Intracellular Electrophysiology: An electrochemical atlas of organelles

细胞内电生理学：细胞器电化学图谱

• 批准号: 10693891
• 负责人: Yamuna Krishnan
• 金额: $ 114.8万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10693891
• 关键词: Apoptosis; Atlases; Biological Assay; Cell physiology; Characteristics; Chemicals; Communication; Cues; Cytoplasm; Development; Disease; Electrophysiology (science); Endoplasmic Reticulum; Equation; Face; Health; Hodgkin Disease; Homeostasis; Ion Transport; Ions; Lysosomes; Maps; Membrane; Modeling; Molecular; Mutation; Neurodegenerative Disorders; Neurons; Organelles; Parkinsonian Disorders; Pathway interactions; Physiology; Process; Proteins; Signal Transduction; Synapses; Tissues; lipid metabolism; prevent; protein protein interaction; seal; small molecule; targeted treatment; voltage

PROJECT SUMMARY The long-term objective of this proposal is to build an electrochemical atlas of organelles to guide the rational manipulation of inter-organelle contacts in the context of neurodegenerative diseases. A new mode of intracellular communication is emerging at the level of organelles, whereby the membranes of two juxtaposed organelles are physically connected, via protein-protein interactions on their cytoplasmic faces, referred to as inter-organelle contacts. Ions and small molecules are actively transferred from one organelle to the other across these contacts, traversing two sealed membranes. Inter-organelle contacts are vital to cell function, tissue homeostasis and physiology because they regulate processes ranging from lipid metabolism to apoptosis. However, we still do not know what signals initiate contact formation or what switches on chemical transport across contacts, nor can we discriminate between functional and dysfunctional contacts. Hence, although we know of specific mutations in proteins that disrupt contact, leading to diverse neurodegenerative diseases, we still do not know how to restore these contacts and treat those diseases. I posit that the electrochemical states of organelles, alone and in contact, will inform which pathways and molecules should be targeted to rectify aberrant contacts in disease states. My rationale is that, if we abstract out the molecular details, inter-organelle contacts resemble neuronal synapses. Even in synapses, ions flow on cue across two sealed, abutting membranes. Just as ion-transport mechanisms across neuronal membranes were revealed by Hodgkin and Huxley’s electrochemical model, an analogous model of organelle membranes will reveal ion flow mechanisms across inter-organelle contacts and which specific flows are impacted in disease. I propose to build an electrochemical atlas of organelles as a universal reference to study contacts in health and disease. This atlas will be a compendium of equations comprising electrochemical models of major organelles, alone and in contact. By enabling us to discriminate normal and aberrant contacts, I envisage the atlas will reveal common pathways across diseases that can be targeted to restore contacts with impacted ion flows. The inability to assay ions or voltage in organelles has prevented the development of electrochemical models of their membranes. Over the last decade, my lab developed a chemical platform to quantify ions and voltage in organelles. By integrating electrophysiology to this platform, I propose to now map out the electrochemical characteristics of organelle membranes in isolation and in contact, and make an electrochemical atlas of organelles. We will apply the atlas to elucidate how Ca2+ flow across aberrant contacts between the endoplasmic reticulum and the lysosome can be rectified to restore lysosomal Ca2+ in parkinsonism. Dysregulated lysosomal Ca2+ is a common factor across many neurodegenerative diseases and the value of the electrochemical atlas is its pioneering ability to reveal common pathways that can be targeted for treatment in a disease cross-cutting manner.

项目摘要 该建议的长期目标是建立一个细胞器的电化学地图集，以指导 在神经退行性疾病的背景下，合理地操纵轨道间接触。一种新的模式 细胞内通信正在细胞器水平上出现，从而使两个并列的膜 细胞器通过蛋白质 - 蛋白质相互作用在其细胞质面部的物理连接，称为 掌控触点。离子和小分子从一个细胞器中主动转移到另一个细胞器中 这些接触，穿越两个密封的膜。轨道间接触对细胞功能，组织至关重要 稳态和生理学是因为它们调节从脂质代谢到凋亡的过程。 但是，我们仍然不知道哪些信号启动接触形成或哪些切换化学运输 在触点之间，我们也不能区分功能和功能失调的触点。因此，尽管我们 知道破坏接触的蛋白质中的特定突变，导致潜水神经退行性疾病，我们 仍然不知道如何恢复这些联系并治疗这些疾病。 我指出，单独和联系的细胞器的电化学状态将告知哪些途径和 分子应针对纠正疾病状态的异常接触。我的理由是，如果我们抽象 淘汰分子细节，轨道间触点类似于神经元突触。即使在突触中，离子也流动 提示在两个密封的桥接机制上。就像神经元机制的离子传输机制 由霍奇金（Hodgkin）和赫兹利（Huxley）的电化学模型揭示，这是细胞器膜的类似模型 将揭示跨轨间接触的离子流动机制，以及哪些特定流动在疾病中受到影响。 我建议建立一个细胞器的电化学地图集，以此作为研究健康联系的普遍参考 疾病。该地图集将是包括主要细胞器电化学模型的方程组合， 单独和接触。通过使我们能够区分正常和异常的接触，我设想地图集将揭示 跨疾病的常见途径可以针对恢复受影响的离子流的接触。 无法分析细胞器中的离子或电压阻止了电化学的发展 其机制的模型。在过去的十年中，我的实验室开发了一个化学平台来量化离子和 细胞器中的电压。通过将电生理学集成到该平台，我建议现在绘制 细胞器膜的电化学特性隔离和接触，并进行电化学 细胞器的地图集。我们将应用地图集来阐明Ca2+如何跨越异常接触 内质网和溶酶体可以纠正以恢复帕金森氏症中的溶酶体Ca2+。 失调的溶酶体Ca2+是许多神经退行性疾病的常见因素，并且值的值 电化学地图集是其开创性的能力，可以揭示可以在A中进行治疗的公共途径 疾病交叉切割方式。