Role of MicroRNAs in Fetal Alcohol Syndrome

描述（由申请人提供）：怀孕期间酗酒会严重影响胎儿发育，导致胎儿酒精综合征（FAS）。酒精尤其会损害发育中的大脑，导致小脑畸形、智力迟钝和多动症。FAS是导致智力迟钝的主要原因之一，是一个重大的公共卫生问题。在发育中的大脑中，神经元死亡是酒精最显著的病理效应之一，这种神经元的丧失是许多与该综合征相关的行为缺陷的基础。在脑生长突增期间，神经元对酒精引起的死亡特别敏感。脑生长突增是大脑快速生长的时期，在此期间，许多神经元通过延长神经突和形成突触连接而在形态上成熟。为什么发育中的神经元在大脑生长突增期间特别容易受到酒精的影响尚不清楚，但可能是由于酒精与调节神经元形态发育的基因表达模式之间的相互作用。microrna是一种小的非编码rna，通过控制许多基因的表达来调节中枢神经系统的发育。两个对大脑发育特别重要的microrna是microRNA-132 （miR-132）和miR-124，它们都在大脑中富集，并调节神经元的形态发生和神经突的生长。该提议的中心假设是，酒精通过干扰miR-132和miR-124的表达，破坏神经元成熟，使神经元容易受到酒精毒性的影响。因此，本提案的实验将集中在大脑发育过程中酒精与这些microrna之间的相互作用。在本提案中，我们将确定miR-132和miR-124的表达是否受发育调控，它们的表达水平是否与酒精易感性时期有关，以及酒精是否会影响它们的表达。我们还将确定miR-132和miR-124的实验操作是否会改变神经元形态和对酒精的易感性。我们将确定这些microrna的异位表达是否促进神经突生长并保护发育中的神经元免受酒精毒性。相反，我们将确定miR-132和miR-124的沉默是否会损害神经突的生长，并增加发育中的神经元对酒精诱导的细胞死亡的易感性。因此，这些研究将检查酒精对两种相关且重要的microrna的影响，并确定它们在成熟依赖性酒精抗性中的作用，这是FAS的一种重要现象。

DESCRIPTION (provided by applicant): Alcohol abuse during pregnancy can profoundly affect the developing fetus, resulting in fetal alcohol syndrome (FAS). Alcohol particularly damages the developing brain, leading to microencephaly, mental retardation, and hyperactivity. One of the leading causes of mental retardation, FAS is a major public health problem. In the developing brain, neuronal death is one of alcohol's most prominent pathologic effects, and this loss of neurons underlies many of the behavioral deficits associated with the syndrome. Neurons are particularly sensitive to alcohol-induced death during the brain growth spurt, a period of rapid brain growth, during which many neurons morphologically mature by extending neurites and forming synaptic connections. Why developing neurons are particularly vulnerable to alcohol during the brain growth spurt is unknown, but may be due to an interaction between alcohol and patterns of gene expression regulating neuronal morphological development. MicroRNAs are small, non-coding RNAs that regulate the development of the central nervous system by controlling the expression of many genes. Two microRNAs of particular importance to brain development are microRNA-132 (miR-132) and miR-124, both of which are enriched in brain and regulate neuronal morphogenesis and neurite outgrowth. The central hypothesis of this proposal is that alcohol disrupts neuronal maturation and renders neurons vulnerable to alcohol toxicity by interfering with miR-132 and miR-124 expression. Thus, the experiments of this proposal will focus on the interaction between alcohol and these microRNAs during brain development. In this proposal, we will determine whether miR-132 and miR-124 expression are developmentally regulated, whether their expression levels are related to periods of alcohol vulnerability, and whether alcohol affects their expression. We will also determine whether experimental manipulations of miR-132 and miR-124 alter neuronal morphology and vulnerability to alcohol. We will determine whether ectopic expression of these microRNAs promotes neurite outgrowth and protects developing neurons against alcohol toxicity. Conversely, we will determine whether silencing of miR-132 and miR-124 impairs neurite outgrowth and increases the vulnerability of developing neurons to alcohol-induced cell death. Thus, these studies will examine the effect of alcohol on two related and important microRNAs and determine their role in maturation-dependent alcohol resistance, a phenomenon of fundamental importance in FAS. PUBLIC HEALTH RELEVANCE: Alcohol abuse during pregnancy can profoundly affect the developing fetus, resulting in fetal alcohol syndrome (FAS). Alcohol damages the developing brain, leading to microencephaly, mental retardation, and hyperactivity. In this proposal we will examine the effect of alcohol on microRNAs, master switches that control the expression of several genes involved in the morphological maturation of neurons.