FIGURE 2.

CpG demethylation in vitro correlates with enhanced levels of MMP13 and IL1B gene expression in cultured human primary chondrocytes. Primary human chondrocytes were cultured without or with 5-aza-dC and the CpG methylation status of the MMP13 proximal promoter (A) or the IL1B proximal promoter (B) was analyzed. All data are shown as means ± S.E. and represented as percentage of methylation in the 5-aza-dC-treated cells relative to that in the non-treated control cells set at 100% for each CpG site (*, p < 0.05).