Introduction:

1. Slowing the Progression of Arthritis in the Rabbit by Inhibiting Collagen Breakdown Alysia Rudis & Joshua Wilburn Introduction: Arthritis is caused by the breakdown of collagen in joint cartilage by the enzyme MMP-13. The antibiotic doxycycline is a general inhibitor of MMPs, and, by inhibiting the activity of MMP-13, is an effective method of slowing the progression of arthritis. At present, doxycycline is used to treat both Rheumatiod Arthritis and Osteoarthritis. Methodology: The rabbit's HIG-82 synovial cell line was used to model arthritis. MMP-13 was prepared by adding PMA, which guarantees that it’s presence, and APMA, which activates it. The enzyme MMP-13 was mixed with a quenched substrate. When the enzyme cleaves the substrate, it fluoresces. This fluorescence was used to measure the amount of MMP-13 activity. Doxycycline, which decreases the amount of enzyme activity, was added in increasing concentrations: 0, 25, 50, 75, 100, and 200 micromols. The decrease in the fluorescence produced by the cleaved substrate when doxycycline was present was used to measure the decrease in activity of the enzyme. The same experiment was performed on three different plates, and the data was normalized. Hypothesis: Increasing the concentration of doxycycline will decrease the activity of the MMP-13 enzyme. Results of Regression (using BUGS): -Hierarchal model -Bayesian regression with non-informative priors -By standardizing the concentration values by their mean, the dependency between alpha and beta was reduced, which balances the data and complete dependency is achieved Results of ANOVA: -Two-way ANOVA using concentration and plate: showed significant differences between the means of the concentrations and little or no difference between the means of plates, as should be expected F(c) = 2002.0 – 9.281c • Conclusions: • Residuals are normal, as expected. • The regression model can be used to make predictions regarding the activity level of the enzyme based on the concentration of doxycyclene present. • -The hypothesis that the activity of MMP-13 will be reduced as the concentration of doxycycline increases is proven to be true by both the negative correlation between the concentration of doxycycline and the amount of fluorescence shown in the regression and the ANOVA results. Acknowledgements: http://arthritis.about.com/od/oa/a/doxcycline.htm http://www.tldp.com/issue/178/Rheumatoid%20Arthritis%20Drug.html http://www.answers.com/topic/synovial-joint-2 http://www.medicalook.com/Joint_pain/Rheumatoid_arthritis.html http://healthguide.howstuffworks.com/fibromyalgia-in-depth4.htm *Amber Schreck – For providing data and theory behind experiment. *This data came from the BMED 3160 lab.