Increased NDRG1 expression suppresses angiogenesis via PI3K/AKT pathway in human placental cells

Abstract

To observe whether and how N-myc downstream-regulated gene 1 (NDRG1) regulates placental angiogenesis via JEG-3 placental-derived cells. Expression of NDRG1 in stably transfected JEG-3 cells was detected using western blot and real-time quantitative polymerase chain reaction. Angiogenesis was examined by tube formation assay. The levels of placental growth factor (PLGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were examined using enzyme-linked immunosorbent assay. The expression of vascular endothelial growth factor (VEGF), PI3K, and AKT was examined by western blot. The relationship between PI3K and NDRG1 was detected by co-immunoprecipitation. NDRG1 was significantly down-regulated at both the mRNA and protein level by lentivirus (Lv)-NDRG1-shRNA (P<0.001), whereas it was significantly up-regulated by Lv-NDRG1 (P<0.001). NDRG1 knockdown significantly increase the expression of PLGF and VEGF in JEG-3 cells (P<0.001), while NDRG1 knockdown significantly reduced the secretion of sFlt-1 (P<0.001). NDRG1 was specific bound to PI3K, and NDRG1 knockdown significantly up-regulated the expressions of PI3K and AKT in JEG-3 cells (P<0.001). NDRG1 suppresses angiogenesis in preeclampsia, and the PI3K/AKT signaling pathway may be involved in the regulation of angiogenesis by NDRG1.