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1دورية أكاديمية
العنوان البديل: Hypoxic postconditioning protects myocardium by regulating autophagy in aging cardiomyocytes through piRNA-005854. (English)
المصدر: Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu; 5/8/2024, Vol. 28 Issue 13, p2054-2060, 7p
مصطلحات موضوعية: LACTATE dehydrogenase, ISCHEMIC postconditioning, REPERFUSION injury, MYOCARDIAL injury, WESTERN immunoblotting, GALACTOSE, CREATINE kinase
الملخص (بالإنجليزية): BACKGROUND: Ischemic postconditioning is one of the effective ways to reduce ischemia-reperfusion injury and has been more and more widely used in clinical practice in recent years, but its specific molecular mechanism has yet to be studied. OBJECTIVE: To investigate the role and mechanism of piRNA-005854 in the aging cardiomyocytes caused by hypoxic postconditioning. METHODS: In vitro, cardiomyocytes were administered 8 mg/mL D-galactose for 9 days to induce their aging. β-Galactosidase staining was used to observe the aging of cardiomyocytes. Senescent cells were treated with hypoxia/reoxygenation and hypoxic postconditioning. ELISA was utilized to detect changes in myocardial injury markers creatine kinase isoenzyme MB and lactate dehydrogenase levels. Western blot assay was applied to detect the expression changes of autophagy-related proteins LC3II, p62, ULK1 and phosphorylated ULK1 in aging cardiomyocytes. qRT-PCR was employed to determine the expression level of piRNA-005854. piRNA-005854 inhibitor and piRNA-005854 mimics were transferred into aging cardiomyocytes and followed with hypoxic postconditioning. Western blot assay was used to examine the expression of LC3II, p62, ULK1 and phosphorylated ULK1. RESULTS AND CONCLUSION: (1) D-galactose induced obvious senescence of cardiomyocytes 9 days later. (2) Compared with the normoxia group, creatine kinase isoenzyme MB and lactate dehydrogenase levels increased in the hypoxia/reoxygenation group (P < 0.01); LC3 II/I expression was increased; p62 expression was decreased; ULK1 phosphorylation level was increased, and piRNA-005854 expression was increased (P < 0.01). (3) Compared with the hypoxia/ reoxygenation group, creatine kinase isoenzyme MB and lactate dehydrogenase levels significantly reduced in the hypoxic postconditioning group (P < 0.01); LC3 II/I expression significantly decreased (P < 0.05); p62 expression increased (P < 0.01); ULK1 phosphorylation level decreased (P < 0.05), and piRNA-005854 expression decreased (P < 0.01). (4) After transfection of piRNA-005854 inhibitor, LC3II/I expression was decreased (P < 0.01); the expression of p62 was increased significantly (P < 0.05); the phosphorylation level of ULK1 was decreased significantly (P < 0.01). After transfection of piRNA-005854 mimics, LC3II/ I expression was increased significantly; the expression of p62 was decreased, and the phosphorylation level of ULK1 was increased significantly (P < 0.01). (5) The results show that piRNA-005854-mediated reduction of ULK1-dependent autophagy level is a possible mechanism that hypoxic postconditioning exerts its protective effect on aging cardiomyocytes. [ABSTRACT FROM AUTHOR]
Abstract (Chinese): 背景：缺血后处理是减轻缺血再灌注损伤的有效方式之一, 近年来被越来越广泛地应用于临床实践, 但其具体分子机制还有待研究。 目的：探讨piRNA-005854在衰老心肌细胞缺氧后处理中的作用及机制。 方法：体外给予心肌细胞8 mg/mL D-半乳糖9 d诱导其衰老, β-半乳糖苷酶染色观察心肌细胞的衰老情况；衰老后细胞给予缺氧/复氧处 理和缺氧后处理, ELISA检测心肌损伤标志物肌酸激酶同工酶MB以及乳酸脱氢酶水平；Western blot检测衰老心肌细胞中自噬相关蛋白 LC3Ⅱ、p62和ULK1及其磷酸化ULK1的表达；qRT-PCR检测piRNA-005854的表达水平；进一步用piRNA-005854 inhibitor及piRNA-005854 mimics 转染衰老心肌细胞并进行缺氧后处理, Western blot检测LC3Ⅱ、p62和ULK1及其磷酸化ULK1的表达。 结果与结论：①D-半乳糖诱导9 d后心肌细胞出现明显衰老；②与正常氧组比较, 缺氧/复氧组肌酸激酶同工酶MB以及乳酸脱氢酶水平增 加(P < 0.01)；LC3Ⅱ/Ⅰ表达升高、p62表达降低、ULK1磷酸化水平升高、piRNA-005854表达升高(P < 0.01)；③与缺氧/复氧组比较, 缺氧后 处理组肌酸激酶同工酶MB以及乳酸脱氢酶水平明显减少(P < 0.01)；LC3Ⅱ/Ⅰ表达明显降低(P < 0.05)、p62表达升高(P < 0.01)、ULK1磷酸化 水平降低(P < 0.05)、piRNA-005854表达降低(P < 0.01)；④转染piRNA-005854 inhibitor后, LC3Ⅱ/Ⅰ表达降低(P < 0.01), p62表达明显升高(P < 0.05), ULK1磷酸化水平明显降低(P < 0.01)；转染piRNA-005854 mimics后, LC3Ⅱ/Ⅰ表达显著升高, p62表达降低, ULK1磷酸化水平明显增 加(P < 0.01)；⑤结果表明, piRNA-005854介导的ULK1依赖性自噬水平降低是衰老心肌细胞缺氧后处理发挥保护作用的可能机制。 [ABSTRACT FROM AUTHOR]
: Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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2دورية أكاديمية
العنوان البديل: Role of LncRNA MALAT1 in myocardial autophagy reduction in aging rats after ischemic postconditioning. (English)
المصدر: Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu; 7/18/2023, Vol. 27 Issue 20, p3173-3179, 7p
مصطلحات موضوعية: LINCRNA, ISCHEMIC postconditioning, SPRAGUE Dawley rats, REPERFUSION injury, PROTEIN expression
الملخص (بالإنجليزية): BACKGROUND: Ischemic postconditioning can alleviate myocardial ischemia-reperfusion injury, but the specific mechanism is not clear. OBJECTIVE: To investigate the mechanism of long non-coding RNA (lncRNA) MALAT1 in the reduction of autophagy levels in aging myocardium induced by ischemic postconditioning. METHODS: Twenty-seven Sprague-Dawley rats aged 22-24 months were randomly divided into three groups, with nine rats in each group: sham operation, ischemia-reperfusion, and ischemic postconditioning groups. Morphological changes of myocardial tissue were observed by hematoxylin-eosin staining and Masson staining. Rat myocardial cells (H9C2) were induced in vitro with 8 mg/mL D-galactose for 9 days and then divided into normoxia, hypoxia-reoxygenation, and hypoxia postconditioning groups. Western blot was used to detect the protein expression levels of LC3II/I and p62. Fluorescence quantitative PCR was used to detect the expression of lncRNA MALAT1 in aging myocardium and aging cardiomyocytes. Autophagy double-labeled adenovirus (RFP-GFP-LC3) was used to observe the changes of autophagic flux in aging cardiomyocytes. lncRNA MALAT1 interference fragment and overexpression plasmid were transfected into aging cardiomyocytes and the protein expression levels of LC3II/I and p62 were detected by western blot. RESULTS AND CONCLUSION: Compared with the ischemia-reperfusion group, the myocardial tissue structure of the ischemic postconditioning group was basically clear, the nucleus was intact, and the deposition of blue collagen fibers in the myocardial tissue was reduced. Compared with the ischemia-reperfusion group, the expression of LC3II/I was decreased and the expression of p62 was increased in the ischemic postconditioning group (P < 0.05). Compared with the hypoxia-reperfusion group, the expression of LC3II/I was decreased (P < 0.01) and the expression of p62 was increased (P < 0.05) in the hypoxia postconditioning group, and the number of intracellular autophagosomes and autophagolysosomes was decreased (P < 0.05). Compared with the ischemiareperfusion group, the expression of MALAT1 in the aging myocardial tissue was decreased the ischemic postconditioning group (P < 0.01); compared with the hypoxia-reperfusion group, the expression of MALAT1 in aging cardiomyocytes was decreased in the hypoxic postconditioning group (P < 0.01). Compared with the hypoxia postconditioning+si-NC group, the expression of LC3II/I was decreased and the expression of p62 was increased in the hypoxia postconditioning +si-lncRNA MALAT1 (P < 0.01); compared with the hypoxia postconditioning+ad-NC group, the expression of LC3II/I was increased and the expression of p62 was decreased in the hypoxia postconditioning+ad-lncRNA MALAT1 group (P < 0.01). To conclude, the lncRNA MALAT1 mediated reduction of autophagy levels is an important mechanism underlying the protective effect of ischemic postconditioning in aging myocardium. [ABSTRACT FROM AUTHOR]
Abstract (Chinese): 背景：缺血后处理可缓解心肌缺血再灌注损伤，但是其具体机制尚不清楚。 目的：探讨lncRNA MALAT1在缺血后处理所引起衰老心肌自噬水平降低中的作用。 方法： 27只22-24月龄SD大鼠随机分为3组：假手术组、缺血再灌注组和缺血后处理组，每组9只，采用苏木精-伊红染色和Masson染色 观察心肌组织形态学变化； 体外使用8 mg/mL D-半乳糖诱导大鼠心肌(H9C2)细胞9 d后，分为正常氧组、缺氧复氧组和缺氧后处理组。 Western blot检测衰老心肌组织及衰老心肌细胞中LC3Ⅱ/Ⅰ和p62蛋白的表达；采用qRT-PCR检测衰老心肌组织和衰老心肌细胞中MALAT1相 对表达；转染自噬双标腺病毒(RFP-GFP-LC3)观察衰老心肌细胞自噬流的变化；衰老心肌细胞转染MALAT1干扰片段和过表达质粒，Western blot检测各组细胞中LC3Ⅱ/Ⅰ和p62蛋白的表达。 结果与结论： 与缺血再灌注组比较，缺血后处理组心肌组织结构基本清晰，细胞核完整，心肌组织间蓝色胶原纤维沉积减少； 与缺 血再灌注组比较，缺血后处理组LC3Ⅱ/Ⅰ表达降低且p62表达增高(P < 0.05)； 与缺氧复氧组比较，缺氧后处理组LC3Ⅱ/Ⅰ表达降低(P < 0.01)且p62表达增加(P < 0.05)，细胞内自噬体和自噬溶酶体数量均减少(P < 0.01)； 与缺血再灌注组比较，缺血后处理组衰老心肌组织的 MALAT1表达降低(P < 0.01)；与缺氧复氧组比较，缺氧后处理组衰老心肌细胞的MALAT1表达降低(P < 0.01)； 衰老心肌细胞转染MALAT1 干扰片段和过表达质粒后，与缺氧复氧+si-NC组比较，缺氧复氧+si-MALAT1组LC3Ⅱ/Ⅰ表达降低且p62表达增加(P < 0.01)；与缺氧后处理+ ad-NC组比较，缺氧后处理+ad-MALAT1组LC3Ⅱ/Ⅰ表达增加且p62表达降低(P < 0.01)； 结果表明：lncRNA MALAT1介导的自噬水平降低是 衰老大鼠心肌缺血后处理发挥保护作用的重要机制。 [ABSTRACT FROM AUTHOR]
: Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
