Figure 4

Sulf-1 and Sulf-2 expression in specific zones of normal and osteoarthritis (OA) cartilage. The number of Sulf-1- or Sulf-2-positive cells was counted in the superficial, middle, and deep zones of sections from normal (n = 8) and OA (n = 8) cartilage that were stained with specific antibodies. In normal cartilage, the percentage of Sulf-2-positive cells was highest in the superficial zone. The superficial zone in OA cartilage was eroded. The OA middle zone had significantly more Sulf-1-positive cells than the other zones (*P < 0.01). Sulf-2 expression in normal cartilage was significantly higher than Sulf-1 (P = 0.02).