A Comparison of Glycosaminoglycan Synthesis by Human Fibroblasts from Normal Skin, Normal Scar, and Hypertrophic Scar

Abstract

Fibroblasts isolated from normal skin, normal scar, and hypertrophic scar tissues were compared with respect to their growth curves, protein contents, and abilities to synthesize glycosaminoglycans (GAGs). While no significant differences were found with respect to protein content or population doubling times, we did find significant differences in the proportions of radiolabel incorporated into the various GAGs among the 3 groups of cell lines. Using a dual-label technique to label both hyaluronic acid and the sulfated GAGs, we isolated labeled constituents from the extracellular, the pericellular, and the cellular fractions by pronase digestion and gel filtration and identified the various GAGs by electrophoresis and selective digestion with enzymes. Of the GAGs isolated from the extracellular fraction, hypertrophic scar fibroblasts incorporated proportionately more 35S into chondroitin sulfate and less into heparan sulfate and more [3H]glucosamine into hyaluronic acid than did normal skin fibroblasts. Of the GAGs isolated from the cellular fraction, hypertrophic scar fibroblasts incorporated proportionately more 35S into heparin and less into dermatan sulfate and more [3H]glucosamine into hyaluronic acid than did normal skin fibroblasts. These differences in biosynthesis may help to explain the differences in GAG content in skin and scars found in vivo and to give insight into the development of hypertrophic scars.