母胎界面滋养细胞与MDSCs的交互作用在子痫前期发生过程中的作用及机制研究

Abnormal uterine spiral arterial remodeling caused by insufficient invasiveness of trophoblast cells is an important cause of preeclampsia (PE). Our previous study found that the abnormality of trophoblast epithelial-mesenchymal transition (EMT) is closely related to insufficient remodeling of uterine spiral arteries. The number of myeloid-derived suppressor cells (MDSCs) in the decidual tissue of PE patients was reduced, which was positively correlated with the protein expression of Snail in placental tissues. In vitro studies have confirmed that MDSCs can up-regulate the protein expression of Snail in trophoblasts and promote their EMT, migration and invasion. Therefore, we speculate that trophoblast cells can recruit MDSCs to the maternal-fetal interface by secreting chemokines. MDSCs can secrete cytokines to induce trophoblast EMT. The abnormal interaction between them may lead to the occurrence of PE. In order to verify the above hypothesis, our group used flow analysis, chemotaxis experiments, transwell invasion experiments, immunofluorescence staining, Co-IP and animal models to clarify the mutual regulatory network between trophoblast cells and MDSCs at maternal-fetal interface and focus on exploring the molecular mechanism of MDSCs regulating the expression of Snail in trophoblast cells, laying a theoretical foundation for the treatment of PE with MDSCs as an intervention.

滋养细胞侵袭能力不足所导致的子宫螺旋动脉重塑异常是子痫前期（PE）发生的重要原因。我们前期的研究发现：滋养细胞上皮间质转化（EMT）异常与子宫螺旋动脉重塑不足密切相关。PE患者蜕膜中髓系来源的抑制性细胞（MDSCs）数量是减少的，其与胎盘组织中Snail蛋白的表达呈正相关。体外研究证实：MDSCs能够上调滋养细胞内Snail蛋白的表达并促进其EMT、迁移和侵袭。由此我们推测：滋养细胞能够通过分泌趋化因子招募MDSCs到母胎界面，MDSCs能够分泌细胞因子诱导滋养细胞EMT，二者之间相互作用异常可能导致PE的发生。为验证上述假说，本课题组利用流式分析、趋化实验、transwell侵袭实验、免疫荧光、Co-IP和动物模型等方法，明确母胎界面滋养细胞与MDSCs之间的相互调控网络，重点阐述MDSCs调控滋养细胞内Snail表达的分子机制，为以MDSCs为干预手段来治疗PE奠定理论基础。

子痫前期（preeclampsia，PE）是一种妊娠期特有疾病，影响着全球约 3%-5%的孕妇，是导致孕产妇和新生儿死亡的主要原因之一。到目前为止，对于PE尚缺乏有效的治疗方法，适时终止妊娠仍然是其唯一的治疗方法。滋养细胞侵袭能力不足所导致的子宫螺旋动脉重塑异常是PE发生的重要原因。在本项目的资助下，我们从免疫学角度围绕子痫前期发生的分子机制进行了一系列深入的研究：（1）在人类胎盘和蜕膜组织的研究中，我们证实：滋养细胞上皮间质转化（EMT）异常与子宫螺旋动脉重塑不足密切相关。PE患者蜕膜中髓系来源的抑制性细胞（MDSCs）数量是减少的，其与胎盘组织中Snail蛋白的表达呈正相关。这些表明：MDSCs可能参与滋养细胞EMT和螺旋动脉重塑过程的调控。（2）在母胎界面，我们发现滋养细胞分泌的CCL15能够通过CCR1促进MDSCs的招募。反过来，MDSCs通过分泌的IL-10上调滋养细胞内Snail蛋白的表达，促进滋养细胞EMT、迁移和侵袭。滋养细胞和血管内皮细胞的共培养实验证实：Snail介导滋养细胞诱导的内皮细胞血管形成。（3）在机制方面，我们筛选出正常妊娠和子痫前期胎盘组织中具有差异表达且具有调控Snail蛋白功能的去泛素化基因DUB3。免疫共沉淀实验（Co-IP）证明DUB3与Snail之间的调控关系，DUB3能够增加滋养细胞中Snail蛋白的稳定性。（4）通过构建子痫前期大鼠模型，我们证明：相对于对照组，IL-10或（和）CCL15中和抗体处理显著增加了妊娠鼠的收缩压和蛋白尿，降低了胎盘和子代鼠的重量。与此同时，鼠胎盘组织中Snail蛋白的表达明显减少，进一步加剧了子宫螺旋动脉重塑的不足。（5）本研究明确了母胎界面滋养细胞与MDSCs之间的相互调控网络，重点阐述MDSCs调控滋养细胞内Snail表达的分子机制，为以MDSCs为干预策略来治疗PE奠定理论基础。（6）在本项目资助下，已发表SCI论文1篇（Pharmacological Research 2022，标注NSFC资助和项目批准号），另投稿中SCI论文1篇（标注NSFC资助和项目批准号）。