决明子蒽醌苷通过Nrf2/ARE信号通路抑制冠心病大鼠心肌损伤

Anthraquinone glycoside from cassia inhibits myocardial injury of the rats with coronary heart disease through Nrf2/ARE signal pathway

目的 从核因子E2相关因子2(nuclear factor-E2-related factor 2,Nrf2)/抗氧化反应元件(antioxidant response element, ARE)信号通路角度,探究决明子蒽醌苷(anthraquinone glycoside from cassia, AQGC)对冠心病大鼠的心肌保护机制。方法 脂肪乳灌胃+注射维生素D3+注射垂体后叶素建立大鼠冠心病模型,随机分为模型组、AQGC组、Nrf2抑制剂组、AQGC+Nrf2抑制剂组、缺氧诱导因子-1α(hypoxia inducible factor-1α, HIF-1α)抑制剂组,每组10只,另取10只手术组大鼠。超声心动图检测大鼠心功能;HE及TUNEL法检测心肌病理损伤及凋亡状况;ELISA法检测血清总胆固醇、心肌组织活性氧簇(ROS)、丙二醛(MDA)水平;免疫组织化学法检测Nrf2阳性表达;Western blot法检测Nrf2及下游炎症、氧化应激、凋亡相关蛋白表达。结果 与正常对照组相比,模型组大鼠心肌组织炎症浸润、细胞肥大、胞核变形等病理损伤严重,心功能下降、心肌组织细胞凋亡、氧化应激及炎症反应加重,Nrf2下游抗氧化反应减弱、HIF-1α/E1B相互作用蛋白3(BNIP3)介导的促凋亡途径激活。抑制Nrf2活性,可进一步促进冠心病大鼠心肌组织炎症、氧化应激及凋亡反应,加重心肌组织损伤,进一步导致心功能下降。抑制HIF-1α活性或AQGC干预治疗,均可促进Nrf2介导的抗炎、抗氧化应激及抗凋亡反应激活,缓解冠心病大鼠心肌损伤,改善心功能。AQGC与Nrf2抑制剂联合应用后,AQGC促进Nrf2活化、改善冠心病大鼠心肌组织损伤的作用被明显削弱。结论 AQGC可通过促进Nrf2活化,发挥抗炎、抗氧化应激及抗凋亡作用,来改善冠心病大鼠心肌损伤症状。

Objective From the aspect of nuclear factor E2-related factor 2(Nrf2)/antioxidant response element(ARE) signaling pathway, to explore the myocardial protective mechanism of anthraquinone glycoside from cassia(AQGC) on coronary heart disease rats. Methods Gavage of fat emulsion + injection of Vitamin D3 + injection of pituitrin was used to establish a rat model of coronary heart disease, and the model was randomly divided into model group, AQGC group, Nrf2 inhibitor group, AQGC + Nrf2inhibitor group, hypoxia inducible factor-1α(HIF-1α) inhibitor group, with 10 rats in each group, and another 10 rats were used as the sham operation group. Echocardiography was used to detect rat heart function;HE and TUNEL methods were used to detect myocardial pathological damage and apoptosis;ELISA method was used to detect the serum total cholesterol, myocardial tissue reactive oxygen species(ROS) and malondialdehyde(MDA) levels;immunohistochemical method was used to detect the positive expression of Nrf2;Western Blot method was used to detect the expression of Nrf2 and downstream inflammation, oxidative stress, and apoptosis related proteins. Results Compared with the normal control group, the rats in the model group had severe pathological damage such as inflammation infiltration, cell hypertrophy, and nuclear deformation, the decreased heart function, the apoptosis of myocardial tissue cells,increased oxidative stress and inflammation, the Nrf2 downstream antioxidant response was weakened, and the pro-apoptotic pathway mediated by HIF-1α/E1B interacting protein 3(BNIP3) was activated. Inhibition of Nrf2 activity could further promote myocardial tissue inflammation, oxidative stress and apoptosis in rats with coronary heart disease, aggravate myocardial tissue damage, and further lead to a decline in cardiac function. Inhibition of HIF-1α activity or administration of AQGC could promote Nrf2-mediated activation of anti-inflammatory, anti-oxidative stress and anti-apoptotic responses, relieve myocardial damage in rats with coronary heart disease,and improve cardiac function. After the combined application of AQGC and Nrf2 inhibitor, the effects of AQGC in promoting Nrf2activation and improving myocardial tissue damage in coronary heart disease rats were significantly weakened. Conclusion AQGC could improve the myocardial injury symptoms of coronary heart disease rats by promoting the activation of Nrf2, exerting anti-inflammatory, anti-oxidative stress and anti-apoptotic effects.