Abstract
The effects of all-trans retinoic acid on glycosaminoglycan (GAG) accumulation were determined in cultured primary human skin fibroblasts. Confluent cultures treated with retinoic acid accumulated less [3H]GAG than those without the compound, an effect with an apparent threshold of 10 nM which was dose dependent in the concentration range tested (0–10 μM). At 10 μM, the inhibition was 54%. Greater than 80% of the labeled macromolecular material was streptomyces hyaluronidase digestible in cultures labeled with [3H]acetate. The incorporation of H2[35S]O4 into chondroitin sulfate and dermatan sulfate was unaffected, as was total protein synthesis. Retinol also inhibited accumulation of [3H]GAG, but was far less potent. T3 and dexamethasone can inhibit [3H]hyaluronate synthesis. When retinoic acid was added to cultures treated with either of these hormones at concentrations that maximally inhibit [3H] GAG accumulation, there was a further decrease in the rate of macromolecular accumulation. The retinoic acid effect evolved over 24–48 h after addition to the culture medium. A pulse-chase study failed to demonstrate any effect on [3H]GAG degradation.