Understanding the beneficial effects of doxycycline on the dystrophic phenotype of the mdx mouse

ABSTRACT Introduction: The purpose of this study was to better understand the beneficial effects of doxycycline on the dystrophic muscles of the mdx mouse. Methods: Doxycycline (DOX) was administered for 36 days, starting on postnatal day 0, via drinking water. Untreated mdx mice received plain water for the same period and served as a control group. Results: DOX decreased the levels of metalloproteinase‐9 and tumor necrosis factor‐alpha in the biceps brachii and diaphragm of the mdx mice. It also reduced the total amount of calcium in the muscles studied, concomitant with an increase in the levels of calsequestrin 1. Conclusions: The results show that DOX can affect factors that are important in dystrophic pathogenesis and highlight its potential as a readily accessible therapy in clinical trials for treatment of Duchenne muscular dystrophy. Muscle Nerve 50:283–286, 2014