Western blotting of MMP-1, -3, and -13 release in the secretome of cartilage explants in culture. (A) Representative MMP-1 western blot image and densitometric analysis showing significant decrease in IL-1β-stimulated release of MMP-1 in response to carprofen treatment. (B) Representative MMP-3 western blot image and densitometric analysis displaying the significant reduction of IL-1β MMP-3 release attributed to carprofen treatment. (C) Representative MMP-13 western blot image and densitometric analysis showing significantly higher MMP-13 release in the presence of IL-1β alone, compared with carprofen + IL-1β. All cartilage-explant supernatants were incubated for 6 days. This experimental design was carried out with tissues obtained from three separate animals, with three treatment replicates from each animal (n = 9). Statistical analysis completed = unpaired t-test. Treatments were as follows: untreated control, IL-1β (10 ng/ml), carprofen (100 μg/ml), or carprofen (100 μg/ml) + IL-1β (10 ng/ml). Error bars indicate standard deviation. ***P < 0.001. M, molecular weight markers; +positive control.
Williams et al. Arthritis Research & Therapy 2013 15:R223 doi:10.1186/ar4424