Circ_0007611 stimulates IL-1 receptor accessory protein to inhibit trophoblast cell proliferation and induce cell apoptosis.

Preeclampsia (PE) is a common pregnancy disorder, and mounting evidence has revealed that circular RNA participates in PE development. However, the detailed molecular mechanism of circ_0007611 in PE progression remains unknown. RNA expressions of circ_0007611, microRNA-558 (miR-558), and IL-1 receptor accessory protein (IL1RAP) were detected by quantitative real-time polymerase chain reaction. Cell proliferation was investigated by clonogenicity, 5-Ethynyl-29-deoxyuridine, and DNA content quantitation assays. Cell apoptotic rate and angiogenesis were analyzed by cell apoptosis and tube formation assays, respectively. Protein expression was detected by western blot. The binding relationship between miR-558 and circ_0007611 or IL1RAP was identified by a dual-luciferase reporter or RNA immunoprecipitation assay. Circ_0007611 and IL1RAP expressions were significantly upregulated, while miR-558 was downregulated in the placental tissues of PE women in comparison with normal placental tissues. Functionally, circ_0007611 overexpression inhibited trophoblast cell proliferation and angiogenesis and induced cell apoptosis; however, circ_0007611 downregulation showed the opposite effects. Mechanistically, circ_0007611 acted as a miR-558 sponge, and miR-558 bound to IL1RAP. Besides, miR-558 overexpression or IL1RAP absence relieved circ_0007611-induced trophoblast cell dysfunction. Moreover, miR-558 contributed to cell proliferation and tube formation and inhibited cell apoptosis by reducing IL1RAP expression in trophoblast cells. Circ_0007611 aggravated trophoblast cell disorders by the miR-558/IL1RAP pathway in PE.