Figure 4.

Effects of IL-1β-mediated signaling on mRNA expression of GREM1, FRZB and DKK1. Chondrocytes received a single dose of 10 or 100 ng/ml IL-1β, or a daily medium refreshment containing 10 ng/ml IL-1β. Chondrocytes were stimulated up to 96 hours and mRNA expression was analyzed by quantitative PCR at the indicated time points for GREM1(A), FRZB(B), and DKK1(C). Data expressed as fold-change relative to untreated time point-matched control and represent the mean of three donors ± standard deviation. *P <0.05 compared with unstimulated cells. DKK1, dickkopf 1 homolog (Xenopus laevis); FRZB, frizzled-related protein; GADPH, glyceraldehyde 3-phosphate dehydrogenase; GREM1, Gremlin 1.