P–322 Addressing progesterone and cAMP signalling pathways for decidualization induction of endometrial stromal cells of patients with endometriosis

Abstract Study question Which compounds/compound combinations are most effective in decidualization induction of endometrial stromal cells (ESCs) of patients with and without endometriosis? Summary answer Combination of compounds addressing different steps in the signalling cascade of decidualization induce decidualization more effectively than application of the individual compounds alone. What is known already Decidualization is the monthly recurring differentiation process of the ESCs in preparation for embryo implantation in human. Undifferentiated ESCs reveal an increased potential to proliferate and invade after retrograde menstruation. This may lead to the formation of ectopic lesions and the manifestation of the chronic gynaecological disease of endometriosis due to an impairment of the decidualization process. Study design, size, duration Compounds and compound combinations addressing the progesterone receptor- or the cAMP-mediated pathway were evaluated with regard to their own and their synergistic potential to induce decidualization of ESCs from women with (n = 10) and without (n = 10) endometriosis during a 6-day treatment. Participants/materials, setting, methods Human primary ESCs were isolated via enzymatic-mechanic digestion from eutopic endometrium from women with and without endometriosis and treated for 6 days in vitro with different progestins (progesterone, medoxyprogesterone acetate (MPA)), 8-Br-cAMP, forskolin, or phosphodiesterase (PDE)-inhibitor (Rolipram) alone or in combination. The degree of decidualization induction was quantified by morphological, biochemical (prolactin) and molecular (HAND2, FOXO1) parameters by means of ELISA, flow cytometric analysis, Realtime PCR and Western blot analysis. Main results and the role of chance After 6 days of treatment, decidualization was induced by forskolin as well as by 8-Br-cAMP whereas progestins or PDE alone hardly induced prolactin secretion by ESCs as a marker of decidualization. A change of morphology from undifferentiated fibroblast-like cells to rounded cells could be observed in parallel with the secretion of prolactin. Forskolin and 8-Br-cAMP-induced decidualization was significantly enhanced by MPA but not by progesterone. These effects were similar in ESCs from women with and without endometriosis. Moreover, forskolin-induced decidualization was significantly enhanced by simultaneous application of PDE. Interestingly, this effect was higher in cells of patients with endometr