AIMS Accumulated evidence indicates that the dysregulation of circular RNAs (circRNAs) plays pivotal roles in many human diseases including preeclampsia (PE). Circ_0063517 has been verified to be down-regulated in PE. But the role of circ_0063517 in PE is still unclear. This research aims to probe into the effect of circ_0063517 on angiogenesis in PE development. MAIN METHODS The expression of circ_0063517, endothelin receptor type B (ETBR) and miR-31-5p was assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). MTT assay, colony formation assay, scratch assay, transwell assay, and tube formation assay were performed to detect proliferation, migration, and angiogenesis, respectively. Dual luciferase reporter system and RNA immunoprecipitation (RIP) assay were carried out to determine the interaction between miR-31-5p and circ_0063517(or ETBR). ETBR, VEGFRA, and VEGFR2 levels were detected by western blot analysis. The effect of circ_0063517 and ETBR on angiogenesis was evaluated in N-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced PE in vivo. KEY FINDINGS The levels of circ_0063517 and ETBR were down-regulated in the placenta tissue of PE patients. Conversely, the level of miR-31-5p was up-regulated in PE. Overexpression of circ_0063517 or knockdown of miR-31-5p facilitated growth, migration, and angiogenesis of vascular endothelial cells. Circ_0063517 knockdown-induced repression of the expression of ETBR, VEGFA, and VEGFR2 was partly counteracted by ETBR overexpression. Mechanistically, circ_0063517 sponged miR-31-5p to regulate ETBR expression. Finally, circ_0063517 promoted angiogenesis via enhancing ETBR expression in PE in vivo. SIGNIFICANCE Our findings suggest that circ_0063517-miR-31-5p-ETBR axis regulates angiogenesis during the pathological process of PE.

中文翻译：

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Circ_0063517充当ceRNA，靶向miR-31-5p-ETBR轴，以调节先兆子痫中血管内皮细胞的血管生成。

AIMS积累的证据表明，环状RNA（circRNA）的失调在包括子痫前期（PE）在内的许多人类疾病中起着关键作用。Circ_0063517已被验证在PE中被下调。但是circ_0063517在PE中的作用仍不清楚。本研究旨在探讨circ_0063517对PE发育中血管生成的影响。主要方法通过定量逆转录聚合酶链反应（RT-qPCR）评估circ_0063517，B型内皮素受体（ETBR）和miR-31-5p的表达。进行MTT测定，菌落形成测定，刮擦测定，transwell测定和管形成测定，以分别检测增殖，迁移和血管生成。进行了双重荧光素酶报告系统和RNA免疫沉淀（RIP）分析，以确定miR-31-5p与circ_0063517（或ETBR）之间的相互作用。通过蛋白质印迹分析检测ETBR，VEGFRA和VEGFR2水平。在N-硝基-L-精氨酸甲酯盐酸盐（L-NAME）诱导的PE体内评估了circ_0063517和ETBR对血管生成的影响。主要发现PE患者胎盘组织中circ_0063517和ETBR的水平下调。相反，PE中miR-31-5p的水平上调。circ_0063517的过表达或miR-31-5p的敲低促进了血管内皮细胞的生长，迁移和血管生成。Circ_0063517敲低诱导的ETBR，VEGFA和VEGFR2表达的抑制被ETBR过表达部分抵消。机械上，circ_0063517用海绵擦拭miR-31-5p以调节ETBR表达。最后，circ_0063517通过增强体内PE中的ETBR表达来促进血管生成。意义我们的发现表明，circ_0063517-miR-31-5p-ETBR轴在PE的病理过程中调节血管生成。