Figure 5. SEMA3B inhibited PI3K/AKT and GSK3β signaling in CTBs and the same effects were observed in sPE.

(A) SEMA3B and wortmannin (WM) inhibited PI3K activity, which was stimulated by VEGF. DMSO was used as a vehicle control. Mean ± SEM, 2-tailed Student’s t test. *P < 0.05, **P < 0.01. (B) The addition of SEMA3B to UtMVECs resulted in the dissociation of the p85 and the p110α subunits of PI3K, which was rescued by the addition of VEGF. (C) In COS-1 cells, SEMA3B inhibited AKT Ser473 phosphorylation (activation), which increased during CTB differentiation/invasion (0–12 hours). The addition of SEMA3B inhibited AKT phosphorylation, which was enhanced by exogenous VEGF. (D) In COS-1 cells, SEMA3B inhibited GSK3β Ser9 phosphorylation (inactivation), which increased during CTB differentiation/invasion (0–12 hours). Exogenous SEMA3B inhibited GSK3β phosphorylation, which was enhanced by VEGF. GSK3α Ser21 phosphorylation was variable. (E) In CTBs, sPE correlated with dissociation of the p85 and p110α (and γ) subunits of PI3K relative to control cells isolated from normal third trimester placentas. (F) In freshly isolated CTBs, sPE was associated with decreased phosphorylation of AKT Ser473 and GSK3β Ser9. α-Actin was used as a loading control. (G) In chorionic villi, sPE was associated with phosphorylation (inactivation) of β-catenin. (A–D) The same results were obtained in 3 separate experiments that used different preparations of cells. (F and G) The results shown are representative of analyses of a total of 6 CTB isolates from different placentas of women diagnosed with sPE.