Function of Two-Pore Domain K Channels in Vascular Smooth Muscle

描述（由申请人提供）：这是一项探索性拨款提案，旨在确定血管平滑肌中TWIK-2钾通道的功能。TWIK-2是新发现的“双孔域”钾通道家族（K2P）的成员。虽然它在全身的许多组织中表达，但TWIK-2在血管组织中尤其丰富。TWIK-2在动脉或任何其他组织中的功能尚不清楚。在R21资助的精神下，该提案涉及确定TWIK-2在血管平滑肌中的作用的“早期和概念阶段”的“探索性和发展性研究”。由于TWIK-2没有选择性的激活剂或抑制剂，我们通过删除第一个编码外显子制作了TWIK-2敲除小鼠。这个外显子包含起始密码子和一部分孔区。这项提议的目的是利用我们的TWIK-2敲除小鼠模型来确定TWIK-2在血管平滑肌中的作用。钾离子通道在渗透胁迫和细胞凋亡、增殖和迁移过程中参与血管直径的调节、体积调节。在这些过程中，我们将讨论以下关于TWIK-2的具体目标：在specific Aim 1中，我们将确定TWIK-2是否参与血管直径的调节。在Specific Aim 2中，我们将确定TWIK-2是否参与血管平滑肌的体积调节。在细胞凋亡或渗透胁迫过程中，由于K通道激活而引起的体积变化。在Specific Aim 3中，我们将确定TWIK-2是否参与血管平滑肌的增殖和/或迁移。我们将在野生型和TWIK-2敲除小鼠中结合使用技术来测量血管平滑肌功能和电学特性的差异。TWIK-2是一种潜在的、重要的血管功能调节剂。我们的研究为进一步研究TWIK-2在病理过程中的作用提供了必要的基础。

DESCRIPTION (provided by applicant): This is an exploratory grant proposal directed at determining the function of the TWIK-2 potassium channel in vascular smooth muscle. TWIK-2 is a member of a newly discovered "Two-Pore Domain" potassium channel family (K2P). While it is expressed in a number of tissues throughout the body, TWIK-2 is particularly enriched in vascular tissue. The function of TWIK-2 in arteries or any other tissue is not known. In the spirit of the R21 Grant, this proposal involves "exploratory and developmental research" in the "early and conceptual stages" of determining the role of TWIK-2 in vascular smooth muscle. Since there are no selective activators or inhibitors for TWIK-2, we have made a TWIK-2 knockout mouse by deleting the first coding exon. This exon contains the start codon and a portion of the pore region. The goal of this proposal is to determine the role of TWIK-2 in vascular smooth muscle using our TWIK-2 knockout mouse model. Potassium channels are involved with the regulation of vascular diameter, volume regulation during osmotic stress and apoptosis, proliferation, and migration. We will address the following specific aims regarding TWIK-2 in these processes: In Specific Aim 1, we will determine if TWIK-2 is involved with the regulation of vascular diameter. In Specific Aim 2, we will determine if TWIK-2 is involved with volume regulation in vascular smooth muscle. Changes in volume as a result of K channel activation occur during apoptosis or osmotic stress. In Specific Aim 3, we will determine if TWIK-2 is involved with proliferation and/or migration of vascular smooth muscle. We will use a combination of techniques in wild type and TWIK-2 knockout mice to measure differences in function and electrical properties of vascular smooth muscle. TWIK-2 is a potentially novel and significant regulator of vascular function. Our studies should provide the essential foundation for future studies to determine the role of TWIK-2 in pathological processes. PUBLIC HEALTH RELEVANCE: Potassium channels are involved with normal physiological processes and can become dysfunctional during pathological conditions. TWIK-2, a newly discovered potassium channel, is highly expressed in arteries. The function of TWIK-2 is not presently known. The proposed research will investigate the functional role of TWIK-2 in arteries. An understanding of the role for TWIK-2 in arteries will help in understanding the regulation of blood flow and blood pressure. TWIK-2 could be a major target for therapeutic manipulation during pathological states.