Fig. 2. Effects of DMD treatment: DMD muscle fibres without treatment display hallmarks of muscle decay, such as centralized nuclei, fibrosis, capillary rarefaction and continuous inflammation (no treatment).

Upon current and novel pharmacologic treatment, inflammation and muscle fibre decay may be decelerated, without alteration of the underlying mechanical strain leading to cell death, e.g., by necroptosis. In contrast, therapeutic strategies aiming at dystrophin re-expression (AONs = antisense olignucleotides targeting exon skipping) correct the disease-causing deficit of dystrophin, either temporally (AONs), or for prolonged intervals (AAV-microdystrophin) or permanently (AAV-Cas9).