金属硫蛋白（MT）对子痫前期（PE）氧化应激和氧化损伤的影响

Pre-eclampsia (PE) is a leading cause of maternal, perinatal mortality and morbidity worldwide, but there have not been effective means of prevention and treatment. In view of the pivot role of oxidative stress and damage in the onset and development of PE and that metallothionein (MT) is the most effective antioxidant known to present, our previous work also suggests that MT presents a protective effect on oxidative stress. Therefore, in this study, we will investigate the protective effect of zinc-induced MT expression on oxidative stress and damage in an animal model of PE. Base on the investigation, we will give zinc supplementation to induce MT expression among subjects with high-risk of PE. The levels of MT and anti-MT antibody and MT isoform (subtype) expression are measured in blood and/or placental tissues collected from the early and late phases of PE patients. The effects of MT on reactive oxygen species and reactive nitrogen species, oxidative damage (MDA and 3-NT), other antioxidants (GSH) and the vascular growth unbalance and abnormal apoptosis caused by oxidative damage during PE development are observed. In addition, we analyze the single nucleotide polymorphisms and methylation levels in MT genes of PE and follow-up for PE course and birth outcome in order to determine the role of MT as an anti-oxidant in PE. Our work will provide scientific basis for the development of biological and genetic markers for the early warning of PE and potential targets for PE prevention and treatment.

子痫前期（PE）是引起孕产妇、围产儿发病和死亡的主要产科疾病，但一直无有效的防治手段。鉴于氧化应激和损伤在PE发生发展的核心作用，而金属硫蛋白（MT）是迄今所知体内最有效的抗氧化物，我们以往的工作也提示MT具有对氧化应激的保护作用。因此在本项目中我们将在模型动物中明确锌诱导MT对PE的保护作用，并对PE高风险人群给予锌干预PE的发病，通过观察孕早、晚期PE血和/或胎盘组织MT及其抗体、MT基因异构体(亚型)表达水平与氧化活性物（ROS和RNS）、氧化损伤标志物（MDA和3-NT）、其他抗氧化物（GSH）含量以及PE发展过程中氧化损伤所致血管生成障碍和异常细胞凋亡的关系，同时检测PE中MT基因多态性和甲基化水平并追踪PE病程和出生结局，探讨MT在PE中抗氧化损伤效应及其机制，为寻找PE早期预警的生物和遗传标志、PE防治的潜在靶标和措施提供科学依据。

氧化应激和损伤在妊娠并发症子痫前期（PE）发生发展的核心作用以及金属硫蛋白（MT）强大的抗氧化作用促使我们探讨两者间的关系。本项目利用一氧化氮合成酶抑制剂亚硝基左旋精氨酸甲酯（L-NAME）建立类PE大鼠模型，经葡萄糖酸锌干预后MT水平升高，并可逆转L-NAME诱发的氧化应激和损伤、过度炎症反应、异常的细胞凋亡和血管生成因子失衡。人群研究发现，孕妇服用矿物质（钙和锌）可一定程度提高血浆MT水平但不改变PE的发病风险，可能与用药剂量或时间不足有关。对MT的基因分型发现MT-1A的 rs11076161G、MT-1B的rs7191779C及rs8052334T、MT-1DP的rs8044719G等与妊娠高血压综合征（HDP）包括PE 的风险显著相关，而且rs11076161、rs10636、rs7191779 和 rs8044719 的 4 位点是与HDP关联的最优组合模式。此外，血浆MT及其亚型MT-1F、MT-1X和MT-1B水平改变与多种妊娠并发症如先兆早产、先兆流产、妊娠期糖尿病（GDM）和HDP等相关，HDP血清白介素-13（IL-13）水平升高，而PE血清sIL13-Rα1、PIGF以及炎症因子IL-6水平升高。与对照组比较，PE胎盘组织MT-2A和MT-1E表达上调，而且MT-2A启动子区域3个CpG位点甲基化差异显著。蛋白芯片（QAH-CAA-440）筛查的结果显示PE早孕期血清中水平差异的蛋白质涉及PE关键致病机制如过激炎症反应、滋养细胞侵袭力不足以及螺旋小动脉重塑障碍相关的6个主要信号转导通路或病理学过程，但尚需要在更大样本的出生队列中验证。上述结果提示MT基因多态性及其模式、血浆MT及其亚型或许可作为包括PE在内多种妊娠并发症的早期生物标志，葡萄糖酸锌可能具有一定的防治PE的作用，但临床上补充锌剂应重点考虑可诱导MT的适宜剂量、用药时机和持续时间等因素。