title: Expression of leukemia inhibitory factor and its receptor in preimplantation embryos.
abstract: OBJECTIVE
  To examine the expression of leukemia inhibitory factor (LIF) and its receptor (LIF-R) transcripts in human and murine preimplantation embryos.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  Human oocytes were obtained from patients undergoing IVF treatment. Two-cell murine embryos were obtained from ICR strain mice.
  
  
  METHODS
  Second-day intracytoplasmic sperm injection procedures were performed on oocytes that failed to be fertilized by IVF. Embryos were cultured to various stages and collected for study.
  
  
  METHODS
  The transcript levels of LIF and LIF-R in these embryos were examined and semiquantitated using single-cell reverse transcription-polymerase chain reaction methodology.
  
  
  RESULTS
  Leukemia inhibitory factor and LIF-R transcripts were detectable in most human preimplantation embryos (30 of 34 and 31 of 34 embryos showed LIF and LIF-R messenger RNA, respectively). There was a trend toward decreased expression of both transcripts in embryos at the four-cell stage and in embryos in which growth had been arrested for 24-48 hours. The expression of LIF and LIF-R genes in murine embryos was inconsistent.
  
  
  CONCLUSIONS
  Preimplantation human embryos express LIF and LIF-R messenger RNA. It is suggested that LIF may be able to affect embryo development through its action at stages before implantation in an autocrine or paracrine manner.
authors.affiliation: Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei.
authors.forename: H F
authors.initials: HF
authors.lastname: Chen
authors.forename: J Y
authors.initials: JY
authors.lastname: Shew
authors.forename: H N
authors.initials: HN
authors.lastname: Ho
authors.forename: W L
authors.initials: WL
authors.lastname: Hsu
authors.forename: Y S
authors.initials: YS
authors.lastname: Yang
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D015139:Blotting, Southern; D006131:Growth Inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008222:Lymphokines / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012333:RNA, Messenger / Q000378:metabolism; D018121:Receptors, Cytokine / Q000235:genetics / Q000378:metabolism*; D053606:Receptors, OSM-LIF
chemical_list: D006131:Growth Inhibitors; D015850:Interleukin-6; C507837:LIF protein, human; C507840:LIFR protein, human; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; C507838:Lif protein, mouse; C507841:Lifr protein, mouse; D008222:Lymphokines; D012333:RNA, Messenger; D018121:Receptors, Cytokine; D053606:Receptors, OSM-LIF