title: Transcription factor AP-2α promotes EGF-dependent invasion of human trophoblast.
abstract: The basic helix-span-helix transcription factor activating protein (AP)-2α is critically involved in cell-specific hormone expression of syncytializing human trophoblasts. Its role in invasive trophoblast differentiation, however, remains largely elusive. Using RT-PCR, Western blotting, and immunofluorescence of first-trimester placentae, we here show that AP-2α is expressed in extravillous trophoblasts (EVTs) both in situ and in vitro as well as in invasive trophoblast cell lines. Its protein expression was increased upon supplementation of epidermal growth factor (EGF) both in primary EVTs and trophoblastic SGHPL-5 cells. Gene silencing of AP-2α using small hairpin microRNA (shRNAmir) did not affect basal invasion of SGHPL-5 cells through Matrigel-coated filters but reduced EGF-stimulated invasion. Similarly, treatment of primary EVTs with AP-2α small interfering RNA decreased EGF-dependent invasion. Proliferation of SGHPL-5 cells and primary EVTs, measured by cumulative cell numbers and 5-bromo-2'-deoxyuridine labeling, respectively, were not affected on loss of AP-2α. EGF-dependent induction of matrix metalloproteinase (MMP)-2, pro- and active form of urokinase plasminogen activator, and chorionic gonadotropin (CG)-β was noticed in shRNAmir-control cells, whereas these genes were suppressed in EGF-treated shRNAmir-AP-2α cells. Similarly, EGF-stimulated MMP-2 and CGβ protein expression was reduced in AP-2α small interfering RNA-treated primary EVTs. Knockdown of AP-2α also decreased luciferase activity of the CGβ5 promoter in SGHPL-5 cells, which was compensated upon transient overexpression of AP-2α cDNA. In conclusion, we show that AP-2α expression positively affects human trophoblast invasion under EGF-stimulated conditions, likely by inducing critical invasion-promoting genes such MMP-2, urokinase plasminogen activator, and CG.
authors.affiliation: Department of Obstetrics and Fetal-Maternal Medicine, Reproductive Biology Unit, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Biadasiewicz
authors.forename: Stefan
authors.initials: S
authors.lastname: Sonderegger
authors.forename: Peter
authors.initials: P
authors.lastname: Haslinger
authors.forename: Sandra
authors.initials: S
authors.lastname: Haider
authors.forename: Leila
authors.initials: L
authors.lastname: Saleh
authors.forename: Christian
authors.initials: C
authors.lastname: Fiala
authors.forename: Jürgen
authors.initials: J
authors.lastname: Pollheimer
authors.forename: Martin
authors.initials: M
authors.lastname: Knöfler
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D049109:Cell Proliferation; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050656:Transcription Factor AP-2 / Q000235:genetics / Q000378:metabolism*; D014327:Trophoblasts / Q000187:drug effects / Q000378:metabolism*; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D006063:Chorionic Gonadotropin; D050656:Transcription Factor AP-2; D004815:Epidermal Growth Factor; D014568:Urokinase-Type Plasminogen Activator; D020778:Matrix Metalloproteinase 2