Fig. 4

Deletion of cPLA2 protects against surgically-induced OA. a Representative Safranin O/Fast Green stained images of knee joints from WT and cPLA2 KO male mice (n = 7) at 12 weeks after DMM or sham surgery. Scale bar = 100 μm. b, c 2 min travel distance (b) and von Frey pain assay (c) in WT and cPLA2 KO mice at the indicated time after DMM surgery (n = 7). d Representative immunohistochemical staining images of cPLA2, Col2, Mmp13, aggrecan neoepitope, p16, and p21 in knee joint sections from each group (n = 7). Scale bar = 50 μm. e 3D micro-CT images of pathological changes in mouse knee joints 12 weeks post-surgery (n = 4). f 3D micro-CT images of osteophyte formation, calcified meniscus and synovial tissue, with red-marked regions indicating osteophytes (n = 4). g Quantification of osteophyte number (Op.N, I), size (Op.TV, J), and the volume of calcified meniscus and synovial tissue (Cal Tis.V, K). g Data are mean±s.d., P-values by two-tailed unpaired Student’s t-test