Inflammation plays a crucial role in muscle remodeling and repair after acute and chronic damage, in particular in
muscular dystrophies, a heterogeneous group of
genetic diseases leading to muscular degeneration. Defect of
nitric oxide (NO) generation is a key pathogenic event in
muscular dystrophies, thus NO donors have been explored as new
therapeutics for this disease. We have investigated the immune-modulating effect of one of such drugs,
molsidomine, able to slow the progression of
muscular dystrophy in the α-Sarcoglican-null mice, a model for the
limb girdle muscular dystrophy 2D, sharing several hallmarks of muscle degeneration with other
muscular dystrophies. α-Sarcoglican-null mice were treated with
molsidomine and
drug effects on the inflammatory infiltrates and on muscle repair were assessed at selected time points. We found that
molsidomine treatment modulates effectively the characteristics of the inflammatory infiltrate within dystrophic muscles, enhancing its healing function. Initially
molsidomine amplified macrophage recruitment, promoting a more efficient clearance of cell debris and effective tissue regeneration. At a later stage
molsidomine decreased significantly the extent of the inflammatory infiltrate, whose persistence exacerbates muscle damage: most of the remaining macrophages displayed characteristics of the transitional population, associated with reduced
fibrosis and increased preservation of the muscle tissue. The dual action of
molsidomine, the already known NO donation and the immunomodulatory function we now identified, suggests that it has a unique potential in tissue healing during chronic muscle damage. This, alongside its already approved use in human, makes
molsidomine a
drug with a significant therapeutic potential in
muscular dystrophies.