Fig. 2.

PA28γ expression increased in both in vitro and in vivo models of osteoarthritis (OA). a) Representative safranin O/solid green staining images, toluidine blue staining images, and immunohistochemical images of PA28γ in articular cartilage of destabilized medial meniscus (DMM) and sham mice, measuring scale = 100 μm, magnification: ×200. b) Osteoarthritis Research Society International (OARSI) score of DMM and sham mice (n = 6, ****p < 0.0001). c) Quantitative analysis of PA28γ-positive chondrocyte in cartilage from DMM and sham mice (n = 3, ****p < 0.0001). d) PA28γ mRNA levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR) after chondrocytes were stimulated with various concentrations of interleukin-1β (IL-1β) for 48 hours (**p < 0.01). e) PA28γ mRNA levels were measured by qRT-PCR after chondrocytes were stimulated with 5 ng/ml IL-1β for different durations (***p < 0.001, ****p < 0.0001). f) Western blotting and quantitative data of PA28γ expression 48 hours obtained after stimulating chondrocytes with various concentrations of IL-1β (**p < 0.01). g) PA28γ representative western blotting and quantitative data obtained after stimulating chondrocytes with 5 ng/ml IL-1β for different durations (**p < 0.01, ***p < 0.001, ****p < 0.0001).