Difucosylated oligosaccharide Lewis Y is contained within integrin αvβ3 on RL95-2 cells and required for endometrial receptivity

Objective: To investigate whether Lewis Y (LeY) carried by integrin alpha v beta 3 influences integrin alpha v beta 3-mediated adhesion in an in vitro implantation model. Design: Laboratory research. Setting: Reproduction and glycobiology research laboratory. Intervention(s): Specific antibody blockage of LeY or integrin alpha v beta 3 and knockdown of FUT4 expression in RL95-2 cells by transient transfection of FUT4 siRNA. Main Outcome Measure(s): The expression of integrin alpha v beta 3 and LeY in both endometrial tissues and RL95-2 cells was measured. LeY carried by integrin alpha v beta 3 was identified by examining the immunoprecipitated integrin alpha v beta 3. The effect of knocking down FUT4 on the expression of integrin alpha v beta 3 and LeY and their impact on the adhesion of JAR cells to the RL95-2 cells were assessed. Result(s): Integrin alpha v beta 3 and LeY are expressed in both secretory-stage human endometrial tissue and in RL95-2 cells. Although integrin alpha v beta 3 carries LeY, knocking down FUT4 expression only reduces the expression of LeY but not of integrin alpha v beta 3. Knocking down FUT4, antibody blockade of LeY or integrin alpha v beta 3 consistently decreases the adhesion of JAR cells to the RL95-2 cells and prevents focal adhesion kinase (FAK) phosphorylation. Conclusion(s): LeY carried by integrin alpha v beta 3 plays a critical role on the attachment of JAR cells to the RL95-2 cells and activates integrin alpha v beta 3/FAK signaling. (Fertil Steril (R) 2011;95:1446-51. (C)2011 by American Society for Reproductive Medicine.)