Fetal growth restriction (FGR) ranks second among causes of perinatal death. Circular RNA hsa_circ_0074371 (hsa_circ_0074371) is reported to be downregulated in FGR placentae. However, the role and regulatory mechanism of hsa_circ_0074371 in FGR pathogenesis are indistinct. Expression of hsa_circ_0074371, microRNA (miR)-582-3p, and low-density lipoprotein receptor-related protein 6 (LRP6) mRNA in FGR placentae and trophoblast cells (HTR-8/SVneo) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between hsa_circ_0074371 or LRP6 and miR-582-3p was verified by dual-luciferase reporter and/or RNA immunoprecipitation (RIP), RNA pull-down assays. The proliferation, cell cycle progression, apoptosis, migration, and invasion of HTR-8/SVneo cells were evaluated by Cell Counting Kit-8 (CCK-8), flow cytometry, wound healing, or transwell assays. Caspase3 activity was analyzed with a commercial kit. The protein levels of c-myc, cyclinD1, matrix metalloproteinase (MMP) 2, MMP9, and LRP6 were examined by western blotting. We observed that hsa_circ_0074371 and LRP6 were downregulated while miR-582-3p was upregulated in FGR placentae and HTR-8/SVneo cells. Hsa_circ_0074371 modulated LRP6 expression via sponging miR-582-3p. Hsa_circ_0074371 knockdown induced cell cycle arrest, apoptosis, and inhibited cell proliferation, migration, and invasion in HTR-8/SVneo cells. MiR-582-3p inhibitor reversed hsa_circ_0074371 silencing me on proliferation, migration, and invasion of HTR-8/SVneo cells. LRP6 overexpression overturned the inhibitory effect of miR-582-3p mimic on proliferation, migration, and invasion of HTR-8/SVneo cells. In conclusion, hsa_circ_0074371 downregulation inhibited proliferation, migration, and invasion of trophoblast cells via sponging miR-582-3p and decreasing LRP6 expression, providing a new mechanism related to FGR pathogenesis.

胎儿生长受限 (FGR) 在围产期死亡原因中排名第二。据报道，环状 RNA hsa_circ_0074371 (hsa_circ_0074371) 在 FGR 胎盘中下调。但hsa_circ_0074371在FGR发病机制中的作用和调控机制尚不明确。实时定量聚合酶链反应检测hsa_circ_0074371、microRNA (miR)-582-3p和低密度脂蛋白受体相关蛋白6 (LRP6) mRNA在FGR胎盘和滋养层细胞(HTR-8/SVneo)中的表达(qRT-PCR)。hsa_circ_0074371 或 LRP6 与 miR-582-3p 之间的关系通过双荧光素酶报告基因和/或 RNA 免疫沉淀 (RIP)、RNA pull-down 测定来验证。采用 Cell Counting Kit-8 (CCK-8)、流式细胞仪、伤口愈合或 transwell 检测。用商业试剂盒分析 Caspase3 活性。通过蛋白质印迹检测 c-myc、cyclinD1、基质金属蛋白酶 (MMP) 2、MMP9 和 LRP6 的蛋白质水平。我们观察到 hsa_circ_0074371 和 LRP6 下调，而 miR-582-3p 在 FGR 胎盘和 HTR-8/SVneo 细胞中上调。Hsa_circ_0074371 通过海绵化 miR-582-3p 调节 LRP6 表达。Hsa_circ_0074371 敲低可诱导细胞周期停滞、凋亡，并抑制 HTR-8/SVneo 细胞中的细胞增殖、迁移和侵袭。MiR-582-3p 抑制剂逆转 hsa_circ_0074371 对 HTR-8/SVneo 细胞的增殖、迁移和侵袭的沉默。LRP6 过表达推翻了 miR-582-3p 模拟物对 HTR-8/SVneo 细胞增殖、迁移和侵袭的抑制作用。综上所述，