Multigenerational Epigenetic Effects of Cannabis Exposure

描述（由申请人提供）：大麻（大麻sativa）是美国青少年和育龄年轻人最常滥用的非法药物，具有重大的社会和公共卫生影响。虽然研究工作已经开始描述直接反复接触大麻的行为和神经生物学后果，但对多代人的可能影响尚不清楚。我们实验室获得的初步数据表明，父母在青少年时期接触过d -四氢大麻酚（THC；大麻的主要精神活性成分）的成年大鼠表现出动机降低和抑郁样表型，以及与焦虑相关的行为，这些行为是对海洛因摄入量增加的倾向的反应。此外，雄性和雌性F1后代纹状体中编码多巴胺、阿片样物质和谷氨酸神经递质系统的基因表达减少。雌性F1后代往往有更严重的障碍，强调了性别的重要性，这可能与精神疾病中所见的性别差异有关。本研究的目的是通过转录组测序来表征具有四氢大麻酚暴露史的父母F1后代伏隔核（NAc）的整个mrna群体，并研究全基因组DNA甲基化和染色质修饰，以确定该中边缘脑区域跨代干扰的表观遗传环境。分子研究将与行为测试相结合，以评估F1雄性和雌性的奖励、抑郁和焦虑行为。我们将在NAc中使用体内基因操作来解决基因表达障碍和特定行为表型之间的因果关系。为了确定是否存在持续的跨代遗传，在F1代中显示受损的表型和表观遗传标记将被跟踪到F2后代中。总的来说，这些研究将为大麻暴露的跨代影响提供基本的机制见解，可以指导与成瘾和精神疾病易感性相关的行为表型谱的治疗干预措施的发展。

DESCRIPTION (provided by applicant): Marijuana (Cannabis sativa) is the most commonly abused illicit drug by teens and young adults of childbearing age in the USA with significant social and public health implications. While research efforts have begun to characterize the behavioral and neurobiological consequences of direct repeated exposure to cannabis, the possible impact across multiple generations is not known. Preliminary data obtained in our lab suggests that adult rats from parents with adolescent exposure to D-tetrahydrocannabinol (THC; primary psychoactive component of cannabis) exhibit reduced motivation and a depression-like phenotype, as well as anxiety-related behaviors that develop in response to their tendency for increased heroin intake. In addition, both male and female F1 offspring show decreased striatal expression of genes that encode several components of the dopamine, opioid and glutamate neurotransmitter systems. Female F1 offspring tended to have more significant disturbances, emphasizing the importance of gender that could potentially be relevant to sex differences seen in psychiatric disorders. The goal of this proposal is to characterize the whole population of mRNAs in the nucleus accumbens (NAc) of F1 offspring from parents with a history of THC exposure by transcriptome sequencing, as well as to study whole genome DNA methylation and chromatin modifications to identify the epigenetic milieu underlying the cross- generational disturbances in this mesolimbic brain region. The molecular studies will be combined with behavioral tests to assess reward-, depression- and anxiety-like behaviors in F1 males and females. We will address the causality between gene expression impairments and specific behavioral phenotypes using in vivo gene manipulations in the NAc. In order to determine whether there is persistent transgenerational transmission, phenotypic and epigenetic marks shown to be impaired in the F1 generation will be followed into the F2 progeny. Overall, these studies will provide fundamental mechanistic insights into the cross-generational impact of cannabis exposure that could guide the development of therapeutic interventions for the spectrum of behavioral phenotypes associated with vulnerability to addiction and psychiatric disorders.