Figure 4.

High levels of Cx43 protein and PCNA are observed in OA cartilage since early stage to late grades of the disease. A: Representative patterns of staining with PCNA. Cartilage sections from healthy joints (n = 4) and cartilage from OA patients (n = 4 for knee OA; n = 6 for hip OA). Negative control. B: Quantitative image analysis of IHC staining with PCNA is shown. *P < 0.05, **P < 0.01 by a Kruskal-Wallis test with a Dunn’s multiple comparison test. C: IHC coupled with Gill's haematoxylin counterstaining using anti-Cx43 and PCNA antibody. Superficial layer grouped cells found in some of the cartilage sections from OA patients were highly positive for PCNA and Cx43 (H&E; original magnification, ×20 and ×100, respectively).