Tuning L-Type Ca Channel Activity in Arterial Smooth Muscle by Kv Channel-Mediated Clustering

通过 Kv 通道介导的聚类调节动脉平滑肌中的 L 型 Ca 通道活性

基本信息

批准号：
10210432
负责人：
Luis F Santana
金额：
$ 50.81万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10210432
关键词：
Address Affect Animals Arteries Binding Biophysics Blood Pressure Calcium Caliber Calmodulin Cell membrane Cells Coupling Data Development Dihydropyridines Dose Electrophysiology (science)Equilibrium Feedback Female Genes Genetic Models Image Ion Channel Ions Knock-in Mouse Lead Mediating Mediator of activation protein Membrane Membrane Potentials Mesenteric Arteries Modeling Molecular Mus Muscle Cells Muscle Tonus Muscle function Optics Organ Permeability Physiological Physiology Play Potassium Channel Process Property Regulation Resistance Role Sex Differences Signal Transduction Smooth Muscle Smooth Muscle Myocytes Structure System Systemic blood pressure Tail Vascular Smooth Muscle Work constriction experimental study insight large-conductance calcium-activated potassium channels male mutant novel pressure response sensor sex skills spatial relationship voltage

项目摘要

Project Summary Dihydropyridine-sensitive, L-type Cav1.2 and delayed rectifier Kv2.1 channels play critical roles in the regulation of excitability and contraction in arterial smooth muscle. A salient feature of Cav1.2 channels is that they form clusters within which they undergo dynamic, reciprocal interactions that allow functional coupling of adjacent channels and thus amplification of Ca2+ signaling, which is critical to the development of myogenic tone. At present, however, the mechanisms controlling Cav1.2 clustering are unknown. The Trimmer and Santana labs have joined forces to address this fundamental issue. New preliminary data from our labs suggest a novel model that represents a paradigm shift relative to the generally accepted canonical role of Kv2.1, and K+ channels in general, as acting solely as K+ conducting electrical determinants of the intrinsic membrane properties of arterial myocytes. In this model, the Kv2.1 channel has a physical role to increase clustering and thus cooperative gating of Cav1.2 channels. Our data indicate that the balance between the separable electrical and structural roles of Kv2.1 channels fine tunes membrane potential, Cav1.2 clustering, functional coupling of these channels, and hence Ca2+ influx, myogenic tone, and, ultimately, blood pressure. A key finding that underscores the significance of our work is that Kv2.1 expression varies with sex, leading to significant differences in Ca2+ influx and myogenic tone between female and male arterial myocytes. The combination of our complementary skill sets allows us to implement a multi-scale systems approach that involves the use of cellular, molecular, biophysical, imaging, gene editing and whole-animal approaches to rigorously investigate the mechanisms controlling Kv2.1 and Cav1.2 organization, and how they impact cell, organ, and whole-body functions under physiological conditions. The project has three specific aims. Aim 1 is to determine the impact of altered Kv2.1 expression levels on clustering and activity of Cav1.2 channels, and myogenic tone in arterial smooth muscle, and on blood pressure. Aim 2 is to define the mechanisms underlying Kv2.1-mediated regulation of Cav1.2 function. Finally, Aim 3 is to use novel genetic models to define the cell autonomous role of Kv2.1, and its separable conducting and non-conducting functions, in regulating Cav1.2 function, and the myogenic response in arterial smooth muscle cells, and systemic blood pressure. The proposed studies have the potential of transforming our understanding of how ion channels are organized in vascular smooth muscle, and provide insights into how arterial diameter and blood pressure are differentially regulated in females versus males.

项目概要二氢吡啶敏感的 L 型 Cav1.2 和延迟整流 Kv2.1 通道在调节动脉平滑肌的兴奋性和收缩性。 Cav1.2通道的一个显着特点是它们形成簇，在簇内进行动态的、相互的相互作用，从而允许功能耦合相邻通道，从而放大 Ca2+ 信号传导，这对于肌源性的发展至关重要语气。然而目前，控制 Cav1.2 聚类的机制尚不清楚。修剪器和桑塔纳实验室联手解决这一根本问题。我们实验室的新初步数据提出了一种新颖的模型，该模型代表了相对于普遍接受的规范角色的范式转变 Kv2.1 和一般 K+ 通道，仅充当本征的 K+ 传导电决定因素动脉肌细胞的膜特性。在该模型中，Kv2.1通道具有物理作用以增加聚类，从而对 Cav1.2 通道进行协作门控。我们的数据表明，两者之间的平衡 Kv2.1 通道可分离的电学和结构作用微调膜电位、Cav1.2 聚类、这些通道的功能耦合，从而产生 Ca2+ 流入、肌源性张力，并最终影响血压。一个强调我们工作重要性的关键发现是 Kv2.1 表达随性别而变化，导致女性和男性动脉肌细胞之间 Ca2+ 流入和肌原性张力存在显着差异。这我们互补的技能组合的结合使我们能够实施多尺度系统方法，涉及使用细胞、分子、生物物理、成像、基因编辑和整体动物方法严格研究控制 Kv2.1 和 Cav1.2 组织的机制，以及它们如何影响细胞，生理条件下的器官和全身功能。该项目有三个具体目标。目标 1 是确定改变的 Kv2.1 表达水平对 Cav1.2 通道的聚类和活性的影响，以及动脉平滑肌的肌源性张力和血压。目标 2 是定义底层机制 Kv2.1 介导的 Cav1.2 功能调节。最后，目标 3 是使用新颖的遗传模型来定义细胞 Kv2.1 在调节 Cav1.2 中的自主作用及其可分离的传导和非传导功能功能、动脉平滑肌细胞的生肌反应以及全身血压。这拟议的研究有可能改变我们对离子通道如何组织的理解血管平滑肌，并提供有关动脉直径和血压如何差异的见解与男性相比，女性受到监管。