American Ginseng-mediated Autophagy and Suppression of Inflammation (Project 3)

摘要 慢性心力衰竭是不同心血管疾病（CVD）的最后一步，仍然是心血管死亡的主要原因，无法治愈。迄今为止，通过阻断或抑制过度活化的单一途径（如炎性细胞因子和氧化应激）的治疗方法被证明是无效的甚至有害的，所述单一途径已被确定为在CVD中起致病作用。在这种背景下，传统中药的治疗理念，旨在通过协调多个信号通路，而不是阻断或抑制单一的过度激活的信号通路，以维持系统的稳态提出了一个新的研究方向。然而，这一概念一直被批评为“神秘”的索赔草药治疗心血管疾病，由于相互矛盾的研究结果和缺乏机制分析的草药治疗心血管疾病的有效性和安全性。事实上，草药预防适应不良心脏重塑和心力衰竭的分子机制仍有待建立。 利用加拿大国家研究理事会、国家测量标准研究所（NRCC-INMS）在国家补充和替代医学中心（NCCAM）的指导下提供的标准化西洋参提取物，我们已经从机理上探索了人参的心脏保护作用，人参是在亚洲国家已被用作民间药物数千年的人参属的根。我们的研究结果有力地支持了一个新的工作假设，即西洋参抑制氧化应激和炎症反应，以及随后的适应不良的心脏重塑和功能障碍，通过协调自噬活性和Nrf 2信号在心脏中。为了验证这一假设，我们提出了以下三个具体目标： 目标1。确定自噬和Nrf 2在调节巨噬细胞中的氧化应激和炎性细胞因子产生的西洋参介导的抑制以及心肌细胞中的氧化应激、肥大性生长和细胞死亡中的作用; 目标2.确定西洋参活性成分对自噬和Nrf 2通路的协调作用，从而阻断氧化应激和炎症的恶性循环; 目标3.确定西洋参通过激活心肌自噬和Nrf 2抑制适应不良性心脏肥大和功能障碍的活性成分; 这些实验将首次证明美国人参激活的自噬对于美国人参激活的Nrf 2介导的心脏保护是必不可少的。总体而言，该提案的结果不仅提供了一种新的西洋参介导的心脏保护的分子机制，而且还建立了用于细分人参心脏保护活性成分的生物标志物。

Abstract Chronic heart failure, the final step of different cardiovascular diseases (CVD), remains the leading cause of cardiovascular death without a cure. To date, the therapeutic approaches by blocking or inhibiting over-activated single pathway such as inflammatory cytokines and oxidative stress which have been firmly established to play a causative role in CVD turn out to be ineffective or even harmful. In this context, the therapeutic concept of traditional herb medicine that aims to maintain systemic homeostasis by orchestrating multiple signaling pathways rather than blocking or inhibiting single over-activated signaling pathway raises a novel research direction. However, this concept has always been criticized as the 'mystical' claim for herb medicines to treat CVD, due to the contradictory findings and the lack of mechanistic analysis of herb medicine's efficacy and safety for the treatment of CVD. Indeed, the molecular mechanism by which herb medicines protect against maladaptive cardiac remodeling and heart failure remains to be established. Utilizing a standardized American ginseng extract from the National Research Council of Canada, Institute for National Measurement Standards (NRCC-INMS) under the guidelines of National Center for Complementary and Alternative Medicine (NCCAM), we have mechanistically explored the cardiac protective actions of ginseng, the root of genus Panax that has been used as a folk medicine for several thousand years in Asian countries. Our findings strongly support a novel working hypothesis that American ginseng suppresses oxidative stress and inflammatory responses, as well as the subsequent maladaptive cardiac remodeling and dysfunction via coordinating autophagic activity and Nrf2 signaling in the heart. To test this hypothesis, we propose three specific aims as follows: Aim 1. To determine role of autophagy and Nrf2 in regulating the American ginseng-mediated suppression of oxidative stress and inflammatory cytokine production in macrophages as well as oxidative stress, hypertrophic growth and cell death in cardiomyocytes; Aim 2. To determine the active components of American ginseng for the coordination of autophagy and Nrf2 pathway thereby blocking the vicious cycle of oxidative stress and inflammation in vitro; Aim 3. To determine the active components of American ginseng for the suppression of maladaptive cardiac hypertrophy and dysfunction via activating both myocardial autophagy and Nrf2 in the heart; These experiments will demonstrate for the first time that American ginseng-activated autophagy is essential for American ginseng-activated Nrf2-mediated cardiac protection. Overall, the outcome of this proposal will not only provide a novel molecular mechanism of American ginseng-mediated cardiac protection, but also establish biomarkers for the sub-fractionating of the active components of ginsengs for cardiac protection.