MicroRNAs as Biomarkers of Exposure and Effect in Fetal Alcohol Spectrum Disorders

 描述（申请人提供）：胎儿酒精谱系障碍（FASD）的诊断在婴儿期和许多受影响的非综合征儿童中是困难的，这些儿童没有表现出面部红斑。已经开发出有前途的胎粪和血液代谢生物标志物。然而，这些暴露标志物只能适度预测不良反应，并且只能在有限的发育窗口期间获得的生物基质中进行测量。我们将评估循环血浆microRNA（cirmiRNAs）的生物标志物潜力，这些小的非蛋白质编码RNA分泌到血流中，可以在不同的出生后年龄获得，并可能作为内分泌因子。PI米兰达及其同事发现，在子宫内母体酒精暴露导致新生绵羊的cirmiRNAs表达模式改变，包括先前鉴定的乙醇敏感性miRNA，miR-9，其消融导致斑马鱼表型与产前酒精暴露中观察到的相似。基于这些临床前数据，我们假设产前酒精暴露会导致人类cirmiRNA表达模式的改变，这可能可以作为暴露的生物标志物，并且产前酒精暴露改变的特定cirmiRNA也将作为胎儿酒精相关缺陷的生物标志物神经发育和/或生长。为了验证这一假设，我们建议在南非开普敦的开普敦有色人种（混合血统）人群中的一个独特的酒精暴露婴儿队列中筛选cirmiRNA生物标志物，该人群是全球胎儿酒精综合征发病率最高的人群之一。PI Jacobson及其同事目前正在对该人群的婴儿进行研究，其中包括在怀孕期间前瞻性获得的详细的母亲饮酒量访谈，由畸形专家进行的FASD诊断，新生儿结构MRI数据，身体生长测量以及6.5和12个月的认知评估。产后在2周时，将从该队列的30-35名重度暴露婴儿和30-35名对照婴儿中获得血浆样品用于miRNA谱分析。6.5个月产后使用实时PCR阵列，我们将尝试识别区分酒精暴露婴儿和对照婴儿的cirmiRNAs谱。然后，我们将确定酒精暴露改变的cirmiRNAs是否能预测胎儿酒精相关的发育结果，包括较小的出生尺寸，结构性脑异常，认知功能较差和FASD诊断。该提案解决了开发产前酒精暴露和新生儿期及以后获得的样本的影响的诊断生物标志物的迫切需要。它响应PA-13-197，“细胞外RNA在介导酒精对健康影响中的作用”，其特别关注生物标志物的开发。FASD中独特的cirmiRNAs谱的证据有可能揭示新的内分泌机制介导胎儿酒精暴露的影响，这可能为开发新的治疗方法提供基础。

 DESCRIPTION (provided by applicant): Diagnosis of fetal alcohol spectrum disorders (FASD) is difficult in infancy and in the many affected nonsyndromal children, who do not manifest facial stigmata. Promising meconium- and blood-based metabolic biomarkers have been developed. However, these markers of exposure are only moderately predictive of adverse effects and are measured in biological substrates that can be obtained only during limited developmental windows. We will assess the biomarker potential of circulating plasma microRNAs (cirmiRNAs), small non-protein-coding RNAs that are secreted into the blood stream, can be acquired at different postnatal ages, and may serve as endocrine factors. PI Miranda and colleagues have found that in utero maternal alcohol exposure leads to an altered expression pattern of cirmiRNAs in newborn sheep, including a previously identified ethanol-sensitive miRNA, miR-9, the ablation of which leads to a zebra fish phenotype similar to that seen in prenatal alcohol exposure. Based on these pre-clinical data, we hypothesize that prenatal alcohol exposure leads to an altered expression pattern of cirmiRNAs in humans that may serve as a biomarker for exposure and that specific cirmiRNAs altered by prenatal alcohol exposure will also serve as biomarkers for fetal alcohol-related deficits in neurodevelopment and/or growth. To test this hypothesis, we propose to screen for cirmiRNA biomarkers in a unique cohort of alcohol-exposed infants from the Cape Colored (mixed ancestry) population in Cape Town, South Africa, which has among the highest worldwide incidence of fetal alcohol syndrome. PI Jacobson and colleagues are currently conducting a study of infants from this population, which includes detailed maternal alcohol consumption interviews obtained prospectively during pregnancy, FASD diagnosis by expert dysmorphologists, neonatal structural MRI data, physical growth measurements, and cognitive assessments at 6.5 and 12 mo. postpartum. Plasma samples will be obtained for miRNA profiling from 30-35 heavily exposed and 30-35 control infants from this cohort at 2 wk. and 6.5 mo. postpartum. Using real-time PCR arrays, we will attempt to identify a profile of cirmiRNAs that distinguish alcohol-exposed infants from controls. We will then determine whether the cirmiRNAs that are altered by alcohol exposure predict fetal alcohol-related developmental outcomes, including smaller birth size, structural brain anomalies, poorer cognitive function, and FASD diagnosis. This proposal addresses a critical need for developing diagnostic biomarkers for both prenatal alcohol exposure and effect from samples acquired during and beyond the neonatal period. It is responsive to PA-13-197, "The Role of Extracellular RNA in Mediating the Health Effects of Alcohol," with its specific focus on biomarker development. Evidence of distinctive cirmiRNAs profiles in FASD has potential to uncover novel endocrine mechanisms mediating effects of fetal alcohol exposure that may provide the basis for development of novel therapies.