Ascorbic acid stimulates production of glycosaminoglycans in cultured fibroblasts

The effect of ascorbic acid on collagen synthesis is well characterized. Proteoglycans and their attached glycosaminoglycans are components of the extracellular matrix closely associated with collagen fibers. We examined whether ascorbic acid also plays a role in glycosaminoglycan production. Synthesis and deposition of glycosaminoglycans into the extracellular matrix and secretion into the media were followed in human skin fibroblasts cultured in the presence and absence of ascorbic acid. Specific glycosaminoglycans were identified and quantitated by differential enzyme digestion, ion-exchange column chromatography, and cellulose-acetate electrophoresis. No major qualitative changes in glycosaminoglycans were observed. However, quantitatively, synthesis of glycosaminoglycans increased 30 to 90%, and deposition into the extracellular matrix increased 80% in the presence of ascorbic acid. This effect was only in part secondary to decreased levels of collagen, and the diminished capacity of underhydroxylated collagen to bind proteoglycans. The effect of ascorbic acid on extracellular macromolecules is thus more pervasive than previously assumed.