Fig. 1

Histological characteristics and TLR4 expression in CFA-induced TMJOA mice. A Scheme regarding the establishment of TMJOA mice by bilateral intra-articular CFA injection and analyzed at 1, 2, and 4 weeks post-injection. B, C Representative images of H&E, Masson staining, and TLR4 immunofluorescence staining for TMJ tissue slices. B Quantitative analysis showed that there was a time course of condylar cartilage thinning and unmineralized bone increase 1, 2, and 4 weeks after CFA injection, with the expression of TLR4 enhanced in the condylar cartilage and synovium of CFA-induced TMJOA mice (C), one-way ANOVA, mean ± SEM, n = 6 (*p < 0.05, **p < 0.01, ***p < 0.001 vs saline group, ns indicates no significant difference). D H&E staining disclosed remarkable inflammatory exudation (b), inflammatory cell infiltration (d), lipid droplet and lymphoid follicle formation (f), and synovial lining layer thickening (h) in inflammatory synovial tissues of CFA-induced TMJOA mice at 1 week, accompanied by CD34 immunochemical staining in the synovial vascular region of TMJOA mice. E Quantitative analysis revealed that the number of synovial lining layers increased in CFA-induced TMJOA mice at 1 week, Student’s t test, mean ± SEM, n = 6 (***p < 0.001)