Synthesis of type III collagen by fibroblasts from the embryonic chick cornea

Abstract

Synthesis of collagen types I, II, III, and IV in cells from the embryonic chick cornea was studied using specific antibodies and immunofluorescence . Synthesis of radioactively labeled collagen types I and III was followed by fluorographic detection of cyanogen bromide peptides on polyacrylamide slab gels and by carboxymethylcellulose chromatography followed by disc gel electrophoresis .Type III collagen had been detected previously by indirect immunofluorescence in the corneal epithelial cells at Hamburger-Hamilton stages 20-30 but not in the stroma at any age. Intact corneas from embryos older than stage 30 contain and synthesize type I collagen but no detectable type III collagen . However, whole stromata subjected to collagenase treatment and scraping (to remove epithelium and endothelium) and stromal fibroblasts from such corneas inoculated in vitro begin synthesis of type III collagen within a few hours while continuing to synthesize type I collagen . As demonstrated by double-antibody staining, most corneal fibroblasts contain collagen types I and III simultaneously . Collagen type III was identified biochemically in cell layers and media after chromatography on carboxymethylcellulose by detection of disulfide-linked al(III)3 by SDS gel electrophoresis .The conditions under which the corneal fibroblasts gain the ability to synthesize type III collagen are the same as those under which they lose the ability to synthesize the specific proteoglycan of the cornea: the presence of corneal-type keratan sulfate . KEY WORDS collagen -cornea fibroblasts -immunofluorescence " antibodiesThe factors that normally control the synthesis of type III collagen remain to be elucidated . Fibrous connective tissues generally contain both collagen type I and collagen type III, but the ratio between them varies with the tissue : the medial layer of the aorta contains, and aortic smooth muscle cells synthesize, -70% type III and^-30% type 1(5, 30) ; J . CELL BIOLOGY © The Rockefeller University Press " 0021-9525/80/03/0501/12 $1 .00 Volume 84 March 1980 501-512 dermis contains, and dermal fibroblasts synthesize, -10-20% type III and -80-90% type I (5, 13); tendon contains mostly type I (40) with some type III, which is located in the endotendineum (2) .Under constant conditions in vitro, the ratio between collagen types I and III synthesized remains constant for many cell generations (21) . However, changes in serum concentration or cell density can alter the ratio, with the highest proportions of type III collagen being synthesized in 501 on

In vitro immunoexpression of extracellular matrix proteins in dental pulpal and gingival human fibroblasts

“…Whereas col I was expressed by both cell lineages, there was no immunoexpression of col III in none of the studied cells. It has been suggested that treatment of cells with proteolytic enzymes, for instance trypsin digestion, leads to a greater degradation of col III relative to col I (Conrad et al. 1980, Van Amerongen et al.…”

Changes in Distribution of the Long Form of Type XII Collagen during Chicken Corneal Development

“…Such localization indicates that the long form of Type XII collagen mediates periodic interactions between collagen fibrils and other extracellular matrix components to stabilize them. In fact, Types I, II, III, IV, V VI, IX, XIV, and XVII collagen molecules were detected immunohistochemically in avian cornea (Conrad et al 1980;Linsenmayer et al 1984Linsenmayer et al ,1986Birk et al 1986;Fitch et al 1988Fitch et al ,1990Sugrue 1991;Chen et al 1993;Watanabe et al 1994;Gordon et al 1996Gordon et al ,1997Doane et al 1998). Among them, Types IX and XIV are associated with collagen fibrils, Type IX collagen forms a complex with Type II collagen in the primary corneal stroma (Fitch et al 1988Cai et al 1994), and structurally related Types XII and XIV collagen molecules also form complexes with Type I collagen (Koch et al 1995).…”

Human Fetal Keratocytes Have Multipotent Characteristics in the Developing Avian Embryo

“…Upon migration into the region of the presumptive cornea, neural crest cells down-regulate HNK-1 [59], transform from mesenchymal to fibroblastic morphology [33], and initiate the expression of molecular markers such as collagens, keratan sulfate, and chondroitin sulfate [60][61][62][63]. During subsequent development, the newly formed keratocytes synthesize the extracellular matrix and maintain the transparency of the corneal stroma.…”