Trophoblast giant-cell differentiation involves changes in cytoskeleton and cell motility.
Trophoblast giant-cell differentiation is well-characterized at the molecular level, yet very little is known about how molecular changes affect the cellular functions of trophoblast in embryo implantation. We have found, using both explanted E7.5 mouse embryo ectoplacental cone and the rat choriocarcinoma (Rcho-1) cell line, that trophoblast differentiation is distinguished by dramatic changes in cytoarchitecture and cell behavior. Undifferentiated trophoblast cells contain little organized actin and few small, peripheral focal complexes and exhibit high membrane protrusive activity, while differentiated trophoblast giant cells contain prominent stress fibers, large internal as well as peripheral focal adhesions, and become immotile. The dramatic changes in cell behavior and cytoskeletal organization of giant cells correlate with changes in the activities of the Rho family of small GTPases and a decrease in tyrosine phosphorylation of focal adhesion kinase. Together, these data provide detailed insight into the cellular properties of trophoblast giant cells and suggest that giant-cell differentiation is characterized by a transition from a motile to a specialized epithelial phenotype. Furthermore, our data support a phagocytic erosion, rather than a migratory infiltration, mechanism for trophoblast giant-cell invasion of the uterine stroma.
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Department of Cell Biology, University of Virginia Health System, School of Medicine, Charlottesville, VA 22908, USA.
Aeder
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Sutherland
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D000199:Actins / Q000502:physiology; D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D002465:Cell Movement; D003599:Cytoskeleton / Q000502:physiology; D010064:Embryo Implantation / Q000502:physiology; D047108:Embryonic Development; D005260:Female; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D015726:Giant Cells / Q000166:cytology / Q000502:physiology; D066298:In Vitro Techniques; D008954:Models, Biological; D010766:Phosphorylation; D011247:Pregnancy; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051381:Rats; D014327:Trophoblasts / Q000166:cytology* / Q000502:physiology; D014599:Uterus / Q000166:cytology; D020741:rho GTP-Binding Proteins / Q000378:metabolism
D000199:Actins; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496052:Ptk2 protein, rat; D020741:rho GTP-Binding Proteins