H3K14 hyperacetylation‑mediated c‑Myc binding to the miR‑30a‑5p gene promoter under hypoxia postconditioning protects senescent cardiomyocytes from hypoxia/reoxygenation injury
H3K14 hyperacetylation‑mediated c‑Myc binding to the miR‑30a‑5p gene promoter under hypoxia postconditioning protects senescent cardiomyocytes from hypoxia/reoxygenation injury
复制标题
缺氧后处理下 H3K14 高度乙酰化介导的 c-Myc 与 miR-30a-5p 基因启动子的结合可保护衰老心肌细胞免受缺氧/复氧损伤
DOI：
10.3892/mmr.2021.12107
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Yideng Jiang
中科院分区：
文献类型：
--
作者：
Lingbo Xu;Huiping Zhang;Yanhua Wang;Wei Guo;Lingyu Gu;Anning Yang;Shengchao Ma;Yong Yang;Kai Wu;Yideng Jiang
我们的前期研究发现，低氧后处理（hypoxia postconditioning，HPostC）上调miR-30 a-5 p基因表达，通过DNA甲基转移酶3B诱导miR-30 a-5 p基因启动子区DNA低甲基化，对衰老的H9 C2细胞缺氧/复氧损伤具有保护作用。提示miR-30 a-5 p可能是老年心肌缺血性心脏病潜在的防治靶点。本研究旨在探讨缺血性心脏病老年心肌组织中miR-30 a-5 p转录的可能机制。用8 mg/ml D-半乳糖处理心肌细胞9天，然后暴露于缺氧条件。使用细胞活力测定法测定细胞活力。采用逆转录-定量PCR和蛋白质印迹法检测组蛋白去乙酰化酶2（HDAC 2）、LC 3B-Ⅱ/Ⅰ、beclin-1和p62的表达水平。进行染色质免疫沉淀-PCR和荧光素酶报告基因测定，以评估HPostC后衰老心肌细胞中c-Myc结合和活性对miR-30 a-5 p启动子的影响。结果发现，HPostC增强了衰老心肌细胞中miR-30 a-5 p基因启动子处H3 K14的乙酰化水平，这归因于HDAC 2表达的降低。此外，c-Myc可通过上调miR-30 a-5 p的转录抑制衰老心肌细胞自噬。在机制上，观察到暴露于罗米地辛的H3 K14乙酰化水平增加促进c-Myc与miR-30 a-5 p基因启动子区的结合，这导致miR-30 a-5 p的转录增加。综上所述，这些结果表明HDAC 2介导的H3 K14超乙酰化促进c-Myc与miR-30 a-5 p基因启动子的结合，这有助于HPostC衰老心脏保护。
Our previous study reported that microRNA (miR)-30a-5p upregulation under hypoxia postconditioning (HPostC) exert a protective effect on aged H9C2 cells against hypoxia/reoxygenation injury via DNA methyltransferase 3B-induced DNA hypomethylation at the miR-30a-5p gene promoter. This suggests that miR-30a-5p may be a potential preventative and therapeutic target for ischemic heart disease in aged myocardium. The present study aimed to investigate the underlying mechanisms of miR-30a-5p transcription in aged myocardium in ischemic heart disease. Cardiomyocytes were treated with 8 mg/ml D-galactose for 9 days, and then exposed to hypoxic conditions. Cell viability was determined using a cell viability assay. Expression levels of histone deacetylase 2 (HDAC2), LC3B-II/I, beclin-1 and p62 were detected via reverse transcription-quantitative PCR and western blotting. Chromatin immunoprecipitation-PCR and luciferase reporter assays were performed to evaluate the effect of c-Myc binding and activity on the miR-30a-5p promoter in senescent cardiomyocytes following HPostC. It was found that HPostC enhanced the acetylation levels of H3K14 at the miR-30a-5p gene promoter in senescent cardiomyocytes, which attributed to the decreased expression of HDAC2. In addition, c-Myc could positively regulate miR-30a-5p transcription to inhibit senescent cardiomyocyte autophagy. Mechanically, it was observed that increased H3K14 acetylation level exposed to romidepsin facilitated c-Myc binding to the miR-30a-5p gene promoter region, which led to the increased transcription of miR-30a-5p. Taken together, these results demonstrated that HDAC2-mediated H3K14 hyperacetylation promoted c-Myc binding to the miR-30a-5p gene promoter, which contributed to HPostC senescent cardioprotection.