Unraveling epigenetic mechanisms of opioid addiction susceptibility using multigenerational animal models

吸毒成瘾是一个巨大的公共卫生问题，给我们的生活造成了广泛的负担。 经济和社会。滥用毒品的有害后果远远超出了吸毒者的范围 严重影响他们的家庭越来越多的证据表明， 在怀孕期间服用药物的父亲表现出大脑功能的改变， 行为异常我们已经建立了一个高度翻译的范式， 给药后，采用吗啡自身给药的大鼠研究这一现象。我们的结果 证明长期服用吗啡的父亲（父系）的雄性后代比那些长期服用吗啡的雄性后代更容易受到影响。 易产生成瘾样特征并自行施用吗啡。这几代人 动物模型提供了一个罕见的窗口，让我们了解更容易发展的受试者群体。 成瘾，这是一个历史上很难识别的人群。在这里，我们可以可靠地和 系统地生产出表现出增加吸毒行为的动物，这提供了一种独特的 有机会深入研究成瘾易感性的潜在机制。这一多方面 该项目将结合联合收割机行为和分子生物学方法，以确定功能 相关的机制，赋予更高的倾向发展成瘾。 拟议的研究将解决两个主要问题：（1）哪些生殖系表观遗传 重编程事件对于形成成瘾脆弱性的发展至关重要， 成年？(2)哪些功能相关的神经表观遗传过程， 在我们的多代吸毒模型中出现类似成瘾的行为？这项建议会 通过鉴定精子miRNA表达和DNA的变化来描绘成瘾的生物标志物 甲基化导致的慢性父亲吗啡暴露。我们假设阿片类药物- 衍生的精子分子特征是成瘾易感性的预测， 后代我们将直接测试这种可能性，通过评估特定的功能相关性， 精子甲基标记和个体精子miRNA在塑造神经发育向更高水平发展中的作用 成年动物的服药和药物强化功效提高。我们还将探测共价键 在成年吗啡家系中， 显示吸毒增加的后代。基因靶向表观遗传编辑将用于 描述了在神经奖赏回路中调节药物服用行为的组蛋白标记。这 研究将建立一种策略来描述与成瘾相关的功能机制 易感性，并建立一个平台，研究环境侮辱如何塑造和影响 个人发展为精神疾病的可能性。

Drug addiction is a massive public health concern that inflicts extensive burdens on our economy and society. The harmful consequences of drug abuse extend far beyond the addicts and gravely impact their families. A growing body of evidence suggests that the children of fathers who consumed drugs around the time of conception show altered brain function and behavioral abnormalities. We have established a highly translational paradigm of paternal opioid drug taking, using morphine self-administration in rats to study this phenomenon. Our results demonstrate that the male progeny of fathers (sires) that took morphine chronically are more susceptible to develop addiction-like traits and self-administer morphine. This multigenerational animal model offers a rare window into a pool of subjects that are more vulnerable to develop addiction, a population that has been historically difficult to identify. Here, we can reliably and systematically produce animals that show increased drug taking behavior, which offers a unique opportunity to delve into the mechanisms underlying addiction susceptibility. This multifaceted project will combine behavioral and molecular biological approaches to identify functionally relevant mechanisms that confer a higher propensity to develop addiction. The proposed studies will address two major questions: (1) which germline epigenetic reprogramming events are critical for shaping development toward addiction vulnerability into adulthood? (2) what are the functionally relevant neuro-epigenetic processes that increase addiction-like behavior in our multigenerational model of drug taking? This proposal will delineate biomarkers of addiction by identifying changes in sperm miRNA expression and DNA methylation caused by chronic paternal morphine exposure. We hypothesize that the opioid- derived sperm molecular signature is predictive of addiction susceptibility in the resulting progeny. We will directly test this possibility by assessing the functional relevance of specific sperm methyl marks and individual sperm miRNAs in shaping neurodevelopment toward higher drug taking and elevated drug reinforcing efficacy in adult animals. We will also probe covalent modifications of nuclear histone proteins that package DNA in the brains of adult morphine-sired progeny that show increased drug taking. Gene-targeted epigenetic editing will be used to characterize histone marks that regulate drug taking behavior in neural reward circuits. This research will establish a strategy to delineate functional mechanisms associated with addiction susceptibility and develop a platform to study how environmental insults can shape and affect the likelihood of individuals to develop psychiatric diseases.