Zhu Hao, Sun Bao, Zhu Liang, Zou Guoyou, Shen Qiang
Department of Orthopaedics, The Affiliated Shanghai General Hospital of Nanjing Medical University, Shanghai, China.
Department of Orthopaedics, Yancheng First Hospital, Affiliated Hospital of Nanjing University Medical School, Yancheng, China.
Front Cell Dev Biol. 2021 Mar 5;9:642437. doi: 10.3389/fcell.2021.642437. eCollection 2021.
Low back pain is tightly associated with intervertebral disc degeneration (IVDD) and aberrant nucleus pulposus (NP) is a critical cause. miRNAs N6-methyladenosine (m6A) modification accounts for the TNF-α-induced senescence of NP cells. The aim of this study was to investigate whether m6A modification regulates TNF-α-mediated cell viability, cell cycle arrest, and cell senescence and how it works. The results showed that METTL14 expression positively correlated with m6A and TNF-α expression in HNPCs. The knockdown of METTL14 led to the inhibition of the TNF-α-induced cell senescence. METTL14 overexpression promoted cell senescence. METTL14 regulated the m6A modification of miR-34a-5p and interacted with DGCR8 to process miR-34a-5p. The miR-34a-5p inhibitor inhibited the cell cycle senescence of HNPCs. miR-34a-5p was predicted to interact with the SIRT1 mRNA. SIRT1 overexpression counteracted the miR-34a-5p-promoted cell senescence. METTL14 participates in the TNF-α-induced m6A modification of miR-34a-5p to promote cell senescence in HNPCs and NP cells of IVDD patients. Downregulation of either METTL14 expression or miR-34a-5p leads to the inhibition of cell cycle arrest and senescence. SIRT1 mRNA is an effective binding target of miR-34a-5p, and SIRT1 overexpression mitigates the cell cycle arrest and senescence caused by miR-34a-5p.
下腰痛与椎间盘退变（IVDD）密切相关，髓核（NP）异常是一个关键原因。微小RNA（miRNA）的N6-甲基腺苷（m6A）修饰参与了肿瘤坏死因子-α（TNF-α）诱导的NP细胞衰老。本研究旨在探讨m6A修饰是否调节TNF-α介导的细胞活力、细胞周期阻滞和细胞衰老以及其作用机制。结果显示，在人NP细胞（HNPCs）中，METTL14表达与m6A及TNF-α表达呈正相关。敲低METTL14可抑制TNF-α诱导的细胞衰老。过表达METTL14则促进细胞衰老。METTL14调节miR-34a-5p的m6A修饰，并与DGCR8相互作用以加工miR-34a-5p。miR-34a-5p抑制剂可抑制HNPCs的细胞周期衰老。预测miR-34a-5p与沉默信息调节因子1（SIRT1）mRNA相互作用。过表达SIRT1可抵消miR-34a-5p促进的细胞衰老。METTL14参与TNF-α诱导的miR-34a-5p的m6A修饰，以促进IVDD患者的HNPCs和NP细胞衰老。下调METTL14表达或miR-34a-5p均可导致细胞周期阻滞和衰老受到抑制。SIRT1 mRNA是miR-34a-5p的有效结合靶点，过表达SIRT1可减轻miR-34a-5p引起的细胞周期阻滞和衰老。
