Shuang Wang1,2, Tao Yao3, Fan Deng4, Wenqian Yu1, Yiting Song5, Jingyi Chen6, Zhihua Ruan7. 1. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, China. 2. Dongfeng General Hospital, Hubei University of Medicine, Shiyan, 442000, China. 3. Department of Anesthesiology, Shenzhen Bao'an Maternity and Child Health Hospital, Shenzhen, 518100, China. 4. Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China. 5. Department of Anesthesiology, Shenzhen Bao'an Maternity and Child Health Hospital, Shenzhen, 518100, China. yingting_song@sina.com. 6. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, China. year0216@163.com. 7. Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan, 442000, China. oncemonkey@126.com.
Abstract
BACKGROUND/AIMS: LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is reported to be highly expressed in myocardial I/R injury and closely related to autophagy. However, the exact biological role of MALAT1 and its underlying mechanism in myocardial I/R injury remain to be elucidated. METHODS: We established incultured H9C2 cardiomyocytes an oxygen-glucose deprivation and reoxygenation (OGD/R) model for 6 h and then reoxygen-glucose for 4 h. We measured cell damage and autophagy levels after OGD/R by real-time quantitative PCR and Western blot. The relationships between miR-20b and MALAT1, beclin1 were confirmed by luciferase reporter assay. RESULTS: We found that the expression of MALAT1 and beclin1, cell damage levels (lactate dehydrogenase (LDH) release, 222.4 ± 29.4 vs. 577.5 ± 27.4 U/L; creatine kinase MB isoenzyme (CK-MB), 1.0 ± 0.2 vs. 4.3 ± 0.4; cardiac troponin I (cTn-I), 1.0 ± 0.3 vs. 3.0 ± 0.3; p < 0.05), and autophagy levels were significantly increased after OGD/R model, while cell viability (100.0 vs. 54.2 ± 2.2%, p < 0.05) and the expression of miR-20b and P62 were reduced; the trend of all the above data was significantly reversed by MALAT1 siRNA. In addition, the luciferase reporter assay results confirmed that MALAT1 directly binds to miR-20b-5p and functions as a ceRNA for miR-20b-5p to regulate beclin1. As a result, MALAT1 overexpression antagonized while MALAT1 knockdown enhanced the inhibitory effects of miR-20b-5p on beclin1-related cardiomyocytes autophagy in OGD/R injury. CONCLUSION: LncRNA MALAT1 promotes OGD/R-induced cardiomyocytes injury through sponging miR-20b to enhance beclin1-mediated autophagy.
BACKGROUND/AIMS: LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is reported to be highly expressed in myocardial I/R injury and closely related to autophagy. However, the exact biological role of MALAT1 and its underlying mechanism in myocardial I/R injury remain to be elucidated. METHODS: We established incultured H9C2 cardiomyocytes an oxygen-glucose deprivation and reoxygenation (OGD/R) model for 6 h and then reoxygen-glucose for 4 h. We measured cell damage and autophagy levels after OGD/R by real-time quantitative PCR and Western blot. The relationships between miR-20b and MALAT1, beclin1 were confirmed by luciferase reporter assay. RESULTS: We found that the expression of MALAT1 and beclin1, cell damage levels (lactate dehydrogenase (LDH) release, 222.4 ± 29.4 vs. 577.5 ± 27.4 U/L; creatine kinase MB isoenzyme (CK-MB), 1.0 ± 0.2 vs. 4.3 ± 0.4; cardiac troponin I (cTn-I), 1.0 ± 0.3 vs. 3.0 ± 0.3; p < 0.05), and autophagy levels were significantly increased after OGD/R model, while cell viability (100.0 vs. 54.2 ± 2.2%, p < 0.05) and the expression of miR-20b and P62 were reduced; the trend of all the above data was significantly reversed by MALAT1 siRNA. In addition, the luciferase reporter assay results confirmed that MALAT1 directly binds to miR-20b-5p and functions as a ceRNA for miR-20b-5p to regulate beclin1. As a result, MALAT1 overexpression antagonized while MALAT1 knockdown enhanced the inhibitory effects of miR-20b-5p on beclin1-related cardiomyocytes autophagy in OGD/R injury. CONCLUSION: LncRNA MALAT1 promotes OGD/R-induced cardiomyocytes injury through spongingmiR-20b to enhance beclin1-mediated autophagy.
Authors: Yanqun Cao; Jia Liu; Quzhe Lu; Kai Huang; Baolin Yang; James Reilly; Na Jiang; Xinhua Shu; Lei Shang Journal: Int J Mol Med Date: 2022-05-20 Impact factor: 5.314