母―胎界面真核细胞翻译起始因子5A1调控滋养细胞功能及其分子机制研究

Abortion can lead to serious consequences on women's mental and physical health. The etiology of spontaneous abortion is complex and the exact mechanism has not yet been completely elucidated. The trophoblasts are the only cells of the conceptus in direct contact with maternal tissues or blood. Trophoblast cells have unique cell biological functions. Appropriate trophoblast cells proliferation, migration and invasion are critical for embryo implantation, placental development and maternal-fetal circulation. Our previous study found that eIF5A1 has a regulatory role in murine spontaneous abortions. Further experiments found that eIF5A1 strong positive staining in normal human and mouse trophoblasts, while it was significantly lower expression in the spontaneous abortion group, so we speculate that eIF5A1 may have specific roles in trophoblast cells function regulation. Based on this assumption, this project intends to delve into eIF5A1 on trophoblast cell biological function. Also, we identify the upstream and downstream regulators of eIF5A1 in trophoblast cells by using cellular biology, molecular biology and bioinformatics technologies. Our aims are to further elucidate the processes involved in eIF5A1 signal transduction and to identify their biological functions. This study will help us to further reveal the mechanism of maternal–fetal interactions, explore the causes of spontaneous abortion, and provide theoretical experimental evidence for the prevention and treatment of spontaneous abortion.

自然流产是一种严重影响妇女身心健康的疾病，其病因复杂，至今尚未完全阐明。滋养细胞是唯一与母体系统直接接触的胎儿细胞。滋养细胞具有独特的生物学功能，适度的滋养细胞增殖，迁移与有控性侵袭是胚胎着床，胎盘发育并建立母胎循环的关键步骤。我们前期的研究发现eIF5A1具有调控小鼠自发性流产作用，进一步实验发现在人类和小鼠正常对照组滋养细胞eIF5A1强阳性表达，自然流产组中eIF5A1表达降低，我们推测滋养细胞eIF5A1表达与其发挥某些特定的功能有关。在此基础上，本课题拟深入研究eIF5A1对滋养细胞生物学功能的影响，通过细胞生物学、分子生物学、生物信息学等分析技术确认eIF5A1调控滋养细胞功能的上下游调节分子，并进一步阐明eIF5A1发挥调节功能的信号途径及其生物学意义。我们的研究将有助于进一步解析妊娠期母体与胎儿相互作用机制，自然流产的原因，为自然流产的预防及今后可能的治疗方向提供理论参考。

自然流产是一种严重影响妇女身心健康的疾病，其病因复杂，至今尚未完全阐明。滋养细胞是唯一与母体系统直接接触的胎儿细胞，具有独特的生物学功能，适度的滋养细胞增殖，迁移与有控性侵袭是胚胎着床，胎盘发育并建立母胎循环的关键步骤。我们前期研究发现真核细胞翻译起始因子5A1（eIF5A1）具有调控小鼠自发性流产作用，在人类和小鼠正常对照组滋养细胞eIF5A1强阳性表达，自然流产组eIF5A1表达降低，我们推测滋养细胞eIF5A1表达与其发挥某些特定的功能有关。本项目通过细胞生物学、分子生物学、生物信息学等分析技术，针对母―胎界面eIF5A1调控滋养细胞功能及其分子机制展开研究。研究表明eIF5A1促进滋养细胞的细胞活力、增殖与迁移，抑制滋养细胞凋亡。通过基因表达谱芯片分析（RNA-Seq测序）方法筛选差异表达基因，发现沉默eIF5A1后钙调蛋白依赖性蛋白激酶1D基因（CAMK1D）显著下调表达。后续研究明确CAMK1D是eIF5A1下游调节因子，沉默及过表达eIF5A1基因可引起CAMK1D表达发生相应的变化，沉默CAMK1D表达可逆转eIF5A1对滋养细胞生物学行为的影响，eIF5A1通过与CAMK1D相互作者用发挥功能。抑制eIF5A1通过下调CAMK1D的表达，抑制滋养细胞的增殖，迁移和侵袭能力，并诱导细胞凋亡。进一步通过正反向实验等研究发现，过表达长链非编码RNA PVT1促进滋养细胞活力，增殖和迁移，而抑制PVT1促进miR-424表达，并且miR-424可以调节PVT1在滋养细胞中的功能，miR-424通过调控eIF5A1表达在滋养细胞中发挥其功能。临床样本分析发现，与选择性人工流产组相比，自然流产组绒毛组织中PVT1和eIF5A1表达降低，而miR-424表达增加。研究表明PVT1/miR-424/eIF5A1/CAMK1D通路调控滋养细胞生物学功能。我们的研究将有助于进一步解析妊娠期母体与胎儿相互作用机制，自然流产的原因，为自然流产的预防及今后可能的治疗方向提供理论参考。