态平衡。一氧化氮引起的血浆不稳定状态的变化 锌被假设为抑制促凋亡途径，但可能有助于 与非凋亡性氧化剂诱导的内皮细胞损伤和 坏死。申请人建议：1)确定锌在 肺内皮细胞NO的细胞内信号转导及测定 这些细胞中锌稳态的分子决定因素，2)识别 锌影响内皮细胞对凋亡敏感性的机制 或坏死性(叔丁基氢过氧化氢)刺激，并评估 锌对NO诱导的对这些刺激的敏感性的变化，以及3)决定 肺内皮细胞锌-金属硫蛋白在正常小鼠肺耐受中的作用 和高速公路上的MT)由于没有。

DESCRIPTION (Adapted from the Applicant's Abstract): Zinc is an integral component of a large number of gene products including enzymes, transcription factors, and structural proteins. The intracellular free concentration of zinc is maintained at extraordinarily low levels by the actions of various zinc transporters, vesicular storage sites, and metal binding proteins of which metallothionein (MT) is a major contributor. Little is known regarding the mechanisms of zinc homeostasis in endothelial cells. Endothelium has been the locus of early structural and functional changes in a variety of pro-oxidative conditions many of which are affected by the simultaneous production of NO. The applicant hypothesizes that S-nitrosylation of zinc thiolate clusters in MT is a critical component of cellular redox sensitivity linking NO to zinc homeostasis in endothelial cells. The resultant NO-induced changes in labile zinc are hypothesized to inhibit pro-apoptotic pathways but may contribute alternatively to non-apoptotic oxidant-induced endothelial cell injury and necrosis. The applicant proposes to: 1) determine a role for zinc in intracellular signaling of NO in lung endothelial cells and determine the molecular determinants of zinc homeostasis in these cells, 2) identify mechanisms by which Zn affects endothelial cell sensitivity to apoptotic (LPS) or necrotic (tert butylhydroperoxide) stimuli and evaluate the contribution of Zn to NO-induced changes in sensitivity to these stimuli, and 3) determine the role of pulmonary endothelial cell Zn-MT in the resistance of intact mice (wt and MT over expressers) due to conditioning with NO.