NITRIC OXIDE PRODUCTION BY ANG II IN ENDOTHELIUM

描述(来自应用程序的逐字)：长期目标是 在生化和细胞水平上识别信号转导 血管紧张素II(Ang II)与一氧化氮产生的联系(S) (NO)，一种有效的血管扩张剂，在内皮细胞中。Ang II的这种效果是在 与它在心血管系统中所扮演的强有力的角色形成鲜明对比 血管收缩药。潜在的假设是，这些显然 血管紧张素转换酶II的相互矛盾的影响反映了与AT1和AT1偶联的信号事件 血管紧张素转换酶II的血管扩张作用是 由AT2受体通过目前未知的信号通路介导。 这一点来自于新的发现，即血管紧张素转换酶II不刺激血管生成。 肺内皮细胞通过内皮型一氧化氮合酶表达增加 一氧化氮合酶(ENOS)。初步数据表明，这是通过 AT2受体，并支持Ang II与G结合的机制 蛋白偶联AT2受体导致酪氨酸磷酸化增加， 最终导致eNOS蛋白表达增加。此外， 通过AT1受体的信号似乎负调控eNOS蛋白 表情。目的研究AT1/AT2受体的特性。 内皮细胞的亚型分布，以及进一步的研究 Ang II刺激eNOS基因和蛋白表达的机制。的作用 血管紧张素Ⅱ受体亚型在介导血管紧张素Ⅱ依赖性增强中的作用 将测定肺内皮细胞的缺氧性血管收缩反应。目标是 第二个目的是鉴定对百日咳毒素敏感的G蛋白 与AT2受体有关。在目标3中被激活的酪氨酸激酶(S)， 或蛋白酪氨酸磷酸酶(S)被抑制，并提供 Ang II和NO产生之间的信号联系将被确定。 受体拮抗剂、结合研究以及信使核糖核酸和蛋白质水平分析 将用于识别受体亚型。药理抑制剂， 反义寡核苷酸和抗体免疫中和实验将 被用来研究各种信号成分(Mg II)的作用 受体、GTP结合蛋白和蛋白激酶)。这些研究可能 为一种新的假设提供了分子基础，该假说将使 血管紧张素转换酶II对血管平滑肌细胞的生理作用 而不是内皮细胞。这些研究具有重要的医学意义。 心脏和肺部疾病，这涉及血液的病理变化 压力。

DESCRIPTION (Verbatim from the application): The long-term goals are to identify at the biochemical and cellular levels the signal transduction pathway(s) which link Angiotensin II (Ang II) to the production of nitric oxide (NO), a potent vasodilator, in endothelial cells. This effect of Ang II is in sharp contrast to its well-known role in the cardiovascular system as a potent vasoconstrictor. The underlying hypothesis is that these apparently contradictory effects of Ang II reflect signaling events coupled to the AT1 and AT2 receptors, respectively, and that the vasodilatory effects of Ang II are mediated by the AT2 receptors via currently unidentified signaling pathways. This emerges from the novel findings that Ang II stimulates NO production in pulmonary endothelial cells, via increased expression of endothelial nitric oxide synthase (eNOS). Preliminary data indicate that this is mediated via the AT2 receptor, and support a mechanism by which Ang II binding to a G protein-coupled AT2 receptor leads to an increase in tyrosine phosphorylation, which ultimately results in increased eNOS protein expression. Furthermore, signaling via the AT1 receptor appears to negatively regulate eNOS protein expression. Aim I is directed at the characterization of AT1/AT2 receptor subtype distribution on endothelial cells, and further investigation of the mechanism of Ang II-stimulated eNOS mRNA and protein expression. The role of the Ang II receptor subtypes in mediating Ang II dependent enhancement of hypoxic vasoconstriction in pulmonary endothelium will be determined. The goal of the second aim is to identify the pertussis toxin-sensitive G protein that is linked to AT2 receptor. In Aim 3 the tyrosine kinase(s) that are activated, or protein tyrosine phosphatase(s) that are inhibited, and that provide the signaling linkage between Ang II and NO production, will be identified. Receptor antagonists, binding studies, and analysis of mRNA and protein levels will be used to identify the receptor subtypes. Pharmacological inhibitors, antisense oligonucleotides and antibody immunoneutralization experiments will be used to investigate the role of various signaling components (Mg II receptors, GTP binding proteins and protein kinases). These studies could provide a molecular basis for a novel hypothesis that would rationalize the physiologically important but opposing effects of Ang II on smooth muscle cells versus endothelial cells. These studies are of significant medical importance to heart and pulmonary disease, which involve pathological changes in blood pressure.