sFRP5通过非经典Wnt信号通路调控炎症反应在子痫前期发病中的作用机制的研究

Preeclampsia (PE) is a serious pregnancy complications, the decrease of invasion of extra-villoustrophoblasts (EVT) and aberrant spiral artery remodelling is key point.Inceasing evidences confirmed that PE is associated with excessive activation of placental inflammation. Decidual macrophage was involved in the regulation of inflammation in the maternal-fetal interface and placental vascular remodeling. Its abnormal activation was closely related to the pathogenesis of PE. SFRP5 is one of the negative regulatorof Wnt signaling pathways. It has an anti-inflammatory effect and can inhibit the release of inflammatory cytokines through the Wnt5a/JNK signaling pathway. Our preliminary study found that the methylation of sFRP5 promoter in term placenta tissue of preeclampsia is higher than normal term placenta resulting in a lower protein level. While Wnt5a was significantly higher in PE placenta .We have found Wnt5a suppressed the migration and invasion of trophoblast cell lines HTR8 / SVneo by activating the non-cannonical Wnt signaling pathways, which indicates the abnormal expression of sFRP5 / Wnt5a was involved in the pathogenesis of PE. We will knock down the expression of sFRP5 with RNAi or increase Wnt5a expression with recombinant protein in macrophages of normal pregnancy to mimic the pathological status of PE, studying whether macrophages in the maternal-fetal interface is abnormally activated with phenotypic and functional alteration to induce or exaggerate the inflammatory response, resulting in endothelial cell injury and aberrant trophoblast invasion. The involvment of JNK and NFκB inflammation signaling pathways are also studied.

子痫前期(PE)是严重的妊娠并发症，已有研究证实PE与胎盘炎症反应过度激活有关。蜕膜巨噬细胞参与了母胎界面的炎症反应调控和胎盘血管重塑，其异常激活与PE发生密切相关。sFRP5是具有抗炎作用的Wnt负调控因子，可以通过抑制非经典的Wnt5a/JNK信号通路抑制炎症因子的释放。我们前期实验发现PE胎盘组织中sFRP5在的甲基化水平升高，蛋白表达水平降低，Wnt5a异常升高，Wnt5a可以通过激活非经典Wnt信号通路抑制滋养细胞株HTR8/SVneo的迁移和侵袭，说明sFRP5/Wnt5a的表达异常参与了PE的发病。我们拟在体外实验中通过降低巨噬细胞sFRP5的表达或上调Wnt5a表达，模拟PE的病理状态，研究母胎界面的巨噬细胞是否因此而激活发生表型和功能的转变，诱发炎症反应或者放大炎症反应，造成内皮细胞损伤和滋养细胞侵袭力下降。并研究JNK和NFκB炎症信号通路是否参与这一过过程的调控。

胎盘滋养细胞浅着床和螺旋动脉重铸异常是子痫前期发病的中心环节，过度炎症在胎盘血管重塑异常中起重要作用。本研究以具有抗炎作用的Wnt抑制因子sFRP5为着眼点，运用重组蛋白模拟PE中高sFRP5环境，研究sFRP5单独及在LPS造成的炎症状态下对巨噬细胞及滋养细胞、血管内皮细胞功能的影响。同时研究NF-κB信号和Wnt/β-catenin通路在这一过程中的调控作用。我们的结果发现在子痫前期患者的巨噬细胞Wnt/β-catenin和NF-κB信号过度激活抑制滋养细胞的功能，同时子痫前期患者的血清中存在高水平的sFRP5，后者可能是对全身或局部过度炎症的反应。sFRP5一方面通过抑制Wnt/β-catenin和NF-κB信号抑制巨噬细胞的激活，另一方面通过抑制Wnt/β-catenin信号通路导致滋养细胞迁移和侵袭和血管内皮细胞的迁移功能受抑制，加重了胎盘血管重塑异常。改善全身和局部的炎症状态，阻断上述通路的各个环节，可以改善巨噬细胞、胎盘微血管内皮细胞/绒毛外滋养细胞的生物学功能，从而实现分子生物学水平上的“胎盘血管再建”，为子痫前期等胎盘缺血性疾病的诊治提供新思路。