Peri-implantation dialogue
Embryo: hCG and other factors and receptors
Uterus: LIF and other cytokines, growth factors, integrins, receptors
Adhesion & Penetration
Changes: microvilli (terminal web), MUC-1, junctions, basement membrane
Basement membrane
Decidua
Macaque implantation: Also in Hamilton et al. Human Embryology Williams and Wilkins Phil (1972)4th ed.
Drawing implantation:
MUC-1 oligos binding sites for lectins.
Integrin
a
v
B
3 - some evidence in mice that antibody to it decreases implantation
(absence of this integrin in menopausal endometrium)
Integrin receptor for vitronectin at opening window of receptivity
Attachment- Integrin receptors for laminin
Migration - receptors for fibronectin (a5B1)
Laminin and collagen IV disappear from basement membrane before trophoblast arrives
Glycogen, cytokine (LIF), integrin (
a
v
b
3)
->adhesion; a6B1->fibronectin receptor so no invasion; a1B1->laminin and collagen-IV; so invasion
Proteolysis basement membrane and ECM