Abstract：
Epigenetic changes are important considerations for degenerative diseases. DNA methylation regulates crucial genes by epigenetic mechanism, impacting cell function and fate. DNA presents hypermethylation in degenerated nucleus pulposus (NP) tissue, but its role in intervertebral disc degeneration (IVDD) remains elusive. This study aimed to demonstrate that methyltransferase mediated hypermethylation was responsible for IVDD by integrative bioinformatics and experimental verification. Methyltransferase DNMT3B was highly expressed in severely degenerated NP tissue (involving human and rats) and in-vitro degenerated human NP cells (NPCs). Bioinformatics elucidated that hypermethylated genes were enriched in oxidative stress and ferroptosis, and the ferroptosis suppressor gene SLC40A1 was identified with lower expression and higher methylation in severely degenerated human NP tissue. Cell culture using human NPCs showed that DNMT3B induced ferroptosis and oxidative stress in NPCs by downregulating SLC40A1, promoting a degenerative cell phenotype. An in-vivo rat IVDD model showed that DNA methyltransferase inhibitor 5-AZA alleviated puncture-induced IVDD. Taken together, DNA methyltransferase DNMT3B aggravates ferroptosis and oxidative stress in NPCs via regulating SLC40A1. Epigenetic mechanism within DNA methylation is a promising therapeutic biomarker for IVDD.
摘要：
表观遗传变化是退行性疾病的重要考虑因素。DNA甲基化通过表观遗传机制调节关键基因，影响细胞功能和命运。DNA在变性髓核（NP）组织中呈现超甲基化，但其在椎间盘退变（IVDD）中的作用仍然难以捉摸。本研究旨在通过综合生物信息学和实验验证来证明甲基转移酶介导的高甲基化是IVDD的原因。甲基转移酶DNMT3B在严重变性的NP组织（涉及人和大鼠）和体外变性的人NP细胞（NPC）中高度表达。生物信息学阐明了高甲基化基因在氧化应激和铁凋亡中的富集，在严重变性的人NP组织中，铁凋亡抑制基因SLC40A1被鉴定为较低的表达和较高的甲基化。使用人NPCs的细胞培养表明，DNMT3B通过下调SLC40A1诱导NPCs的铁凋亡和氧化应激，促进变性细胞表型。体内大鼠IVDD模型显示DNA甲基转移酶抑制剂5-AZA减轻了穿刺诱导的IVDD。一起来看,DNA甲基转移酶DNMT3B通过调控SLC40A1加重NPCs的铁凋亡和氧化应激。DNA甲基化中的表观遗传机制是IVDD的有希望的治疗生物标志物。
