Endometrial receptors mediate spheroids-endometrium attachment

Implantation in humans involves cross talk between §an active blastocyst and receptive endometrium. The §role of the endometrial receptors in this complex §embryo-maternal interaction is still unclear. We §tested gene and protein expression of endometrial §receptors (Plexin-B1, c-Met and Progesterone §receptor A) and the effect of these receptors in §endometrial receptivity. Methods: Two endometrial §cell lines were used: HEC-1A and RL95-2 considered §as being of low and high receptivity, respectively. §Western blot and RT-PCR analysis were utilized to §study the receptor expression profile. The role of §endometrial receptors in endometrial receptivity was §studied by attachment and invasion assays of JAR §spheroids on endometrial cells. Different §manipulations of inhibition and stimulation of the §endometrial receptors were used.§Conclusion: Differential endometrial receptor §profiles are expressed during the receptivity §period. The attachment and invasion processes are §separately regulated. We suggest a biologically §functional role for PB1, PRA and the complex PB1-c-§MET in endometrial receptivity and in the attachment §process.