MSC通过miR-494调控M2型巨噬细胞转化影响子痫前期的机制研究

Pre-eclampsia (PE), a pregnancy-specific disorder, is the second leading cause of pregnant or lying-in women' death in China. However, its pathogenesis is still unknown, and there is no effective therapy method. Immune dysfunction is one of the most favored pathogenesis. Decidual macrophages at the fetomaternal interface are important for maternal tolerance of fetal antigens, as well as for host defense against intrauterine infections. The inadequacy of M2 macrophages differentiation in fetomaternal interface leads to the onset of PE. .Mesenchymal stem cells (MSCs) are capable of modulating the immune system through interaction with a wide range of immune cells. Although the interaction of MSCs with T-lymphocytes, B-lymphocytes, natural killer cells and dendritic cells have been investigated in detail, there is very little known about the interaction of MSCs with cells of monocytic lineages, specifically macrophages. Recently, one literature reported that activity of indoleamine 2,3-dioxygenase was partially implicated in the differentiation of the monocyte fraction of peripheral blood mononuclear cells (PBMC) into interleukin-10-secreting M2 immunosuppressive macrophages. In addition, deciduas-derived MSCs expressed different cytokines between PE and normal pregnancies. However, little is known about the potential roles of MSCs in PE development and progression..We found that MSCs can arrive in fetomaternal interface, and can improve the outcome of PE-like model mice, and they also can regulate M2 macrophages differentiation. MSCs derived from PE patient decidua display lower proliferation ability and higher expression of miR-494. Recent studies indicate that microRNAs (miRNAs) act as regulatory signals for maintaining of stemless, self-renewal, and differentiation in MSCs. We suppose that aberrant high expression of miR-494 will affect the M2 macrophages differentiation through decreasing the proliferation ability and secretion of indoleamine 2,3-dioxygenase of MSCs, and then change immune response of macrophages in fetomaternal interface, which results in malfunction of immune balance, and finally induces development and progression of PE. We found that transplanted normal MSC could re-establish immune balance in fetomaternal interface of PE. Our project is to illustrate the state of immune and pregnancy in fetomaternal interface when MSCs modified by miR-494 are used to cure PE-like model mice; to reveal the effect of miR-494 on regulating the proliferation and immune regulation function of MSCs and its mechanism; to explore the molecular mechanism of MSCs regulating macrophages cell in fetomaternal interface. We will provide new insight and technology to understand pathogenesis of PE and find new effective method to prevent and cure this disease.

子痫前期（PE）是妊娠常见并发症，我国孕产妇死亡的第二原因。但发病机制未明，且缺乏有效治疗手段。免疫失调被认为是PE的发病机制之一,我们发现间充质干细胞（MSC）能够在母胎界面处改善PE样小鼠模型的症状，且可调节M2型巨噬细胞转化。同时发现PE患者MSC增殖能力减弱，且microRNA-494(miR-494)高表达。已有研究证明microRNA能够调节MSC的干性维持、增殖以及分化等。而MSC可能通过分泌吲哚胺2，3双加氧酶（IDO）的表达来阻碍M2型巨噬细胞的转化。推测：高表达miR-494的MSC通过改变其增值能力以及降低IDO的表达阻碍了M2型巨噬细胞的转化，引起母胎界面巨噬细胞免疫应答的异常，进而导致了PE的发生和发展。本项目将揭示miR-494对MSC增殖以及免疫调节作用的影响及其机制；探索在母胎界面处MSC调控巨噬细胞功能的分子机制；提供MSC移植改善PE的依据。

子痫前期（PE）是妊娠常见且严重的并发症，也是我国孕产妇死亡的第二位原因。但其发病机制未明，且缺乏有效治疗手段。免疫失调被认为是PE的发病机制之一, 母胎界面M2型巨噬细胞转化不足参与了PE的发生。我们发现间充质干细胞（MSC）能够到达母胎界面处，改善PE样小鼠模型的症状，且可调节M2型巨噬细胞转化。PE患者MSC增殖能力减弱，同时microRNA-494 (miR-494)高表达。.实验研究结果显示，PE患者蜕膜来源的MSC中miRNA的表达谱明显改变，其中miR-494的表达明显升高。在研究中，我们发现高表达miR-494可以降低MSC中VEGF的表达，进而抑制MSC的增殖、迁移、侵袭能力以及促血管生成能力，而不影响细胞的凋亡。高表达miR-494后，MSC可以通过靶向COX2抑制PGE2的分泌，抑制巨噬细胞向M2型转化，引起母胎界面巨噬细胞免疫应答的异常，进而导致了PE的发生和发展。在LPS诱导的PE模型中，我们发现使用姜黄素可以通过促进AKT的磷酸化，减少胎盘炎症反应，改善PE患者的症状。此外，我们发现lnc-RNA-MALAT1在PE患者中低表达。低表达MALAT1后，VEGF生成减少，MSC增殖、侵袭、迁移及成血管能力降低；低表达MALAT1后，IDO生成减少，巨噬细胞向M2型分化减少，引起母胎界面处血管生成减少，巨噬细胞免疫应答异常，进而导致PE的发生和发展。高表达MALAT1后，MSC 的增殖、迁移、侵袭及成血管能力增加，且巨噬细胞向M2极化比例增加。