1. Nitric oxide enhances aggrecan degradation by aggrecanase in response to TNF-α but not IL-1β treatment at a post-transcriptional level in bovine cartilage explants 
A.L. Stevens, Ph.D., C.A. Wheeler, B.S., S.R. Tannenbaum, Ph.D., A.J. Grodzinsky, Sc.D. 
Osteoarthritis and Cartilage 
Volume 16, Issue 4, Pages (April 2008)
DOI: /j.joca
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

2. Fig. 1
Five-day accumulated total nitrate and nitrite release to the medium (nmol/mgwet weight) as a measure of NO production plotted as mean±s.e.m. from greater than three explants per joint pooled from five different joints (animals) (*P<0.001 cytokine compared to control and **P<0.01 cytokine compared to cytokine+NMA).
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

3. Fig. 2
Accumulated sGAG release to medium over 5-day cytokine treatment in the presence or absence of l-NMA plotted as mean±s.e.m. IL-1β and TNF-α alone cause a 3–5 fold increase in sGAG release compared to untreated controls (P<0.001 for all points). l-NMA inhibited roughly half the sGAG release caused by treatment with TNF-α (P<0.01 for all time points).
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

4. Fig. 3
Anti-aggrecan-G1-NITEGE-COOH Western blot to probe mechanism of sGAG loss in response to IL-1β and TNF-α treatment with and without NOS inhibitor, l-NMA. A band is visualized in all cytokine-treated conditions; however, the TNF-α+l-NMA band is significantly lighter than that with TNF-α alone or with IL-1β±l-NMA. This immunoblot is representative of five different experiments and corresponding blots.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

5. Fig. 4
Casein (A) and Gelatin (B) zymograms of 5-day culture medium. (A) The casein zymogram for both IL-1β and IL-1β–l-NMA contains a 54kDa band, corresponding to pro-MMP-3 that appears as a doublet, with a lighter upper band and a brighter lower band. A faint doublet is seen for TNF-α treatment and, in addition, a 90kDa band is seen with all cytokine treatments. (B) The gelatin zymogram contained a 72kDa band (arrow) and a lower 65kDa band in all samples, corresponding to the pro- and active forms of MMP-2, respectively. Only cytokine-treated samples had a 92kDa band corresponding to MMP-9. l-NMA had no effect on MMP-3, MMP-9 or MMP-2 expression or activation as seen in medium samples.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

6. Fig. 5
Relative gene expression by real time PCR and clustering analyses. (A) Expression of ADAMTS4 and ADAMTS5 at 26 and 50h time points, relative to controls, in response to treatment with l-NMA alone, IL-1β±l-NMA and TNF-α±l-NMA. (B) Centroid profile for gene cluster 1 (Group 1 genes) which showed decreased expression or was unchanged in response to cytokine treatment. Centroids represent 26 and 50h time points clustered together. (C) Centroid profile for gene cluster 2, showing genes that were up-regulated in response to cytokine treatment. (Groups produced from clustering 26h alone (see Table I) vs 26 and 50h together were identical, except IGF-2 and TIMP-3 in Table I swapped groups.) The * indicates statistical significance compared to the untreated control sample by pair-wise comparison (Wilcoxon Sign Rank test with Bonferroni correction for multiple comparison; P<0.05).
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

7. Fig. 6
Projection plot of gene behavior represented by the first three principal components. The genes readily separated into two clusters which correspond to genes that respond positively to IL-1β and TNF-α treatment (triangles; Group 2 of Table I) and those genes that either did not respond or responded negatively to the cytokine treatment (squares; Group 1). The black circles indicate the group centroids which are significantly different from each other (P<0.001; Student's t test).
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions