Prenatal microRNA neuro-therapeutics for fetal alcohol exposure

 描述(由申请人提供)：由于意外怀孕和酗酒模式在美国的普遍存在，孕妇在怀孕早期饮酒很难预防。暴露在怀孕前三个月是常见的，此时神经干细胞(NSCs)开始产生神经元，增加了神经发育障碍的风险。有一个迫切的，尚未得到满足的生物医学干预需求，以减轻酒精暴露的影响。缺乏这样的干预措施意味着，我们几乎无法帮助后来因胎儿酒精暴露而寻求产前护理的妇女。我们的长期目标是找到方法来减轻乙醇等致畸物质对大脑的损害。我们逆转乙醇影响的方法集中在产前干预，以操纵残留的胎儿神经干细胞的生长潜力。这一方法是基于我们的关键发现，即乙醇不会杀死神经干细胞，但会促进早熟。一类小的调控RNA，miRNAs，介导了许多这些乙醇效应。乙醇解除了miRNA(miR153，miR335)对分化促进转录因子(NdTF)的控制，如NfiA、NFIB和NeuroD1，导致NSCs过早表达ndTF。此外，烟碱型乙酰胆碱受体(NAChR)激动剂可以阻止甚至逆转乙醇对miRNAs及其靶向ndTf的影响。总而言之，这些数据支持两个假设：(1)乙醇通过干扰miRNA-ndTF网络来耗尽NSC，从而防止NSC过早成熟；(2)miRNAs和nAChR激动剂都可以防止甚至逆转胎儿酒精暴露的影响。目标1将确定促进乙醇对神经干细胞自我更新和成熟影响的关键ndTF，而目标2将确定阻止乙醇影响的关键miRNAs。目的3将确定控制miRNA-ndTF网络和防止乙醇介导的神经干细胞丢失的药理学干预措施。我们将评估nAChR对NSC更新和成熟的直接影响(即，varenicline暴露)，以及ndTF和miRNA介导的nAChR激活对NSC更新和成熟的影响。在这些目标中，我们将使用创新的病毒介导策略来操纵ndTF和miRNAs，以及一种新的小鼠可诱导报告模型来追踪受影响的NSCs及其子代。这项建议意义重大，因为它是 期望为一种新的方法奠定理论和实验框架，以解决未得到满足的修复性胎儿治疗以预防FASD的需求。它具有创新性，因为它提出了一个新的概念模型，将细胞靶点(miRNA-ndTF网络)与治疗方法(varenicline和nAChR药理学)联系起来，以重新编程酒精暴露后的神经发生。作为这些研究的结果，我们希望确定核心分子和药理学方法，以修复暴露于一种强大而常见的致畸物质酒精后的胎儿损伤。

 DESCRIPTION (provided by applicant): Maternal alcohol consumption during early pregnancy is difficult to prevent due to the prevalence of both unplanned pregnancies and binge patterns of alcohol consumption in the US. Exposure is common during the 1st trimester, when neural stem cells (NSCs) begin producing neurons, increasing the risk for neurodevelopmental disability. There is a critical, un-met need for biomedical interventions to mitigate effects of alcohol exposure. A lack of such interventions means that we can do little to help women who subsequently seek prenatal care for fetal alcohol exposure. Our long-term goal is to find ways to mitigate brain damage due to teratogens like ethanol. Our approach to reversing ethanol's effects focuses on intervening prenatally to manipulate the growth potential of residual fetal NSCs. This approach is based on our key findings that ethanol does not kill NSCs, but promotes premature maturation. A class of small regulatory RNAs, miRNAs, mediates many of these ethanol effects. Ethanol deregulates miRNA (miR153, miR335) control of differentiation-promoting transcription factors (ndTFs) like Nfia and Nfib and NeuroD1, resulting in premature ndTF expression in NSCs. Moreover, nicotinic acetylcholine receptor (nAChR) agonists can prevent and even reverse effects of ethanol on miRNAs and their target ndTFs. Collectively, these data support two hypotheses: (1) ethanol depletes NSCs by interfering with miRNA-ndTF networks that prevent premature NSC maturation, and (2) both miRNAs and nAChR agonists prevent and perhaps even reverse effects of fetal ethanol exposure. Aim 1 will identify key ndTFs that facilitate ethanol effects on NSC self-renewal and maturation while Aim 2 will identify key miRNAs that block ethanol effects. Aim 3 will identify pharmacological interventions that control miRNA-ndTF networks and prevent ethanol- mediated loss of NSCs. We will assess direct nAChR effects (i.e., varenicline exposure), as well as ndTF- and miRNA-mediated effects of nAChR activation, on NSC renewal and maturation. In these aims, we will manipulate ndTFs and miRNAs with innovative viral-mediated strategies, and a novel murine inducible reporter model to track affected NSCs and their daughter progeny. This proposal is significant in that it is expected to lay the theoretical and experimental framework for a new approach to address the un-met need for reparative fetal therapy to prevent FASD. It is innovative because it advances a novel conceptual model that links a cellular target (miRNA-ndTF networks) to a therapeutic approach (varenicline and nAChR pharmacology), to reprogram neurogenesis in the aftermath of alcohol exposure. As an outcome of these studies we expect to identify core molecular and pharmacological approaches to repair fetal damage following exposure to a potent and common teratogen, alcohol.