Figure 4
From: Production of interleukin-1 receptor antagonist by human articular chondrocytes
IL-1β and IL-6 stimulate human sIL-1Ra promoter activity. C-20/A4 cells were transfected with the enh-1680 reporter gene construct. Negative controls were performed using empty pGL3-enhancer (pGL3-enh). Cells were left unstimulated (white bars), or were stimulated with 1 ng/ml IL-1β (grey bars) or with a combination of 1 ng/ml IL-1β, 10 ng/ml IL-6 and 100 ng/ml sIL-6R (black bars) for 48 hours. *P < 0.001 versus unstimulated cells transfected with the same plasmid.