人脐带间充质干细胞来源的细胞外囊泡通过与 METTL3 相互作用减轻巨噬细胞中 NLRP3 的 m6A 水平，从而缓解膝骨关节炎小鼠模型的骨关节炎。

Extracellular vesicles derived from human umbilical cord mesenchymal stem cells alleviate osteoarthritis of the knee in mice model by interacting with METTL3 to reduce m6A of NLRP3 in macrophage.

机构信息

Department of Orthopedics, the First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China.

Department of Orthopedics, Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211100, Jiangsu, China.

出版信息

Stem Cell Res Ther. 2022 Jul 16;13(1):322. doi: 10.1186/s13287-022-03005-9.

DOI:10.1186/s13287-022-03005-9

PMID:35842714

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9288728/

Abstract

BACKGROUND

Osteoarthritis (OA) is a prevalent degenerative joint disease that not only significantly impairs the quality of life of middle-aged and elderly individuals but also imposes a significant financial burden on patients and society. Due to their significant biological properties, extracellular vesicles (EVs) have steadily received great attention in OA treatment. This study aimed to investigate the influence of EVs on chondrocyte proliferation, migration, and apoptosis and their protective efficacy against OA in mice.

METHODS

The protective impact of EVs derived from human umbilical cord mesenchymal stem cells (hucMSCs-EVs) on OA in mice was investigated by establishing a mouse OA model by surgically destabilizing the medial meniscus (DMM). Human chondrocytes were isolated from the cartilage of patients undergoing total knee arthroplasty (TKA) and cultured with THP-1 cells to mimic the in vivo inflammatory environment. Levels of inflammatory factors were then determined in different groups, and the impacts of EVs on chondrocyte proliferation, migration, apoptosis, and cartilage extracellular matrix (ECM) metabolism were explored. N6-methyladenosine (m6A) level of mRNA and methyltransferase-like 3 (METTL3) protein expression in the cells was also measured in addition to microRNA analysis to elucidate the molecular mechanism of exosomal therapy.

RESULTS

The results indicated that hucMSCs-EVs slowed OA progression, decreased osteophyte production, increased COL2A1 and Aggrecan expression, and inhibited ADAMTS5 and MMP13 overexpression in the knee joint of mice via decreasing pro-inflammatory factor secretion. The in vitro cell line analysis revealed that EVs enhanced chondrocyte proliferation and migration while inhibiting apoptosis. METTL3 is responsible for these protective effects. Further investigations revealed that EVs decreased the m6A level of NLRP3 mRNA following miR-1208 targeted binding to METTL3, resulting in decreased inflammatory factor release and preventing OA progression.

CONCLUSION

This study concluded that hucMSCs-EVs inhibited the secretion of pro-inflammatory factors and the degradation of cartilage ECM after lowering the m6A level of NLRP3 mRNA with miR-1208 targeting combined with METTL3, thereby alleviating OA progression in mice and providing a novel therapy for clinical OA treatment.

摘要

背景

骨关节炎（OA）是一种常见的退行性关节疾病，不仅显著降低中老年人群的生活质量，还给患者和社会带来沉重的经济负担。由于其显著的生物学特性，细胞外囊泡（EVs）在 OA 治疗中的应用受到了广泛关注。本研究旨在探讨 EVs 对软骨细胞增殖、迁移和凋亡的影响及其对 OA 小鼠的保护作用。

方法

通过手术不稳定内侧半月板（DMM）建立 OA 小鼠模型，研究人脐带间充质干细胞（hucMSCs-EVs）衍生的 EVs 对 OA 的保护作用。从接受全膝关节置换术（TKA）的患者的软骨中分离出人软骨细胞，并与 THP-1 细胞共培养以模拟体内炎症环境。然后在不同组中测定炎症因子水平，并探讨 EVs 对软骨细胞增殖、迁移、凋亡和软骨细胞外基质（ECM）代谢的影响。还测量了细胞中 mRNA 的 N6-甲基腺苷（m6A）水平和甲基转移酶样 3（METTL3）蛋白表达，以及 microRNA 分析，以阐明外泌体治疗的分子机制。

结果

结果表明，hucMSCs-EVs 通过减少促炎因子的分泌，减缓 OA 进展，减少骨赘生成，增加 COL2A1 和 Aggrecan 表达，抑制膝关节炎中 ADAMTS5 和 MMP13 的过度表达。体外细胞系分析表明，EVs 增强软骨细胞增殖和迁移，同时抑制凋亡。METTL3 负责这些保护作用。进一步研究表明，EVs 通过 miR-1208 靶向结合 METTL3 降低 NLRP3 mRNA 的 m6A 水平，从而减少炎症因子的释放，防止 OA 进展。