Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, 610041, China.
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.
Cell Stress Chaperones. 2023 Nov;28(6):921-933. doi: 10.1007/s12192-023-01386-1. Epub 2023 Oct 24.
Exposure to hypobaric hypoxia (HH) environment causes stress to the body, especially the oxygen-consuming organs. Chronic HH conditions have adverse effects on the myocardium. Thus, we conducted this experiment and aim to evaluate such adverse effects and explore the therapeutic role of epigallocatechin-3-gallate (EGCG) in rats' heart under chronic HH conditions. For that purpose, we transported rats from plain to a real HH environment at high altitude for establishing the HH model. At high altitude, animals were treated with EGCG while the salidroside was used as the positive control. General physiological data were collected, and routine blood test results were analyzed. Cardiac magnetic resonance (CMR) was examined to assess the structural and functional changes of the heart. Serum levels of cardiac enzymes and pro-inflammatory cytokines were examined. Oxidative markers in the left ventricle (LV) were detected. Additionally, ultrastructural and histopathological changes and apoptosis of the LV were assessed. Furthermore, the antioxidant stress-relevant proteins nuclear factor E2-related factor 2 (Nrf2) and the heme oxygenase-1 (HO-1) were detected. The experiment revealed that EGCG treatment decreased HH-induced elevation of cardiac enzymes and relieved mitochondrial damage of the LV. Notably, EGCG treatment significantly alleviated oxidative stress in the LV and inflammatory response in the blood. Western blot confirmed that EGCG significantly upregulated Nrf2 and HO-1. Therefore, EGCG may be considered a promising natural compound for treating the HH-induced myocardial injuries.
暴露于低气压缺氧（HH）环境会给身体带来压力，特别是对耗氧器官。慢性 HH 条件对心肌有不良影响。因此，我们进行了这项实验，旨在评估慢性 HH 条件下 EGCG 对大鼠心脏的这种不良影响，并探索其治疗作用。为此，我们将大鼠从平原运到高海拔的真实 HH 环境中建立 HH 模型。在高海拔地区，动物接受 EGCG 治疗，同时使用红景天苷作为阳性对照。收集一般生理数据，并分析常规血液测试结果。通过心脏磁共振（CMR）检查评估心脏的结构和功能变化。检测血清中心脏酶和促炎细胞因子的水平。检测左心室（LV）中的氧化标志物。此外，评估 LV 的超微结构和组织病理学变化以及细胞凋亡。还检测了抗氧化应激相关蛋白核因子 E2 相关因子 2（Nrf2）和血红素加氧酶-1（HO-1）。实验表明，EGCG 治疗可降低 HH 引起的心脏酶升高，并缓解 LV 的线粒体损伤。值得注意的是，EGCG 治疗可显著减轻 LV 的氧化应激和血液中的炎症反应。Western blot 证实 EGCG 可显著上调 Nrf2 和 HO-1。因此，EGCG 可能被认为是治疗 HH 引起的心肌损伤的一种有前途的天然化合物。
