LIPOPOLYSACCHARIDE STIMULATION OF HYALURONATE SYNTHESIS BY HUMAN GINGIVAL FIBROBLASTS INVITRO

Exposure of gingival fibroblasts to LPS caused a dose-dependent increase in hyaluronate synthesis. Stimulation of hyaluronate synthesis by LPS was significantly greater 24 h after exposure and by 48 h an approx. 50% increase was evident. In parallel, there was an increase in the activity of the hyaluronate synthetase enzyme. Inhibition of PGE2 synthesis by indomethacin abolished the stimulatory effect of LPS on hyaluronate synthesis. Thus, this stimulatory effect of LPS on hyaluronic acid synthesis may be a secondary response to the induction of PGE2. The molecular size of newly synthesized hyaluronate was not affected by LPS. The metabolic changes observed may be a primary response of the cells to bacterial toxins and may aid extracellular matrix repair.