Maternal vascular responses to extracellular mitochondrial DNA during pregnancy

项目总结 妊娠期高血压疾病，包括先兆子痫，是导致孕产妇死亡的主要原因之一。 死亡。已有研究表明，在子痫前期，胎盘低灌流/缺血可导致前列环素释放。 炎症因子与母体血管壁相互作用，导致母体血管功能障碍和 高血压。连接胎盘衍生因子和母体血管功能障碍的分子通路有 我不明白。此外，决定胎盘衍生因子在体内释放的机制 母体循环的研究还不够深入。拟议的研究将通过测试来解决这些知识差距 细胞外线粒体DNA(MtDNA)作为母体血管功能障碍与母体血管功能障碍之间新的联系的作用 胎盘缺血，先兆子痫的常见特征。患有先兆子痫的妇女的血浆含量增加 循环中的无细胞线粒体DNA，已被证明在各种疾病中具有免疫原性和促炎作用 炎症状态。此外，临床研究已经证明， 循环线粒体DNA与先兆子痫的风险。在这里，我们提出循环中的无细胞线粒体DNA 来源于胎盘是先兆子痫患者母体血管功能障碍的主要原因，部分原因是 对Toll样受体9(TLR-9)的影响。目标1：我们将确定一种连接分子机制 细胞外线粒体DNA与妊娠期母体血管功能障碍我们假设血管 暴露于细胞外mtDNA将通过激活TLR-9诱导母体血管张力增加 发信号。这一假设将使用一种涉及分离的母体动脉的综合方法进行检验， 血管细胞，以及健康未怀孕和怀孕大鼠体内线粒体DNA的挑战。目标2：我们将 确定胎盘缺氧诱导mtDNA释放的潜在机制。我们将测试 假设胎盘低氧会导致活性氧的产生增加，进而 通过诱导细胞死亡和增加自噬，触发线粒体DNA释放到细胞外空间。至 为了解决这一假设，我们将使用人类滋养层细胞和大鼠胎盘外植体。目标3：我们将 确定循环中线粒体DNA的增加是否参与了血吸虫病的发生或维持。 先兆子痫的母体心血管综合征。我们将检验这一假设，即增加流通 线粒体DNA在模拟胎盘缺血的动物模型中触发母体心血管综合征 先兆子痫的临床终点和循环mtDNA浓度高于正常 怀孕的老鼠。这项研究可能会产生翻译影响，因为它将为 减少线粒体DNA释放，中和细胞外线粒体DNA，或 在妊娠期间循环中有高浓度无细胞线粒体DNA的女性中，抑制TLR-9。

PROJECT SUMMARY Hypertensive disorders of pregnancy, including preeclampsia, are among the leading causes of maternal deaths. It has been suggested that in preeclampsia, placental hypoperfusion/ischemia results in release of pro- inflammatory factors that interact with the maternal vascular wall to induce maternal vascular dysfunction and hypertension. The molecular pathways linking placenta-derived factors and maternal vascular dysfunction are not understood. Furthermore, the mechanisms determining the release of placenta-derived factors in the maternal circulation are underexplored. The proposed studies will address these knowledge gaps by testing the role of extracellular mitochondrial DNA (mtDNA) as a novel link between maternal vascular dysfunction and placental ischemia, common features of preeclampsia. Plasma from women with preeclampsia has increased circulating cell-free mtDNA, which has been shown to be immunogenic and pro-inflammatory in various inflammatory conditions. Furthermore, clinical studies have demonstrated a positive association between circulating mtDNA and the risk of developing preeclampsia. Here, we propose that circulating cell-free mtDNA derived from the placenta is a major contributor to maternal vascular dysfunction in preeclampsia, due in part to its effects on Toll-like receptor 9 (TLR-9). Aim 1: we will determine a molecular mechanism linking extracellular mtDNA with maternal vascular dysfunction during pregnancy. We hypothesize that vascular exposure to extracellular mtDNA will induce an increase in maternal vascular tone through activation of TLR-9 signaling. This hypothesis will be tested using an integrative approach involving isolated maternal arteries, vascular cells, and an in vivo mtDNA challenge in healthy non-pregnant and pregnant rats. Aim 2: we will determine a potential mechanism by which placental hypoxia induces release of mtDNA. We will test the hypothesis that placental hypoxia causes increased generation of reactive oxygen species, which in turn triggers the release of mtDNA into the extracellular space by inducing cell death and increasing autophagy. To address this hypothesis, we will use human trophoblast cells and rat placental explants. Aim 3: we will determine whether increased circulating mtDNA is involved in the pathogenesis or maintenance of the maternal cardiovascular syndrome in preeclampsia. We will test the hypothesis that increased circulating mtDNA triggers the maternal cardiovascular syndrome in an animal model with placental ischemia that mimics clinical end-points of preeclampsia and has higher concentrations of circulating mtDNA compared to normal pregnant rats. This research may have a translational impact because it will provide a pre-clinical platform for the development of pharmacological strategies to reduce mtDNA release, neutralize extracellular mtDNA, or inhibit TLR-9 in those women who have high concentrations of circulating cell-free mtDNA during pregnancy.