Maternal-fetal amino acid transfer across placenta in a mouse model of prenatal alcohol exposure

项目摘要/摘要 宫内生长受限(IUGR)是胎儿酒精谱系障碍(FASD)的一个显著特征，它是 这是产前酒精暴露(PAE)的后果。胎盘是妊娠的一种特殊器官，供应 营养物质，如氨基酸(AAs)，为胎儿的生长提供营养。原子吸收特别重要，当它们 由于胎盘AA转运和/或mTOR信号减少，胎儿生长受损， IUGR随之而来。事实上，在许多与IUGR相关的妊娠障碍中，胎盘AA供应减少，但 目前尚不清楚这是否会导致PAE的胎儿生长缺陷。我假设PAE导致 IUGR，至少部分通过减少胎盘AA对胎儿的供应，这是 下调胎盘mTOR信号、AA转运和改变AA代谢。我进一步建议 在南非PAE队列中可以看到，母亲蛋白质摄入不足加剧了这种功能失调的AA 代谢，以加剧PAE造成的生长缺陷。为了测试这一点，我将给怀孕的老鼠喂一种蛋白质- 在整个怀孕期间有足够的(NP)或低蛋白质(LP)饮食，并摄入酒精或等热量的麦芽糊精 在妊娠晚期(GD14.5-GD17.5)，胎盘急剧上调AA转运至 加速胎儿生长。在GD17.5，我将全面评估母体、胎盘和胎儿AA 新陈代谢。AIM 1进行了全面的代谢组学分析，以表征PAE如何降低AA 沿母体-胎盘-胎儿轴的供应和代谢命运。AIM 2进行转录组分析， 胎盘蛋白印迹和免疫组织化学检测胎盘表达下调的假说 AA转运体和代谢基因参与了PAE中AA水平的改变。《目标3》演绎西部 在胎盘中印迹，以检验这些AA运输和新陈代谢的变化伴随而来的假设 通过抑制胎盘mTOR通路，这是AA可获得性和胎儿生长的主要调节因素。我 进一步预测在低脂饮食下PAE将加剧这些变化。这些研究使用了尖端技术。 创建PAE如何影响胎盘AA供应的全球肖像，并提供关于PAE如何影响胎盘AA供应的新机制洞察 PAE和PAE-LP与FASD中的IUGR表型有关。这些发现为未来的发展奠定了基础 检查出生后神经和代谢健康的研究，遗传风险因素的调节作用，以及 补充母体氨基酸和/或增加母体蛋白质摄入量的效果 PAE妊娠的结局。

Project Summary/Abstract Intrauterine growth restriction (IUGR) is a distinctive feature of fetal alcohol spectrum disorder (FASD), which is a consequence of prenatal alcohol exposure (PAE). Placenta is a specialized organ of pregnancy that supplies nutrients, such as amino acids (AAs), to the fetus for its growth. AAs are especially important and, when they are limiting due to reductions in placental AA transport and/or mTOR signaling, fetal growth is impaired and IUGR ensues. Indeed, placental AA supply is reduced in many pregnancy disorders associated with IUGR, but whether this contributes to fetal growth deficits in PAE remains unknown. I hypothesize that PAE causes IUGR, at least in part, by reducing placental AA supply to the fetus, and that this is a consequence of downregulated placental mTOR signaling, AA transport, and altered AA metabolism. I further propose that inadequate maternal protein intake, as seen in South African PAE cohorts, worsens this dysfunctional AA metabolism to exacerbate the growth deficits caused by PAE. To test this, I will feed pregnant mice a protein- sufficient (NP) or a low protein (LP) diet throughout pregnancy and administer alcohol or isocaloric maltodextrin during late gestation (GD14.5 – GD17.5), the period during which placenta sharply upregulates AA transport to accelerate fetal growth. At GD17.5, I will comprehensively assess maternal, placental, and fetal AA metabolism. Aim 1 performs a comprehensive metabolomics analysis to characterize how PAE decreases AA supply and metabolic fate along the maternal-placental-fetal axis. Aim 2 performs transcriptomics analysis, western blotting and immunohistochemistry in placenta to test the hypothesis that downregulation of placental AA transporters and metabolic genes contributes to the altered AA levels in PAE. Aim 3 performs western blotting in placenta to test the hypothesis that these changes in AA transport and metabolism are accompanied by inhibition of placental mTOR pathways, which is a major regulator of AA availability and fetal growth. I further predict PAE will exacerbate these changes under a LP diet. These studies use cutting-edge techniques to create a global portrait of how PAE affects placental AA supply and offer novel mechanistic insight into how PAE and PAE-LP contribute to the IUGR phenotype seen in FASD. These findings lay groundwork for future studies that examine postnatal neural and metabolic health, the modulatory effect of genetic risk factors, and the effectiveness of maternal AA supplementation and/or increasing maternal protein intake to improve outcomes of PAE pregnancies.