Tendon Extracellular Matrix Alterations in Ullrich Congenital Muscular Dystrophy.

摘要: Collagen VI is a non-fibrillar collagen expressed in skeletal muscle and most connective tissues. Mutations genes cause two major clinical forms, Bethlem myopathy Ullrich congenital muscular dystrophy (UCMD). In addition to weakness, patients affected by myopathies show axial proximal joint contractures distal hypermobility, which suggest the involvement of tendon function. We examined peroneal biopsy tenocyte culture 15-year-old patient UCMD with compound heterozygous COL6A2 mutations. patient's biopsy, we found striking morphological alterations fibrils, consisting irregular profiles reduced mean diameter. The organization pericellular matrix tenocytes, primary site fibril assembly, was severely affected, as determined immunoelectron microscopy, showed an abnormal accumulation altered distribution I fibronectin. culture, web formation cell surface association were impaired; large aggregates VI, matched labeling, frequently detected extracellular matrix. addition, metalloproteinase MMP-2, matrix-regulating enzyme, increased conditioned medium gelatin zymography western blot. Altogether, these data indicate that deficiency may influence matrix, resulting dysfunctional fibrillogenesis. contribute complex pathogenesis related myopathies.