Sung Pei-Hsun, Luo Chi-Wen, Chiang John Y, Yip Hon-Kan
Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine Kaohsiung 83301, Taiwan, ROC.
Center for Shockwave Medicine and Tissue Engineering, Kaohsiung Chang Gung Memorial Hospital Kaohsiung 83301, Taiwan, ROC.
Am J Transl Res. 2020 Jul 15;12(7):3255-3271. eCollection 2020.
This study tested the hypothesis that combined histone methyltransferase G9a inhibitor (i.e., UNC0638) and erythropoietin (EPO) was superior to either one alone for protecting myocardium from acute myocardial infarction (AMI) damage.
Adult-male SD rats (n=30) were equally categorized into group 1 (sham-operated control), group 2 (AMI), group 3 (AMI-EPO/1000 IU/kg, I.M./3 h after AMI), group 4 (AMI- UNC0638/5 mg/kg I.P./3 h after AMI) and group 5 [AMI-UNC0638-EPO 3 h after AMI] treatment. Animals were euthanized at day 21 after AMI induction. By day 21, left-ventricular-ejection-fraction (LVEF) was highest in group 1, lowest in group 2, significantly higher in group 5 than in groups 3 and 4, but no difference between the latter two groups (all P<0.0001). The protein expressions of inflammatory (MMP-2/MM-9), fibrotic (fibronectin/Smad3/TGF-ß), apoptotic/DNA-damaged (caspas-3/PARP/γ-H2AX), cell-stress response (HIF-1α/p-Akt/p-mTOR) and autophagic (beclin-1/ratio of LC3B-II to LC3B-I) biomarkers exhibited an opposite pattern, whereas the protein expressions of endothelial integrity (CD31/vWF) and anti-oxidant (SIRT1/SIRT3) exhibited an identical pattern of LVEF among the five groups (all P<0.0001). The protein expressions (SDF-1α/VEGF/CXCR4) and cellular expressions (C-kit/CD31+//Sca-1/CD31+//KDR/CD34+) of angiogenesis biomarkers were significantly progressively increased from groups 1 to 5 (all P<0.0001). The infarction/fibrotic areas, myocyte size and number of G9a cells exhibited an opposite pattern, whereas the small-vessel density displayed an identical trend of LVEF among the groups (all P<0.0001). Flow cytometric analysis showed cellular levels of inflammation (Ly6G+/MPO+/CD11b/c+), oxidative-stress (DCFDA+) and apoptosis (early+/late+) exhibited an opposite pattern to LVEF among the groups (all P<0.0001).
EPO-BIX01294 effectively protected myocardium against AMI-induced damage.
本研究检验了以下假设，即组蛋白甲基转移酶G9a抑制剂（即UNC0638）与促红细胞生成素（EPO）联合使用在保护心肌免受急性心肌梗死（AMI）损伤方面优于单独使用其中任何一种。
成年雄性SD大鼠（n = 30）被平均分为1组（假手术对照组）、2组（AMI组）、3组（AMI-EPO/1000 IU/kg，腹腔注射/AMI后3小时）、4组（AMI-UNC0638/5 mg/kg腹腔注射/AMI后3小时）和5组[AMI后3小时给予AMI-UNC0638-EPO]进行治疗。在诱导AMI后第21天对动物实施安乐死。到第21天时，左心室射血分数（LVEF）在1组中最高，在2组中最低，5组显著高于3组和4组，但后两组之间无差异（所有P<0.0001）。炎症（MMP-2/MM-9）、纤维化（纤连蛋白/Smad3/TGF-β）、凋亡/DNA损伤（caspas-3/PARP/γ-H2AX）、细胞应激反应（HIF-1α/p-Akt/p-mTOR）和自噬（beclin-1/LC3B-II与LC3B-I的比值）生物标志物的蛋白表达呈现相反模式，而内皮完整性（CD31/vWF）和抗氧化（SIRT1/SIRT3）的蛋白表达在五组中呈现与LVEF相同的模式（所有P<0.0001）。血管生成生物标志物的蛋白表达（SDF-1α/VEGF/CXCR4）和细胞表达（C-kit/CD31+/Sca-1/CD31+/KDR/CD34+）从1组到5组显著逐渐增加（所有P<0.0001）。梗死/纤维化面积、心肌细胞大小和G9a细胞数量呈现相反模式，而小血管密度在各组中呈现与LVEF相同的趋势（所有P<0.0001）。流式细胞术分析显示，细胞炎症水平（Ly6G+/MPO+/CD11b/c+）、氧化应激（DCFDA+）和凋亡（早期+/晚期+）在各组中呈现与LVEF相反的模式（所有P<0.0001）。
EPO-BIX01294能有效保护心肌免受AMI诱导的损伤。
