Synthesis of glycosaminoglycans by human cervical fibroblasts in culture: Effects of prostaglandin E(2) and cyclic AMP

Objective: To study the mechanism of action of prostaglandin E(2) (PGE(2)) and its analogue sulprostone leading to production of glycosaminoglycans (GAGs) in the human uterine cervix. Sturdy design: We analysed the effects of PGE(2) and its analogue sulprostone upon production of adenosine 3',5'-monophosphate (cAMP), in human cultured fibroblasts. We also studied the effects of PGE(2), sulprostone and a cAMP analogue (8-Bromo-cAMP), on the incorporation of [H-3]glucosamine into GAGs in human cervical fibroblasts in culture. Results: Following treatment with PGE(2) (10(-4)-10(-6) M), we observed a significant increase in the production of cAMP from 96.3 +/- 8.4 pmol/10(6) cells without phosphodiesterase inhibitor 3-isobutyl-methylxanthine (IBMX) to 325 +/- 63 pmol/10(6) cells with 10(-4) M IBMX (Spearman correlation test; P < 0.05). Under the same conditions, the effects of sulprostone (10(-6) M) were limited (from 8.1 +/- 1.5 to 51.3 +/- 14.1 pmol/10(6) cells without and with IBMX, respectively; not significant). Both PGE(2) and 8-bromo-cAMP (from 10(-12) to 10-4 M) increased [H-3]glucosamine uptake into GAGs (Spearman correlation test; P < 0.05). Sulprostone (10(-12)-10(-4) M) was unable to reproduce such an effect even after a 24 or 48 h treatment. Conclusion: Since firstly, PGE(2) acts through EP(1), EP(2) and EP(3) specific receptors, whereas the action of sulprostone is only mediated by EP(1) and EP(3), and secondly EP(2) receptor is coupled with cAMP production, we conclude that cAMP is involved in mediating the action of PGE(2) upon GAG synthesis by human cultured cervical fibroblasts.