Identification of Novel Drugs that Counter Huntington's Disease

病理性细胞死亡发生在亨廷顿病（HD）、帕金森病、 阿尔茨海默氏病和肌萎缩侧索硬化症（ALS）以及急性脑外伤和脑损伤后， 缺血抑制半胱天冬酶（驱动程序性细胞死亡的酶）的药物减缓慢性 降解并减少急性损伤后的损伤。因为细胞色素c的释放 线粒体触发半胱天冬酶激活，阻断这一关键步骤应该会破坏细胞死亡程序。我们 提出的药物发现方案有五个部分，构成以下五个具体目标： 1)测试抑制细胞色素c释放的化合物保护培养的 在神经系统疾病的四种细胞模型中， 2)测定分子变化（即，半胱天冬酶激活，Bcl-2的翻译后变化 蛋白质，促凋亡因子从线粒体释放，线粒体膜丢失 在这些培养的细胞中。将测试在（1）中发现具有保护性的每种化合物 对这些生化和生理过程的影响。 3)在HD的动物模型（R6/2小鼠）中测试那些拯救HD的实验药物。 培养的神经元细胞死亡。 4)确定R6/2小鼠大脑中的分子和生理变化， 这些药物的管理。 5)在R6/2小鼠中测试新药的有益作用是否会增加已知药物的有益作用。 HD的治疗 初步结果部分显示，米诺环素对分离的 线粒体、培养的神经元和小鼠CNS的组织。这样的观察激发了1040的屏幕 NINDS文库中的化合物，因为它们能够阻断细胞色素c从纯化的线粒体释放。 潜在的假设是，其他药物是否应该在无细胞的细胞中具有类似于米诺环素的作用？ 系统，它们在体内易于具有相当的神经保护作用。此屏幕的结果是 提出了关于米诺环素的其他数据如下，即，这种药物可以在细胞模型中拯救神经元， 细胞死亡并减缓R6/2小鼠的神经变性。使用上面概述的程序，我们希望 鉴定和表征减缓HD进展的其他化合物。

Pathological cell death occurs in the course of Huntington'sdisease (HD), Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS) and also after acute brain trauma and cerebral ischemia. Drugs that inhibit caspases (enzymes that drive programmed cell death) slow down chronic degenerations and decrease damage following acute insult. Because the release of cytochrome c from mitochondria triggers caspase activation, blocking that critical step should derail the cell death program. Our proposed scheme for drug discovery has five portions which constitute the following five Specific Aims: 1) Testing compounds that inhibit the release cytochrome c for their ability to protect cultured neurons from pro-apoptotic stimuli in four cellular models of neurological disease. 2) Assaying molecular changes (i.e., caspase activation, post-translational changes to Bcl-2 proteins, release from mitochondria of apoptogenic factors, loss of mitochondrial membrane potentials) in these cultured cells. Each compound found to be protective in (1) will be tested for its effects on these biochemical and physiological processes. 3) Testing in an animal model of HD (the R6/2 mouse) those experimental drugs that rescue cultured neurons from cell death. 4) Determining the molecular and physiological changes in the brains of R6/2 mice that result from administration of these drugs. 5) Testing in R6/2 mice whether the beneficial effects of novel drugs add to those of known therapies for HD. The Preliminary Results section shows that minocycline has parallel effects upon isolated mitochondria, cultured neurons, and tissues of the mouse CNS. Such observations motivated a screen of 1040 compounds in an NINDS library for their ability to block cytochrome c release from purified mitochondria. The underlyingassumption is that should other drugs have action similar to minocycline in the cell-free system, they are apt to have comparable neuroprotective effects in vivo. The results of this screen are presented. Additional data on minocycline follows, i.e., that the drug rescues neurons in cellular models of cell death and slows neurological degeneration in R6/2 mice. Using the program outlined above, we hope to identify and characterize other compounds that slow the progress of HD.