Cell-specific role and therapeutic potential of KCa3.1 in atherosclerosis

冠状动脉疾病的发病机制很复杂，多种细胞类型对病变大小有影响 和构图。急性冠脉综合征最常与复合体破裂有关， 脆弱的斑块，在其他方面临床上是良性的。进展到相对良性的， 稳定的病变或容易破裂、脆弱的斑块与关键病变特征有关，即 血管内平滑肌(SM)和胶原含量、巨噬细胞浸润和坏死核心区 损伤。本提案的目标是：1)确定SM特定的角色和基础 中间电导，钙激活K+通道，KCa3.1(编码为 Kcnn4)，指示动脉粥样硬化病变的形成和成分，以及2)确定翻译 临床批准的KCa3.1抑制剂在大型哺乳动物风湿性心脏病模型病变发展中的潜力 冠状动脉疾病。作为支持，我们提供了第一个因果联系的遗传证据 KCa3.1与病变大小、SM和巨噬细胞募集之间的关系。总体假设是 KCa3.1的激活增加了SM和巨噬细胞向内膜的迁移，并参与了损伤 队形。相反，无论是通过基因沉默还是通过药物作用，阻断KCa3.1都会减少 动脉粥样硬化病变的大小和有益的改变成分。目标1将确定以下方面的贡献 KCa3.1在平滑肌中以动脉粥样硬化病变的形成和组成为主。具体地说，我们将使用 SM特异的、可诱导的KO小鼠研究KCa3.1在确定斑块大小、组成 和基因表达。目标2将定义上行(REST)和下行(DOCK2)机制 测定KCa3.1对SM和动脉粥样硬化的影响。我们将利用转基因小鼠 研究REST和DOCK2在介导KCa3.1对表型、增殖、 迁移，斑块大小和成分。此外，我们将使用RNA测序来鉴定新的 KCa3.1对动脉粥样硬化形成机制的影响我们将在AIM 3中使用VSM沿袭跟踪 用SM谱系追踪确定SMC-KCa3.1在SMC内膜向中膜迁移中的作用 以及动脉粥样硬化病变发展过程中泡沫细胞的转分化。最后，目标4将 确定FDA批准的KCa3.1抑制剂senicapoc对动脉粥样硬化发展的影响 在CAD的猪模型中。我们使用以下工具纵向跟踪冠状动脉疾病进展 家族性高胆固醇血症猪血管造影和血管内超声检测KCa3.1抑制能力 有了Senicapoc，可以缩小冠状动脉病变的大小，促进更有利的成分。 长期目标是提供临床前的基础，以转化现有的治疗工具和 开发以KCa3.1和/或下游信号为靶点的下一代药物 操纵动脉粥样硬化病变成分。

Pathogenesis of coronary artery disease is complex, with multiple cell types contributing to lesion size and composition. Acute coronary syndromes are most often associated with rupture of complex, vulnerable plaques that are otherwise clinically benign. The progression to either a relatively benign, stable lesion or a rupture-prone, vulnerable plaque has been linked to key lesion characteristics, i.e. smooth muscle (SM) and collagen content, macrophage infiltration and necrotic core area within the lesion. The objectives of this proposal are to 1) determine the SM-specific role and underlying mechanism(s) by which the intermediate conductance, Ca2+-activated K+ channel, KCa3.1 (encoded by Kcnn4), dictates atherosclerotic lesion formation and composition and 2) determine the translational potential of clinically approved KCa3.1 inhibitors on lesion development in a large mammal model of coronary artery disease (CAD). In support, we provide the first genetic evidence of a causal link between KCa3.1 and lesion size and SM and macrophage recruitment. The overall hypothesis is that KCa3.1 activation increases migration of SM and macrophages into the intima and contributes to lesion formation. Conversely, blocking KCa3.1, both by genetic silencing or pharmacologically, will decrease atherosclerotic lesion size and beneficially alter composition. Aim 1 will determine the contribution of KCa3.1 in smooth muscle to atherosclerotic lesion formation and composition. Specifically, we will use SM-specific, inducible KO mice to examine the role of KCa3.1 in determining plaque size, composition and gene expression. Aim 2 will define both upstream (REST) and downstream (DOCK2) mechanisms determining KCa3.1 effects on SM and atherosclerosis. We will use genetically modified mice to examine the role of REST and DOCK2 in mediating SM effects of KCa3.1 on phenotype, proliferation, migration, plaque size and composition. In addition, we will use RNA sequencing to identify novel mechanisms of atherosclerosis development by KCa3.1. We will use VSM lineage-tracking in Aim 3 will use SM lineage-tracking to determine role of SMC-KCa3.1 in mediating SMC intimal to medial migration and foam cell transdifferentiation during atherosclerotic lesion development. Finally, Aim 4 will determine the effect of the FDA approved KCa3.1 inhibitor, senicapoc, on atherosclerosis development in a swine model of CAD. We longitudinally track coronary artery disease progression using angiography and IVUS in familial hypercholesterolemic (FH) swine to test the ability of KCa3.1 inhibition with senicapoc, to decrease the size and promote a more favorable composition of coronary lesions. The long-term goal is to provide the pre-clinical foundation for translating current therapeutic tools and developing the next generation drugs targeting KCa3.1 and/or downstream signaling to beneficially manipulate atherosclerotic lesion composition.