title: Human endometrial epithelial cells express ephrin A1: possible interaction between human blastocysts and endometrium via Eph-ephrin system.
abstract: Eph receptor tyrosine kinases and their cell membrane-bound ligands, ephrins, are well known to function in cell-to-cell interaction and to play an important role in cell migration and adhesion during embryonic development in mammals. To investigate the involvement of the Eph-ephrin system in human embryo implantation, the expression of Eph receptors and ephrins was examined in human blastocysts and the endometrium. Immunohistochemical examination showed that ephrin A1 was expressed on human endometrial luminal and glandular epithelial cells in both the proliferative (cycle d 8-13; n = 8) and secretory (cycle d 18-24; n = 7) phases. RT-PCR analysis of isolated endometrial epithelial cells and stromal cells showed that ephrin A1 mRNA was predominantly expressed in endometrial epithelial cells. Northern blot analysis also confirmed the expression of ephrin A1 mRNA in the endometrium. In addition, nested RT-PCR analysis revealed the mRNA expression of Eph A1, one of the representative receptors for ephrin A1, in human blastocysts obtained from patients undergoing in vitro fertilization treatment. These findings indicate a possible interaction between human blastocysts and endometrial epithelial cells via the Eph-ephrin system. Because intracytoplasmic signals are induced by Eph receptors after ephrin stimulation, this system may be involved in the activation process of the human embryo during the implantation period.
authors.affiliation: Department of Gynecology and Obstetrics, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan. fuji@kuhp.kyoto-u.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Shinya
authors.initials: S
authors.lastname: Yoshioka
authors.forename: Keiji
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Kenzo
authors.initials: K
authors.lastname: Kosaka
authors.forename: Yukiyasu
authors.initials: Y
authors.lastname: Satoh
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nishioka
authors.forename: Miho
authors.initials: M
authors.lastname: Egawa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Higuchi
authors.forename: Shingo
authors.initials: S
authors.lastname: Fujii
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D015152:Blotting, Northern; D004717:Endometrium / Q000166:cytology / Q000502:physiology*; D036382:Ephrin-A1 / Q000235:genetics / Q000378:metabolism*; D036342:Ephrins / Q000502:physiology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D036382:Ephrin-A1; D036342:Ephrins; D012333:RNA, Messenger