Novel Approach to Stabilize Atherosclerotic Plaque in Carotid Artery

摘要 不稳定/脆弱的斑块，其特征是薄帽状纤维动脉粥样硬化，因脂池而导致核心坏死 通过巨噬细胞，可能导致严重的临床情况，包括短暂性脑缺血发作，中风，失语症， 以及其他马达缺陷。斑块血管平滑肌细胞(VSMCs)炎症和凋亡 细胞外基质降解增加是斑块不稳定的主要原因。 尽管进行了广泛的研究，但易损斑块启动的致病因素(S)尚不清楚。基座 根据我们的新发现，我们假设脂多糖(LPS)或最低限度的oxLDL诱导 易损/不稳定颈动脉斑块及拮抗TREM-1和TLR4稳定动脉粥样硬化 颈动脉有斑块。这些研究将在动脉粥样硬化的尤卡坦小型猪模型中进行。 颈动脉闭塞，类似于人类的闭塞性颈动脉疾病。这款车型将 模拟颈动脉疾病患者的真实情况，从而将对 了解疾病过程的病理生理学，并使我们能够开发更好的治疗方法 稳定易损斑块的方法。目标1：该假说预测， 动脉粥样硬化尤卡坦猪颈动脉内皮细胞内脂蛋白或低密度脂蛋白诱导 颈动脉斑块样人不稳定斑块的组织学、形态和生化特征 通过增加巨噬细胞TREM-1、MMP1、MMP9、TLR4和M1的表达，降低巨噬细胞 胶原、Trem-2和M2巨噬细胞。我们将探讨脂多糖诱导的斑块不稳定性的影响。 灰阶和多普勒超声、光学相干断层扫描与组织学、免疫组织化学 免疫荧光分析纤维帽变薄、炎症、坏死核、内膜增生 泡沫状巨噬细胞、VSMCs凋亡、脂核、坏死、斑块内出血和血管 改建。这些发现将在稳定和不稳定的颈动脉斑块中进行体内和体外的比较。 我们还将检测和比较TREM-1、TREM-2、TREM-2、 基质金属蛋白酶-1、基质金属蛋白酶-9、I型胶原(α1)、III型胶原(α1)、M1-M2巨噬细胞、VSMC、表达及相互作用 与TREM-1联合应用的TLRs，除了TREM-1对泡沫细胞形成、炎症释放的影响外 细胞因子，以及VSMCs和巨噬细胞之间的相互作用。目标2：假设预测 给予TREM-1和TLR4拮抗剂将防止不稳定斑块的发展 在动脉粥样硬化猪的颈动脉。抑制性TREM-1多肽LR12的作用 多肽(安慰剂)和TLR4拮抗剂TAK-242将在下列情况下在颈动脉进行检查 脂多糖/oxLDL给药。此外，还将检查体内和体外的功能/生化参数。 这项研究的发现将证实TREM-1是否是治疗干预和 扩展知识以开发更好的分子来对抗TREM-1并设计I期临床试验。

ABSTRACT Unstable/vulnerable plaques, that are characterized by a thin cap fibroatheroma, necrotic core due to lipid pools by macrophages, may result in serious clinical conditions, including transient ischemic attack, stroke, aphasia, and other motor defects. Inflammation, apoptosis of plaque vascular smooth muscle cells (VSMCs) and increased degradation of extracellular matrices are the primary underlying cause of plaque instability. Despite extensive research, the causative factor(s) in the initiation of vulnerable plaque is unknown. Based on our novel findings, we hypothesize that lipopolysaccharide (LPS) or minimally oxLDL induce vulnerable/unstable carotid plaque and antagonizing TREM-1 and TLR4 stabilizes atherosclerotic plaque in carotid arteries. These studies will be performed in atherosclerotic Yucatan microswine model with occlusion of carotid arteries that resemble to occlusive carotid artery disease in human. This model will mimic the real situation in patients with carotid artery disease, and thus, will make a direct contribution to understanding the pathophysiology of the disease process and allow us to develop better therapeutic approaches to stabilize vulnerable plaques. Aim 1: The hypothesis predicts that the administration of LPS or minimally oxLDL in the carotid artery of atherosclerotic Yucatan microswine induces histological, morphological and biochemical features of carotid plaque like human unstable plaque by increasing the expression of TREM-1, MMP-1, MMP-9, TLR4 and M1 macrophages and decreasing collagen, TREM-2, and M2 macrophages. We will probe the effect of LPS-induced plaque instability by gray scale and Doppler ultrasound, Optical coherence tomography and the histology, immunohistochemistry and immunofluorescence to analyze thinned fibrous cap, inflammation, necrotic core, intimal proliferation with foamy macrophages, VSMCs apoptosis, lipid core, necrosis, intraplaque hemorrhage, and vascular remodeling. These findings will be compared in-vivo and in-vitro in the stable and unstable carotid plaques. We will also examine and compare the mRNA transcripts and protein expression of TREM-1, TREM-2, MMP-1, MMP-9, collagen I(α1), collagen III(α1), M1-M2 macrophages, VSMCs, expression and interaction of TLRs with TREM-1, in addition to the effect of TREM-1 on foam cell formation, release of inflammatory cytokines, and in the cross-talk between VSMCs and macrophages. Aim 2: The hypothesis predicts that the administration of TREM-1 and TLR4 antagonists will prevent the development of unstable plaque in the carotid artery of atherosclerotic swine. Effect of an inhibitory TREM-1 peptide, LR12, a scrambled peptide (placebo), and TAK-242, a TLR4 antagonist, will be examined in carotid arteries following LPS/oxLDL administration. Also, in-vivo and in-vitro functional/biochemical parameters will be examined. The findings from this study will confirm if TREM-1 is a novel target for therapeutic intervention and extend the knowledge to develop better molecules to antagonize TREM-1 and design phase I clinical trials.