Fig. 1: 5-ASA attenuates OA caused by OSCAR overexpression in mouse articular cartilage.
From: 5-aminosalicylic acid suppresses osteoarthritis through the OSCAR-PPARγ axis
a, b Cultured primary chondrocytes from C57BL/6 J mice were infected with Ad-Control (Ad-C; 800 MOI) or the indicated MOI of Ad-OSCAR (n = 5). a Western blotting with anti-OSCAR antibody. b qRT-PCR analysis of OSCAR mRNA expression. c–e C57BL/6 J mice underwent IA injections once per week for 3 weeks with Ad-Control or Ad-OSCAR (both 800 MOI) and were sacrificed a week later (n = 10 mice per each group) (c). Cartilage sections from their knee joints were subjected to immunohistochemistry for OSCAR (d) and Safranin-O/hematoxylin staining (e). Representative images are shown. The latter slides were used to score the following OA variables (f): The ratio of hyaline cartilage (HC) to calcified cartilage (CC) and synovitis (n = 10 mice per group). Scale bar, 25 µm. g–i The knee joints of C57BL/6 J mice were IA-injected with Ad-Control or Ad-OSCAR weekly for 8 weeks and, starting 1 week after the first adenovirus injection, 0.5, 1, or 2 mg/kg 5-ASA or vehicle (Veh; PBS) was IA-injected weekly for 8 weeks starting 1 week after the first adenovirus injection. The last 5-ASA/vehicle injections occurred 1 week after the last adenovirus injection and 1 week before the sacrifice at week 9 (n = 10 mice per group) (g). Safranin-O/hematoxylin staining of cartilage sections (h) was then conducted. Representative images are shown. The slides were used to score the following OA variables (i): articular cartilage destruction (as indicated by the OARSI grade), osteophyte maturity, subchondral bone plate thickness (SBP Th.), and synovitis. The OARSI grade, synovitis, and osteophyte maturity data are shown as means ± 95% confidence intervals (CI). Differences between groups were determined with the Kruskal–Wallis test followed by the Mann–Whitney U test. The HC/CC ratio and SBP thickness data were shown as means ± s.e.m. Differences between groups were determined with a two-tailed t-test. Exact P values can be found in the accompanying Source Data. Scale bars, 25 μm.
