title: Arterial endothelial cytokines guide extravillous trophoblast invasion towards spiral arteries; an in-vitro study with the trophoblast cell line ACH-3P and female non-uterine endothelial cells.
abstract: BACKGROUND
  Invasion of extravillous trophoblasts (EVT) is tightly linked to appropriate cell to cell contact as well as paracrine guidance of EVT by maternal uterine cells, conducted by a variety of locally expressed cytokines. Here we investigated the interaction of the first trimester trophoblast cell line ACH-3P with adult iliac arterial (AEC) and venous endothelial cells (VEC).
  
  
  METHODS
  The impact of ACH-3P conditioned medium (Cdm), obtained at 2.5% and 21% oxygen, on endothelial cell viability (LDH-Assay) and network formation (Matrigel-Assay) was tested. We investigated cytokine expression of AEC- and VEC-Cdm and confirmed results with ELISA analysis, and investigated the influence of Cdm on ACH-3P proliferation and invasion. Additionally, direct co-culture experiments with ACH-3P and AEC on Matrigel were performed. A subset of experiments was verified with primary trophoblasts as well as with first trimester placenta in situ specimens.
  
  
  RESULTS
  ACH-3P-Cdm significantly enhanced cell viability of AEC and VEC after 72 h. ACH-3P-Cdm at 2.5% oxygen stabilized endothelial network structures in Matrigel up to 24 h, similar to the effect of a direct co-culture of AEC and ACH-3P. AEC and VEC showed a similar pattern of secreted cytokines. However, elevated levels of cytokines secreted by AEC were found for GRO, IL-6, MMP-1 and uPAR. ELISA confirmed elevated concentrations of IL-6 and uPAR in AEC compared to VEC. ACH-3P and primary trophoblasts more likely invaded towards AEC-Cdm than towards VEC-Cdm. Addition of IL-6 to Cdm increased the invasion potential of both cell types. AEC- and VEC-Cdm reduced ACH-3P cell proliferation after 24 h of culture. IL-6 was highly expressed in uterine AEC compared to VEC as visualized by immunohistochemistry.
  
  
  CONCLUSIONS
  The presented results clearly demonstrate that cytokines of both cell types, AEC and trophoblasts, differentially contribute to successful guidance and interaction in the process of trophoblast invasion.
authors.affiliation: From the Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21/7, 8010 Graz, Austria. Electronic address: gregor.weiss@medunigraz.at.
authors.forename: Gregor
authors.initials: G
authors.lastname: Weiss
authors.affiliation: From the Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21/7, 8010 Graz, Austria.
authors.forename: Berthold
authors.initials: B
authors.lastname: Huppertz
authors.affiliation: From the Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21/7, 8010 Graz, Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Siwetz
authors.affiliation: From the Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21/7, 8010 Graz, Austria.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Lang
authors.affiliation: From the Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21/7, 8010 Graz, Austria.
authors.forename: Gerit
authors.initials: G
authors.lastname: Moser
mesh_terms: D000328:Adult; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000378:metabolism* / Q000494:pharmacology*; D003656:Decidua / Q000187:drug effects / Q000502:physiology; D042783:Endothelial Cells / Q000378:metabolism*; D005260:Female; D006801:Humans; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010929:Placentation / Q000187:drug effects*; D011247:Pregnancy; D014327:Trophoblasts / Q000187:drug effects* / Q000502:physiology; D055988:Uterine Artery / Q000166:cytology / Q000502:physiology*; D014599:Uterus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D016207:Cytokines
keywords: Cytokines; Extravillous trophoblast; Invasion; Placenta; Spiral arteries