Circ_0015382 Regulates the miR-942-5p/NDRG1 Axis to Suppress Trophoblast Cell Functions

Circular RNAs (circRNAs) are non-coding RNAs that exert vital function in many human diseases, including preeclampsia (PE). Circ_0015382 is considered to be a key regulator of PE progression, so more molecular mechanisms need to be further studied. Real-time quantitative PCR was used to detect the mRNA levels of circ_0015382, miR-942-5p, and N-myc downstream regulated 1 (NDRG1). Western blot analysis was conducted to assess the protein levels. MTT and EdU assays were used to assess cell proliferation. Cell invasion was analyzed by transwell assay. Tube formation assay was conducted to detect cell angiogenesis. Dual-luciferase reporter assay and RNA immunoprecipitation were used to analyze the target relationship between miR-942-5p and circ_0015382 or NDRG1. Our data showed that circ_0015382 and NDRG1 were up-regulated, while miR-942-5p was down-regulated in the placental tissues of PE patients. Trophoblast cell proliferation, invasion, and angiogenesis were promoted by knockdown of circ_0015382. Circ_0015382 could sponge miR-942-5p, and NDRG1 was a target of miR-942-5p. MiR-942-5p inhibitor could reverse the promoting effects of si-circ_0015382 on trophoblast cell functions. Besides, the enhancing effects of miR-942-5p mimic on trophoblast cell proliferation, invasion, and angiogenesis could be eliminated by NDRG1 overexpression. In conclusion, our data showed that circ_0015382 inhibited trophoblast cell proliferation, invasion, and angiogenesis through regulating miR-942-5p/NDRG1 axis, providing a new mechanism for the regulation of PE progression.