Human endometrial CD98 is essential for blastocyst adhesion.
BACKGROUND
Understanding the molecular basis of embryonic implantation is of great clinical and biological relevance. Little is currently known about the adhesion receptors that determine endometrial receptivity for embryonic implantation in humans.


RESULTS
Using two human endometrial cell lines characterized by low and high receptivity, we identified the membrane receptor CD98 as a novel molecule selectively and significantly associated with the receptive phenotype. In human endometrial samples, CD98 was the only molecule studied whose expression was restricted to the implantation window in human endometrial tissue. CD98 expression was restricted to the apical surface and included in tetraspanin-enriched microdomains of primary endometrial epithelial cells, as demonstrated by the biochemical association between CD98 and tetraspanin CD9. CD98 expression was induced in vitro by treatment of primary endometrial epithelial cells with human chorionic gonadotropin, 17-β-estradiol, LIF or EGF. Endometrial overexpression of CD98 or tetraspanin CD9 greatly enhanced mouse blastocyst adhesion, while their siRNA-mediated depletion reduced the blastocyst adhesion rate.


CONCLUSIONS
These results indicate that CD98, a component of tetraspanin-enriched microdomains, appears to be an important determinant of human endometrial receptivity during the implantation window.
Fundación IVI, Instituto Universitario IVI, Universidad de Valencia, Valencia, Spain.
Francisco
F
Domínguez
Carlos
C
Simón
Alicia
A
Quiñonero
Miguel Ángel
MÁ
Ramírez
Elena
E
González-Muñoz
Hans
H
Burghardt
Ana
A
Cervero
Sebastián
S
Martínez
Antonio
A
Pellicer
Manuel
M
Palacín
Francisco
F
Sánchez-Madrid
María
M
Yáñez-Mó
D001755:Blastocyst / Q000166:cytology*; D002448:Cell Adhesion; D004717:Endometrium / Q000166:cytology / Q000276:immunology*; D005260:Female; D027261:Fusion Regulatory Protein-1 / Q000276:immunology*; D006801:Humans
D027261:Fusion Regulatory Protein-1