Einzelzellbiologie

Abstrakt

Duchenne muscular dystrophy (DMD): Should it be considered a systemic disease?

Giuseppe Morici and Maria R. Bonsignore

Duchenne muscular dystrophy (DMD) is an X-linked muscle disease characterized by progressive loss of skeletal muscle and the development of respiratory failure due to impairment of respiratory muscles. Similar to human DMD, the mdx mouse model lacks dystrophin but is characterized by relatively mild muscle injury, allowing the effects of mild endurance exercise on dystrophic skeletal muscle to be tested. We aimed to investigate the effects of exercise on airway cells in trained mdx mice by applying the same protocol previously tested in Swiss mice. We found that mdx mice showed little exercise-induced airway inflammation but developed increasing airway cell apoptosis over time, regardless of whether they were exercised or inactive. These results indicated a subclinical progressive depletion of protective mechanisms in the airway epithelium of the mdx mouse, possibly involving the chaperonin Hsp60. Furthermore, a lack of goblet cells was detected in the airways of mdx mice at all time points of the study, regardless of whether they were inactive or exercised. We suggest that a disruption of the Notch signaling pathway, previously described in dystrophic skeletal muscle, may be involved in the almost absent secretory cell phenotype in the airways of mdx mice. Overall, our results suggest that dystrophin may affect other tissues besides skeletal muscle and exert physiological effects in non-muscle tissues that are currently not well defined.