DNA Methylation-Induced BNIP3P1 Expression Promotes Pre-Eclampsia Progression via the miR-128-3p/BNIP3 Axis

Abstract

Pre-eclampsia (PE) is a severe, pregnancy-specific disorder characterized by abnormal trophoblast function, leading to impaired placental development and adverse maternal and fetal outcomes. Despite extensive research, the precise molecular mechanisms underlying PE pathogenesis remain incompletely understood. Emerging evidence suggests that long noncoding RNAs (lncRNAs), particularly pseudogenes, play critical roles in regulating trophoblast function, contributing to PE development. This study aims to investigate the role of the lncRNA pseudogene BNIP3P1 in the development of PE, focusing on its regulatory interactions with the miR-128-3p/BNIP3 axis and the involvement of DNA methylation in BNIP3P1 expression. Placental tissues from PE patients (n = 30) and healthy controls (n = 15) were analyzed for BNIP3P1 and BNIP3 expression using qRT-PCR, western blot, and immunohistochemistry (IHC). In Vitro functional assays utilizing HTR-8/SVneo and JAR trophoblast cell lines were employed to assess the effects of BNIP3P1 overexpression and miR-128-3p/BNIP3 interaction on cell proliferation, invasion, migration, and apoptosis. The DNA methylation status of the BNIP3P1 promoter was analyzed using methylation-specific PCR (MSP) and demethylation treatment with 5-Azacytidine. Additionally, a PE mouse model induced by SFLT-1 recombinant protein was used to evaluate the role of BNIP3P1 In Vivo. BNIP3P1 and BNIP3 were significantly upregulated in PE placental tissues and were positively correlated with clinical indicators such as blood pressure, albumin-to-creatinine ratio (ACR), and serum uric acid levels. In Vitro, BNIP3P1 overexpression inhibited trophoblast cell proliferation, invasion, and migration while promoting apoptosis, effects that were reversed by miR-128-3p overexpression. In Vivo, BNIP3P1 overexpression exacerbated PE-like symptoms, including hypertension and proteinuria, while knockdown of BNIP3 alleviated these symptoms. Mechanistically, bioinformatics analysis and experimental validation confirmed that BNIP3P1 regulates miR-128-3p, which in turn modulates BNIP3 expression. Additionally, BNIP3P1 expression was shown to be regulated by DNA methylation, with hypermethylation of its promoter observed in PE placental tissues. Inhibition of DNA methylation with 5-Azacytidine enhanced trophoblast proliferation, invasion, and migration, while reducing apoptosis and ameliorating PE-like symptoms In Vivo. BNIP3P1 regulates trophoblast function through the miR-128-3p/BNIP3 axis and is epigenetically controlled by DNA methylation in PE. Targeting the BNIP3P1/miR-128-3p/BNIP3 axis may provide novel therapeutic strategies for PE treatment.