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

Fertil Steril. 2013 Oct;100(4):1160-9. doi: 10.1016/j.fertnstert.2013.06.023. Epub 2013 Jul 19.

Abstract

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.

Keywords: AKT; LIF; PEGLA; apoptosis; embryo attachment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Biopsy
  • Blastocyst / drug effects*
  • Blastocyst / enzymology
  • Blastocyst / pathology
  • Caspase 3 / metabolism
  • Down-Regulation
  • Embryo Culture Techniques
  • Embryo Implantation / drug effects*
  • Endometrium / drug effects*
  • Endometrium / metabolism
  • Female
  • Fluorescent Antibody Technique
  • Gene Expression Regulation, Developmental / drug effects
  • Gene Expression Regulation, Enzymologic / drug effects
  • Humans
  • Leukemia Inhibitory Factor / antagonists & inhibitors*
  • Leukemia Inhibitory Factor / metabolism
  • Leukemia Inhibitory Factor / pharmacology*
  • Phosphorylation
  • Polyethylene Glycols / pharmacology*
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA, Messenger / metabolism
  • Real-Time Polymerase Chain Reaction

Substances

  • LIF protein, human
  • Leukemia Inhibitory Factor
  • RNA, Messenger
  • pegylated MH35-BD-Q29A+G124R protein
  • Polyethylene Glycols
  • AKT1 protein, human
  • Proto-Oncogene Proteins c-akt
  • CASP3 protein, human
  • Caspase 3