MicroRNA-362-5p promotes the proliferation and inhibits apoptosis of trophoblast cells via targeting glutathione-disulfide reductase

Gestational diabetes mellitus (GDM), a common complication of pregnancy, harms the health of pregnant women and fetuses. MicroRNAs (miRNAs) dysregulation in placenta is involved in GDM. Herein, we explored the roles of miR-362-5p in GDM. After high glucose (HG) treated HTR-8/SVneo cells, CCK-8 and flow cytometry were conducted to assess the capability of the proliferation and apoptosis, respectively. The data demonstrated that HG inhibited proliferation and induced apoptosis of HTR-8/SVneo cells. MiR-362-5p level was reduced in HG-treated cells and placenta tissues of GDM patients, measured by qPCR. Overexpressed miR-362-5p accelerated the proliferation and restrained apoptosis of HG-treated cells. Furthermore, glutathione-disulfide reductase (GSR) was verified as a target of miR-362-5p, through TargetScan database and dual-luciferase reporter assay. GSR was upregulated in GDM placenta tissues and was negatively regulated by miR-362-5p. Enforced GSR level abolished the effects of miR-362-5p overexpression on the proliferation and apoptosis of HTR-8/SVneo cells. Furthermore, miR-362-5p increased p-PI3K, p-AKT and bcl-2, while reduced bax and cleaved caspase3, which were abolished by GSR. In conclusion, miR-362-5p promoted cell proliferation and inhibited apoptosis via targeting GSR and activating PI3K/AKT pathway. The findings mentioned above suggested that miR-362-5p might be a therapy target of GDM.

妊娠糖尿病（Gestational diabetes mellitus, GDM）是妊娠期常见并发症，可对孕妇及胎儿的健康造成损害。胎盘组织中的微小RNA（microRNAs, miRNAs）表达失调参与了GDM的发病过程。本研究旨在探讨miR-362-5p在GDM中的作用。本研究采用高糖（high glucose, HG）处理HTR-8/SVneo细胞，分别通过CCK-8实验与流式细胞术检测细胞增殖与凋亡能力。实验结果显示，HG可抑制HTR-8/SVneo细胞的增殖并诱导其凋亡。经实时定量聚合酶链反应（quantitative real-time polymerase chain reaction, qPCR）检测发现，HG处理的细胞及GDM患者胎盘组织中miR-362-5p的表达水平均显著下调。过表达miR-362-5p可促进HG处理的HTR-8/SVneo细胞增殖，并抑制其凋亡。此外，通过TargetScan数据库预测及双荧光素酶报告基因实验验证，谷胱甘肽二硫化物还原酶（glutathione-disulfide reductase, GSR）被证实为miR-362-5p的靶基因。GSR在GDM患者胎盘组织中表达上调，且其表达受miR-362-5p的负向调控。过表达GSR可抵消miR-362-5p过表达对HTR-8/SVneo细胞增殖与凋亡产生的影响。此外，miR-362-5p可上调p-PI3K、p-AKT及Bcl-2的表达，而下调Bax及剪切型caspase-3的表达，上述效应均可被GSR所逆转。综上，miR-362-5p可通过靶向调控GSR并激活PI3K/AKT通路，促进细胞增殖并抑制细胞凋亡。上述研究结果表明，miR-362-5p有望成为GDM的治疗靶点。