Figure 3

EphB4 receptor (a) gene expression level in human normal (n = 5) and osteoarthritic (OA) (n = 8) chondrocytes, and (b) total protein production as analyzed following immunohistochemistry as described in Materials and Methods in normal (n = 4) and OA (n = 4) cartilage or in the superficial or deep zones of the cartilage. Of note, the arbitrary unit of the EphB4 receptor gene is expressed as × 10^-2. (c) Representative immunohistological sections showing EphB4 receptor in the superficial and (d) deep zone of human normal cartilage and in the (e) superficial and (f) deep zone of OA cartilage. The insets represent in (c) a negative control done with immunoabsorption with only background staining and in (e) a higher magnification of positive cells stained for ephrin B2. c, d, e, f and inset in c: original magnification ×100, and inset in e: original magnification ×400. Arrows indicate stained chondrocytes. Statistical significance was assessed by Student's t-test and P values are as underlined.