Maternal vascular responses to extracellular mitochondrial DNA during pregnancy

项目摘要 妊娠高血压疾病，包括先兆子痫，是孕产妇死亡的主要原因之一。 死亡有人认为，在先兆子痫中，胎盘灌注不足/缺血会导致促性腺激素释放。 与母体血管壁相互作用以诱导母体血管功能障碍的炎性因子， 高血压胎盘源性因子与母体血管功能障碍之间的分子通路是 不明白。此外，胎盘组织中决定胎盘源性因子释放的机制 母体循环还未被充分研究。拟议的研究将通过测试解决这些知识差距 细胞外线粒体DNA（mtDNA）作为母体血管功能障碍与 胎盘缺血，先兆子痫的共同特征。先兆子痫妇女的血浆中 循环无细胞mtDNA，已被证明是免疫原性和促炎性的各种疾病， 炎性条件。此外，临床研究表明， 循环线粒体DNA和发展先兆子痫的风险。在这里，我们提出，循环游离mtDNA 胎盘来源的血凝素是先兆子痫母体血管功能障碍的主要原因，部分原因是 Toll样受体9（TLR-9）。目的1：我们将确定一种分子机制， 细胞外线粒体DNA与妊娠期母体血管功能障碍的关系。我们假设血管 暴露于细胞外mtDNA将通过TLR-9的激活诱导母体血管张力的增加 信号这一假设将使用涉及分离的母体动脉的综合方法进行检验， 血管细胞，并在健康的非妊娠和妊娠大鼠体内mtDNA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 假设胎盘缺氧导致活性氧产生增加， 通过诱导细胞死亡和增加自噬来触发mtDNA释放到细胞外空间。到 为了解决这一假设，我们将使用人滋养层细胞和大鼠胎盘外植体。目标3：我们将 确定循环mtDNA的增加是否参与了 先兆子痫的母体心血管综合征我们将检验一个假设， 线粒体DNA在胎盘缺血动物模型中触发母体心血管综合征， 先兆子痫的临床终点，并且与正常相比具有更高的循环mtDNA浓度 怀孕的老鼠这项研究可能会产生转化的影响，因为它将提供一个临床前平台， 开发减少mtDNA释放、中和细胞外mtDNA或 抑制TLR-9在那些妇女谁拥有高浓度的循环无细胞mtDNA在怀孕期间。

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.