title: Expression pattern and function of Notch2 in different subtypes of first trimester cytotrophoblast.
abstract: BACKGROUND
  Notch signalling has been shown to control cytotrophoblast (CTB) proliferation, differentiation and motility suggesting that the conserved signalling pathway could be critical for human placental development. Since individual Notch receptors have not been elucidated, we herein investigated expression pattern and function of Notch2 in different first trimester trophoblast subpopulations.
  
  
  METHODS
  Localisation of Notch2 was analysed in first trimester placental and decidual tissues using immunofluorescence. Notch2 transcript and protein levels were studied by qRT-PCR and Western blotting in proliferative EGF receptor (EGFR)(+) and differentiated HLA-G(+) CTBs, respectively, isolated from early placentae by MACS. CTB migration through fibronectin-coated transwells as well as proliferation (EdU labelling) in floating villous explant cultures and primary CTBs were investigated in the presence of Notch2 siRNAs or specific antibodies blocking Notch2 cleavage.
  
  
  RESULTS
  In tissue sections Notch2 expression was higher in HLA-G(+) distal cell column trophoblasts (dCCTs) compared to proximal CCTs. Accordingly, expression of Notch2 mRNA and protein were elevated in isolated HLA-G(+) CTBs compared to EGFR(+) CTBs. Notch2 was also detectable in interstitial CTBs as well as in intramural CTBs associated with maternal decidual vessels. Antibody-mediated inhibition of Notch2 signalling did not affect proliferation, but increased migration of SGHPL-5 cells and primary CTBs. Similarly, Notch2 siRNA treatment promoted trophoblast motility.
  
  
  CONCLUSIONS
  Notch2 is present in differentiated cells of the extravillous trophoblast lineage, such as dCCTs, interstitial and intramural CTBs, suggesting diverse roles of the particular receptor. Notch2 signalling, activated by cell-cell contact of neighbouring dCCTs, could attenuate trophoblast migration.
authors: Department of Obstetrics and Fetal-Maternal Medicine, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria.
authors: K
authors: K
authors: Plessl
authors: Department of Obstetrics and Fetal-Maternal Medicine, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria.
authors: S
authors: S
authors: Haider
authors: Gynmed Clinic, Vienna, Austria.
authors: C
authors: C
authors: Fiala
authors: Department of Obstetrics and Fetal-Maternal Medicine, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria.
authors: J
authors: J
authors: Pollheimer
authors: Department of Obstetrics and Fetal-Maternal Medicine, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria. Electronic address: martin.knoefler@meduniwien.ac.at.
authors: M
authors: M
authors: Knöfler
mesh_terms: D000328:Adult; D002448:Cell Adhesion; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D003656:Decidua / Q000166:cytology / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental; D059951:HLA-G Antigens / Q000378:metabolism; D006801:Humans; D010929:Placentation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D034622:RNA Interference; D034741:RNA, Small Interfering; D051883:Receptor, Notch2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D046509:Tissue Culture Techniques; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism*
chemical_list: D059951:HLA-G Antigens; C497764:NOTCH2 protein, human; D034741:RNA, Small Interfering; D051883:Receptor, Notch2; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Extravillous trophoblast; Human placenta; Migration; Notch2