Conclusions
The study reveals a mechanism of uterine lumen closure by identifying that ST6GAL1-mediated α2,6-sialylation of cell adhesion molecules contributes to endometrial fold extension through regulating collective migration of uterine LE.
Methods
Uterine and endometrium tissues during implantation were collected in pigs. MALDI-TOF MS was used to characterize the N-glycomic profiles. Histochemistry, siRNA transfection, Western blotting, lectin immumoprecipitation, mass spectrometry and assays of wounding healing and cell aggregation were performed to investigate the molecular basis.
Results
We observed that uterine luminal epithelium (LE) migrated collectively during endometrial fold extension. For the first time, we identified a large number of N-glycan compositions from endometrium during implantation using MALDI-TOF MS. Notably, the α2,6-linked sialic acid and ST6GAL1 were highly expressed in uterine LE when the endometrial folds extended greatly. Subsequently, the role of ST6GAL1-mediated 2,6-sialylation in collective epithelial migration was demonstrated. Finally, we found that ST6GAL1-mediated α2,6-sialylation of E-cadherin may participate in collective migration of uterine LE. Conclusions: The study reveals a mechanism of uterine lumen closure by identifying that ST6GAL1-mediated α2,6-sialylation of cell adhesion molecules contributes to endometrial fold extension through regulating collective migration of uterine LE.