FOCAL ADHESION COMPLEXES AND LUNG ENDOTHELIAL APOPTOSIS

描述（改编自申请人的摘要）：细胞凋亡引起血管内皮细胞凋亡。 细胞损伤并调节血管细胞响应损伤的生长。的 研究者已经描述了肺内皮细胞凋亡由 腺苷加同型半胱氨酸（A/H）。初步结果表明，A/H 引起细胞内选定成分的重新定位和半胱天冬酶诱导的降解， 粘着斑（FA）复合物。FA复合物是酪氨酸磷酸化的蛋白质 介导细胞外基质与细胞相互作用的聚集体 细胞骨架初步结果表明，蛋白酪氨酸磷酸酶 （PTB）活性参与A/H诱导的内皮细胞凋亡机制的早期阶段。 细胞凋亡蛋白质酪氨酸磷酸化对于维持细胞的功能是重要的。 细胞骨架组织和细胞粘附，以及细胞基质的破坏 粘附可引起锚定依赖性细胞的凋亡。他们建议 A/H激活PTP 1B，进而使粘着斑（FA）去磷酸化 激酶，允许DNA片段化和凋亡的解离。使用 培养的牛肺动脉内皮细胞（BPAEC）和A/H模型， 细胞凋亡，他们将确定：1）是否A/H引起酪氨酸 FA复合物的蛋白质组分的去磷酸化和解离; 2） FA复合物破坏是否需要PTB活化; 3）是否 过表达天然FA激酶或组成型磷酸化形式的 FA激酶钝化，是否过表达的显性负片段， FA激酶增强A/H诱导的细胞凋亡和粘着斑破坏 复合物;以及4）凋亡是否与再定位和 PTP 1B活化增强以及PTP 1B过表达是否增强A/H 凋亡和FA复合物的破坏。这些研究将提供重要的 深入了解FA复合物的酪氨酸磷酸化作用， 细胞凋亡的调控。对内皮细胞凋亡的了解将使 发展调节血管损伤和修复的方法。

DESCRIPTION (Adapted from the Applicant's Abstract): Apoptosis causes vascular cell injury and regulates vascular cell growth in response to injury. The investigators have described lung endothelial cell apoptosis caused by adenosine plus homocysteine (A/H). Their preliminary results indicate that A/H causes relocalization and caspase-induced degradation of selected components of focal adhesion (FA) complexes. FA complexes are tyrosine phosphorylated protein aggregates which mediate the interaction of extracellular matrix with cell cytoskeleton. Preliminary results indicate that protein tyrosine phosphatase (PTPase) activity is involved early in the mechanism of A/H-induced endothelial cell apoptosis. Protein tyrosine phosphorylation is important to maintenance of cytoskeletal organization and cell adhesion, and disruption of cell-substratum adhesion can cause apoptosis of anchorage-dependent cells. They propose that A/H activates PTP1B which, in turn, dephosphorylates focal adhesion (FA) kinase, allowing dissociation of DNA fragmentation and apoptosis. Using cultured bovine pulmonary artery endothelial cells (BPAEC) and the A/H model of apoptosis, they will determine: 1) whether A/H causes tyrosine dephosphorylation and dissociation of protein components of FA complexes; 2) whether PTPase activation is required for FA complex disruption; 3) whether over-expression of native FA kinase or a constitutively phosphorylated form of FA kinase blunts and whether over-expression of a dominant negative fragment of FA kinase enhances A/H-induced apoptosis and disruption of focal adhesion complexes; and 4) whether apoptosis is associated with relocalization and enhanced activation of PTP1B and whether over-expression of PTP1B enhances A/H apoptosis and disruption of FA complexes. These studies will provide important insights into the role of tyrosine phosphorylation of FA complexes in regulation of apoptosis. Understanding of endothelial apoptosis will allow development of means of regulating vascular injury and repair.