RESUMO
Duchenne muscular dystrophy (DMD) is an incurable disease caused by mutations in the X-linked DMD gene that encodes a structural muscle protein, dystrophin. This, in turn, leads to progressive degeneration of the skeletal muscles and the heart. Hydrogen sulfide (H2S), the pleiotropic agent with antioxidant, anti-inflammatory, and pro-angiogenic activities, could be considered a promising therapeutic factor for DMD. In this work, we studied the effect of daily intraperitoneal administration of the H2S donor, sodium hydrosulfide (NaHS, 100 µmol/kg/day for 5 weeks) on skeletal muscle (gastrocnemius, diaphragm and tibialis anterior) pathology in dystrophin-deficient mdx mice, characterized by decreased expression of H2S-generating enzymes. NaHS reduced the level of muscle damage markers in plasma (creatine kinase, lactate dehydrogenase and osteopontin). It lowered oxidative stress by affecting the GSH/GSSG ratio, up-regulating the level of cytoprotective heme oxygenase-1 (HO-1) and down-regulating the NF-κB pathway. In the gastrocnemius muscle, it also increased angiogenic vascular endothelial growth factor (Vegf) and its receptor (Kdr) expression, accompanied by the elevated number of α-SMA/CD31/lectin-positive blood vessels. The expression of fibrotic regulators, like Tgfß, Col1a1 and Fn1 was decreased by NaHS in the tibialis anterior, while the level of autophagy markers (AMPKα signalling and Atg genes), was mostly affected in the gastrocnemius. Histological and molecular analysis showed no effect of H2S donor on regeneration and the muscle fiber type composition. Overall, the H2S donor modified the gene expression and protein level of molecules associated with the pathophysiology of DMD, contributing to the regulation of oxidative stress, inflammation, autophagy, and angiogenesis.