Evaluating NAD Supplementation as a Novel Treatment for Arrhythmias

评估 NAD 补充剂作为心律失常的新型治疗方法

基本信息

批准号：
10381462
负责人：
Charles M Brenner
金额：
$ 58.26万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10381462
关键词：
Acetylation Action Potentials Affect Arrhythmia Binding Binding Proteins Bioenergetics Brugada syndrome Cardiac Cardiac Myocytes Cell Line Cell membrane Cells Characteristics DNA Damage Data Deacetylation Dihydroxyacetone Phosphate Dilated Cardiomyopathy Disease Dose Electrocardiogram Electrophysiology (science)Engineering Enzymes Gel Genes Genetic Transcription Glycerol-3-Phosphate Dehydrogenase Goals Heart Heart Atrium Heart failure In Vitro Inherited Ion Channel Laboratories Mediating Membrane Metabolic Metabolism Mus Muscle Cells Mutation Myocardial NADH Neonatal Niacinamide Oxidation-Reduction Oxidative Phosphorylation Oxidoreductase Pharmacology Phosphorylation Play Poly(ADP-ribose) Polymerases Post-Translational Protein Processing Predisposition Property RNA Splicing Rattus Reactive Oxygen Species Reporting Role SIRT1 gene Signal Transduction Sirtuins Sodium Sodium Channel Structure Sudden Death Sudden infant death syndrome Supplementation Syndrome System Testing Translations age related alpha Actinin alpha-glycerophosphoric acid dietary in vivo inhibitor inorganic phosphate loss of function mutation metabolome mouse model nicotinamide riboside supplementation nicotinamide-beta-riboside novel prevent response trafficking treatment effect

项目摘要

The inward depolarizing Na+ current (INa) through the cardiac Na+ channel Nav1.5, encoded by SCN5A, plays a critical role in regulating the action potential of myocytes in the heart. Nav1.5 post- translational modifications (PTMs) and binding proteins can alter channel abundance and/or electrophysiological properties. Loss of function mutations in SCN5A cause inherited arrhythmia syndromes including Brugada syndrome (BrS) and conduction system disease by changes in transcription, translation, channel properties and membrane trafficking. Alterations in Nav1.5 can also exacerbate arrhythmias in common acquired conditions such as heart failure. NAD+ and NADH are critical regulators of myocardial bioenergetics and redox state, and NAD+ is a required substrate for sirtuins that regulate acetylation. Our laboratory reported that mutations in the NAD+/NADH dependent enzyme Gylcerol-3 Phosphate Dehydrogenase-1 Like (GPD1-L) cause BrS by altering Nav1.5 membrane trafficking. We and others then showed that NAD+ increases INa in cell lines and cardiac myocytes, at least in part through changes in reactive oxygen species (ROS) and PKC- mediated phosphorylation in the intracellular Nav1.5 Domain III-IV linker. We have engineered Gpd1l- targeted mice that have decreased INa, conduction disease, arrhythmias and altered Nav1.5 PTMs. Nicotinamide Riboside (NR), a highly bioavailable NAD+ precursor, increases INa in heterologous expression systems and myocytes, and shortens QRS duration in mice. The mechanism(s) by which NAD+ supplementation alters Nav1.5 membrane trafficking and INa remains unclear. In addition, how multiple PTMs alter Nav1.5 and INa in a coordinated manner has not been studied. The central hypothesis of this proposal is that cellular metabolism alters the NAD+ metabolome, regulating Nav1.5 by coordinated interactions of PTMs and binding proteins that act at the Nav1.5 Domain III-IV linker. To test this hypothesis, we will 1) Determine how NAD+ precursors and inhibitors modify the NAD+ metabolome, redox state, Nav1.5 PTMs, INa and arrhythmias using cardiac myocytes and mouse models; 2) Determine whether NAD+ precursors act in a coordinated manner at the Nav1.5 Domain III-IV linker via SIRT1-mediated deacetylation, PKC-mediated phosphorylation and α-actinin 2 binding; and 3) Identify the Nav1.5 PTMs modulated by GPD1-L. The primary goal of this proposal is to identify the mechanisms by which NAD+ metabolism affects Nav1.5 expression and function. Ultimately, we hope to determine whether increasing membrane Nav1.5 with NAD+ precursors or other metabolic modulators can prevent arrhythmias in inherited Na+ channel deficiency syndromes and in more common conditions such as heart failure.

通过心脏 Na+ 通道 Nav1.5 的内向去极化 Na+ 电流 (INa)，编码为 SCN5A 在调节 Nav1.5 后心脏肌细胞的动作电位中发挥着关键作用。翻译修饰 (PTM) 和结合蛋白可以改变通道丰度和/或 SCN5A 功能突变导致遗传性心律失常。综合症，包括布鲁格达综合症（BrS）和传导系统疾病 Nav1.5 中的转录、翻译、通道特性和膜运输也可能发生改变。在心力衰竭等常见获得性疾病中加剧心律失常。 NAD+和NADH是心肌生物能和氧化还原状态的关键调节因子，NAD+是心肌生物能和氧化还原状态的重要调节因子。我们的实验室报告了调节乙酰化的去乙酰化酶所需的底物。 NAD+/NADH 依赖性酶 Gylcerol-3 磷酸脱氢酶 1 样 (GPD1-L) 通过以下方式引起 BrS 然后我们和其他人发现 NAD+ 会增加细胞系中的 INa。和心肌细胞，至少部分是通过活性氧 (ROS) 和 PKC- 的变化介导的细胞内 Nav1.5 结构域 III-IV 连接子的磷酸化我们设计了 Gpd1l-。针对 INa 降低、传导疾病、心律失常和 Nav1.5 PTM 改变的小鼠。烟酰胺核苷 (NR) 是一种高生物利用度的 NAD+ 前体，可增加异源体内的 INa 表达系统和肌细胞，并缩短小鼠的 QRS 持续时间。 NAD+ 补充剂如何改变 Nav1.5 膜运输和 INa 仍不清楚。尚未研究多个 PTM 以协调的方式改变 Nav1.5 和 INa。该提案的中心假设是细胞代谢改变 NAD+ 代谢组，通过 PTM 和作用于 Nav1.5 的结合蛋白的协调相互作用来调节 Nav1.5 为了检验这一假设，我们将 1) 确定 NAD+ 前体和抑制剂的作用。使用心肌细胞修改 NAD+ 代谢组、氧化还原状态、Nav1.5 PTM、INa 和心律失常和小鼠模型；2) 确定 NAD+ 前体是否在 Nav1.5 中以协调的方式起作用通过 SIRT1 介导的脱乙酰化、PKC 介导的磷酸化和 α-肌动蛋白 2 实现结构域 III-IV 连接子结合；和 3) 识别 GPD1-L 调节的 Nav1.5 PTM。该提案的主要目标是确定 NAD+ 代谢影响的机制最终，我们希望确定Nav1.5的表达和功能是否增加。 Nav1.5 与 NAD+ 前体或其他代谢调节剂可以预防遗传性 Na+ 的心律失常通道综合症缺乏以及心力衰竭等更常见的情况。