Gu Qingqing, Chen Qianwe, Wang Yu, Cai Dabei, Xiao Tingting, Wang Qingjie, Sun Ling
Department of Cardiology, the Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou 213000, Jiangsu, China.
Department of Cardiology, the Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi 214000, Jiangsu, China. Corresponding author: Sun Ling, Email:
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue. 2025 Jun;37(6):583-589. doi: 10.3760/cma.j.cn121430-20240711-00582.
To investigate the role of telomerase reverse transcriptase (TERT) in alleviating doxorubicin (DOX)-induced cardiotoxicity.
(1) Cell experiments: rat H9c2 cardiomyocytes were divided into control group (CON group), null adenovirus transfection group (NC group), TERT overexpression adenovirus transfection group (TERT group), DOX group (treated with 1 μmol/L DOX for 12 hours), DOX+NC group, and DOX+TERT group (null adenovirus or TERT overexpression adenovirus were transfected for 24 hours and then treated with 1 μmol/L DOX for 12 hours). The mRNA expression of TERT in cardiomyocytes was detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The level of mitochondrial membrane potential was detected by immunofluorescence. The expression levels of intracellular Bax, Bcl-2, microtubule-associated protein 1 light chain 3 (LC3) and p62 were detected by Western blotting. (2) Animal experiments: male C57BL/6 mice were randomly divided into a sham operation group (Sham group), DOX group (acute cardiotoxicity model was constructed by intraperitoneal injection of DOX 15 mg/kg), DOX+NC group and DOX+TERT group (modeled after transfection with airborne adenovirus or TERT overexpression adenovirus for 7 days). After 7 days of modeling, the area of myocardial fibrosis was detected by Sirius scarlet staining, and cardiac function was detected by echocardiography.
(1) Cellular experiments: the mRNA expression level of TERT was significantly higher in the TERT group compared with the CON and NC groups. Compared with the CON group, the TERT mRNA expression level of cardiomyocytes in the DOX group and the DOX+NC group were significantly lower, the level of mitochondrial membrane potential was significantly lower, the protein expressions of Bax and LC3 were significantly increased, and the protein expressions of Bcl-2 and p62 were significantly decreased. No significant differences were found between the DOX group and DOX+NC group. Compared with the DOX group and DOX+NC group, the TERT mRNA expression level was increased in the DOX+TERT group (relative expression: 1.02±0.10 vs. 0.61±0.05, 0.54±0.03, both P < 0.05), the level of mitochondrial membrane potential was significantly increased (1.14±0.05 vs. 0.96±0.01, 0.96±0.01, both P < 0.05), the protein expressions of Bax and LC3 were significantly decreased, and the protein expressions of Bcl-2 and p62 were significantly increased (Bax/β-actin: 0.88±0.01 vs. 1.31±0.02, 1.26±0.01; LC3-II/I: 2.16±0.05 vs. 2.64±0.06, 2.58±0.02; Bcl-2/β-actin: 0.65±0.01 vs. 0.40±0.01, 0.41±0.01; p62/β-actin: 0.45±0.01 vs. 0.23±0.02, 0.29±0.01; all P < 0.05). (2) Animal experiments: compared with the Sham group, the percentage of myocardial fibrosis area was significantly increased and left ventricular ejection fraction (LVEF) and fractional shortening (FS) were significantly decreased in the DOX group and DOX+NC group. Compared with the DOX group and DOX+NC group, the percentage of myocardial fibrotic area was significantly decreased in the DOX+TERT group (%: 2.33±0.06 vs. 3.76±0.07, 3.87±0.06, both P < 0.05), and the LVEF and FS were significantly increased [LVEF (%): 67.00±1.14 vs. 54.60±1.57, 53.40±2.18; FS (%): 38.60±0.51 vs. 30.60±1.10, 30.00±0.71; all P < 0.05].
Up-regulation of TERT expression can inhibit DOX-induced cardiomyocyte autophagy and apoptosis, attenuate DOX-induced myocardial fibrosis in mice, improve cardiac function, and thus alleviate DOX-induced cardiotoxicity.
探讨端粒酶逆转录酶（TERT）在减轻阿霉素（DOX）诱导的心脏毒性中的作用。
（1）细胞实验：将大鼠H9c2心肌细胞分为对照组（CON组）、空腺病毒转染组（NC组）、TERT过表达腺病毒转染组（TERT组）、DOX组（用1μmol/L DOX处理12小时）、DOX + NC组和DOX + TERT组（空腺病毒或TERT过表达腺病毒转染24小时后，再用1μmol/L DOX处理12小时）。采用实时荧光定量聚合酶链反应（RT-qPCR）检测心肌细胞中TERT的mRNA表达。通过免疫荧光检测线粒体膜电位水平。采用蛋白质印迹法检测细胞内Bax、Bcl-2、微管相关蛋白1轻链3（LC3）和p62的表达水平。（2）动物实验：将雄性C57BL/6小鼠随机分为假手术组（Sham组）、DOX组（腹腔注射15mg/kg DOX构建急性心脏毒性模型）、DOX + NC组和DOX + TERT组（经空气传播腺病毒或TERT过表达腺病毒转染7天建模）。建模7天后，采用天狼星红染色检测心肌纤维化面积，采用超声心动图检测心脏功能。
（1）细胞实验：TERT组TERT的mRNA表达水平显著高于CON组和NC组。与CON组相比，DOX组和DOX + NC组心肌细胞TERT mRNA表达水平显著降低，线粒体膜电位水平显著降低，Bax和LC3蛋白表达显著增加，Bcl-2和p62蛋白表达显著降低。DOX组和DOX + NC组之间无显著差异。与DOX组和DOX + NC组相比，DOX + TERT组TERT mRNA表达水平升高（相对表达：1.02±0.10 vs. 0.61±0.05，0.54±0.03，均P < 0.05），线粒体膜电位水平显著升高（1.14±0.05 vs. 0.96±0.01，0.96±0.01，均P < 0.05），Bax和LC3蛋白表达显著降低，Bcl-2和p62蛋白表达显著增加（Bax/β-肌动蛋白：0.88±0.01 vs. 1.31±0.02，1.26±0.01；LC3-II/I：2.16±0.05 vs. 2.64±0.06，2.58±0.02；Bcl-2/β-肌动蛋白：0.65±0.01 vs. 0.40±0.01，0.41±0.01；p62/β-肌动蛋白：0.45±0.01 vs. 0.23±0.02，0.29±0.01；均P < 0.05）。（2）动物实验：与Sham组相比，DOX组和DOX + NC组心肌纤维化面积百分比显著增加，左心室射血分数（LVEF）和缩短分数（FS）显著降低。与DOX组和DOX + NC组相比，DOX + TERT组心肌纤维化面积百分比显著降低（%：2.33±0.06 vs. 3.76±0.07，3.
