Fig. 4.

Effect of α-MSH on MMP-13 secretion (a) and gene expression (b) in IL-1β or TNF-α-stimulated chondrocytes. Human primary chondrocytes were incubated for 4 h at 37 °C with 10⁻⁶M α-MSH and further cultured for 40 h in the presence or absence of 10 ng/mL IL-1β or TNF-α. MMP-13 concentration in the supernatans (a) and gene expression (b) were then measured. Data from 4 separate experiments (± S.E.M.) are shown. * p < 0.0001 vs Medium; °p < 0.05 vs TNF-α