Abstract:

Objective To discuss the effect of the expression of stathmin 1 （STMN1） in placenta tissue of the pre-eclampsia （PE） patients on the invasion and migration functions of the trophoblast cells， and to clarify the related mechanism. Methods The placenta tissues of 17 healthy pregnant women （control group） and 15 PE patients （PE group） were selected. The human trophoblast HTR-8 cells were divided into siRNA-STMN1 group （transfected with siRNA-STMN1）， siRNA-NC group （transfected with negative control sequence siRNA-NC），pcDNA3.1-STMN1 group （transfected with pcDNA3.1-STMN1）， and pcDNA3.1-NC group （transfected with negative control sequence pcDNA3.1-NC）. The expression intensities of STMN1 and epithelial-mesenchymal transition（EMT）-related proteins in placenta tissue of the patients in two groups were observed by immunohistochemistry （IHC） staining； the proliferation rates of the HTR-8 cells in various groups were detected by CCK-8 method； the migration abilities of the HTR-8 cells in various groups were detected by cell scratch experiment； the invasion abilities of the HTR-8 cells in various groups were detected by Transwell chamber experiment； the expression levels of STMN1 mRNA in placenta tissue of the patients in two groups and HTR-8 cells were detected by real-time fluorescence quantitative PCR （RT-qPCR） method； the expression levels of STMN1， E-cadherin， and N-cadherin proteins in placenta tissue of the patients in two groups and HTR-8 cells were detected by Western blotting method. Results Compared with control group， the systolic blood pressure， diastolic blood pressure， and the level of urine protein of the patients in PE group were significantly increased （P<0.01）， and the body weight of the newborn was increased （P<0.05）.The IHC staining results showed that compared with control group， the expression intensities of STMN1 and E-cadherin proteins in placenta tissue of the patients in PE group were increased， and the expression intensity of N-cadherin protein was decreased.The CCK-8 results showed that compared with siRNA-NC group， the proliferation rate of the HTR-8 cells in siRNA-STMN1 group was decreased（P<0.05）； compared with pcDNA3.1-NC group，the proliferation rate of the HTR-8 cells in pcDNA3.1-STMN1 group was increased（P<0.05）.The cell scratch experiment results showed that compared with siRNA-NC group，the migration rate of the HTR-8 cells in siRNA-STMN1 group was decreased（P<0.05）；compared with the pcDNA3.1-NC group， the migration rate of the HTR-8 cells in pcDNA3.1-STMN1 group was increased （P<0.05）. The Transwell chamber experiment results showed that compared with siRNA-NC group， the number of invasion cells in siRNA-STMN1 group was significantly decreased （P<0.01）； compared with pcDNA3.1-NC group， the number of invasion cells in pcDNA3.1-STMN1 group was significantly increased （P<0.01）. The RT-qPCR results showed that compared with control group， the expression level of STMN1 mRNA in placenta tissue of the patients in PE group was decreased （P<0.05）； compared with siRNA-NC group， the expression level of STMN1 mRNA in the HTR-8 cells in siRNA-STMN1 group was significantly decreased （P<0.01）； compared with pcDNA3.1-NC group， the expression level of STMN1 mRNA in the HTR-8 cells in pcDNA3.1-STMN1 group was significantly increased （P<0.01）. The Western blotting results showed that compared with control group， the expression level of STMN1 protein in placenta tissue of the patients in PE group was decreased （P<0.05）. Compared with siRNA-NC group， the expression levels of STMN1 and N-cadherin proteins in the HTR-8 cells in siRNA-STMN1 group were decreased （P<0.05）， and the expression level of E-cadherin protein was increased （P<0.05）. Compared with pcDNA3.1-NC group， the expression levels of STMN1 and N-cadherin proteins in the HTR-8 cells in pcDNA3.1-STMN1 group were increased （P<0.05）， and the expression level of E-cadherin protein was decreased （P<0.05）. Conclusion The expression of STMN1 in placenta tissue of the PE patients is significantly reduced，suggesting that STMN1 may be involved in the development of PE by regulating the EMT process of the trophoblast cells and inhibiting the cell proliferation， invasion， and migration.

Key words: Preeclampsia, Stathmin 1, Trophoblast cell, Cell proliferation, Cell invasion, Epithelial-mesenchymal transition