MECHANISMS OF NEURONAL APOPTOSIS IN VIVO

描述（改编自申请人的摘要）： 成人发作的中枢神经系统（CNS）疾病中的神经元变性， 包括阿尔茨海默病（AD）和肌萎缩侧索硬化症（ALS）， 不明白。最近的研究表明，AD和ALS中的神经变性是 凋亡，通过程序性细胞死亡（PCD）发生。研究者已 开发了一种动物模型来研究神经元凋亡。枕叶皮质 成年大鼠和小鼠中的消融，轴突切断和靶剥夺模型， 导致丘脑进行性退行性神经元变性， 结构性凋亡。这种细胞凋亡与细胞凋亡相关。 神经元细胞体内的活性线粒体和对DNA的氧化损伤。 研究者建议评估神经元凋亡的机制， vivo.研究人员将检验神经元凋亡是神经元死亡的一个重要原因的假设。 通过Bcl-2和Bax的亚细胞易位和 线粒体的细胞色素C，其在时间上对应于 半胱天冬酶和DNA片段化因子。Bcl-2和Bax在细胞凋亡中的作用 神经元凋亡的机制将通过评估是否 在过度表达Bcl-2的受损转基因小鼠中神经元损失减少， 在Bax缺乏的小鼠中。线粒体通透性的参与 转换和细胞色素C的释放将通过损伤后治疗来确定 与渗透性转换阻断剂环孢菌素A一起使用。此外该 研究者提出，这些神经元中PCD的信号是氧化的 应力研究者将检验逆行神经元 轴突切断后的死亡是核DNA损伤诱导的p53依赖性凋亡。的 研究人员将评估垂死的神经元是否承受氧化损伤， DNA和蛋白质在染色质溶解和早期 凋亡参与氧化应激作为一种机制， 在轴突切断/靶剥夺后体内诱导神经元凋亡将 通过确定氧化损伤和细胞凋亡是否 在缺乏神经元或可诱导的 一氧化氮合酶和过表达人野生型超氧化物的小鼠 歧化酶将评估这种神经元凋亡对p53的依赖性 p53基因缺陷小鼠中。然后研究者将使用抗氧化剂 治疗（Trolox和尿酸），以防止或延迟神经元凋亡。这些 研究将确定神经元凋亡的可能分子机制， 并可能导致新的治疗性神经保护的设计 对未来治疗AD和ALS至关重要的实验。

DESCRIPTION (Adapted from the applicant's abstract): The mechanisms for neuronal degeneration in adult-onset central nervous system (CNS) diseases, including Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS), are not understood. Recent studies suggest that neurodegeneration in AD and ALS is apoptosis, occurring by programmed cell death (PCD). The investigator has developed an animal model to study neuronal apoptosis. Occipital cortex ablation in adult rat and mice, a model of axotomy and target deprivation, causes progressive retrograde neuronal degeneration in thalamus that is structurally apoptosis. This apoptosis is associated with accumulation of active mitochondria within the neuronal cell body and oxidative damage to DNA. The investigator proposes to evaluate the mechanisms for neuronal apoptosis in vivo. The investigator will test the hypothesis that apoptosis in neurons is signaled by subcellular translocation of Bcl-2 and Bax and release of cytochrome C from mitochondria, which correspond temporally with activation of caspases and DNA fragmentation factors. The participation Bcl-2 and Bax to the mechanisms for neuronal apoptosis will be determined by evaluating whether neuronal loss is reduced in lesioned transgenic mice overexpressing Bcl-2 and in mice deficient in Bax. The participation of mitochondrial permeability transition and cytochrome C release will be determined by post-injury treatment with the permeability transition blocker cyclosporin A. In addition, the investigator proposes that a signal for PCD in these neurons is oxidative stress. The investigator will test the hypothesis that retrograde neuronal death after axotomy is nuclear DNA damage-induced, p53-dependent apoptosis. The investigator will evaluate whether dying neurons sustain oxidative damage to DNA and proteins during the transition between chromatolysis and early apoptosis. The participation of oxidative stress as a mechanism for the induction of neuronal apoptosis in vivo after axotomy/target deprivation will be further examined by determining whether oxidative injury and apoptosis are attenuated in transgenic mice that are deficient in neuronal or inducible nitric oxide synthase and in mice that overexpress human wild-type superoxide dismutase 1. The dependence of this neuronal apoptosis on p53 will be evaluated in lesioned p53-deficient mice. The investigator will then use antioxidant therapies (Trolox and uric acid) to prevent or delay neuronal apoptosis. These studies will identify possible molecular mechanisms of neuronal apoptosis in vivo and could lead to the design of new therapeutic neuroprotection experiments critical for the future treatment of AD and ALS.