Ginsenoside Rb1 Decreases Injury-Induced Vascular Restenosis

描述（由申请人提供）：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其对心血管疾病具有潜在益处。研究表明，人参的活性成分人参皂苷对动脉粥样硬化斑块形成和各种血管损伤具有保护作用。我们假设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) 可以阻断同型半胱氨酸 (HCY) 诱导的内皮血管舒缩功能、自由基产生和 eNOS 表达的有害影响。为了扩展初步研究，我们提出了一项更全面的研究，以阐明 Rb1 对血管损伤后 HCY 夸大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 通过维持功能性 eNOS 系统和减少氧化应激，有效阻止 HCY 增强的血管功能障碍和再狭窄。提出了两个具体目标： 具体目标 1：确定 Rb1 治疗的 eNOS 救援和 ROS 抑制在 HCY 诱导的细胞应激中的分子机制。假设：eNOS 功能障碍和氧化应激在 HCY 诱导的动脉粥样硬化形成和再狭窄中发挥重要作用。这两个系统密切相关，但却是不同的实体。 Rb1 通过调节 eNOS 表达和 O2.- 产生来发挥其保护作用。为此，我们将通过分析人冠状动脉内皮细胞 (HCAEC) 中的 eNOS 表达、活性和调节来研究 eNOS 系统（具体目标 1a）。我们还将研究 HCAEC 中活性氧 (ROS) 产生的来源，并确定 ROS 介导的信号通路是否参与 HCY 诱导的内皮功能障碍（具体目标 1b）。具体目标 2：确定 Rb1 对导丝损伤后小鼠模型中 HCY 增强的内膜增生的影响。将使用载脂蛋白 E 缺陷 (ApoE-/-) 小鼠中导丝诱导的颈总动脉损伤模型。再狭窄的程度和成分将使用分子成像技术和组织学方法进行监测。这一应用可能会带来一种新的策略，将补充和替代医学结合起来，以改善 HCY 相关的细胞应激和血管成形术后内膜增生。考虑到人参化合物的治疗应用历史和最近对其分子作用的发现，开发人参化合物是一个很好的机会。我们的应用采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替代治疗策略。 公共健康相关性：本申请利用综合的分子、细胞和动物模型方法来研究人参皂苷 Rb1 对同型半胱氨酸加剧的血管功能障碍的影响和机制。这一应用可能会带来一种新的策略，将补充和替代医学结合起来，以改善与危险因素相关的细胞应激。我们希望我们的研究将为大规模临床研究奠定坚实的基础，并为老龄化人群的血管再狭窄提供替代治疗策略。

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.