K+ Channel Trafficking and Modulation by Mink and MiRP1

Mink 和 MiRP1 的 K 通道传输和调制

• 批准号: 8589064
• 负责人: Geoffrey W Abbott
• 金额: $ 5.09万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-04 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8589064
• 关键词: Actins; Action Potentials; Address; Adult; Age; Age of Onset; Aging; Animals; Anti-Arrhythmia Agents; Arrhythmia; Atrial Fibrillation; Biochemistry; Cadherins; Cardiac; Cardiac Myocytes; Cells; Cloning; Complex; Computer Simulation; Confocal Microscopy; Connexin 43; Data; Development; Drug Targeting; Dynamin; Electron Microscopy; Electrophysiology (science); Endocytosis; Etiology; Event; Excision; Exhibits; Family; Family suidae; Functional disorder; Funding; Future; Gap Junctions; Genes; Genetic; Genetic Variation; Goals; Health; Heart; Heart Atrium; Hereditary Disease; Human; Incidence; Inherited; Intercalated disc; Life; Link; Lung; Mediating; Messenger RNA; MicroRNAs; Mink; Modeling; Molecular; Molecular Chaperones; Mus; Muscle; Muscle Cells; Mutation; Operative Surgical Procedures; Oryctolagus cuniculus; Pathology; Patients; Physiological; Physiology; Postoperative Period; Potassium; Potassium Channel; Prevention strategy; Protein Chemistry; Proteins; Regulation; Role; Simulate; Staging; Testing; Tissues; Transmembrane Domain; United States; Variant; Ventricular; Ventricular Arrhythmia; Work; base; design; improved; man; member; multi-scale modeling; patch clamp; prevent; public health relevance; research study; stem; trafficking; voltage

DESCRIPTION (provided by applicant): Voltage-gated potassium (Kv) channels repolarize excitable cells such as cardiac myocytes. Dysfunction of cardiac myocyte Kv channels causes life-threatening cardiac arrhythmias, but these channels are also useful antiarrhythmic drug targets. Thus, it is essential to understand their function, regulation and molecular composition, and determine how these differ regionally and between species. The current proposal draws from our preceding decade of work on cloning and defining the diverse physiological roles of members of the KCNE family of single- transmembrane-domain Kv channel ancillary subunits. Following our previous findings that KCNE2 mutations associate with inherited and acquired human ventricular arrhythmias, more recently we generated the kcne2 (-/-) mice line and used it to determine the primary roles of KCNE2 in adult murine ventricles - modulation of two Kv channels and their native current correlates: Kv4.2 (Ito,f) and, unexpectedly, Kv1.5 (IK,slow1). We also defined a new role for KCNE1, as an endocytic chaperone of the KCNQ1 a subunit, and found that both KCNE1 and KCNE2 can influence the a subunit composition of functional Kv channels. KCNQ1, KCNE1 and KCNE2 mutations associate with both atrial and ventricular arrhythmias. Kv1.5 mutations associate with atrial fibrillation (AF), and its function is relatively atrial-specific in human heart, potentially making it a useful target for atrial antiarrhythmics. Most forms of AF have no know genetic basis, and correlate with other factors such as aging, or following surgery to the heart or lungs. A fuller understanding of the native physiology of all these Kv subunits, and how they contribute to both inherited, and age-onset or post-surgery (acquired) forms of AF, is important to improving human cardiac health. Here, we propose to determine the roles of KCNE2 in atrial physiology and in the etiology of AF, utilizing kcne2 (-/-) mice (which exhibit pacing-induced AF), rabbit and swine models of post-operative AF, confirmatory experiments with human atrial tissue, and in silico multiscale atrial models. The studies comprise three Specific Aims. First, we will use a molecular approach to determine which atrial Kv complexes KCNE2 regulates, how its genetic disruption causes AF and Kv channel remodeling, how these mechanisms mirror post-operative AF in larger animals, and the role of Sp1, miR-1 and miR-133 in this remodeling. Second, we will use an electrophysiology/computer modeling approach to determine the function of KCNE2 in mouse and rabbit atria, compare the cellular functional effects arising from kcne2 genetic disruption and post-operative AF, and simulate the mechanistic basis for the resultant arrhythmias, from the cellular to the tissue level. Third, we will define the relationship between KCNE2, Kv1.5, and the intercalated discs (IDs), and determine why KCNE2 disruption prevents Kv1.5 ID targeting in the murine ventricles but not atria.

描述（由申请人提供）：电压门控钾（Kv）通道使可兴奋细胞（例如心肌细胞）重新极化。心肌细胞 Kv 通道功能障碍会导致危及生命的心律失常，但这些通道也是有用的抗心律失常药物靶点。因此，有必要了解它们的功能、调节和分子组成，并确定这些在区域和物种之间的差异。当前的提案借鉴了我们过去十年对单跨膜域 Kv 通道辅助亚基 KCNE 家族成员的克隆和定义不同生理作用的工作。根据我们之前的发现，KCNE2 突变与遗传性和获得性人类室性心律失常相关，最近我们生成了 kcne2 (-/-) 小鼠品系，并用它来确定 KCNE2 在成年小鼠心室中的主要作用 - 两个 Kv 通道的调节和它们的原生电流相关：Kv4.2 (Ito,f) 和 Kv1.5 (IK,slow1)。我们还定义了 KCNE1 的新角色，作为 KCNQ1 a 亚基的内吞伴侣，并发现 KCNE1 和 KCNE2 都可以影响功能性 Kv 通道的 a 亚基组成。 KCNQ1、KCNE1 和 KCNE2 突变与房性和室性心律失常相关。 Kv1.5 突变与心房颤动 (AF) 相关，其功能在人类心脏中相对具有心房特异性，可能使其成为房性抗心律失常药物的有用靶点。大多数形式的房颤没有已知的遗传基础，并且与其他因素相关，例如衰老或心脏或肺部手术后。更全面地了解所有这些 Kv 亚基的天然生理学，以及它们如何促进遗传性、年龄发病或手术后（获得性）形式的 AF，对于改善人类心脏健康非常重要。在这里，我们建议利用 kcne2 (-/-) 小鼠（表现出起搏诱导的 AF）、术后 AF 的兔和猪模型，通过验证实验来确定 KCNE2 在心房生理学和 AF 病因学中的作用。人类心房组织和计算机多尺度心房模型。这些研究包括三个具体目标。首先，我们将使用分子方法来确定 KCNE2 调节哪些心房 Kv 复合物、其基因破坏如何导致 AF 和 Kv 通道重塑、这些机制如何反映大型动物术后 AF 的情况，以及 Sp1、miR-1 和miR-133参与了这种重塑。其次，我们将使用电生理学/计算机建模方法来确定 KCNE2 在小鼠和兔子心房中的功能，比较 kcne2 基因破坏和术后 AF 引起的细胞功能效应，并模拟由此产生的心律失常的机制基础，从细胞水平到组织水平。第三，我们将定义 KCNE2、Kv1.5 和闰盘 (ID) 之间的关系，并确定为什么 KCNE2 破坏会阻止 Kv1.5 ID 靶向小鼠心室而不是心房。