从Nrf2/ARE-HO-1信号轴研究桃红四物汤减轻心肌缺血/再灌注损伤的机制

Multiple factors including enhanced oxidative stress are demonstrated to be account for the myocardial ischemia/reperfusion (I/R) injury, which is still lack of effective prevention and therapy strategy. With the characteristics of multi-component and multi-target, Chinese medicinal formulae exhibits great advantages in the prevention and treatment of myocardial I/R injury. However, the exact mechanisms are mostly unknown. Nrf2/ARE-HO-1 axis could inhibit oxidative stress and has been considered to be a novel therapy target for the myocardial I/R injury. Recently, the applicant found that Taohong Siwu Decoction (TSD) could alleviate myocardial I/R injury in rat, alongside with increased Akt phosphorylation and Nrf2 translocation to nucleus. Thus, the applicant inferred that TSD pretreatment could promote Akt phosphorylation and Nrf2 translocation, then the subsequent activation of Nrf2/ARE-HO-1 axis in the setting of myocardial I/R injury. The present study aim to investigate the effect of TSD on myocardial I/R injury in animal model and cardiomyocytes hypoxia/reoxygenation (H/R) model. The main purposes of present study contain (1) TSD could alleviate myocardial I/R injury in a dose-dependent manner, (2) TSD could promote Nrf2 translocation to nucleus via up-regulating Akt phosphorylation, then activate subsequent Nrf2/ARE-HO-1 axis, (3) Activation of Nrf2/ARE-HO-1 axis by TSD could reduce myocardial apoptosis via inhibiting oxidative stress and mitochondrial damage in the context of myocardial I/R injury. The results of present study could provide TSD with the theoretical basis and molecular targets for prevention and treatment of the myocardial I/R injury.

心肌缺血/再灌注(I/R)损伤的发生与氧化应激增强等多种因素有关，目前无有效防治手段。中药方剂具有多组分、多靶点的特点，在心肌I/R损伤防治中有巨大优势，但大多作用机制不明。Nrf2/ARE-HO-1信号轴抑制氧化应激，是防治心肌I/R损伤的新靶点。申请人前期研究发现桃红四物汤(TSD)可减轻心肌I/R损伤，同时Akt磷酸化增强，Nrf2核转位增加，因此推测TSD可能通过促进Akt磷酸化继而促使Nrf2核转位，由此激活Nrf2/ARE-HO-1信号轴。本研究拟建立大鼠心肌I/R损伤和细胞缺氧/复氧(H/R)损伤模型，研究(1)TSD以浓度依赖方式减轻心肌I/R损伤；(2)TSD促进Akt磷酸化，促使Nrf2核转位，激活Nrf2/ARE-HO-1信号轴；(3)此信号轴可减轻氧化应激，抑制线粒体损伤，减少细胞凋亡，减轻心肌I/R损伤。研究结果将为TSD防治心肌I/R损伤提供理论依据及分子靶点。

1.既往研究证实STIM1介导的钙离子内流参与了心肌缺血再灌注(I/R)损伤，课题组首先研究了白藜芦醇减轻心肌I/R损伤的新机制。本研究通过动物实验和细胞实验，证实白藜芦醇可以下调STIM1表达，减少再灌注损伤时钙离子内流，减轻钙超载，最终减少心肌梗死的面积。研究结果以论著的形式发表于Journal of physiology and biochemistry(IF=5.08)，被引27次；该研究拓展了白藜芦醇心肌保护作用的机制，为减轻心肌I/R损伤这一临床研究的热点和难点问题提供了新的切入点；.2.课题组研究了Cordycepin减轻心肌I/R的机制。AMPK/mTOR通路介导的自噬参与了心肌I/R损伤的发生。本研究通过开展动物实验和细胞实验，证实Cordycepin在缺血再灌注损伤时可以保护心肌细胞，促进心功能恢复，而通过AMPK/mTOR促进自噬是其心肌保护作用的机制之一。研究结果以论著的形式发表于Journal of physiology and biochemistry(IF=5.08)。该研究首次探讨了Cordycepin对心肌I/R损伤的保护作用及其机制，首次证实I/R损伤时Cordycepin通过AMPK/mTOR通路促进自噬，保护心肌细胞，促进心功能的恢复，为减轻心肌I/R损伤这一临床研究的热点和难点问题提供了新的切入点；.3.课题组探讨了桃红四物汤及其主要成分amygdalin对对心肌I/R损伤的保护作用及其机制，并首次证实I/R损伤时amygdalin通过Nrf2/SLC7A11/GPX4通路抑制铁死亡，保护心肌细胞，促进心功能的恢复，研究结果已经撰写论著投稿。课题组开展的这些研究为心肌I/R损伤这一临床热点问题提供了新的思路，实现科技成果“人无我有、人有我优”，为这些药物及相关中药制剂的临床应用提供了新的基础研究证据。