The Role of Mitochondrial VDACs in Apoptosis

描述(申请人提供)：细胞凋亡是定向细胞的一种形式 死亡对于各种生物过程是必不可少的，包括 胚胎发育、癌症监测和宿主防御。不适当 细胞凋亡发生在自身免疫性疾病、恶性肿瘤和获得性和 遗传性神经退行性疾病。有两条平行的细胞凋亡途径 已被发现，其中一种是由细胞色素c的释放所介导的 线粒体膜间间隙，第二个绕过细胞色素c 直接激活caspase8释放细胞色素的机制 C仍然存在争议，有证据表明线粒体外部 膜通道；VDAC，开放以传导细胞色素c。在哺乳动物中存在 三种VDAC亚型。该实验室已经培养出了细胞系和小鼠 不适用于每个VDAC或VDAC的子集。建议使用这些电池 确定VDAC在细胞色素c介导中的作用的品系和小鼠 细胞凋亡。具体来说，细胞凋亡的动力学和程度将是 在缺陷的细胞系和小鼠中确定。细胞色素c的释放将是 促凋亡和抗凋亡蛋白因子的直接定量和结合 突变的线粒体将被测量。诱导后的表达谱 将使用微阵列cDNA进行细胞凋亡的研究。最后，要点 将在VDAC中引入突变，以消除电压依赖 关闭通道以确定开放的通道是否干扰细胞凋亡。这些 研究可能证实VDAC作为抑制或促进细胞凋亡的靶点。

DESCRIPTION (provided by applicant): Apoptosis is a form of directed cellular death that is essential for a variety of biological processes, including embryonic development, cancer surveillance, and host defense. Inappropriate apoptosis occurs in autoimmune disorders, malignancy, and acquired and heritable neurodegenerative disease. Two parallel pathways for apoptosis have been uncovered, one mediated by the release of cytochrome c from the mitochondrial intermembrane space, and a second that bypasses cytochrome c release by directly activating caspase 8. The release mechanism for cytochrome c remains controversial, with evidence suggesting that the mitochondrial outer membrane channels; VDACs, open to conduct cytochrome c. In mammals there exist three VDAC isoforms. The laboratory has generated cell lines and mice that are deficient for each VDAC or a subset of VDACs. It is proposed to use these cell lines and mice to define the role VDACs play in cytochrome c mediated apoptosis. Specifically, the kinetics and extent of apoptosis will be determined in the deficient cell lines and mice. Cytochrome c release will be directly quantified and binding of pro and anti-apoptotic protein factors to mutant mitochondria will be measured. Expression profiles following induction of apoptosis will be performed using microarrayed cDNAs. Finally, point mutations will be introduced into VDACs that will abrogate voltage dependent channel closure to determine if open channels interfere with apoptosis. These studies may validate VDACs as targets for inhibiting or enhancing apoptosis.