The Role of Mitochondrial VDACs in Apoptosis

描述（由申请人提供）：细胞凋亡是一种定向细胞凋亡的形式。 死亡对于各种生物过程至关重要，包括 胚胎发育、癌症监测和宿主防御。不适当 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细胞凋亡的两个平行途径 被发现，一个介导的释放细胞色素c从 线粒体膜间隙，第二个绕过细胞色素c 通过直接激活caspase 8释放。细胞色素的释放机制 c仍然存在争议，有证据表明，线粒体外 膜通道; VDACs，开放以传导细胞色素c。在哺乳动物中， 三种VDAC同种型。该实验室已经产生了细胞系和小鼠， 对于每个VDAC或VDAC的子集是不足的。建议使用这些细胞 系和小鼠，以确定VDAC在细胞色素c介导的 凋亡具体地，将通过细胞凋亡的动力学和程度来确定细胞凋亡的发生。 在缺陷细胞系和小鼠中测定。细胞色素c的释放将是 直接定量并结合促凋亡和抗凋亡蛋白因子， 将测量突变的线粒体。诱导后的表达谱 将使用微阵列cDNA进行细胞凋亡。最后，点 将在VDAC中引入突变， 通道关闭以确定开放通道是否干扰细胞凋亡。这些 研究可以验证VDAC作为抑制或增强细胞凋亡的靶标。

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.