Expression of activated Cdc42-associated kinase in the placenta of pregnant women with preeclampsia and its regulatory effect on invasion of trophoblasts

Abstract:

Objective：To investigate the expression of activated Cdc42-associated kinase（ACK1） in the placenta of normal women with full-term pregnancy versus pregnant women with preeclampsia（PE），the regulatory effect of ACK1 on invasion of trophoblasts，and the role of ACK1 in the pathogenesis of PE. Methods：Placenta tissue samples were collected from 23 normal women with full-term pregnancy and 23 pregnant women with PE who underwent elective cesarean section in The First Affiliated Hospital of Chongqing Medical University from October 2015 to October 2016. Immunohistochemistry and Western blot were used to measure the expression of ACK1 in the placenta. The trophoblast cell line（HTR8/SVneo cells） was divided into normoxia control group（N group），hypoxia/reoxygenation（H/R） group，and ACK1 lentivirus knockdown group（ACK1 shRNA group）. Transwell assay was used to evaluate the invasion of cells and flow cytometry was used to measure the apoptosis of cells. Western blot was used to measure the protein expression of ACK1，matrix metalloproteinase-9（MMP-9），and tissue inhibitor of metalloproteinase-2（TIMP2） in HTR8/SVneo cells. Results：The expression of ACK1 in the placenta of PE patients was significantly lower than that in the placenta of normal women with full-term pregnancy（t=3.890，P=0.018）. Compared with the N group，the ACK1 shRNA group and the H/R group had significant reductions in the protein expression of ACK1（t=12.260，P=0.000；t=10.740，P=0.000） and MMP-9（t=8.071，P=0.000；t=7.745，P=0.001） and a significant increase in the protein expression of TIMP1（t=10.690，P=0.000；t=14.330，P=0.000）. The ACK1 shRNA group and the H/R group had a significant reduction in the number of cells migrating to the lower chamber（t=12.260，P=0.000；t=11.320，P=0.000）. The H/R group had a significant increase in cell apoptosis rate（t=2.260，P=0.000），while the ACK1 shRNA group had no significant change in apoptosis rate（t=8.317，P=0.088）. Conclusion：Downregulation of ACK1 expression inhibits the invasion of trophoblasts，suggesting that ACK1 may play an important role in the pathogenesis of PE.