Fig. 4.

Transgenic activating mutation of TGF-β1 results in a TMJ-OA phenotype. a HE (left) and Safranin O and fast green (right) staining analyses of glycosaminoglycan (red) in the condylar cartilage of 10-month-old CED mice and WT littermates. Mandibular condylar cartilage cell layers (FC fibrocartilage layer, CC: calcified cartilage layer). b FC/CC, c Mankin and d OARSI scores of CED mice. e Immunohistochemical staining of p-Smad2/3 and Osterix (brown) in the mandibular condylar cartilage of ageing mice (left). p-Smad2/3- and Osterix-positive cells (brown) were counted in the cartilage layer (right). f Representative µCT images of the condylar subchondral bone. Quantitative analysis of the structural parameters of subchondral bone is shown on the bottom. g TRAP and immunohistochemical (Osterix and p-Smad2/3) staining of the TMJ subchondral bone of CED mice and WT littermates. The percentage of positive cells is shown. Scale bar = 20 μm. n = 6 per group. *P < 0.05, **P < 0.01 one-way ANOVA followed by Tukey’s test. All data are reported as the mean ± s.d