Romaine R. Bruns

Type VI collagen: Immunohistochemical identification as a filamentous component of the extracellular matrix of the developing avian corneal stroma

Selected stages of the developing chicken cornea have been examined for type VI collagen, employing monoclonal antibodies specific for this molecule. By immunofluorescence, the molecule is not detectable in 5 1/2 day corneas, a time at which the epithelial-derived, acellular primary stroma is the only corneal matrix present. One day later, the presumptive stromal fibroblasts have invaded this stroma and have initiated synthesis of the secondary (mature) stroma. By that time, a strong fluorescent signal for the type VI collagen molecule is detectable throughout the stroma. It is present in all subsequent ages examined. The molecule is not restricted to the cornea, and is present in most stromal matrices examined, including those of the sclera, eyelid, and nictitating membrane. Immunoelectron microscopy was also performed, utilizing a colloidal gold-labeled secondary antibody. These data show that the type VI collagen is not a component of the striated collagen fibrils, but instead is assembled in the form of thin filaments. The monoclonal antibody bound to the filaments at periodic intervals of about 100 nm.

Collagen and glycosaminoglycans in cell adhesion

Abstract Human skin fibroblasts plated in medium (DMEM+10% fetal calf serum, FCS) containing active bacterial collagenase, chondroitinase ABC, and streptomyces hyaluronidase; and controls without the enzymes attach and spread equally well on plastic culture dishes. This observation suggests that collagen and glycosaminoglycans degraded by the enzymes, either separately or in combination with one another, are not necessary components in the early attachment and spreading of human skin fibroblasts on plastic.