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Twik-2钾通道在血管平滑肌中的功能。Twik-2是新发现的双孔结构域钾通道家族(K2P)的成员。虽然它在全身的许多组织中都有表达，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。本着R21拨款的精神，这项建议涉及“探索性和发展性研究”，处于确定twik-2在血管平滑肌中的作用的“早期和概念性阶段”。由于twik-2没有选择性的激活剂或抑制物，我们通过删除第一个编码外显子的方法获得了twik-2基因敲除小鼠。该外显子包含起始密码子和部分孔区。这项建议的目的是利用我们的twik-2基因敲除小鼠模型来确定twik-2在血管平滑肌中的作用。钾通道参与血管内径的调节、渗透应激时的容量调节以及细胞的凋亡、增殖和迁移。我们将针对Twik-2在这些过程中的以下具体目标进行讨论：在特定目标1中，我们将确定Twik-2是否参与血管直径的调节。在特定的目标2中，我们将确定Twik-2是否参与血管平滑肌的容量调节。K通道激活引起的体积变化发生在细胞凋亡或渗透应激过程中。在具体目标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基因敲除小鼠中使用组合技术来测量血管平滑肌功能和电特性的差异。Twik-2是一种潜在的新的和重要的血管功能调节因子。我们的研究应该为未来的研究提供必要的基础，以确定Twik-2在病理过程中的作用。 与公众健康相关：钾通道参与正常的生理过程，在病理条件下可能会变得功能失调。Twik-2是一种新发现的钾通道，在动脉中高度表达。Twik-2的功能目前尚不清楚。这项拟议的研究将调查Twik-2在动脉中的功能作用。了解Twik-2在动脉中的作用将有助于理解血流和血压的调节。在病理状态下，Twik-2可能是治疗操作的主要靶点。

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.