Determination of Fetal Gene Expression in Women with Preterm & Term Birth

描述（由申请人提供）：早产是一个主要的公共卫生问题，定义为在妊娠37周之前分娩。每年有多达360，000名孕妇早产。早产儿比足月儿有更大的死亡和残疾风险。 尽管进行了数十年的研究，但缺乏减少或消除自发性早产（sPTB）的一级预防策略。这项研究将探讨胎儿下丘脑-垂体-肾上腺（HPA）轴激活在sPTB中的作用，并确定潜在的新的治疗靶点，用于原发性sPTB预防。本建议的目的是确定sPTB是否与胎儿HPA轴基因表达差异相比，足月分娩。我们的中心假设是，早产的胎儿有更多的HPA轴基因表达的上调相比，那些在长期交付。我们根据已发表的文献阐述了我们的中心假设，这些文献表明，促肾上腺皮质激素释放激素（CRH）是一种调节HPA轴活性的下丘脑神经肽，对分娩的调节是不可或缺的。 我们将通过完成两个具体目标来检验我们的中心假设：1：使用先前收集的自发性早产和足月分娩的孕中期羊水标本来量化HPA轴关键调控基因的孕中期胎儿表达; 2）前瞻性地检测胎儿HPA轴相关基因在两组胎儿中的表达，（羊水和脐带血）和母体（血液）隔室。这些目标将通过对sPTB（<34周）或自然足月分娩（>37周）妇女的羊水上清液进行回顾性和前瞻性分析来实现。在提取无细胞胎儿RNA后，通过真实的实时聚合酶链反应（RT-PCR）定量胎儿HPA轴基因表达。此外，全基因组微阵列表达阵列将用于鉴定sPTB中上调或下调的其他潜在胎儿途径。将通过RT-PCR在前瞻性采集的母体血液中鉴定与sPTB相关的胎儿生物标志物。该方法是创新的，因为我们的建议是第一次使用羊水上清液在以前收集和前瞻性收集的交付，以分离cffRNA和测量胎儿HPA轴相关的基因表达在sPTB和足月分娩。这项研究具有重要意义，因为在sPTB并发症的妊娠中识别胎儿HPA轴的差异基因表达将使我们能够开发新的策略来测试原发性sPTB预防。最终，这些知识有可能为预防sPTB的新疗法提供信息。

DESCRIPTION (provided by applicant): Preterm birth is a major public health concern defined as delivery prior to 37 completed weeks of gestation. Each year, up to 360,000 pregnancies deliver preterm. Preterm infants are at greater risk of death and disability than are term infants. Despite decades of research, primary prevention strategies to reduce or eliminate spontaneous preterm birth (sPTB) are lacking. The proposed study will explore the role of fetal hypothalamic-pituitary-adrenal (HPA) axis activation in sPTB and identify potential new therapeutic targets for primary sPTB prevention. The objective of this proposal is to determine whether sPTB is associated with differential fetal HPA axis gene expression compared to term births. Our central hypothesis is that fetuses that are delivered preterm have more up-regulation of HPA axis gene expression compared to those that are delivered at term. We formulated our central hypothesis based on published literature showing that corticotrophin-releasing hormone (CRH), a hypothalamic neuropeptide that regulates HPA axis activity, is integral to the regulation of labor. We will test our central hypothesis by completing two specific aims: 1: To quantify second trimester fetal expression of the key regulatory genes of the HPA axis using previously collected second trimester amniotic fluid specimens in spontaneous preterm and term births; 2) To prospectively measure fetal HPA axis-associated gene expression in both the fetal (amniotic fluid and umbilical cord blood) and maternal (blood) compartments obtained at the time of delivery of spontaneously preterm and term infants. These aims will be achieved through a retrospective and prospective analysis of amniotic fluid supernatant from women with sPTB (<34 weeks) or spontaneous term birth (>37 weeks). Fetal HPA axis gene expression will be quantified via real- time polymerase chain reaction (RT-PCR) after extraction of cell-free fetal RNA. In addition, whole genome microarray expression arrays will be used to identify other potential fetal pathways up or down-regulated in sPTB. Fetal biomarkers related to sPTB will be identified in the prospectively collected maternal blood by RT-PCR. The approach is innovative because our proposal is the first to use amniotic fluid supernatant in previously collected and prospectively collected deliveries to isolate cffRNA and measure fetal HPA axis-associated gene expression in sPTB and term birth. The proposed research is significant because identifying differential gene expression of the fetal HPA axis among pregnancies complicated by sPTB will allow us to develop new strategies to test for primary sPTB prevention. Ultimately, such knowledge has the potential to inform novel therapies to prevent sPTB.