title: Hormonal regulation of endometrial olfactomedin expression and its suppressive effect on spheroid attachment onto endometrial epithelial cells.
abstract: BACKGROUND
  Olfactomedin (Olfm) is a member of a diverse group of extracellular matrix proteins important for neuronal growth. Recent microarray studies identified Olfm as one of the down-regulated transcripts in receptive endometrium at the time of embryo attachment and implantation. However, the underlying molecular mechanisms that govern Olfm expression and its effect on embryo attachment and implantation remain unknown.
  
  
  METHODS
  The expression of Olfm in the human endometrium was investigated by real-time PCR, western blotting and immunohistochemistry on human endometrial biopsies from natural and ovarian stimulated cycles. To investigate the function of Olfm in trophoblast-endometrial cell attachment, an in vitro spheroid-endometrial cell co-culture study was performed.
  
  
  RESULTS
  Human endometrial Olfactomedin-1 and -2(Olfm-1 and -2) transcripts decreased significantly from the proliferative to the secretory phases of the menstrual cycle. Olfm protein was strongly expressed in the luminal and glandular epithelium and moderately in the stromal cells of human endometria. Ovarian stimulation significantly decreased (P < 0.05) the expression of endometrial Olfm-1 and -2 transcripts in patients receiving IVF treatment when compared with those in the natural cycle. Importantly, recombinant Olfm-1 suppressed JAr spheroid attachment onto Ishikawa cells and this was not associated with changes of β-catenin and E-cadherin expression in trophoblast and endometrial cells.
  
  
  CONCLUSIONS
  Decreased expression of Olfm during the receptive phase of the endometrium may allow successful trophoblast attachment for implantation.
authors.affiliation: Department of Obstetrics and Gynaecology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
authors.forename: Suranga P
authors.initials: SP
authors.lastname: Kodithuwakku
authors.forename: Pak-Yiu
authors.initials: PY
authors.lastname: Ng
authors.forename: Yunao
authors.initials: Y
authors.lastname: Liu
authors.forename: Ernest H Y
authors.initials: EH
authors.lastname: Ng
authors.forename: William S B
authors.initials: WS
authors.lastname: Yeung
authors.forename: Pak-Chung
authors.initials: PC
authors.lastname: Ho
authors.forename: Kai-Fai
authors.initials: KF
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D002460:Cell Line; D010064:Embryo Implantation / Q000502:physiology; D004717:Endometrium / Q000378:metabolism*; D004958:Estradiol / Q000097:blood; D047628:Estrogen Receptor alpha / Q000097:blood; D047629:Estrogen Receptor beta / Q000097:blood; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005307:Fertilization in Vitro; D005786:Gene Expression Regulation; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008597:Menstrual Cycle / Q000378:metabolism; D008969:Molecular Sequence Data; D010062:Ovulation Induction; D016133:Polymerase Chain Reaction; D011374:Progesterone / Q000097:blood; D012333:RNA, Messenger / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: D015820:Cadherins; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D012333:RNA, Messenger; D051176:beta Catenin; C081451:olfactomedin; D011374:Progesterone; D004958:Estradiol