PARENT SESSION
Implantation & Early Development

THE REGULATION OF LIF GENE EXPRESSION BY INTERLEUKIN-1 IN THE MOUSE PERI-IMPLANTATION EMBRYOS AND UTERINE ENDOMETRIAL CELLS.

Lee, Jung Bok¹, Kim, Joung Woul², Kim, Moon Kyoo², Do, Byung-Rok¹, Yoon, Hyun Soo^1,2, ^{1 2}

ABSTRACT- Cytokines take a critical role in embryo implantation. Leukemia inhibitory factor (LIF) is the one of these cytokines and it has been shown to be a pleiotropic molecule involved in different activities in various tissues and cell types. LIF mRNA expression is regulated by interleukin-1 (IL-1) in human synovial fibroblasts, lung fibroblasts, and decidual cells. In this study, the effects of IL-1 on LIF transcription were examined in mouse peri-implantation embryos and endometrial cells. The endometrial cells was prepared at 24, 48, 72, 96 and 120 hour post-hCG, and were cultured with Ham's F-10 containing IL-1 (500pg/ml) or IL-1ra (60ng/ml). The embryos were cultured from 2-cell to blastocyst in KSOM containing IL-1 or IL-1ra. LIF mRNA was detected in morula and blastocyst, and in the endometrial cells of day 1 and 4 of pregnancy of in vivo and in vitro culture with medium alone. LIF transcripts were detected first at 8-cell stage and the amount of LIF mRNA had a tendency to increase in blastocyst treated with IL-1. LIF mRNA was detected in the endometrial cells from day 1 to 5 of pregnancy, and the amount of LIF mRNA was abundant in day 4 of pregnancy than other days, in the endometrial cells treated with IL-1. In contrast, LIF mRNA was reduced in blastocyst and the endometrial cells of day 4 of pregnancy treated with IL-1ra. In addition, LIF mRNA was not detected in the endometrial cells of day 1 of pregnancy. These results suggest that LIF mRNA expression is controlled by IL-1 in the embryos and endometrial cells at the time of implantation.

KEY WORDS: cytokines, mouse embryo, endometrium, implantation