miR-145-5p promotes trophoblast cell growth and invasion by targeting FLT1.

OBJECTIVE:We aimed to explore the expression level and biological function of miR-145-5p in preeclampsia (PE). METHODS:The differentially expressed miRNA/mRNA between normal placentas and PE placentas were screened using the GSE84260 and GSE73374 datasets from the Gene Expression Omnibus Database. The expression of miR-145-5p in PE placentas was detected by qRT-PCR. The CCK-8 assay, wound healing and transwell were carried out to determine the cell growth, migration and invasion when miR-145-5p was overexpressed or inhibited. The real-time quantitative PCR (qRT-PCR), Western Blot and dual-luciferase reporter assays were conducted to preliminarily explore possible mechanisms. RESULTS:A total of 33 miRNAs were found significantly differentially expressed in PE patients, 19 were significantly upregulated and 14 were significantly downregulated. The relative miR-145-5p expression was lower in PE placentas than normal placentas. The viability and invasion were suppressed when miR-145-5p was inhibited in trophoblasts cells, while miR-145-5p overexpression promoted the effectiveness. In addition, mRNA and protein expression of FLT1 in HTR-8/SVneo cell was also downregulated with miR-145-5p overexpression, suggesting that FLT1 is the target gene of miR-145-5p. Consistent with miR-145-5p overexpression, the mRNA and protein expression of FLT1 also were upregulated with miR-145-5p interference. Furthermore, the expression of miR-145-5p was regulated by the Hypoxic conditions. CONCLUSIONS:In conclusion, the results showed miR-145-5p may participate in PE development by affecting the proliferation and invasion of trophoblast cells. This is a new perspective to understand the etiology and pathogenesis of PE, which may provide a new breakthrough for the early prediction and diagnosis of PE.