K+ Channel Trafficking and Modulation by Mink and MiRP1

Mink 和 MiRP1 的 K 通道传输和调制

• 批准号: 8258269
• 负责人: Geoffrey W Abbott
• 金额: $ 42.85万
• 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/8258269
• 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 Delivery Systems; 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. PUBLIC HEALTH RELEVANCE: Specific potassium channels govern cardiac repolarization to end each heart-beat in a timely fashion; inherited gene variants in the genes that encode potassium channels, including KCNQ1, KCNE1 and KCNE2, cause lethal cardiac arrhythmias in man. Atrial fibrillation, which afflicts 2.5 million people in the United States, can be caused by mutation in these genes but is more commonly associated with aging and some surgical procedures. Our proposal is designed to determine the mechanistic role of potassium channels in the atrium, focusing primarily on KCNE2, and uncover molecular events leading up to dysfunction of KCNE2 in inherited and acquired forms of atrial fibrillation, in order to facilitate future antiarrhythmic therapy and prevention strategies.

描述（由申请人提供）：电压门控钾（Kv）通道抑制可兴奋细胞，如心肌细胞。心肌细胞Kv通道的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有何差异。目前的建议借鉴了我们前十年的工作克隆和定义不同的生理作用的KCNE家族成员的单跨膜结构域Kv通道辅助亚基。根据我们先前的发现，KCNE 2突变与遗传性和获得性人类室性心律失常相关，最近我们产生了kcne 2（-/-）小鼠系，并使用它来确定KCNE 2在成年小鼠心室中的主要作用-调节两个Kv通道及其天然电流相关性：Kv4.2（Ito，f）和Kv1.5（IK，slow 1）。我们还定义了一个新的角色KCNE 1，作为一个内吞伴侣的KCNQ 1的a亚基，并发现，KCNE 1和KCNE 2可以影响功能性Kv通道的a亚基组成。 KCNQ 1、KCNE 1和KCNE 2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，可能使其成为心房抗房颤的有用靶点。大多数形式的AF没有已知的遗传基础，并与其他因素相关，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和年龄发作或手术后（获得性）形式的AF，对于改善人类心脏健康至关重要。在这里，我们建议确定KCNE 2在心房生理学和AF的病因学中的作用，利用kcne 2（-/-）小鼠（表现出起搏诱导的AF），兔和猪术后AF模型，人类心房组织的验证性实验，以及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KCNE 2调节哪些心房Kv复合物，其遗传破坏如何导致AF和Kv通道重塑，这些机制如何反映较大动物术后AF，以及Sp1，miR-1和miR-133在这种重塑中的作用。其次，我们将使用电生理学/计算机建模方法来确定KCNE 2在小鼠和兔心房中的功能，比较KCNE 2基因破坏和术后AF引起的细胞功能效应，并从细胞到组织水平模拟由此产生的心律失常的机制基础。第三，我们将确定KCNE 2，Kv1.5和闰盘（ID）之间的关系，并确定为什么KCNE 2中断阻止Kv1.5 ID在小鼠心室靶向，而不是心房。 公共卫生关系：特定的钾离子通道控制心脏复极，以及时结束每次心跳;编码钾离子通道的基因中的遗传基因变异，包括KCNQ 1，KCNE 1和KCNE 2，会导致人类致命的心律失常。在美国，有250万人患有心房颤动，可能是由这些基因突变引起的，但更常见的是与衰老和一些外科手术有关。我们的建议旨在确定钾通道在心房中的机制作用，主要集中在KCNE 2上，并揭示导致KCNE 2在遗传性和获得性房颤中功能障碍的分子事件，以促进未来的抗心律失常治疗和预防策略。