Downregulated N-acetylglucosaminyltransferase III is involved in attenuating trophoblast migration and invasion under hypoxia-reoxygenation condition

Objective: Many studies have confirmed that N-acetylglucosaminyltransferase III (GnT-III) is correlated with tumor invasion and metastasis. However, the expression of GnT-III and its role in normal pregnancy and preeclampsia (PE) has not been reached. So the primary objective of this study is to determine GnT-III expression in normal pregnancy and whether its expression is vulnerable to oxidative stress in the trophoblast cells. Methods: Human first trimester villous tissues from normal pregnancies and third trimester placentas from pregnancies with or without preeclampsia (PE) were used for the detection of GnT-III expression. Human first trimester extravillous trophoblast cell line (HTR8/SVneo) exposed to hypoxia/reoxygenation (H/R) condition was employed as an oxidative stress model in vitro to investigate the expression of GnT-III. Results: GnT-III was strongly expressed in cytotrophoblast (CTBs), syncytiotrophoblast (STBs) and the trophoblast columns (TCs) of human placental villi, and decidual cells in the maternal decidua. The expression of GnT-III was decreased in PE placentas compared with the normal control placentas. In addition, GnT-III was found to have decreased expression in H/R-exposed HTR8/SVneo cells, and the invasive and migratory abilities of HTR8/SVneo cells were attenuated, too. Conclusions: These findings suggest that GnT-III is an important regulator at the maternal-fetal interface during early pregnancy. Excessive oxidative stress can decrease GnT-III expression in trophoblast and the decreased expression of GnT-III may be involved in the development of preeclampsia.