Synovial macrophages in osteoarthritis: Roles and features / 中国组织工程研究

ABSTRACT

BACKGROUND: The exact pathogenesis of osteoarthritis is unclear. Studies have shown that macrophages in synovial tissue are involved in sliding-inflammation response and the production of cartilage matrix degradation enzyme. OBJECTIVE: Based on the important role of synovial macrophages in osteoarthritis, to review and summarize the major research achievements and important research methods in this field, laying a foundation for future research on synovial macrophages. METHODS: The first author used computer to search relevant literatures included in PubMed and VIP from 1999 to 2019. The search terms were “osteoarthritis, synovitis, synovial macrophages” in English and Chineserespectively. Manual screening was conducted according to the inclusion criteria, and irrelevant, repetitive and obsolete articles were excluded. Finally, 46 eligible articles were included.RESULTS AND CONCLUSION: There is an inflammatory response in the synovial tissue, and the severity of synovitis is closely related to osteoarthritis symptoms and progression. A large number of macrophages with different activation states are infiltrated in the synovial tissues of osteoarthritis patients at different stages. M1 macrophages are the main subgroup of macrophages involved in the production, cartilage degradation and osteophyte formation of osteoarthritis inflammatory factors, while M2 macrophages have a protective effect on osteoarthritis by secreting anti-inflammatory factors. Inhibiting the differentiation of macrophages into M1 type and promoting their M2 type differentiation can alleviate the pathological changes of osteoarthritis and delay the progression of osteoarthritis. It may be an effective method to treat osteoarthritis by regulating the polarization state of synovial macrophages.