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

冠状动脉疾病的发病机制是复杂的，多种细胞类型有助于病变的大小 和组成。急性冠状动脉综合征最常与复杂的， 脆弱的斑块，否则临床上是良性的。无论是相对良性的， 稳定的病变或易破裂的易损斑块与关键病变特征有关，即， 平滑肌（SM）和胶原蛋白含量，巨噬细胞浸润和坏死核心区域内 损伤。本提案的目标是：1）确定工作人员-管理层的具体作用和基本职能; 中间电导，Ca 2+激活的K+通道，KCa3.1（由 Kcnn 4）决定动脉粥样硬化病变的形成和组成，2）确定翻译的 临床批准的KCa3.1抑制剂在大型哺乳动物模型中对病变发展的潜力 冠状动脉疾病（CAD）。作为支持，我们提供了第一个因果关系的遗传证据 KCa 3.1与病变大小和SM与巨噬细胞募集之间的关系。总的假设是， KCa3.1激活增加SM和巨噬细胞向内膜的迁移并促成损伤 阵相反，通过基因沉默或抑制KCa3.1， 动脉粥样硬化病变大小和有益地改变组成。目标1将决定 KCa3.1在平滑肌中参与动脉粥样硬化病变的形成和组成。具体来说，我们将使用 SM特异性、诱导型KO小鼠，以检查KCa 3.1在确定斑块大小、组成 和基因表达。目标2将定义上游（REST）和下游（DOCK 2）机制 测定KCa 3.1对SM和动脉粥样硬化的作用。我们将用转基因老鼠 检查REST和DOCK 2在介导KCa 3.1对表型，增殖， 迁移、斑块大小和组成。此外，我们将使用RNA测序来鉴定新的 KCa3.1介导的动脉粥样硬化形成机制。我们将在Aim 3中使用VSM血统跟踪， 采用SM谱系追踪法检测SMC-KCa 3.1在介导SMC内膜向中膜迁移中的作用 和泡沫细胞转分化。最后，Aim 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 在猪CAD模型中。我们纵向跟踪冠状动脉疾病的进展， 在家族性高胆固醇血症（FH）猪中进行血管造影和IVUS，以检测KCa 3.1抑制能力 与senicapoc，以减少冠状动脉病变的大小和促进更有利的组成。 长期目标是为转化当前的治疗工具提供临床前基础， 开发靶向KCa3.1和/或下游信号传导的下一代药物， 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.