Abstract: 374

INTERLEUKIN -1 (IL-1) INDUCES THE EXPRESSION OF INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-1 (IGFBP-1) DURING DECIDUALIZATION IN THE PRIMATE.

Z Strakova¹ , S Srisuparp¹ , AT Fazleabas^{1 *}
Dept of OB/GYN, Univ of Illinois, Chicago, IL ¹

During pregnancy uterine stromal fibroblasts are transformed in to differentiated decidual cells. IGFBP-1 is the major secretory product of these decidual cells. Since IL-1 can modulate fetal/maternal interactions, this study determined if IL-1 is one of the factors that potentiates the conceptus induced decidual response in the primate. Human stromal fibroblasts were isolated from the decidua parietalis of term pregnancies. These proliferative cells resemble endometrial stromal cells and are a suitable model for studying the decidualization process. Baboon stromal fibroblasts were isolated from the non-implantation site on day 21 of pregnancy. These cells have initiated the pre-decidual response and are capable of responding to an embryonic stimulus (Kim et al., Endo 140:997, 1999). Following treatment with IL-1 (10 ng/ml) for 4h, a significant increase in cyclooxygenase-2 (COX-2) mRNA expression was detected in stromal cells by RT-PCR. COX-2 mRNA expression was inhibited when IL-1 was co-incubated with IL-receptor antagonist. Since COX-2 is the rate-limiting enzyme for prostaglandin (PG) synthesis, we analyzed the cell culture media for PGE₂. PGE₂ synthesis paralleled IL-1 induced COX-2 mRNA expression. Following 24h of incubation, IL-1 induced mRNA expression for IGFBP-1. The addition of hormones (estradiol-17, medroxyprogesterone acetate and relaxin) further potentiated the expression of IGFBP-1 by IL-1. In contrast, treatment with hormones alone for 24h, did not initiate IGFBP-1 expression. These data suggest that IL-1 is an important intermediate associated with the decidualization in the primate. We hypothesize that the COX-2 mediated PGE₂ synthesis increases intracellular cAMP and synergizes with hormones to induce IGFBP-1 gene transcription. (HD 36759)

    This abstract is being presented on Monday, August 2 at 2:15 PM at Todd 133.