Expression and role of microRNA 18b and hypoxia inducible factor-1α in placental tissues of preeclampsia patients

Abnormal expression of hypoxia inducible factor-1α (HIF-1α) is closely associated with various diseases. By detecting the mRNA and protein expression levels of microRNA 18b (miR-18b) and HIF-1α in placental tissues of preeclampsia (PE) patients and studying the effects of miR-18b on total cellular metabolic activity, migration and invasion in normal human trophoblast cell lines (HTR-8/SVneo), the present study aimed to investigate the effect of miR-18b on targeted regulation of HIF-1α and its clinical significance in the development of PE. Expression levels of miR-18b and HIF-1α mRNA in PE placental tissues were detected by reverse transcription-quantitative polymerase chain reaction and corresponding expression levels of HIF-1α protein were analyzed by western blotting. miR-18b overexpression and inhibited miR-18b expression in HTR-8/SVneo cells, which were constructed by transfecting miR-18b mimic and inhibitor, respectively, were investigated and the total cellular metabolic activity, migration and invasion abilities in different groups of cells were compared. Expression levels of miR-18b were significantly reduced in PE placental tissues and miR-18b inhibitor-transfected HTR-8/SVneo cells, whereas the expression levels of HIF-1α were significantly increased in PE placental tissues and significantly decreased in miR-18b mimic-transfected HTR-8/SVneo cells. Overexpression of miR-18b inhibited the expression of HIF-1α and reduced the cell invasion, migration and viability of HTR-8/SVneo cells. However, inhibition of miR-18b expression promoted the expression of HIF-1α and increased the cell invasion, migration and total cellular metabolic activity of HTR-8/SVneo cells. The present study indicated that abnormal expression of HIF-1α exhibited in PE placental tissues was regulated by miR-18b. Furthermore miR-18b expression was demonstrated to affect cell invasion, migration and viability through target regulation of HIF-1α. The results of the present study suggest that miR-18b and HIF-1α may have important roles in the development of PE.