Interferon-gamma inhibits S-35 incorporation in heparan sulfate synthesized by human skin fibroblasts

Glycosaminoglycans synthesized by human skin fibroblasts were simultaneously radiolabelled with D-[1-H-3]glucosamine and (Na2SO4)-S-35. Considering H-3 incorporation, we found that IFN gamma increased the production of glycosaminoglycan synthesis, including hyaluronic acid, heparan and chondroitin/ dermatan sulfate, In contrast, the production of heparan and chondroitin/dermatan sulfate was slightly decreased on the basis of the S-35 signal. Furthermore, when heparan sulfate was treated with nitrous acid, the release of free S-35 was greater in control than in treated cells, although the H-3 patterns of depolymerization with this agent were similar. These data demonstrate that IFN gamma inhibits the incorporation, of sulfate from extracellular medium into heparan sulfate.