Membrane contact sites regulate cellular excitability

膜接触位点调节细胞兴奋性

• 批准号: 10302271
• 负责人: Eamonn James Dickson
• 金额: $ 31.4万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10302271
• 关键词: Action Potentials; Acute; Address; Adult; Alzheimer' s Disease; Attention; Biophysics; Brain; Calcium; Cell membrane; Cell physiology; Cells; Cellular biology; Cessation of life; Cholesterol; Cholesterol Homeostasis; Chronic; Data; Dementia; Disease; Endoplasmic Reticulum; Event; Fire - disasters; Formulation; Future; Gatekeeping; Goals; Health; Human; Impairment; Ion Channel; Lead; Link; Lipids; Lysosomes; Measures; Mediating; Medicine; Membrane; Metabolism; Modeling; Molecular; Mus; Mutation; Neurodegenerative Disorders; Neurologic; Neurons; Neurosciences; Parkinson Disease; Pathologic; Patients; Phosphatidylinositols; Potassium; Process; Proteins; Published Comment; Regulation; Research; Rest; STIM1 gene; Seizures; Shapes; Signal Transduction; Site; Structure of thyroid parafollicular cell; Supraoptic Vertical Ophthalmoplegia; Testing; Therapeutic; Work; cholesterol control; human disease; inter-alpha-inhibitor; motor impairment; neuronal excitability; neuropathology; novel; novel therapeutic intervention; protein function; receptor; response; treatment strategy; voltage

The long-term goal of this proposal is to develop therapeutic strategies for the treatment of a human disease characterized by pathological changes in cellular cholesterol metabolism, Niemann-Pick type C (NPC) disease. NPC disease is a fatal neurodegenerative disorder that occurs due to mutations within a key gatekeeper protein in cholesterol transport: lysosomal Niemann-Pick type C1. Neurons from NPC patients have dramatically altered cholesterol homeostasis due to reduce transport of cholesterol out of lysosomes to the endoplasmic reticulum. Neurologically, accumulation of lysosomal cholesterol in NPC patient neurons, gives rise to impaired motor functions, psychiatric problems, seizures, dementia, and typically death prior to adulthood. Despite clear neuropathological consequences for cholesterol dysregulation in NPC disease, there has been little research attention invested in understanding whether altered ion channel function, neuronal excitability, and calcium handling, contribute to the neuropathology of NPC disease. Given that phosphoinositides control a wide range of cellular processes including the regulation of plasma membrane ion channel activity, it follows that any interdependence in the membrane pools of these lipids could have critically important implications for this disease. Our central hypothesis is that regulated efflux of cholesterol from lysosomes to the ER, via NPC1, is a rheostat for phosphoinositides and consequently neuronal excitability. To test this hypothesis, we implement a multi-scale approach to rigorously investigate the mechanisms by which cholesterol can regulate the abundance and distribution of phosphoinositides to alter phosphoinositide- dependent ion channel function. Specific Aim 1 will test the hypothesis that alterations in NPC1 function modifies plasma membrane phosphoinositides, to alter ion channel activity, and consequently neuron membrane excitability and function. In Specific Aim 2 we test the hypothesis that alterations in excitability and membrane cholesterol controls the ability of neurons to store and release calcium. Finally, in Specific Aim 3 we will determine specific proteins that have their expression profiles altered in NPC to modify phosphoinositide-dependent ion channel function. The proposed studies have specific relevance in the fields of neuroscience, cell biology and biophysics, but the fundamental importance of phosphoinositides and cholesterol for a plethora of cellular events, mean it will have broad implications for medicine.

该提案的长期目标是开发治疗人类疾病的治疗策略 以细胞胆固醇代谢的病理改变为特征的尼曼-匹克C型（NPC）病。 鼻咽癌是一种致命的神经退行性疾病，由关键看门人突变引起 胆固醇运输中的蛋白质：溶酶体 Niemann-Pick C1 型。来自鼻咽癌患者的神经元 由于减少胆固醇从溶酶体运输到体内，显着改变了胆固醇稳态 内质网。从神经学角度来说，鼻咽癌患者神经元中溶酶体胆固醇的积累会导致 导致运动功能受损、精神问题、癫痫发作、痴呆，通常会在死亡前死亡 成年期。尽管鼻咽癌疾病中胆固醇失调会产生明显的神经病理学后果，但 很少有研究关注了解离子通道功能、神经元功能是否改变 兴奋性和钙处理有助于鼻咽癌疾病的神经病理学。鉴于 磷酸肌醇控制广泛的细胞过程，包括质膜离子的调节 通道活性，因此这些脂质的膜池中的任何相互依赖性都可能严重影响 对这种疾病具有重要意义。我们的中心假设是，胆固醇的流出受到调节 溶酶体通过 NPC1 进入内质网，是磷酸肌醇的变阻器，从而调节神经元的兴奋性。到 检验这一假设，我们采用多尺度方法来严格研究其机制 胆固醇可以调节磷酸肌醇的丰度和分布，从而改变磷酸肌醇 依赖离子通道功能。具体目标 1 将检验 NPC1 功能改变的假设 修饰质膜磷酸肌醇，改变离子通道活性，从而改变神经元 膜的兴奋性和功能。在具体目标 2 中，我们检验了以下假设：兴奋性和 膜胆固醇控制神经元储存和释放钙的能力。最后，在具体目标 3 中 我们将确定在 NPC 中表达谱发生改变的特定蛋白质，以进行修饰 磷酸肌醇依赖性离子通道功能。拟议的研究在以下领域具有具体相关性： 神经科学、细胞生物学和生物物理学，但磷酸肌醇的根本重要性和 胆固醇与大量细胞事件有关，这意味着它将对医学产生广泛的影响。