A Novel Mechanistic Framework for FASD Etiology.

据估计，在美国，胎儿酒精谱系障碍(FASD)影响2%-5%的学龄儿童，估计每个人的成本为140万美元。FASD的两个主要后果是胎儿生长受限和神经发育缺陷。由于对酒精影响多器官系统的复杂作用机制的有限了解，成功预防或改善酒精滥用的这些致畸作用的努力一直受到阻碍。此外，关于FASD结局的病因学报告大多局限于调查间接下游介体。我们认为，控制磷脂酰乙醇(peth；100%特异性，孕期酒精暴露最敏感的生物标记物)形成的分子途径可以为FASD的病因学提供新的见解。 在酒精代谢过程中，磷脂酰胆碱被水解为pEH，而不是磷脂酸(PA，生长/神经元发育所必需的营养物质)。在已建立的FASD模型中，我们新的初步数据显示，酒精降低了PA的生物利用度，同时增加了母体和胎儿体内的peth水平。我们的数据还显示，酒精导致母体子宫动脉(与胎儿生长有关)和胎儿脑血管(与神经发育结果有关)适应性受损。有趣的是，体外将PA添加到子宫和大脑中动脉可逆转酒精诱导的这些血管功能障碍，在体内给予PA可逆转FASD生长缺陷。我们的数据还确定了内皮型一氧化氮合酶(ENOS)和mTORC1信号在这个酒精/peth/PA框架中的作用。在目标1中，我们假设在我们的FASD模型中，PA在酒精介导的血管扩张缺陷以及母体子宫和发育中的颅脑动脉中相关的eNOS途径中起主要作用，酒精通过PA介导的mTORC1系统改变损害了NO系统。在体外机械性阻断PA、mTORC1和相关信号之后，我们将评估子宫和发育的颅脑定向 使用动脉造影术、LC-MS/MS、免疫印迹、免疫荧光、RNA-SEQ、RT-PCR和膜片钳的动脉适应性。在目标2中，我们假设在体内给予PA可以逆转酒精引起的子宫动脉和胎儿颅底血流量的下降，并改善胎儿的营养物质输送、生长表型和酒精敏感神经生物学结果的缺陷。我们将测量生长指数、子宫血流量、子宫氧气/营养物质输送、胎儿颅脑定向血流和神经元功能/形态，以评估PA在两种主要FASD结果的病因学中的作用。我们预计，拟议的实验将在FASD领域提供亟需的突破，确定FASD生长和/或神经发育的有前景的病因学分子途径(S)。 赤字。这些研究将为未来新的预防/治疗研究铺平道路，这些研究旨在通过操纵直接酒精靶点来挽救FASD的主要结果表型。

Fetal Alcohol Spectrum Disorders (FASD) affects an estimated 2–5% of young school age children in the U.S., with an estimated cost of $1.4 million per individual. Two cardinal outcomes of FASD are fetal growth restriction and neurodevelopmental deficits. Efforts to successfully prevent or ameliorate these teratogenic effects of alcohol abuse have been impeded by a limited understanding of alcohol’s complex mechanisms of action, which impact multiple organ systems. In addition, etiological reports on FASD outcomes have been mostly limited to investigating indirect downstream mediators. We propose the molecular pathway governing phosphatidylethanol (PEth; 100% specific, most sensitive biomarker for gestational alcohol exposure) formation can yield novel insights into FASD etiology, as during alcohol metabolism, phosphatidylcholine is hydrolyzed to PEth instead of phosphatidic acid (PA, an essential nutrient for growth/neuron development). In an established FASD model, our novel preliminary data shows alcohol decreases PA bioavailability and concurrently increases PEth levels in maternal and fetal compartments. Our data also show alcohol-induced impairment of maternal uterine artery (related to fetal growth) and fetal brain vascular (related to neurodevelopmental outcomes) adaptations. Interestingly, PA addition in vitro to the uterine and middle cerebral arteries reverses alcohol-induced dysfunction in these vessels, and in vivo PA administration reverses FASD growth deficit. Our data also identify a role for endothelial nitric oxide (NO) synthase (eNOS) and mTORC1 signaling in this alcohol/PEth/PA framework. In Aim #1, we hypothesize that in our FASD model, PA plays a major role in alcohol-mediated vasodilatory deficits and the related eNOS pathway in maternal uterine and developing cranially directed arteries, and that alcohol impairs the NO system via PA-mediated mTORC1 system alteration. Following mechanistic in vitro blockade of PA, mTORC1, and related signaling, we will assess uterine and developing cranially directed arterial adaptations using arteriography, LC-MS/MS, immunoblotting, immunofluorescence, RNA-seq, RT-PCR, and patch clamp. In Aim#2, we hypothesize PA administration in vivo reverses alcohol-induced decreases in uterine artery and fetal cranially directed blood flow, and improves fetal nutrient delivery, growth phenotypes, and deficits in alcohol-sensitive neurobiological outcomes. We will measure growth indices, uterine blood flow, uterine O2/nutrient delivery, fetal cranially directed blood flow, and neuronal function/morphology to assess the role of PA in the etiology of two cardinal FASD outcomes. We anticipate that the proposed experiments will provide a much-needed breakthrough in the FASD field by identifying a promising etiological molecular pathway(s) for FASD growth and/or neurodevelopmental deficits. These studies will pave way for future novel prevention/treatment studies strategically aimed at rescuing FASD cardinal outcome phenotypes through manipulation of direct alcohol targets.