Ultrastructural localization of the core protein of a basement membrane-specific chondroitin sulfate proteoglycan in adult rat skin.

Basement membranes are complex extracellular matrices present at epithelial/mesenchymal interfaces of tissues. The dermal-epidermal junction has been shown to contain numerous components, some of the most well known being laminin, types IV and VII collagens, heparan sulfate proteoglycan, fibronectin, and entactin/nidogen. IN this paper we show, using core protein-specific antibodies, the presence of a newly described basement membrane-specific chondroitin sulfate proteoglycan at the epithelial/mesenchymal interface of adult rat skin. Ultrastructurally, this antigen was proven to reside primarily within the basal lamina, apparently concentrated in the lamina densa. In addition, some of the proteoglycan was also present beneath the lamina densa, associated with the reticular lamina collagen fibrils.