TRANSFORMING GROWTH FACTOR-BETA-2 DIFFERENTIALLY MODULATES INTERLEUKIN-1-BETA-STIMULATED AND TUMOR-NECROSIS-FACTOR-ALPHA-STIMULATED PHOSPHOLIPASE-A2 AND PROSTAGLANDIN-E2 SYNTHESIS IN RAT RENAL MESANGIAL CELLS

Treatment of rat glomerular mesangial cells with transforming growth factor β2 (TGFβ2) stimulates prostaglandin E2 (PGE2) synthesis. Actinomycin D, cycloheximide and diclofenac attenuate the TGFβ2-induced PGE2 formation. As shown previously, two proinflammatory cytokines, interleukin 1β (IL-1β) and tumour necrosis factor α (TNFα), are potent stimuli for PGE2 and phospholipase A2 secretion from mesangial cells. We report here that, whereas TGFβ2 potentiates the IL-1β- and TNFα-evoked PGE2 production, it strongly inhibits the phospholipase A2 secretion induced by both cytokines. In addition, the inhibitory effect of TGFβ2 on phospholipase A2 secretion is not due to the augmented PGE2 formation.