ABSTRACT
BACKGROUND: Type VII collagen is a relatively low abundance extracellular matrix protein among the collagenous molecules. Among the minor collagens. type VII collagen has been demon strated by a immunolocalization studies to be component of anchoring fibrils and structures extending perpendicularly from the lamina densa to the upperpapillary dermis. OBJECTIVE: The purpose of his study is to determine the expression of the type VII collagengene in a group of scleroderma patients as compared to normal skin. METHODS: We have examined the levels of type VII collagen mRNA using quantitative reverse transcription PCR and in sit gybridization in scleroderma skin fibroblasts. Immunofluorescent staining with anti-type VII collan antibody was performed in vitro and in vivo to evaluate the expression of type VII collagen at protein level. RESULTS: 1. the ratio of type VII collagen/GAPDH RT-PCR product were 63.3+/-15.3 in scleroderma and 21.7+7.6 in normal fibroblasts by RT-PCR. 2. The expression of type VII collagen mRNA was considerably lower than type I in scleroderma. A few positive signals by in situ hybridization with type VII collagen cDNA were shown in the dermis. 3. The staining was markedly enhanced in scleroderma fibroblasts and tissues compaired with normal subjects in imunofluorescent staining with anti-Type VII collagn antibody. CONCLUSION: RT-PCR and immunofluorescent staining with antibodies to type VII collagen shows enhanced gene expression in scleroderma skin fibroblasts These data suggest that type VII collagen may be the main soruce of the sclerotic change of skin in scleroderma.