USP2A通过调节蜕膜CD4+T细胞向Treg细胞优势分化诱导母-胎免疫耐受的分子机制研究

The maternal fetal immune nutrition and immune tolerance is the basis for the establishment and maintenance of pregnancy. Our previous work found that USP2A promotes the recruitment of SMAD2/3 and phosphorylation. What’s more, USP2a/ SMAD2/3 signaling molecules are demonstrated to be widespread expressed in maternal fetal interface, these molecules were significantly lower expressed in failed pregnancy maternal fetal trophoblast cells than in that of normal pregnancy. Indicating that USP2a/ SMAD2/3 has an important regulatory role in the maternal fetal interface immune. The applicant intends to use animal models and in vitro models to study the molecular mechanism of USP2A regulating the dominant differentiation of decidual CD4+T cells to Treg cells by blocking and overexpression USP2A and SMAD2/3 with the technique of RT-PCR, Western blot, promoter analysis, chromatin immunoprecipitation, gel electrophoresis and flow cytometry drift cell separation, targeted gene silencing and overexpression. To reveal the specific molecular mechanism of USP2A regulating the dominant differentiation of Treg cells in normal pregnancy CD4+T decidual cells will do good to enrich and develop the theory of maternal fetal immune recognition and immune tolerance, to provide new targets for detection and drug action for abnormal pregnancy and pregnancy related diseases.

母胎免疫营养和免疫耐受是妊娠建立和维持的基础。本研究组前期工作发现USP2A促进SMAD2/3的招募与磷酸化，且在母-胎界面存在USP2a/ SMAD2/3 信号分子的广泛表达，这些分子在人早孕自然流产母-胎界面、反复着床失败母-胎界面滋养细胞与蜕膜基质细胞显著低于正常妊娠，说明USP2a/ SMAD2/3对母胎界面具有重要的免疫调节作用。申请者拟采用RT-PCR、western blot、启动子分析、染色质免疫共沉淀技术、凝胶电泳漂移、流式细胞分离、靶基因沉默和高表达验证等技术，利用动物模型和体外模型，从不同层面探讨阻断和过表达USP2a和SMAD2/3对蜕膜细胞中Treg细胞分化和扩增的调控从而参与母-胎耐受调控的机制。揭示USP2A调控正常妊娠蜕膜细胞中Treg细胞优势分化的具体分子机制，丰富和发展母-胎免疫识别和免疫耐受理论，为异常妊娠和妊娠相关疾病提供新的检测和药物作用靶点。

胎盘充分发育是妊娠建立和维持的基础，滋养层细胞增殖减少、滋养层细胞过度凋亡以及滋养层细胞侵袭不足可导致胎盘发育不足。本项目首先检测到复发性流产患者的胎盘绒毛组织样本中USP2a的mRNA水平和蛋白水平下降。体外实验证实，USP2a的过表达促进了人类滋养细胞的增殖、迁移和侵袭，而USP2a的敲低则抑制了这些过程。从机制上讲，USP2a激活PI3K/Akt/GSK3β信号通路，促进β-catenin的核转位，并进一步激活滋养细胞的上皮-间质转化。此外，转化生长因子-β（TGF-β）上调了滋养细胞中USP2a的表达。进一步通过共培养体系，我们发现M2型巨噬细胞分泌的TGF-β诱导滋养细胞迁移和侵袭，而抗TGF-β抗体可减轻这种影响。总之，这项研究表明，USP2a调节滋养细胞的入侵，USP2a的异常表达可能导致滋养细胞的异常入侵，从而导致复发性流产。揭示USP2a调控早期妊娠母体滋养细胞侵袭的具体分子机制，丰富和发展母-胎免疫识别，为异常妊娠和妊娠相关疾病提供新的检测和药物作用靶点。