301. LEUKEMIA INHIBITORY FACTOR IS A CRITICAL REGULATOR OF DECIDUALIZATION OF ENDOMETRIAL STROMAL CELLS IN HUMANS AND MICE
L. Lin A B , E. M. Menkhorst A and E. Dimitriadis AA Embryo Implantation Laboratory, Prince Henry’s Institute of Medical Research, Clayton, VIC, Australia.
B Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia.
Reproduction, Fertility and Development 22(9) 101-101 https://doi.org/10.1071/SRB10Abs301
Published: 6 September 2010
Abstract
Decidualization is the differentiation of endometrial stromal cells into decidual cells. It is a critical process in embryo implantation, placentation and the establishment of pregnancy. Inadequate decidualization can lead to infertility, abnormal placentation and recurrent miscarriage. Endometrial leukemia inhibitory factor (LIF) is indispensible in blastocyst implantation in mice and dysregulated in infertile women. LIF is produced by 1st trimester decidual cells but its role in decidualization is not known. This study aimed to examine the role of LIF in human and mouse decidualization. Primary human endometrial stomal cells (HESC) were isolated and decidualized (D) by treatment with estradiol (E) +medroxyprogesterone acetate (MPA) for 14 days. HESC were also treated with E+MPA+/–LIF (0.5, 5, 50, 100 and 200 ng/mL) for 14 days. Prolactin secretion was used to assess the extent of decidualization (n = 6). D and non-D HESC were also treated with LIF (0.5, 5, 50, 100 and 200 ng/mL +/– LIF inhibitor) for 15min and the phosphorylation (p) of signal transducer and activator of transcription (STAT)3/STAT3 abundance was detected by Western blot (n = 4). RNA was isolated for analysis of LIF and LIF receptor (R) mRNA expression during decidualization (n = 4). HESC treated with E+MPA+LIF (50, 100 and 200 ng/mL) secreted more prolactin compared to cells treated with E+MPA alone (P < 0.05). LIF increased pSTAT3/STAT3 abundance in D and non-D cells while LIF+LIF inhibitor abolished pSTAT3/STAT3. LIF mRNA was downregulated while LIF-R mRNA increased during decidualization. In vivo, mated mice (n = 5) were injected intraperitoneally with a unique long acting LIF inhibitor post-implantation at day 4.5 of pregnancy and resulted in reduced decidualization compared to control. This is the first study to demonstrate that LIF promoted decidualization of HESC possibly via pSTAT3. It further suggested that LIF regulated decidualization in mice demonstrating a newly identified critical role for LIF in the establishment of pregnancy.
