Downregulated DUXAP8 lncRNA impedes trophoblast cell proliferation and migration by epigenetically upregulating TFPI2 expression.

BACKGROUND: Preeclampsia (PE), a pregnancy complication characterized by new-onset hypertension and proteinuria during the second trimester, is the leading cause of neonatal and maternal morbidity and mortality. In the etiology of PE, failure of uterine spiral artery remodeling may be related to functioning abnormally of trophoblast cells, leading to the occurrence and progression of PE. Recently, long noncoding RNAs (lncRNAs) have been reported to play critical roles in PE nowadays. This study aimed to investigate the expression and functions of the TFPI2 pathway-related lncRNA DUXAP8. METHODS: DUXAP8 expression in the placenta from pregnancies was examined using qPCR. Then, the in vitro functions of DUXAP8 were investigated through MTT, EdU, colony, transwell, and flow cytometry experiments. The downstream gene expression profiles were assessed using RNA transcriptome sequencing analysis and verified using qPCR and western blot. Furthermore, Immunoprecipitation (RIP), chromatin immunoprecipitation (CHIP) and fluorescence in situ hybridization (FISH) were used to detect the interaction between lncDUXAP8/EZH2/TFPI2. RESULTS: The expression of lncRNA DUXAP8 in placenta of patients with eclampsia was significantly decreased. After knockout of DUXAP8, the proliferation and migration of trophoblasts were significantly decreased, and the percentage of apoptosis was increased. Flow cytometry showed that low expression of DUXAP8 increased the accumulation of cells in G2/M phase, while overexpression of DUXAP8 had the opposite effect. We also proved that DUXAP8 epigenetically inhibited TFPI2 expression by recruiting EZH2 and mediating H3K27me3 modification. CONCLUSION: Together, these resulting data clarify that aberrant expression of DUXAP8 is involved in the potential PE development and progress. Unraveling the role of DUXAP8 will provide novel insights into the pathogenesis of PE.