Expression of PPARγ protein in normal and osteoarthritis cartilage. Representative immunostaining of human normal cartilage (a) and cartilage from mild to moderate osteoarthritis (OA) (b) for peroxisome proliferator-activated receptor γ (PPARγ). (c) Normal specimens treated with anti-PPARγ antibody that was preadsorbed with a 20-fold molar excess of the protein fragment corresponding to amino acids 8 to 106 of human PPARγ (control for staining specificity). (d) Percentage of chondrocytes expressing PPARγ in normal and OA cartilage. The results are means ± SEM for 10 normal and 11 OA specimens. *p < 0.05 compared with normal cartilage.