Insulin-Like Growth Factor-1 and Atherosclerosis

项目摘要/摘要 冠心病是全球心血管疾病的主要诱因。尽管有最佳的治疗方法 许多患者仍然容易受到缺血事件的影响。虽然小动物模型已经证明了 为了有效地探索机制，在大型动物模型中进行研究是非常必要的，因为它是 啮齿动物研究和人体试验，并开发新的治疗方法。我们已经证明胰岛素样生长因子-1 胰岛素样生长因子-1减轻APOE-/-小鼠和Rapacz小鼠的动脉粥样硬化负担并促进斑块稳定性 家族性高胆固醇血症猪(FH猪)。我们的新发现表明，IGF-1可以降低 猪冠状动脉内衰老细胞的数量，包括衰老的SMC样细胞和MF样细胞 动脉粥样硬化斑块，特别是纤维帽(FC)。细胞衰老被认为是至关重要的 在衰老和慢性疾病发展中的作用。然而，IGF-1与细胞衰老的关系 动脉粥样硬化性疾病几乎是未知的。衰老细胞参与动脉粥样硬化和纤维帽的形成 在小鼠模型中变薄，但没有关于细胞衰老在动脉粥样硬化形成中的因果作用的信息。 大型动物模型或人类。应用scRNA-seq技术分析APOE-/-小鼠和空白鼠的主动脉 猪斑块的转录组学分析显示与衰老相关的高水平表达 分泌表型(SASP)因子IGF结合蛋白-7(IGFBP7)是一种IGF-1抑制物，在纤维帽中， 主要定位于SMC样细胞，尤其是纤维肌细胞。衰老分数的升高是强烈的 与纤维肌细胞和IGFBP7的高表达有关。我们假设衰老细胞抑制 IGF-1信号转导和SASP诱导的IGF-1抵抗降低了IGF-1的抗动脉粥样硬化作用。 我们的数据显示，衰老培养的SMC的条件培养液抑制SMC的IGF1R信号转导。 该作用可被抗IGFBP7抗体逆转。我们的总体目标是证明去除衰老细胞 使用一种名为ABT263的感觉剂，将减少大型动物模型的动脉粥样硬化，并增强抗动脉粥样硬化作用 IGF-I的作用。我们还将使用功能丧失的小鼠来演示IGFBP7在IGF-1抵抗中的作用 模型，并利用体外研究进一步探索机制。 具体目标1：在大型动物中测试使用增感剂清除衰老细胞的假设 动脉粥样硬化模型将减轻动脉粥样硬化负担并增强IGF-1降低的能力 加重动脉粥样硬化负担，促进斑块稳定。ScRNA-seq，空间转录学，多标记 组织学和激光捕获显微解剖(LCM)将被用来剖析机制。 特异性目标2：特异性目标2：证明在SMC样细胞中IGFBP7基因缺失 增强IGF-1的抗动脉粥样硬化作用。我们将使用SMC选择性IGFBP7缺陷小鼠，scRNA- 通过SEQ分析和体外模型剖析其作用机制。

PROJECT SUMMARY / ABSTRACT Coronary heart disease is a primary contributor to cardiovascular disease worldwide. Despite optimal treatment many patients remain vulnerable to ischemic events. While small animal models have proven extraordinarily effective at exploring mechanisms, studies in large animal models are critically needed, as a bridge between rodent studies and human trials, and to develop new therapies. We have shown that insulin-like growth factor-1 (IGF-1) reduces atherosclerotic burden and promotes features of plaque stability in Apoe-/- mice and in Rapacz swine with familial hypercholesterolemia (FH pigs). Our novel findings indicate that IGF-1 reduces the number of senescent cells, including senescent SMC-like and MF-like cells in pig coronary atherosclerotic plaques, in particular in the fibrous cap (FC). Cellular senescence is thought to play a vital role in aging and in the development of chronic disease. However, the relation between IGF-1, cell senescence and atherosclerotic disease is virtually unknown. Senescent cells contribute to atherogenesis and fibrous cap thinning in mouse models, but there is no information on the causal role of cell senescence in atherogenesis in large animal models or in humans. Using scRNA-seq analysis of aortas from Apoe-/- mice and spatial transcriptomics analysis of porcine plaque we show high-level expression of the senescence-associated secretory phenotype (SASP) factor IGF binding Protein-7 (IGFBP7), an IGF-1 inhibitor, in the fibrous cap, primarily localized to SMC-like cells, particularly fibromyocytes. Elevated senescence scores are strongly associated with fibromyocytes and high IGFBP7 expression. We hypothesize that senescent cells inhibit IGF-1 signaling and that SASP-induced IGF-1 resistance reduces anti-atherosclerotic effects of IGF-1. Our data shows that conditioned medium from senescent cultured SMC inhibits IGF1R signaling in SMC, an effect reversed by anti-IGFBP7 antibody. Our overall goal is to demonstrate that removal of senescent cells using a senolytic, ABT263, will reduce atherosclerosis in a large animal model and potentiate anti-atherosclerotic effects of IGF-I. We will also demonstrate the role of IGFBP7 in IGF-1 resistance using a loss-of-function murine model, and further explore mechanisms using in vitro studies. Specific Aim 1: Test the hypothesis that clearance of senescent cells using a senolytic in a large animal model of atherosclerosis will reduce atherosclerotic burden and potentiate IGF-1 ability to reduce atherosclerotic burden and promote plaque stability. scRNA-seq, spatial transcriptomics, multi-marker histology, and laser capture microdissection (LCM) will be used to dissect mechanisms. Specific Aim 2: Specific Aim 2: Demonstrate that genetic deprivation of IGFBP7 in SMC-like cells enhances anti-atherosclerosis effects of IGF-1. We will use SMC-selective IGFBP7-deficient mice, scRNA- seq analysis and in vitro models to dissect mechanisms.