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.

项目摘要二氢吡啶敏感的L型CAV1.2和延迟整流器KV2.1通道在调节动脉平滑肌的兴奋性和收缩。 Cav1.2频道的一个显着特征是它们形成群集，在其中经历动态的相互作用，允许功能耦合邻近的通道，从而扩增Ca2+信号传导，这对于肌原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合起来解决了这个基本问题。我们实验室的新初步数据建议一个新型模型，该模型代表相对于普遍接受的规范作用的范式转移 Kv2.1和K+通道一般，仅作用于K+导电固有的电气决定因素动脉肌细胞的膜特性。在此模型中，KV2.1渠道具有增加的物理作用聚类，从而对CAV1.2通道的合作登陆。我们的数据表明 KV2.1通道微调膜电位的可分离电和结构作用，CAV1.2聚类，这些通道的功能耦合，因此CA2+流入，肌源性张力以及最终是血压。一个强调我们作品重要性的关键发现是Kv2.1表达式随性别而变化，导致雌性和男性动脉肌细胞之间的Ca2+涌入和肌原张力的显着差异。这我们的互补技能组合的结合使我们能够实施一种多尺度的系统方法涉及使用细胞，分子，生物物理，成像，基因编辑和全动物的方法严格研究控制KV2.1和CAV1.2组织的机制，以及它们如何影响细胞，器官和全身在生理条件下的功能。该项目具有三个特定的目标。目标1是确定改变Kv2.1表达水平对CAV1.2通道的聚类和活性的影响，以及动脉平滑肌和血压上的肌吻合。目标2是定义基本机制 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的自主作用及其可分离的导电和非导向函数在调节CAV1.2中功能和动脉平滑肌细胞中的肌源反应以及全身血压。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在女性与男性中受到监管。