Pre-eclampsia (PE), a common pregnancy-systemic syndrome, is characterized by proteinuria and hypertension and is the leading cause of maternal and fetal mortality. Thus, we aim to investigate the role of G-Protein Coupled Receptor 4 (GPR4) in PE and the underlying molecular mechanism. In this study, GSE66273 microarray data were obtained from the Gene Expression Omnibus(GEO) database of the National Center for Biotechnology Information, and Gene set enrichment analysis (GSEA) was performed by GSEA software. qRT-PCR and Immunohistochemistry (IHC) or western blotting were used to assay for the expression of GPR4 in PE placentas and HTR8/SVneo cells. The influence of acidosis and hypoxia environments on the expression of GPR4 was explored using western blotting. Cell proliferation and migration of HTR8/SVneo cells were measured using EdU and MTT assays and migration assay, respectively. Moreover, expressions of MEK1/2, p-MEK1/2, ERK1/2, and p-ERK1/2 in HTR8/SVneo cells were assayed by western blotting. Our data demonstrated that the expression of GPR4 was up regulated in PE placentas. Increase in acidic pH and hypoxic levels increased the expression of GPR4 in HTR8/SVneo cells. GPR4 inhibited cell proliferation and migration in the HTR8/SVneo cells. GPR4 silencing enhanced the phosphorylation of p-MEK1/2and p-ERK1/2 in HTR8/SVneo cells. Additionally, we found that pathway inhibitor partially reversed the effects of GPR4 on proliferation and migration of HTR8/SVneo cells. In conclusions, these results show that GPR4 suppressed cell proliferation and migration by inhibiting MAPK signaling pathway in PE.

先兆子痫（PE）是一种常见的妊娠系统综合征，以蛋白尿和高血压为特征，是母婴死亡的主要原因。因此，我们旨在研究 G 蛋白偶联受体 4 (GPR4) 在 PE 中的作用和潜在的分子机制。本研究中，GSE66273芯片数据来源于国家生物技术信息中心基因表达综合数据库（GEO），利用GSEA软件进行基因集富集分析（GSEA）。qRT-PCR 和免疫组织化学 (IHC) 或蛋白质印迹法用于检测 GPR4 在 PE 胎盘和 HTR8/SVneo 细胞中的表达。使用蛋白质印迹法探讨酸中毒和缺氧环境对 GPR4 表达的影响。分别使用 EdU 和 MTT 测定以及迁移测定来测量 HTR8/SVneo 细胞的细胞增殖和迁移。此外，通过蛋白质印迹法检测 HTR8/SVneo 细胞中 MEK1/2、p-MEK1/2、ERK1/2 和 p-ERK1/2 的表达。我们的数据表明 GPR4 的表达在 PE 胎盘中上调。酸性pH值和缺氧水平的增加增加了HTR8/SVneo细胞中GPR4的表达。GPR4 抑制 HTR8/SVneo 细胞中的细胞增殖和迁移。GPR4沉默增强了HTR8/SVneo细胞中p-MEK1/2和p-ERK1/2的磷酸化。此外，我们发现通路抑制剂部分逆转了 GPR4 对 HTR8/SVneo 细胞增殖和迁移的影响。总之，这些结果表明 GPR4 通过抑制 PE 中的 MAPK 信号通路来抑制细胞增殖和迁移。