Expression of Leukemia Inhibitory Factor in Human Endometrium and Placenta1

Abstract

Leukemia inhibitory factor (LIF), a cytokine that induces macrophage differentiation in the murine M1 myeloid leukemia cell line, is essential for blastocyst implantation in mice. However, its expression and the role it plays in the human uterus are unknown. To clarify these issues, we examined LIF gene expression in the human uterus by Northern blot hybridization and by a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. Analysis of LIF mRNA showed two hybridization bands, with estimated mRNA sizes of about 4.0-kb pairs and 1.8-kb pairs. LIF mRNA was detected at high levels in endometrial tissue and decidua, but at low levels in the chorionic villus in first trimester and term placenta. In the secretory phase, the endometrial tissue showed higher LIF expression than in the proliferative phase (9.5-fold; p < 0.01). The endometrial tissues were separated into a stroma-enriched fraction (SF) and an epithelium-enriched fraction (EF), and the LIF mRNA levels in each fraction were examined by quantitative RT-PCR. These levels were higher in the EF than in the SF (3.3-fold; p < 0.05). These findings suggest that, in humans, LIF plays a role in uterine function during the menstrual cycle, as well as during pregnancy.

Leukemia inhibitory factor ligand-receptor signaling is important for uterine receptivity and implantation in golden hamsters (Mesocricetus auratus)

“…Since Lif was not expressed in decidual cells of hamsters, we suggest a possible role for circulating Lif on decidual cells. Contrary to this finding in hamsters, Lif expression in decidual cells and its regulation by decidual cytokines and E 2 has been reported in humans (Kojima et al 1994, Sawai et al 1995, 1997. It is also possible that other members of the IL-6-type cytokine family that share the use of glycoprotein gp130 may be involved in decidualization.…”

O6‐methylguanine‐DNA methyltranspherase gene expression in gliomas by means of real‐time quantitative RT‐PCR and clinical response to nitrosoureas

“…The realtime PCR methods we have used are based on a kinetic analysis of the amplification curve. [35][36][37][38][39] At present, real-time PCR system is seemed to be the most sensitive and rapid system for the quantitation of DNA and RNA. 40 Real-time PCR systems were improved by probe-based, rather than intercalator-based PCR product detection.…”

Blocking LIF action in the uterus by using a PEGylated antagonist prevents implantation: A nonhormonal contraceptive strategy

“…LIF mRNA is present in human endometrium at higher levels during the secretory vs. proliferative phase of the menstrual cycle and is also detected in first-trimester decidua (14). LIF protein is maximal in the endometrial glands during the secretory phase, when blastocyst implantation is most likely to occur (15,16), and uterine fluid contains maximal levels of LIF protein during the mid to late secretory phase (17).…”