The role of proteoglycans in collagen gel contraction by human gingival fibroblasts.
Fibroblasts generated from biopsies of normal gingiva contract collagen gels to a significantly greater extent than do fibroblasts generated from chronically inflamed gingiva. The present study demonstrates that proteoglycans play a major role in gel contraction, and that cells from the two sources differ greatly in their ultrastructural features and their capacity to synthesize proteoglycans. Fibroblasts from normal gingiva contained more rough endoplasmic reticulum and mitochondria, and they were more well-spread than cells from chronically inflamed gingiva. We observed a fine granular electron-dense lamina of material especially prominent around the cell processes and on the surface of the collagen fibrils. This material appears to be rich in proteoglycans since it stained with ruthenium red, a dye that binds to proteoglycans, and labeled in cultures incubated for 1 or 4 hr in medium containing 35S-sodium sulfate. Proteoglycans have the capacity to bind matrix components to one another and to cells, and thereby play a major role in gel contraction. Normal fibroblasts have a significantly greater capacity to synthesize proteoglycans, as manifested by label incorporation, that do cells from inflamed tissue, and this may account for their greater capacity to contract collagen gels in vitro.
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D003094:Collagen / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D005881:Gingiva / Q000378:metabolism*; D006801:Humans; D011509:Proteoglycans / Q000096:biosynthesis / Q000502:physiology*
D011509:Proteoglycans; D003094:Collagen