Molecular Basis of Infantile NCL

婴儿 NCL 的分子基础

• 批准号: 6772134
• 负责人: SANDRA L HOFMANN
• 金额: $ 36.08万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-28 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6772134
• 关键词: acyl coA; adult human (21+); child (0-11); clinical research; cysteamine; disease /disorder model; enzyme activity; enzyme deficiency; esterase; family genetics; gene mutation; genetically modified animals; human subject; inborn lysosomal enzyme disorder; infant human (0-1 year); laboratory mouse; lipofuscin; mass spectrometry; neurogenetics; neuronal ceroid lipofuscinosis; neuropathology; phenotype; phosphoprotein phosphatase; protein structure function; thioester; tissue /cell culture

DESCRIPTION (provided by applicant): Infantile neuronal ceroid lipofuscinosis (INCL, or infantile Batten disease) is a hereditary progressive neurodegenerative disorder caused by mutations in a lysosomal enzyme (palmitoyl-protein thioesterase, PPT1) that removes fatty acids from modified cysteine residues in proteins. Little is understood about how deficiency in this enzyme causes neurodegeneration. In the period supported by this award, we have characterized a number of PPT1 mutations and produced knockout mice deficient in PPT1 and a homologous enzyme, PPT2. We found that residual PPT1 activity is the major determinant of age of onset of disease, that PPT1 knockout mice are an excellent model for INCL, and that PPT2 knockout mice have an NCL with unique extraneuronal features. In the current proposal we will delve deeper into the molecular basis of INCL. We will identify the physiological substrates of PPT1 and PPT2 through biochemical analysis of tissues derived from knockout mice. We will investigate the mechanism of action of cysteamine, the first rationally designed drug introduced for the treatment of INCL, through biochemical and metabolic labeling studies. We will also test the hypothesis that perturbations in membrane recycling in the presynaptic endosomal/lysosomal compartment lead to synaptic dysfunction and neuronal cell death in INCL. These studies will use electrophysiological recordings of spontaneous and evoked neurotransmitter release, fluorescent dye imaging, and ultrastructural analysis of presynaptic terminals in cortical and hippocampal cultures derived from PPT1 knockout and control mice. These studies will provide valuable insights into NCL and basic molecular and cellular mechanisms underlying neurodegenerative disorders.

描述（由申请人提供）：婴儿神经蛋白脂肪促性舒张病（含有或婴儿the病）是由溶酶体酶突变引起的遗传性进行性神经退行性疾病（Palmitmitoyl-protein硫代酶，PPT1）引起的，可使脂肪酸蛋白质蛋白具有蛋白质的蛋白质，可使脂肪酸酸化蛋白质中的脂肪酸蛋白质。关于这种酶缺乏会导致神经退行性的缺乏症几乎没有理解。在该奖项支持的时期，我们表征了许多PPT1突变，并产生了缺乏PPT1和同源酶PPT2的敲除小鼠。我们发现，残留的PPT1活性是疾病发作年龄的主要决定因素，PPT1敲除小鼠是含有的绝佳模型，并且PPT2敲除小鼠具有具有独特的外交特征的NCL。在当前的提案中，我们将更深入地研究含有分子基础。我们将通过对基因敲除小鼠衍生的组织的生化分析来鉴定PPT1和PPT2的生理底物。我们将研究Cysteamine的作用机理，Cysteamine是通过生化和代谢标记研究引入的第一种合理设计的药物。我们还将检验以下假设：突触前内体/溶酶体室中膜回收的扰动导致突触功能障碍和含神经元细胞死亡。这些研究将使用自发性和诱发的神经递质释放，荧光染料成像以及从PPT1敲除和对照小鼠衍生的皮质和海马培养物中突触前末端的超结构分析的电生理记录。这些研究将为NCL和基本分子和细胞机制提供宝贵的见解。