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、 阿尔茨海默病和肌萎缩侧索硬化症(ALS)，以及急性脑创伤和脑损伤后 缺血症。抑制半胱氨酸天冬氨酸酶(驱动细胞程序性死亡的酶)的药物延缓慢性 急性侮辱后的退化和减少伤害。因为细胞色素c的释放 线粒体触发caspase激活，阻止这一关键步骤应该会破坏细胞死亡程序。我们的 拟议的药物发现计划有五个部分，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物的能力 神经性疾病的四种细胞模型中促凋亡刺激的神经元。 2)检测分子变化(即半胱氨酸天冬氨酸氨基转移酶激活、翻译后对Bcl-2的变化 蛋白质，从线粒体释放的促凋亡因子，线粒体膜的丢失 这些培养的细胞中。将对(1)中发现的每一种具有保护作用的化合物进行测试 因为它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)中测试这些实验药物 培养的神经元免于细胞死亡。 4)测定R6/2小鼠大脑的分子和生理变化 从这些药物的管理。 5)在R6/2小鼠身上测试新药的有益效果是否与已知药物的效果相加 多动症的治疗。 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中枢神经系统的组织。这样的观察激发了1040个屏幕 NINDS文库中的化合物能够阻止细胞色素c从纯化的线粒体中释放。 基本的假设是，如果其他药物在无细胞条件下具有类似于米诺环素的作用 在体内，它们往往具有类似的神经保护作用。此屏幕的结果为 呈上了。关于米诺环素的更多数据如下，即该药物拯救了神经细胞模型中的神经元。 细胞死亡，减缓R6/2小鼠的神经退化。使用上面概述的程序，我们希望 确定和表征其他延缓HD进展的化合物。

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.