Dysregulated intracellular signaling and inflammatory gene expression during initial disease onset in Duchenne...

Duchenne muscular dystrophy is a debilitating genetic disorder characterized by severe muscle wasting and early death in affected boys. The primary cause of this disease is mutations in the dystrophin gene that result in the absence of the protein dystrophin and the associated dystrophin-glycoprotein complex in the plasma membrane of muscle fibers. In normal muscle, this complex forms a link between the extracellular matrix and the cytoskeleton that is thought to protect muscle fibers from contraction-induced membrane lesions and to regulate cell signaling cascades. Although the primary defect is known, the mechanisms that initiate disease onset have not been characterized. Data collected during early maturation suggest that inflammatory and immune responses are key contributors to disease pathogenesis and may be initiated by aberrant signaling in dystrophic muscle. However, detailed time course studies of the inflammatory and immune processes are incomplete and need to be characterized further to understand the disease progression. The purposes of this review are to examine the possibility that initial disease onset in dystrophin-deficient muscle results from aberrant inflammatory signaling pathways and to highlight the potential clinical relevance of targeting these pathways to treat Duchenne muscular dystrophy.