PATHOGENESIS OF ALS IN SOD1 TRANSGENIC MICE

这个项目的长期目标是调查 过量表达的转基因小鼠作为ALS动物模型的发病机制 突变型细胞内超氧化物歧化酶的表达及运动发育 神经元病。突变启动运动神经元的机制 死亡定义不明确{一种目前正在调查的假说 突变分子的异常折叠允许氢 过氧化氢与活性通道中的还原铜相互作用，从而 成为过氧化反应的底物。这种反应 在关键目标上产生有毒的羟基加合物。 我们将通过分析这种过氧化作用对 降低ALS小鼠疾病表型的措施 过氧化氢的过氧化作用。具体目标(1)是生成 双转基因小鼠同时具有突变型SOD1转基因和变异型 谷胱甘肽过氧化物酶水平(从零到超过正常水平的10倍)。 这些实验将决定是否加速清除 过氧化氢可以改善病程。具体目标(二) 将测试绑定和屏蔽(如果可访问)的可能性 突变活性中心中的铜会减少氢的进入 过氧化氢到这种金属上，从而延缓疾病。铜络合剂 试验包括青霉胺和二乙基二硫代氨基甲酸酯。老鼠会 监测发病时间和总存活率 有了这些干预措施。我们还将监测电生理 量化运动单位功能和活动水平的参数 脑和脊髓中的谷胱甘肽过氧化物酶和过氧化氢酶。我们 我相信这些实验将具有重要意义，因为它们将测试 两种关于神经毒性机制的特定假说 突变的SOD1和潜在的治疗这种致命疾病的策略。

The {long term objective} of this project is to investigate the pathogenesis of ALS using as an animal model transgenic mice which over- express mutant cytosolic superoxide dismutase (SOD) and develop motor neuron disease. The mechanisms whereby mutations initiate motor neuron death are not well defined {One hypothesis currently under investigation is that} abnormal folding of the mutant molecule allows hydrogen peroxide to interact with reduced copper in the active channel, thereby becoming a substrate for a peroxidation reaction. This reaction generates toxic hydroxyl adducts on critical targets. We will test this peroxidation hypothesis by analyzing the effects on the disease phenotype in ALS mice of measures which will reduce peroxidation of hydrogen peroxide. Specific Aim (1) is to generate doubly transgenic mice with both the mutant SOD1 transgene and varying levels of glutathione peroxidase (from none to 10-fold above normal). These experiments will determine whether accelerated clearance of hydrogen peroxide can ameliorate the disease course. Specific Aim (2) will test the possibility that binding and shielding if accessible copper in the mutuant active site will reduce access of hydrogen peroxide to this metal and thereby slow the disease. Copper chelators to be tried include penicillamine and diethyldithiocarbamate. Mice will be monitored for timing of onset of illness and overall survival without and with these interventions. We will also monitor electrophysiological parameters that quantitate motor unit function and activity levels of glutahione peroxidase and {catalase} in brain and spinal cord. We believe these experiments will be significant because they will test both a specific hypothesis regarding the mechanism of neurotoxicity of mutant SOD1 and a potential therapeutic strategy in this lethal disease.