Investigating the interactions of auxillary subunits with the Nav1.5 channel

研究辅助亚基与 Nav1.5 通道的相互作用

• 批准号: 10678156
• 负责人: Lucy Summer Woodbury
• 金额: $ 4.77万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10678156
• 关键词: Action Potentials; Address; Affect; Affinity; Anti-Arrhythmia Agents; Arrhythmia; Binding; Biophysics; Calmodulin; Cardiac; Cardiac Myocytes; DNA Sequence Alteration; Data; Development; Diagnosis; Drug Interactions; Effectiveness; Electrophysiology (science); FGF12 gene; Fibroblast Growth Factor; Fluorescence Resonance Energy Transfer; Fluorometry; Goals; Heart; Heart failure; Human; Image; Individual; Ion Channel Gating; Kinetics; Lead; Left ventricular structure; Lidocaine; Machine Learning; Methods; Mexiletine; Molecular Conformation; Pathology; Patients; Pharmaceutical Preparations; Pharmacology; Pharmacotherapy; Physiological; Protein Isoforms; Protocols documentation; Regulation; Research; Scientist; Series; Sodium; Sodium Channel; Stretching; Techniques; Technology; Testing; Time; Training; Translational Research; United States; Up-Regulation; Validation; Work; clinical application; design; innovation; insight; machine learning algorithm; machine learning model; novel; patient response; programs; ranolazine; response; voltage; voltage clamp

Project Summary/Abstract Within the years 2013 to 2016, 6.2 million patients were diagnosed with heart failure in the United States. Heart failure has multiple causes, and many fatal cases include patients being predisposed to arrhythmias. One mechanism for triggering a pro-arrhythmic state are changes cardiac action potential such as the prolongation of the depolarization. The main contributor of this rapid depolarization is the ionic current supplied by the Nav1.5 voltage gated sodium channel within the human heart. In addition, there are multiple subunits that interact with the channel in a physiological setting including the subunits of intracellular fibroblast growth factor (FGF) 12A, FGF12B, and calmodulin (CaM). In preliminary data, it has been shown that FGF12A is upregulated in the left ventricle in failing hearts and that FGF12B is the most prevalent FGF isoform in the human heart. Both FGF12A, FGF12B and CaM have shown to alter the inactivation of the Nav1.5 channel through modulation of the DIII and DIV voltage sensing domains (VSD). However, there is no research as to the combined effects of these subunits and their potential to synergistically modulate the Nav1.5 VSDs. As the DIII and DIV VSDs are modulated by these proposed subunits, it can be hypothesized that the efficacy of class 1b anti-arrhythmic drugs are also affected by the proposed subunits. These preliminary findings confer to the two hypotheses: (1) combinations of modulating subunits bound to Nav1.5 can collectively alter gating to disrupt activation and inactivaiton and (2) the subunits of FGF12A, FGF12B, and CaM will alter the interaction of efficacy of class 1b anti-arrhythmic drugs. To support these hypotheses, three aims were created. Aim 1 will focus on determining the biophysical changes the combined subunits have on the Nav1.5 VSDs. The aim will be accomplished with the use of voltage clamp fluorometry to examine the changes in the activation of the individual VSDs. Aim 2 will develop a machine learning model to decipher how alterations to the VSD activations change the overall ionic current. Aim 3 will conclude the proposal by looking at changes in the effectiveness of the class 1b anti-arrhythmic drugs lidocaine, mexiletine, and ranolazine in response to varying levels of each subunit. This proposal has implications that stretch both at the biophysical understanding of the Nav1.5 channel to the clinical application in the use of specific anti-arrhythmic drugs. The overall application will provide rigorous and exemplary training for the applicant to successfully become a translation research scientist.

项目概要/摘要 2013年至2016年间，美国有620万患者被诊断患有心力衰竭 国家。心力衰竭有多种原因，许多致命病例包括患者倾向于 心律失常。触发促心律失常状态的一种机制是改变心脏动作电位，例如 去极化的延长。这种快速去极化的主要贡献者是离子电流 由人类心脏内的 Nav1.5 电压门控钠通道提供。此外，还有多个 在生理环境中与通道相互作用的亚基，包括细胞内成纤维细胞的亚基 生长因子 (FGF) 12A、FGF12B 和钙调蛋白 (CaM)。初步数据显示，FGF12A FGF12B 在衰竭心脏的左心室中表达上调，并且 FGF12B 是心脏中最常见的 FGF 亚型 人心。 FGF12A、FGF12B 和 CaM 均已显示可改变 Nav1.5 通道的失活 通过 DIII 和 DIV 电压传感域 (VSD) 的调制。然而，目前还没有研究表明 这些亚基的综合效应及其协同调节 Nav1.5 VSD 的潜力。作为 DIII 和 DIV VSD 由这些提议的亚基调节，可以假设类的功效 1b 抗心律失常药物也受到拟议亚基的影响。这些初步调查结果表明 两个假设：（1）与 Nav1.5 结合的调节亚基的组合可以共同改变门控 破坏激活和失活，并且 (2) FGF12A、FGF12B 和 CaM 的亚基将改变相互作用 1b类抗心律失常药物的疗效。为了支持这些假设，创建了三个目标。目标1将 重点是确定组合亚基对 Nav1.5 VSD 的生物物理变化。目标将 可以通过使用电压钳荧光测定法来检查激活的变化来完成 单独的 VSD。目标 2 将开发一个机器学习模型来破译 VSD 的变化 激活改变了总体离子电流。目标 3 将通过查看以下方面的变化来结束该提案 1b 类抗心律失常药物利多卡因、美西律和雷诺嗪对不同反应的有效性 每个亚基的水平。该提议的影响延伸到了对生物物理学的理解 Nav1.5通道在临床上应用到特定抗心律失常药物的使用。整体应用 将为申请人提供严格且模范的培训，使其成功成为一名翻译研究人员 科学家。