Comparative effects of interleukin 1 and a phorbol ester on rheumatoid synovial cell fructose 2,6-bisphosphate content and prostaglandin E production

The addition of either recombinant human interleukin 1 (IL1 alpha) or 12-O-tetradecanoyl phorbol-13-acetate (TPA) to cultured rheumatoid synovial cells (RSC) caused dose-related increases in PGE production and cellular fructose 2,6-bisphosphate (Fru-2,6-P2). IL1 consistently produced the greater increases in both parameters. A close association between increases in PGE production and Fru-2,6-P2 was demonstrated for both IL1- and TPA-stimulated cells. The combined addition of IL1 with TPA resulted in an additive increase in both parameters. When IL1 was added together with human recombinant interferon-gamma (IFN-gamma), the resulting Fru-2,6-P2 level was synergistically increased, whilst the combination of IFN-gamma and TPA produced only an additive increase. Thus despite their very similar effects on RSC in culture, the data suggests that IL1 and TPA do not act via an identical intracellular mechanism.