Abstract:

Objective To discuss the effect of microRNA-151 （miR-151） on the biological behavior of the human trophoblast cells HTR-8/SVneo under hypoxic conditions，and to clarify the potential mechanism. Methods A total of 47 parturients with preeclampsia （preeclampsia group） and 36 parturients （ normal group） were selected as the research subjects. The expression level of miR-151 in placenta tissue of the subjects in two groups was detected by real-time fluorescence quantitative PCR （RT-qPCR） method. The miR-151 inhibitor and its negative control inhibitor NC were transfected into the HTR-8/SVneo cells， followed by exposure to hypoxia （1% O₂） for 48 h to establish control， hypoxia， hypoxia + inhibitor NC， and hypoxia + inhibitor groups. RT-qPCR method was used to detect the expression levels of miR-151 in the cells in various groups； MTT assay was used to detect the survival rates of the cells in various groups； Transwell chamber assay was used to detect the migration and invasion numbers of the cells in various groups； Western blotting method was used to detect the expression levels of matrix metalloproteinases （MMP）-2 and MMP-9， and epithelial-mesenchymal transition （EMT） related proteins in the cells in various groups； Bioinformatics analysis was used to predict the downstream target genes of miR-151， and the intersection target genes were further analyzed for protein-protein interaction （PPI） network by STRING Database. Results Compared with normal group， the expression level of miR-151 in placenta tissue of the patients in preeclampsia group was significantly increased （P<0.05）. Compared with control group， the proliferation activity， number of invasion cells， and number of migration cells of HTR-8/SVneo cells in hypoxia group were significantly decreased （P<0.05）， the expression levels of MMP-2， MMP-9， N-cadherin， and vimentin in the cells were significantly decreased （P<0.05）， and the expression levels of miR-151 and E-cadherin were significantly increased （P<0.05）. Compared with hypoxia group， the expression levels of MMP-2， MMP-9， N-cadherin， and vimentin in the cells in hypoxia + inhibitor group were significantly increased （P<0.05）； the levels of miR-151 and E-cadherin were significantly decreased （P<0.05）； while there were no significant differences in the above indexes in hypoxia + inhibitor NC group （P>0.05）. The bioinformatics analysis results showed that 34 potential target genes of miR-151， among which RCCCH-type zinc finger protein 1 （RC3H1）， AGO2， AGO3， Fragile X related protein 1 （FXR1）， and transformer 2β （TRA2B） may be the key potential target genes. Conclusion miR-151 is highly expressed in placenta tissue of the patients with preeclampsia. The downregulation of miR-151 expression can promote the proliferation， invasion， and migration of the trophoblast cells under hypoxic conditions.

Key words: Preeclampsia, Trophoblast cell, MicroRNA-151, Proliferation, Invasion, Migration