Polyethylene glycated leukemia inhibitory factor antagonist inhibits human blastocyst implantation and triggers apoptosis by down-regulating embryonic AKT.

OBJECTIVE: To study the effect of polyethylene glycated leukemia inhibitory factor (LIF) antagonist (PEGLA) in the human blastocyst viability and implantation process. DESIGN: In vitro study. SETTING: University hospital and research laboratory. PATIENT(S): Endometrial biopsy samples from fertile donors (n = 20), and surplus, frozen, good-quality human embryos obtained from an in vitro fertilization (IVF) clinic that survived thawing (n = 51). INTERVENTION(S): Timed human endometrial biopsy on the day of luteinizing hormone peak + 4 days (LH + 4). MAIN OUTCOME MEASURE(S): Human embryo attachment rate, embryo quality, and expression of AKT and caspase-3. RESULT(S): PEGLA significantly reduced the embryo attachment rate to the endometrial construct. It decreased both mRNA and protein for LIF in the endometrial construct. Inhibition of embryonic LIF triggered apoptosis. Analysis of these blastocysts by immunofluorescence and real-time polymerase chain reaction showed a down-regulation in AKT activation and an increase in caspase-3 activation compared with the control group of blastocysts. CONCLUSION(S): The LIF inhibitor PEGLA could be a potential nonsteroidal fertility-regulating agent in humans. It acts on endometrial epithelial cells by down-regulating endometrial epithelial LIF. Inhibition of blastocyst LIF decreased its cell survival factor p-AKT and increased apoptosis (cleaved caspase-3). This highlights that embryonic LIF is vital for human embryo implantation.

Expression of aquaporin-1 in endometrial blood vessels in menorrhagia.

Aquaporin-1 (AQP1) is a water channel protein expressed in vascular endothelia and involved in impaired angiogenesis in tumors. Since angiogenesis is an essential component of the regeneration of the endometrium, we sought to analyze the expression of AQP1 in endometrial blood vessels in normal cyclic endometrium as well as in endometrial biopsies of menorrhagia patients. Endometrial biopsies from 16 patients with menorrhagia and 21 healthy fertile women were used for immunohistochemistry assessment of AQP1-stained endothelial structures. RT-PCR was used to confirm the presence of AQP1 mRNA. We detected the expression of AQP1 solely in endometrial blood vessels in the control group, as well as in menorrhagic endometrium. There was no difference between proliferative and secretory endometrium. Furthermore, we observed that the vascular expression of AQP1 in endometrial blood vessels in the menorrhagia group was significantly lower than in controls (p=0.002). There was also a significantly lower number of stained vessels per unit area in the menorrhagia group than in the controls (p=0.006). Thus, the deregulation of aquaporin-1 in menorrhagia may be involved in abnormal endometrial vascular growth and permeability.

Expression of aquaporin 2 in human endometrium.

OBJECTIVE: To study the expression of aquaporin-2 (AQP2) in human endometrium. DESIGN: Prospective clinical study. SETTING: Hospital-based unit for gynecology and obstetrics and research laboratories. PATIENT(S): Healthy women with proven fertility who were divided into four groups according to LH peak. INTERVENTION(S): Endometrial biopsies were obtained from 34 women on cycle days LH+4 to LH+14. MAIN OUTCOME MEASURE(S): Localization of AQP2 in human endometrium during normal cycle using immunohistochemistry, verification of AQP2 expression through detection of AQP2 mRNA in reverse transcriptase-polymerase chain reaction (RT-PCR), detection of pinopodes using scanning electron microscopy, and confirmation of AQP2 on pinopodes in confocal microscopy. RESULT(S): Immunostaining of AQP2 is present in the luminal and glandular epithelium but not in the stroma. Some vessels stained positive for AQP2. When present, pinopodes stained positive, which was confirmed using confocal microscopy. A significant increase in staining intensity was seen in the glandular and luminal epithelium during the mid and late luteal phases of the cycle. The presence of AQP2 in human endometrium was also confirmed by RT-PCR. CONCLUSION(S): AQP2 is present in the human endometrium. The expression of AQP2 appears to be cycle dependent and suggests a role for AQP2 in implantation, edema, and/or menstruation.