Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing 210009, China.
Department of Cardiology, Affiliated Hospital of Nantong University, Nantong 226001, China.
Acta Biochim Biophys Sin (Shanghai). 2020 Dec 29;52(12):1306-1315. doi: 10.1093/abbs/gmaa130.
N6-methyladenosine (m6A), a methylation in the N6 position of adenosine especially in the mRNA, exerts diverse physiological and pathological functions. However, the precise role of m6A methylation in hypoxic preconditioning (HPC) is still unknown. Here, we observed that HPC treatment protected H9c2 cells against H2O2-induced injury, upregulated the m6A level in the total RNA and the expression of methyltransferase like 3 (METTL3), methyltransferase like 14 (METTL14), and long noncoding RNA (lncRNA) H19. Either knockdown of METTL3 or METTL14 notably reversed the HPC-induced enhancement of cell viability, anti-apoptosis ability, and H19 expression. Methylated RNA immunoprecipitation (IP) indicated that knockdown of METTL3 or METTL14 decreased m6A level in the lncRNA H19. Gain-of-function assay demonstrated that H19 overexpression could partially rescue the decreased protection mediated by METTL3 or METTL14 knockdown in HPC-treated H9c2 cells. RNA binding protein immunoprecipitation (RIP) assay showed that METTL3 and METTL14 could directly bind with H19. Our study identified a novel pattern of posttranscriptional regulation in HPC treatment. Since METTL3, METTL14, and lncRNA H19 were involved in HPC protection, they could be considered as potential biomarkers and therapeutic targets in HPC-derived cardiac rehabilitation and therapeutic approaches.
N6-甲基腺苷（m6A）是一种在腺苷的 N6 位发生的甲基化修饰，尤其在 mRNA 中存在，它发挥着多种生理和病理功能。然而，m6A 甲基化在低氧预处理（HPC）中的精确作用尚不清楚。在这里，我们观察到 HPC 处理可保护 H9c2 细胞免受 H2O2 诱导的损伤，上调总 RNA 中的 m6A 水平以及甲基转移酶样 3（METTL3）、甲基转移酶样 14（METTL14）和长非编码 RNA（lncRNA）H19 的表达。METTL3 或 METTL14 的敲低显著逆转了 HPC 诱导的细胞活力、抗凋亡能力和 H19 表达的增强。甲基化 RNA 免疫沉淀（IP）表明，METTL3 或 METTL14 的敲低降低了 lncRNA H19 中的 m6A 水平。功能获得实验表明，H19 的过表达可以部分挽救由 METTL3 或 METTL14 敲低介导的 HPC 处理的 H9c2 细胞中降低的保护作用。RNA 结合蛋白免疫沉淀（RIP）实验表明，METTL3 和 METTL14 可以直接与 H19 结合。我们的研究确定了 HPC 处理中一种新的转录后调控模式。由于 METTL3、METTL14 和 lncRNA H19 参与了 HPC 保护，它们可以被认为是 HPC 衍生的心脏康复和治疗方法中潜在的生物标志物和治疗靶点。
