Benefits of nicotinamide in placental development and in preeclamsia

摘要/摘要 子痫前期（PE）发病的分子机制尚不清楚，有效的预防措施 并且治疗策略仍然难以捉摸。PE是一种妊娠相关的高血压疾病， 在美国，大约每20次怀孕中就有一次，是与怀孕有关的孕产妇死亡的主要原因 和新生儿发病率/死亡率。内皮素-1（ET-1）是一种具有血管收缩作用的21个氨基酸残基的肽， 编码ET-1前体的EDN1单核苷酸多态性（SNP）与PE相关。 Edn 1 H/+小鼠，其中Edn 1表达升高至正常值的3倍，具有正常的血压，尽管升高 循环ET-1。然而，Edn1H/+母鼠在妊娠后期出现全谱PE样表型。 此外，来自Edn 1H/+母鼠的胚胎，无论其Edn 1基因型如何，在胚胎发育期间发育滞后。 早期着床期，外胎盘锥定向紊乱。我们报道了烟酰胺（酰胺形式的 维生素B3，Nam），ADP核糖基环化酶下游的ET-1抑制剂，改善了 两种不同的PE小鼠模型，我们的初步数据显示，Nam可降低尿白蛋白， 当Edn 1H/+母鼠在整个研究期间接受给药时， 怀孕这些观察结果使我们假设Edn 1H/+母鼠中的PE源于异常 胎盘形成是由母体ET-1在着床早期的高表达引起的，Nam可以纠正胎盘形成， 这会破坏并保护大坝不受后期PE发展的影响。因此，具体目标1将对此进行测试。 通过将Nam对Edn 1H/+母鼠PE的早期效应与后期效应分离， 维生素C在不同的妊娠阶段和不同的持续时间开始。妊娠结局，包括血液 在性交后18.5天（DPC）测定血压、尿白蛋白和胎儿数量和体重。在 此外，ET-1系统各组分在着床期的表达及Nam对其的影响， 接受检查。具体目标2将探讨ET-1和Nam对分化的作用机制 通过使用二维和三维培养将人滋养层干细胞转化为指定的滋养层细胞 系统将药理学剂量的单独的ET-1或ET-1加Nam加入到特定的条件培养物中。 介质将通过细胞的形态、运动性和不同类型的细胞标志物的表达来检查细胞。 滋养层具体目的3探讨ET-1和Nam对子宫内膜异位症的作用机制 蜕膜化和血管生成。子宫内膜造口分化的标志物，血液结构 子宫内膜血管内皮生长因子（VEGF）的表达 怀孕将被检查。原代培养的子宫内膜间质细胞将用药理学方法处理。 单独的ET-1或ET-1加Nam的剂量，以及分化标志物和VEGF的表达将被确定。 测定拟议的研究将扩大和加深我们对 母源性遗传因子ET-1与PE的关系，并确定PE的潜在干预策略。

Summary/Abstract The molecular mechanism of pathogenesis of preeclampsia (PE) is largely unknown, and effective prevention and treatment strategies remain elusive. PE is a pregnancy-associated hypertensive condition and complicates approximately one in 20 pregnancies in the US and is a leading cause of pregnancy-related maternal mortality and neonatal morbidity/mortality worldwide. Endothelin-1 (ET-1) is a vasoconstrictive peptide of 21 residues, and single nucleotide polymorphisms (SNPs) in EDN1, coding for a precursor for ET-1, are associated with PE. Edn1H/+ mice in which Edn1 expression is elevated to 3X normal have normal blood pressure, despite elevated circulating ET-1. However, Edn1H/+ dams develop full spectrum of PE-like phenotypes in their late pregnancy. In addition, the embryos from Edn1H/+ dams, regardless of their Edn1 genotypes, lag in development during early implantation stage with disoriented ectoplacental cones. We reported that nicotinamide (amide form of vitamin B3, Nam), inhibitor of ET-1 downstream of ADP ribosylcyclase, ameliorates the PE-like phenotypes in two separate mouse models of PE, and our preliminary data show that Nam decreases urinary albumin excretion and increases the number of survival fetuses when Edn1H/+ dams were treated during the entire pregnancy. These observations have led us to hypothesize that PE in Edn1H/+ dams originates from abnormal placentation caused by a high maternal ET-1 expression at early implantation stage, and that Nam can correct this damage and protect dams from later PE development. Accordingly, Specific Aim 1 will test this hypothesis by dissociating early effects from later effects of Nam on PE of Edn1H/+dams by treatments with this vitamin starting at different gestational stages and for different durations. Pregnancy outcomes including blood pressure, urinary albumin and fetal number and weight will be determined at 18.5 day post coitus (dpc). In addition, the expression of components of ET-1 system and Nam’s effects on them at implantation stage will be examined. Specific Aim 2 will investigate the mechanism of effects of ET-1 and Nam on differentiation from human trophoblast stem cells into designated trophoblast cells by using 2- and 3- dimension culture system. Pharmacological dose of ET-1 alone, or ET-1 plus Nam will be added to the specific conditioned medium. Cells will be examined by their morphology, motility, and expression of markers of different types of trophoblasts. Specific Aim 3 will investigate the mechanism of effects of ET-1 and Nam on impaired uterine decidualization and angiogenesis. The markers of endometrial stomal differentiation, the structure of blood vessels and the expression of vascular endothelial growth factor (VEGF) in uteri at the implantation stage of pregnancy will be examined. Primary cultured endometrial stromal cells will be treated with pharmacological dose of ET-1 alone, or ET-1 plus Nam, and the markers of differentiation and the expression of VEGF will be determined. The proposed research will broaden and deepen our understanding regarding the role of the maternal genetic factor ET-1 on PE and identify a potential intervention strategy for PE.