OBJECTIVE: To investigate insulin-like growth factors (IGF)-I and -II in human endometrial stromal cells during decidualization in vitro and under the influence of hCG. DESIGN: In vitro experiment. SETTING: Research laboratory at a medical university center. PATIENT(S): Premenopausal women undergoing hysterectomy for benign reasons. INTERVENTION(S): Endometrial stromal cells from hysterectomy specimens were isolated and incubated with 17beta-E(2), P, and recombinant hCG. MAIN OUTCOME MEASURE(S): Insulin-like growth factor-I and -II messenger RNA and protein were measured by semiquantitative real-time reverse transcriptase polymerase chain reaction and ELISA. RESULT(S): During decidualization in vitro there was a significant increase of IGF-I level between day 0 and 3, followed by a decrease from day 6 to 9. Insulin-like growth factor-II level, however, was significantly reduced during all days of decidualization compared with day 0. In decidualized endometrial stromal cells, hCG decreased IGF-I in a dose-dependent manner without influencing IGF-II. CONCLUSION(S): Endometrial IGF-I and -II are differentially regulated during decidualization in vitro, suggesting different roles during the differentiation of endometrial stromal cells. Human chorionic gonadotropin as one of the first hormonal signals of the embryo selectively reduces IGF-I and may therefore contribute to the modulation of endometrial receptivity and differentiation during the process of early implantation.
OBJECTIVE: To investigate insulin-like growth factors (IGF)-I and -II in human endometrial stromal cells during decidualization in vitro and under the influence of hCG. DESIGN: In vitro experiment. SETTING: Research laboratory at a medical university center. PATIENT(S): Premenopausal women undergoing hysterectomy for benign reasons. INTERVENTION(S): Endometrial stromal cells from hysterectomy specimens were isolated and incubated with 17beta-E(2), P, and recombinant hCG. MAIN OUTCOME MEASURE(S): Insulin-like growth factor-I and -II messenger RNA and protein were measured by semiquantitative real-time reverse transcriptase polymerase chain reaction and ELISA. RESULT(S): During decidualization in vitro there was a significant increase of IGF-I level between day 0 and 3, followed by a decrease from day 6 to 9. Insulin-like growth factor-II level, however, was significantly reduced during all days of decidualization compared with day 0. In decidualized endometrial stromal cells, hCG decreased IGF-I in a dose-dependent manner without influencing IGF-II. CONCLUSION(S): Endometrial IGF-I and -II are differentially regulated during decidualization in vitro, suggesting different roles during the differentiation of endometrial stromal cells. Human chorionic gonadotropin as one of the first hormonal signals of the embryo selectively reduces IGF-I and may therefore contribute to the modulation of endometrial receptivity and differentiation during the process of early implantation.