H2S and Uterine Vasodilation in Pregnancy and Preeclampsia

项目摘要 一旦怀孕，女性的心血管系统就会发生巨大的结构和功能变化， 适应快速生长的胎儿日益增长的需求，导致子宫动脉深度扩张 例如子宫血流量（UBF）的急剧上升。UBF是妊娠健康的限速因素 因为怀孕期间UBF上升不足会导致宫内生长受限， 先兆子痫（PE），其特征在于全身性内皮损伤和血管功能障碍。自1900年以来， 许多研究已经得出结论，局部内皮一氧化氮（NO）介导的血管舒张是主要的 控制UBF上升的机制。然而，阻断局部NO产生仅部分抑制基线水平， 妊娠相关的UBF升高，表明涉及其他介质。内源性硫化氢 硫化物（H2S），主要由L-半胱氨酸通过两种关键酶合成：胱硫醚合成酶（CBS）和 胱硫醚裂解酶（CSE）是一种非常有效的促血管生成血管扩张剂。我们最初假设当地 CBS/H2S的产生可以填补NO介导妊娠期UA血管舒张的机制。的确， 我们报道了妊娠通过选择性上调EC显著增加UA H2S的生物合成， SM CBS而非CSE在动物（大鼠和母羊）和女性体内表达，H2S刺激 离体加压UA的妊娠依赖性扩张。在PE动物模型和PE女性中，我们 发现妊娠增强子宫肌层UA CBS/H2S显著下调。然而研究 H2S在子宫血流动力学中的作用尚处于起步阶段;许多重要的关键问题需要回答 在CBS/H2S信号在正常妊娠和PE中的生理和病理生理作用之前， 被确定。在这个新的RO1中，我们提出了一个新的假设，即增强UA EC和SM CBS/H2S产生通过与血管相互作用介导妊娠相关的UA扩张 内皮生长因子和EC eNOS-NO以及下调的UA CBS/H2S信号通路有助于 PE中的血管功能障碍。我们将通过多学科的翻译方法来检验这一假设 用生物化学、细胞学、分子学、生理学和药理学方法结合大鼠模型， 体内、离体新鲜分离的人和大鼠UA环、新的人UA EC（hUAEC）和平滑肌细胞 （hUASMC）体外模型，以及来自血压正常与PE孕妇的子宫肌层UA。我们有一个 优秀的团队，在该领域具有长期富有成效的合作研究记录， 完成这一激动人心的重要项目所需的工具。我们认为， 该RO1将提供新的数据，以填补关于以下方面的生理和病理生理作用的知识空白： H2S在子宫血流动力学调节中的作用，这一知识将为临床应用提供令人信服的依据。 研究H2S在PE高危女性中的治疗潜力。

PROJECT SUMMARY Once conceived, a woman’s cardiovascular system undergoes dramatic structural and functional changes to accommodate the increasing demands of the fast growing fetus, resulting in profound uterine artery dilation exemplified by dramatic rise in uterine blood flow (UBF). UBF is a rate-limiting factor for pregnancy health because an insufficient rise in UBF during pregnancy is causative for intrauterine growth restriction and preeclampsia (PE) characterized by systemic endothelial damage and vascular dysfunction. Since 1900’s, numerous studies have concluded that local endothelial nitric oxide (NO)-mediated vasodilation is the major mechanism controlling rise in UBF. However, blockade of local NO production only partially inhibits baseline pregnancy-associated rise in UBF, suggesting that other mediator(s) are involved. Endogenous hydrogen sulfide (H2S), mainly synthesized from L-cysteine by two key enzymes: cystathionine -synthase (CBS) and cystathionine -lyase (CSE), is an extremely potent proangiogenic vasodilator. We initially posited that local CBS/H2S production can fill the mechanism behind NO to mediate UA vasodilation during pregnancy. Indeed, we reported that pregnancy dramatically augments UA H2S biosynthesis by selectively upregulating EC and SM CBS but not CSE expression in animals (rats and ewes) and women in vivo and that H2S stimulates pregnancy-dependent dilation of pressurized UA ex vivo. In animal models of PE and women with PE, we found that pregnancy-augmented myometrial UA CBS/H2S is significantly downregulated. However, research on H2S in uterine hemodynamics is still in its infancy; many important key questions need to be answered before a physiological and a pathophysiological role of CBS/H2S signaling in normal pregnancy and PE can be determined. In this new RO1 we propose to test a novel hypothesis that enhanced UA EC and SM CBS/H2S production mediates pregnancy-associated UA dilation by interacting with vascular endothelial growth factor and EC eNOS-NO and downregulated UA CBS/H2S signaling contributes to the vascular dysfunction in PE. We will test this hypothesis by a multidisciplinary translational approach with biochemical, cellular, molecular, physiological, and pharmacological methods coupled with rat models in vivo, freshly isolated human and rat UA rings ex vivo, novel human UA EC (hUAEC) and smooth muscle cell (hUASMC) models in vitro, and myometrial UAs from normotensive vs. PE pregnant women. We have an outstanding team with a track record of long-term productive collaborative research in the field and unique tools needed to complete this exciting and important project. We believe that the novel studies outlined in this RO1 will provide new data to fill a knowledge gap on the physiological and pathophysiological role for H2S in in uterine hemodynamic regulation and this knowledge will provide a compelling rationale for clinical trials to explore the therapeutic potential of H2S in women in high risk of PE.