Virginia Commonwealth University School of Medicine, Richmond, VA, United States.
Division of Child Heath, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, United Kingdom.
Front Immunol. 2020 Mar 10;11:396. doi: 10.3389/fimmu.2020.00396. eCollection 2020.
Pre-eclampsia (PE) is a disorder of pregnancy, often leading to serious and fatal complications. Endoplasmic reticulum aminopeptidase 1 and 2 (ERAP1/ERAP2) are present in the placenta. They are involved in processes regulating blood pressure, angiogenesis, cytokine receptor shedding, and immune recognition. Previous studies have associated both ERAP1/ERAP2 genetic variants with PE, although the underlying mechanisms remain unknown. Less is known about the roles for these enzymes in early placentation, which could be a contributory factor to PE. To ascertain whether ERAP1/ERAP2 change in PE and whether such a change is present before PE is clinically diagnosed, we analyzed mRNA and ERAP1/2 protein expression in the placenta in the early first trimester (8-14 weeks) and at delivery in normotensive or PE women ( = 12/group). Gene expression was analyzed using qPCR, and protein expression and localization were assessed by immunohistochemistry. Additionally, we profiled peripheral immune cells from normotensive and PE ( = 5/group) women for activation and expression of cytotoxic markers using flow cytometry to investigate a possible correlation with placental expression of ERAP1/2. Finally, we characterized the cytokines released from immune cells isolated from normotensive women and those with PE, stimulated by JEG-3 trophoblast cells. The ERAP1 protein was significantly upregulated in first trimester placentae compared to placentae at delivery from both normotensive and PE women ( < 0.05): expression of placental ERAP1 protein was also relatively higher in normotensive than PE women. Although the protein expression of both ERAP1/ERAP2 was significantly lower in women with PE compared to normotensive controls ( < 0.05), ERAP2 protein expression remained unchanged in normotensive women at delivery compared to expression in the first trimester. Flow cytometry analysis revealed an increase in activation and cytotoxic natural killer (NK) cells in peripheral blood of PE compared to normotensive women. Intriguingly, there was a notable difference in cytokine release from the activated immune cells when further stimulated by trophoblast cells. The immune cells from PE released elevated expressions of interleukin (IL)-2, IL-4, and most notably, pro-inflammatory IL-13 and IL-17α, inflammatory cytokines tumor necrosis factor (TNF)-α and interferon (IFN)-γ, and granulocyte-macrophage colony-stimulating factor (GM-CSF) compared to normal peripheral blood mononuclear cells (PBMCs). Taken together, these findings suggest that differential lymphocyte activation could be associated with altered ERAP1/ERAP2 expression.
子痫前期 (PE) 是一种妊娠疾病，常导致严重和致命的并发症。内质网氨肽酶 1 和 2 (ERAP1/ERAP2) 存在于胎盘。它们参与调节血压、血管生成、细胞因子受体脱落和免疫识别的过程。先前的研究已经将 ERAP1/ERAP2 遗传变异与 PE 相关联，尽管潜在机制尚不清楚。这些酶在早期胎盘形成中的作用知之甚少，这可能是 PE 的一个促成因素。为了确定 ERAP1/ERAP2 在 PE 中的变化，以及这种变化是否在 PE 临床诊断之前就存在，我们分析了正常血压和 PE 妇女（每组 = 12 名）在早期第一孕期（8-14 周）和分娩时胎盘的 mRNA 和 ERAP1/2 蛋白表达。使用 qPCR 分析基因表达，通过免疫组织化学评估蛋白表达和定位。此外，我们使用流式细胞术分析了来自正常血压和 PE（每组 = 5 名）妇女的外周免疫细胞的细胞毒性标志物的激活和表达，以研究其与胎盘 ERAP1/2 表达的可能相关性。最后，我们分析了从正常血压妇女和患有 PE 的妇女中分离出的免疫细胞释放的细胞因子，这些细胞因子受到 JEG-3 滋养层细胞的刺激。与正常血压和 PE 妇女的分娩胎盘相比，ERAP1 蛋白在第一孕期胎盘的表达显著上调（<0.05）：正常血压妇女的胎盘 ERAP1 蛋白表达也相对较高。尽管与正常血压对照组相比，PE 妇女的 ERAP1/ERAP2 蛋白表达均显著降低（<0.05），但正常血压妇女在分娩时的 ERAP2 蛋白表达与第一孕期相比没有变化。流式细胞术分析显示，与正常血压妇女相比，PE 妇女外周血中 NK 细胞的激活和细胞毒性增加。有趣的是，当进一步受到滋养层细胞刺激时，激活的免疫细胞释放细胞因子的情况有明显差异。与正常外周血单个核细胞 (PBMCs) 相比，PE 患者的免疫细胞释放的白细胞介素 (IL)-2、IL-4 以及更显著的促炎因子 IL-13 和 IL-17α、炎症细胞因子肿瘤坏死因子 (TNF)-α 和干扰素 (IFN)-γ 以及粒细胞-巨噬细胞集落刺激因子 (GM-CSF) 表达水平升高。综上所述，这些发现表明淋巴细胞的差异激活可能与 ERAP1/ERAP2 表达的改变有关。
