Deficiency in Cardiac Dystrophin Affects the Abundance of theα-/β-Dystroglycan Complex

[摘要] Although Duchenne muscular dystrophy is primarily categorised as a skeletal muscle disease, deficiency in the membrane cytoskeletal protein dystrophin also affects the heart. The central transsarcolemmal linker between the actin membrane cytoskeleton and the extracellular matrix is represented by the dystrophin-associated dystroglycans. Chemical cross-linking analysis revealed no significant differences in the dimeric status of theα-/β-dystroglycan subcomplex in the dystrophicmdxheart as compared to normal cardiac tissue. In analogy to skeletal muscle fibres, heart muscle also exhibited a greatly reduced abundance of both dystroglycans in dystrophin-deficient cells. Immunoblotting demonstrated that the degree of reduction inα-dystroglycan is more pronounced in maturedmdxskeletal muscle as contrasted to themdxheart. The fact that the deficiency in dystrophin triggers a similar pathobiochemical response in both types of muscle suggests that the cardiomyopathic complications observed inx-linked muscular dystrophy might be initiated by the loss of the dystrophin-associated surface glycoprotein complex.

[学科分类] 基础医学