ZINC HOMEOSTASIS AND PULMONARY ENDOTHELIAL CELL INJURY

描述（改编自申请人的摘要）：锌是一种不可或缺的元素， 大量基因产物的组成部分，包括酶、转录 因子和结构蛋白。细胞内游离锌浓度 由于各种锌的作用， 转运蛋白、囊泡储存位点和金属结合蛋白， 金属硫蛋白（MT）是主要的贡献者。关于这一点，我们知之甚少。 内皮细胞锌稳态的机制。内皮素一直是 在各种促氧化的早期结构和功能变化的位点 条件，其中许多是由NO的同时生产的影响。 申请人假设MT中锌硫醇盐簇的S-亚硝基化是 细胞氧化还原敏感性的一个关键组成部分，将NO与锌联系起来 内皮细胞内稳态。由此产生的NO诱导的不稳定的 锌被假设为抑制促凋亡途径，但可能有助于 替代非凋亡氧化剂诱导的内皮细胞损伤， 坏死申请人建议：1）确定锌在以下方面的作用： 肺内皮细胞中NO的细胞内信号传导，并确定 这些细胞中锌稳态的分子决定因素，2）鉴定 锌影响内皮细胞对凋亡（LPS）敏感性的机制 或坏死（叔丁基过氧化氢）刺激，并评估 Zn对NO诱导的对这些刺激的敏感性的变化，以及3）确定 肺内皮细胞Zn-MT在正常小鼠肺动脉阻力中的作用 和MT过表达者）由于与NO的调节。

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.