Type VI collagen

Type VI collagen is a unique beaded filament collagen found in the interface between the basement membrane and interstitial matrix, where it forms a unique microfibrillar network. Type VI collagen has many binding partners. Mutations in type VI collagen have been particularly associated with muscle weakness disorders such as Bethlem myopathy and other muscle dystrophies. In addition to the structural and binding function of type VI collagen, the C-terminal propeptide is a hormone called endotrophin, which is associated with metabolic syndrome. Consequently, type VI collagen is both a structural and a signaling protein. Furthermore, type VI collagen may act as an early sensor of the injury/repair response and may regulate fibrogenesis by modulating cell–cell interactions, stimulating the proliferation of mesenchymal cells and preventing cell apoptosis. Biomarkers of type VI collagen formation and degradation have been developed and shown to be regulated in different connective diseases.