Ginsenoside Rb1 Decreases Injury-Induced Vascular Restenosis

描述(申请人提供)：人参根是最广泛认可的草药补充剂之一，越来越多的临床证据表明，人参对心血管疾病有潜在的好处。研究表明，人参皂苷是人参的有效成分，对动脉粥样硬化斑块形成和各种血管损伤具有保护作用。我们推测人参根和人参皂苷对血管成形术引起的血管损伤和血管成形术后再狭窄具有保护作用。我们最近证明人参皂苷Rb1(Rb1)可阻断同型半胱氨酸(HCY)对内皮血管运动功能、自由基产生和eNOS表达的不利影响。为了扩展初步研究，我们建议进行更全面的研究，以阐明Rb1对血管损伤后HCY过度激活的细胞应激的分子机制、细胞效应和体内影响。我们的中心假设是，Rb1通过维持功能正常的eNOS系统和减少氧化应激，有效地阻止了HCY增加的血管功能障碍和再狭窄。提出了两个特定的目标：特定的目标1：确定Rb1在HCY诱导的细胞应激中拯救eNOS和抑制ROS的分子机制。假设：eNOS功能障碍和氧化应激在同型半胱氨酸诱导的动脉粥样硬化形成和再狭窄中起重要作用。这两个系统密切相关，但又是截然不同的实体。Rb1通过调节eNOS的表达和O2的产生发挥其保护作用。在这一目标中，我们将通过分析eNOS在人冠状动脉内皮细胞(HCAECs)中的表达、活性和调节来研究eNOS系统(特异性目标1a)。我们还将研究HCAEC中ROS的产生来源，并确定ROS介导的信号通路是否参与了HCY诱导的内皮功能障碍(特异性AIMS 1b)。特定目的2：在小鼠后导丝损伤模型中，确定Rb1对HCY增强型内膜增生的影响。将采用导丝诱导载脂蛋白E缺陷(ApoE-/-)小鼠颈总动脉损伤模型。再狭窄的程度和构成将使用分子成像技术和组织学方法进行监测。这一应用可能会导致一种新的策略，即结合补充和替代药物来改善HCY相关的细胞应激和血管成形术后的内膜增生。鉴于人参化合物治疗应用的历史和最近对其分子作用的发现，人参化合物的开发是一个巨大的机会。我们的应用利用多学科方法来探索Rb1的机制和体内效应。我们希望这一应用将为大规模的临床研究奠定坚实的基础，并有可能为血管损伤和再狭窄提供一种替代治疗策略。 公共卫生相关性：这项应用利用全面的分子、细胞和动物模型方法来研究人参皂苷Rb1对同型半胱氨酸夸大的血管功能障碍的影响和机制。这一应用可能会导致一种新的策略，即结合补充和替代医学来改善与风险因素相关的细胞应激。我们希望我们的研究将为大规模的临床研究奠定坚实的基础，并为老龄化人口中的血管再狭窄提供一种替代的治疗策略。

DESCRIPTION (provided by applicant): Ginseng root is one of the most widely recognized herbal supplements with increased clinical evidence of potential benefits in cardiovascular diseases. Studies have shown that ginsenosides, active constituents of ginseng, have protective roles in atherosclerotic plaque formation and various vascular injuries. We hypothesize that ginseng root and ginsenoside have protective effects against angioplasty-induced vascular damage and post-angioplasty restenosis. We recently have demonstrated that ginsenoside Rb1 (Rb1) blocks homocysteine (HCY)-induced detrimental effects on endothelial vasomotor function, free-radical production, and eNOS expression. To extend the preliminary studies, we propose a more comprehensive investigation to elucidate the molecular mechanisms, cellular effects, and in vivo influences of Rb1 on HCY- exaggerated cellular stress following vascular injury. Our central hypothesis is that Rb1 effectively blocks HCY-augmented vascular dysfunction and restenosis by maintaining a functional eNOS system and decreasing oxidative stress. Two specific aims are proposed: Specific Aim 1: Determine the molecular mechanisms of Rb1-medicated eNOS rescue and ROS suppression in HCY-induced cellular stress. Hypothesis: both eNOS dysfunction and oxidative stress play important roles in HCY-induced atherogenesis and restenosis. These two systems are intimately related, yet distinct entities. Rb1 exerts its protective effects by modulating eNOS expression and O2.- production. In this aim, we will study the eNOS system by analyzing eNOS expression, activity, and regulation in human coronary artery endothelial cells (HCAECs) (Specific Aim 1a). We will also investigate the sources of reactive oxygen species (ROS) production in HCAECs and determine whether ROS-mediated signaling pathway is involved in HCY-induced endothelial dysfunction (Specific Aims 1b). Specific Aim 2: Determine the effects of Rb1 on HCY-augmented intimal hyperplasia in a post-guide wire injured murine model. A guidewire-induced common carotid artery injury model in Apolipoprotein E deficient (ApoE-/-) mice will be used. Degree and composition of restenosis will be monitored using a molecular imaging techniques and histology methods. This application may potentially lead to a new strategy of incorporating complementary and alternative medicine to ameliorate HCY-associated cellular stress and post-angioplasty intimal hyperplasia. Development of ginseng compounds is a great opportunity given their history of therapeutic applications and recent discoveries of their molecular actions. Our application utilizes a multidisciplinary approach to explore the mechanisms and in vivo effects of Rb1. We hope that this application will establish a solid foundation for large- scale clinical research and potentially provide an alternative treatment strategy for vascular damages and restenosis. PUBLIC HEALTH RELEVANCE: This application utilizes a comprehensive molecular, cellular, and animal model approach to investigate the effects and mechanisms of ginsenoside Rb1 on homocysteine-exaggerated vascular dysfunction. This application may potentially lead to a new strategy of incorporating complementary and alternative medicine to ameliorate risk factor-associated cellular stress. We hope that our investigation will establish a solid foundation for large-scale clinical research and provide an alternative treatment strategy for vascular restenosis in an aging population.