Figure 6.
Reduction of TGF-β induced Smad3/4 phosphorylation by IL-β. Human OA and bovine chondroyctes were treated with either TGF-β for 30 min, or pretreated before TGF-β treatment with IL-1β for 30 min, or treated with IL-1β alone for 60 min. Nuclear extracts were then prepared and subjected to Western analysis using anti phospho-Smad2/3 antibodies. Western analysis shows that the levels of phospho-Smad2/3 are significantly reduced in IL-1β pretreated chondrocytes vs TGF-β treatment alone. β-actin protein levels are shown as a control for protein loading and transfer. The data shown are representative of 2 independent experiments.