Department of Pharmacology, School of Pharmacy, Nantong University, Nantong 226001, China.
Int J Mol Sci. 2022 Aug 22;23(16):9473. doi: 10.3390/ijms23169473.
Myocardial ischemia-reperfusion injury (MIRI) leads to cardiac remodeling and heart failure associated with acute myocardial infarction, which is one of the leading causes of death worldwide. Betulinic acid (BA), a widely distributed lupane-type triterpenoid, has been reported to possess antioxidative activity and inhibit apoptosis in MIRI. Due to the low bioavailability and water insolubility of BA, a previous study found a series of BA-derivative compounds by microbial transformation. In this study, we observe whether there are anti-MIRI effects of BTA07, a BA derivative, on cardiac injuries induced by hypoxia/reoxygenation (H/R) in adult rat cardiomyocytes in vitro and in Langendorff-perfused hearts ex vivo, and further explore its mechanism of cardioprotection to find more efficient BA derivatives. The hemodynamic parameters of isolated hearts were monitored and recorded by a Lab Chart system. The markers of oxidative stress and apoptosis in isolated hearts and adult rat cardiomyocytes (ARCMs) were evaluated. The expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), protein kinase B (Akt) and phospho-Akt (pAkt, Ser473) induced by H/R were detected via Western blot. The Langendorff experiments showed that BTA07 improves hemodynamic parameters, reduces myocardium damage and infarct size, inhibits levels of myocardial tissue enzymes lactate dehydrogenase (LDH) and creatine kinase (CK) in the coronary outflow and reduces oxidative stress and the activation of caspase-3 in the myocardium. In vitro, BTA07 reduced cell death and caspase-3 activation and inhibited reactive oxygen species (ROS) generation. Furthermore, the protective effects of BTA07 were attenuated by inhibition of the PI3K/Akt signaling pathway with LY294002 in ARCMs. BTA07 protects ARCMs and isolated hearts from hypoxia-reperfusion partly by inhibiting oxidative stress and cardiomyocyte apoptosis.
心肌缺血再灌注损伤（MIRI）导致心脏重构和心力衰竭，与急性心肌梗死相关，这是全球范围内导致死亡的主要原因之一。白桦酸（BA），一种广泛分布的羽扇豆烷型三萜，已被报道具有抗氧化活性，并抑制 MIRI 中的细胞凋亡。由于 BA 的生物利用度低和水溶性差，先前的研究通过微生物转化发现了一系列 BA 衍生物。在这项研究中，我们观察了 BA 衍生物 BTA07 是否对体外缺氧/复氧（H/R）诱导的成年大鼠心肌细胞损伤和离体Langendorff 灌流心脏具有抗 MIRI 作用，并进一步探讨了其心脏保护机制，以寻找更有效的 BA 衍生物。通过 Lab Chart 系统监测和记录分离心脏的血流动力学参数。评估分离心脏和成年大鼠心肌细胞（ARCMs）中的氧化应激和细胞凋亡标志物。通过 Western blot 检测 H/R 诱导的 B 细胞淋巴瘤 2（Bcl-2）、Bcl-2 相关 X（Bax）、蛋白激酶 B（Akt）和磷酸化 Akt（pAkt，Ser473）的表达水平。Langendorff 实验表明，BTA07 改善血流动力学参数，减轻心肌损伤和梗死面积，抑制冠脉流出液中心肌组织酶乳酸脱氢酶（LDH）和肌酸激酶（CK）的水平，并降低心肌中的氧化应激和半胱天冬酶-3 的激活。在体外，BTA07 减少细胞死亡和半胱天冬酶-3 的激活，并抑制活性氧（ROS）的产生。此外，BTA07 的保护作用在 ARCMs 中被 PI3K/Akt 信号通路抑制剂 LY294002 减弱。BTA07 通过抑制氧化应激和心肌细胞凋亡，部分保护 ARCMs 和离体心脏免受缺氧再灌注损伤。
