turns-00009.parquet:55486
9d24e6dde96d21ecfcb0efb6
turn 3/3gpt-3.5-turbo-0613EnglishSingapore534 words
degenerate_repetitionAbsentFinal dense release
USER
Translate this into Chinese"Ankylosing spondylitis (AS) is a common kind of rheumatic disease that affects 0.1–0.5% of the population worldwide1. As the major component of spondyloarthropathy, AS is characterized by chronic inflammation and ectopic ossification in the entheses, which distinguishes AS from other rheumatic diseases2. However, both the mechanisms of chronic inflammation and ectopic ossification and the relationship between these two features still require further investigation. Mesenchymal stem cells (MSC) are a kind of pluripotent adult stem cell found in vivo3. As both a major source of osteoblasts and a critical regulator of immune cells, MSC play an important role as a bridge connecting bone metabolism and immune homeostasis4–6. Previously, our study, as well as Chin-Hsiu Liu’s results, indicated that the abnormally enhanced osteogenic differentiation capacity of MSC from AS patients (AS-MSC) resulted in pathological osteogenesis and syndesmophyte formation7,8. Moreover, we further demonstrated that AS-MSC secreted a relatively large amount of CCL2 during the enhanced osteogenic differentiation course, which augmented monocyte migration, increased proinflammatory macrophage polarization and enhanced TNF-α secretion at the site of enthesis9. However, whether TNF-α secreted by macrophages, in turn, affects AS-MSC is still an open question. Directional migration to a specific location ensures that MSC exert powerful functions10. Since normal MSC migration contributes to tissue regeneration and immune regulation, it is unsurprising that directional migration of dysfunctional MSC results in disease development. The migration process is under the regulation of various factors11. Engulfment and cell motility protein 1 (ELMO1), which is known as CED12 in Caenorhabditis elegans, is a core molecule involved in cell migration12. ELMO1 functionally binds dedicator of cytokinesis (DOCK) proteins and then regulates cytoskeletal rearrangement via Rac1 activation, which participates in various biological functions, such as directional migration, engulfment of apoptotic cells, nervous system development and cancer cell invasion12–15. Previous studies have shown that the abnormal expression of ELMO1 is greatly involved in several diseases, including diabetic nephropathy, inflammatory arthritis and inflammatory bowel disease16–18. Both the role of ELMO1 in MSC directional migration and its effect on AS pathogenesis are still ambiguous. N6-methyladenosine (m6A), present at approximately three to five sites per mRNA transcript (0.1–0.4% of adenosines) in mammalian cells, is the most abundant internal mRNA modification19. m6A modification regulates gene expression and is widely involved in cell function and development20,21. Differential expression of methyltransferases such as METTL3 and METTL14 or demethylases including FTO and ALKBH5 results in abnormal expression of specific genes, which ultimately contributes to diseases development22–24. However, the effect of m6A modification on AS pathogenesis has never been investigated. In this study, we demonstrate that a high level of TNF-α induced stronger directional migration of AS-MSC compared to MSC from healthy controls (HC-MSC) by increasing ELMO1 expression. Further research showed that this phenomenon resulted from the METTL14 mediated m6A modification of the ELMO1 3′UTR in AS-MSC after TNF-α treatment. A higher expression of ELMO1 in AS-MSC was also found in the enthesis of AS patients in vivo. Moreover, injecting Av-ELMO1 significantly improved inflammation and ectopic ossification in SKG mice serving as a spondyloarthritis model. This study may not only contribute to the elucidation of the pathogenesis of AS but also provide insight into clinical therapy for AS"
ASSISTANT
“强直性脊柱炎(AS)是一种常见的风湿病,全球人口中有0.1-0.5%受到影响。作为脊柱关节病的主要组成部分,AS以慢性炎症和韧带部位的异常骨化为特征,这与其他风湿病有所区别。然而,关于慢性炎症和异常骨化的机制以及两者之间的关系仍需要进一步研究。 间充质干细胞(MSC)是一种存在于体内的多能成体干细胞。作为成骨细胞的主要来源和免疫细胞的重要调节因子,MSC在连接骨代谢和免疫稳态方面发挥着重要作用。我们的研究以及Chin-Hsiu Liu的研究结果表明,AS患者的MSC(AS-MSC)在体外表现出异常增强的成骨分化能力,导致了病理性骨化和软骨桥形成。此外,在骨化分化过程中,AS-MSC分泌出较多的CCL2,增强了单核细胞的迁移,增加了促炎巨噬细胞的极化,并增强了炎症灶中TNF-α的分泌。然而,TNF-α是否由巨噬细胞分泌,并进一步影响AS-MSC仍然是个未解之谜。 定向迁移到特定位置是MSC发挥强大功能的关键。由于正常的MSC迁移有助于组织再生和免疫调节,因此可想而知,功能异常的MSC的定向迁移会导致疾病发展。迁移过程受多种因素调节。参与细胞迁移的关键分子之一是吞噬和细胞运动蛋白1(ELMO1)。ELMO1是在秀丽隐杆线虫中称为CED12的核心分子,它通过与细胞分裂激酶(DOCK)蛋白结合,以激活Rac1从而调节细胞骨架重组,参与定向迁移、吞噬凋亡细胞、神经系统发育和癌细胞侵袭等多种生物学功能。以往的研究已经表明,ELMO1的异常表达与多种疾病密切相关,包括糖尿病肾病、炎性关节炎和炎症性肠病等。ELMO1在MSC定向迁移中的作用以及对AS发病机制的影响仍不清楚。 N6甲基腺苷(m6A)是哺乳动物细胞中每个mRNA转录本中出现约三到五个位点的内部最丰富的mRNA修饰。m6A修饰调节基因表达,在细胞功能和发育中发挥广泛作用。甲基转移酶(例如METTL3和METTL14)和去甲基酶(包括FTO和ALKBH5)的差异表达导致特定基因的异常表达,最终促成疾病的发展。然而,m6A修饰对AS发病机制的影响从未得到研究。 本研究证明,与健康对照组(HC-MSC)相比,高水平的TNF-α诱导AS-MSC更强的定向迁移能力,通过增加ELMO1的表达。进一步研究显示,这种现象是经由METTL14介导的TNF-α处理后AS-MSC中ELMO1 3'UTR的m6A修饰所导致的。在AS患者的韧带部位也发现了AS-MSC中ELMO1的高表达。此外,注射Av-ELMO1明显改善了作为脊柱关节炎模型的SKG小鼠中的炎症和异常骨化。这项研究不仅有助于阐明AS的发病机制,还为AS的临床治疗提供了一些见解。”