Figure 2. sOPN was increased expressed in OA subchondral bone mainly in preosteoblasts and osteoblasts. (A, B) Western blot and qPCR analysis of the expression of OPN in primary osteoblasts of subchondral bone of an OA mouse model and control group; n ≥ 3. (C, D) Representative immunofluorescent and quantitative analysis of sOPN in OSX+ preosteoblasts or OCN+ osteoblasts in the tibial subchondral bone of an OA mouse model and control group. Positive cells were indicated with arrows. The boxed area is magnified in the corner, scale bars = 50 μm. Data are shown as mean ± s. d. and were analyzed by Student’s t test; n = 6, *P < 0.05,**P < 0.01.