Department of Biological Sciences, and Neurology and Neurological Sciences, Stanford University, 371 Serra Street, Stanford, CA 94305, USA.
Neurosci Lett. 2010 Jan 22;469(2):179-83. doi: 10.1016/j.neulet.2009.11.067. Epub 2009 Nov 26.
Neuronal apoptosis following ischemia can be mediated by a caspase-dependent pathway, which involves the mitochondrial release of cytochrome c that initiates a cascade of caspase activation. In addition, there is a caspase-independent pathway, which is mediated by the release of apoptosis-inducing factor (AIF). Using caspase inhibitor gene therapy, we investigated the roles of caspases on the mitochondrial release of cyt c and the release of AIF. Specifically, we used herpes simplex virus-1 amplicon vectors to ectopically express a viral caspase inhibitor (crmA or p35) in mixed cortical cultures exposed to oxygen/glucose deprivation. Overexpression of either crmA or p35 (but not the caspase-3 inhibitor DEVD) inhibited the release of AIF; this suggests that there can be cross-talk between the caspase-dependent and the ostensibly caspase-independent pathway. In addition, both crmA overexpression and DEVD inhibited cyt c release, suggesting a positive feedback loop involving activated caspases stimulating cyt c release.
缺血后的神经元凋亡可以通过半胱天冬酶依赖性途径介导，该途径涉及细胞色素 c 的线粒体释放，从而引发半胱天冬酶激活级联反应。此外，还有一种不依赖半胱天冬酶的途径，由凋亡诱导因子（AIF）的释放介导。我们使用半胱天冬酶抑制剂基因治疗来研究半胱天冬酶在细胞色素 c 线粒体释放和 AIF 释放中的作用。具体来说，我们使用单纯疱疹病毒 1 扩增子载体在暴露于氧/葡萄糖剥夺的混合皮质培养物中外源性表达病毒半胱天冬酶抑制剂（crmA 或 p35）。crmA 或 p35 的过表达（但不是 caspase-3 抑制剂 DEVD）抑制了 AIF 的释放;这表明 caspase 依赖性途径和表面上不依赖 caspase 的途径之间可能存在串扰。此外，crmA 过表达和 DEVD 均抑制细胞色素 c 的释放，这表明涉及激活的半胱天冬酶刺激细胞色素 c 释放的正反馈回路。
