Fig. 4
From: Norepinephrine modulates IL-1β-induced catabolic response of human chondrocytes
Norepinephrine (NE) reverses IL-1β-induced up-regulation of MMPs and down-regulation of matrix proteins. The effect of NE on IL-1β-induced expression of (A) MMPs and (B) extracellular matrix proteins. Chondrocytes were preincubated with NE (0.1, 1.0, and 10 ng/ml) for 2 h followed by treatment with IL-1β (1 ng/ml) for 6, 24, and 48 h. Data represent the mean ± SD of duplicate data from five different donors. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 vs. IL-1β-treated cells by Kruskal-Wallis test with post hoc Dunn’s multiple comparison test