Clinical Genomics and Experimental Therapeutics

临床基因组学和实验治疗学

• 批准号: 10008618
• 负责人: Falk Lohoff
• 金额: $ 295.68万
• 依托单位: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10008618
• 关键词: Acceleration; Addictive Behavior; Address; Affect; Age; Aging; Alcohol consumption; Alcohol dependence; Alcohols; Algorithms; Anhedonia; Animal Model; Anxiety; Autopsy; Behavior; Behavior Disorders; Biological; Blood; Blood Cells; Brain; Brain region; Chronic; Chronology; Clinical; Clinical Protocols; Clinical Research; Cognitive; Collaborations; Complex; DNA; DNA Methylation; Data; Data Analyses; Data Set; Development; Disease; Early-life trauma; Emotional; Emotions; Environment; Environmental Risk Factor; Enzymes; Epigenetic Process; Exhibits; Extinction (Psychology); Feeling hopeless; Fright; Gender; Genes; Genetic; Genetic Heterogeneity; Genome; Genomics; Goals; Heavy Drinking; Hepatocyte; Heritability; Human; Individual; Intervention; Investigation; Investigational Therapies; LDL Cholesterol Lipoproteins; Learning; Liquid substance; Liver; Low-Density Lipoproteins; Malaise; Medial; Medical Genetics; Medicine; Methylation; Modality; Modeling; Molecular; Moods; Motivation; Nature; Negative Reinforcements; Neurobiology; Pain; Pathway interactions; Patients; Phenotype; Pre-Clinical Model; Predisposition; Prefrontal Cortex; Prevention strategy; Process; Proprotein Convertases; Protocols documentation; Public Health; Race; Recording of previous events; Recruitment Activity; Regulation; Relapse; Research; Rewards; Risk; Role; Sample Size; Sampling; Site; Stress; Subtilisins; System; Techniques; Testing; Time; Tissues; Translational Research; Variant; Whole Blood; Withdrawal; addiction; alcohol exposure; alcohol use disorder; biological adaptation to stress; cohort; drinking; drug of abuse; dysphoria; early life stress; epigenetic regulation; epigenome; epigenome-wide association studies; experience; genetic risk factor; genome-wide analysis; interest; lipid metabolism; methylomics; mortality; negative affect; negative emotional state; neuroimaging; novel; persistent symptom; protein expression; receptor; relapse risk; response; trend

We performed a cross-tissue and cross-phenotypic analysis of genome wide methylomic variation in AUD using samples from independent cohorts involving post-mortem brain, blood, liver tissue, and various clinical and neuroimaging phenotypes with the goal of identifying disease-associated methylomic DNA variations. Results show that the gene encoding the enzyme Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) was the primary target of epigenetic changes relevant to AUD across data sets (Lohoff et al, 2018). PCSK9 is predominantly expressed in the liver where it is synthesized and secreted. It targets low-density lipoprotein cholesterol receptors (LDL-R) in the liver cells and interferes with the regulation of LDL cholesterol (LDL-C) in the blood. Epigenetic regulation of PCSK9 expression by alcohol consumption is one potential mechanism to explain lipid metabolism abnormalities found in patients with heavy alcohol use. We continued and expanded on research related to PCSK9 and have several ongoing collaborations with Dr. L. Vendruscolo, Dr. G. Koob, Dr. B. Gao, and Dr. P. Pacher. The collaborations have resulted in the development of a novel animal model of liquid alcohol exposure that more closely resembles alcohol use in humans. In addition, various molecular characterizations have been conducted and are ongoing. Several human clinical studies are being developed. On clinical exam, individuals with AUD often appear older than stated age, suggesting that excessive alcohol consumption might accelerate aging. Studies have shown that individuals with AUD die earlier than healthy controls and are at a significantly increased risk for all-cause mortality 130, 131. Given the potential role of AUD in the aging process, it is important to understand this relationship on a molecular, epigenetic level. To better assess biological age, Hannum and Horvath developed epigenetic clocks that robustly correlate with chronological age 132, 133. These clocks are algorithms that take the weighted average of methylation levels at specific CpG sites to calculate DNA methylation age (DNAm age), which is highly correlated with chronological age. Given our interest in epigenetic regulation in AUD, we hypothesized that individuals with AUD have accelerated biological/epigenetic age. To test this hypothesis, we leveraged our existing data sets and collaborated with Dr. Steve Horvath (UCLA), the inventor of the epigenetic clock. We explored this question in five independent cohorts, including DNA methylation data derived from datasets from blood (n=129, n=329), liver (n=92; n=49), and postmortem prefrontal cortex (n=46). One blood dataset and one liver tissue dataset of individuals with ALC exhibited positive age acceleration (p<0.0001 and p=0.0069, respectively), while the other blood and liver tissue datasets both exhibited trends of positive age acceleration that were not significant (p=0.83 and p=0.57, respectively). Prefrontal cortex tissue exhibited a trend of negative age acceleration (p=0.19) 134. These results warrant further investigation into the role of chronic, heavy alcohol consumption in the aging process in a larger sample while controlling for potential confounds, such as race, gender, and blood cell composition (for whole blood). Another interest of CGET is to investigate the molecular mechanisms of negative affective states and how they contribute to the addiction cycle. Negative emotional states contribute to worsening of the addiction cycle and increase risk for relapse (Ahmed and Koob, 1998; George et al, 2014; Koob, 2015). The withdrawal/negative affect stage in humans is often characterized by symptoms of chronic irritability, physical pain, emotional pain, malaise, dysphoria, anhedonia, hopelessness, and loss of motivation for natural rewards. It is hypothesized that the brain attempts to overcome this state by activating the stress-response system (Koob and Le Moal, 2008), as evidenced by dysregulation of the HPA axis and CRF by all major drugs of abuse. In addition, there is strong evidence that anxiety-like responses occur that are modulated by CRF (Koob, 2015). Not much is known with regard to emotional cognitive processing during this addiction stage, and limited data exist regarding emotional learning as a consequence of negative reinforcement. Brain regions involved in negative emotion processing and learning tend to be located, and perhaps overlap, in the medial prefrontal cortex (mPFC), as shown in previous neuroimaging studies (Lissek et al, 2014; Lohoff et al, 2014; Mickey et al, 2011; Phelps et al, 2004). One hypothesis is that individuals, with a history of trauma/early life stress (ELS), might have a harder time unlearning negative emotional states, including low moods and anxiety. Thus, alcohol provides temporary relief initially. However, as the addiction cycle progresses, individuals experience more negative emotions related to withdrawal that they cannot unlearn and thus continue drinking to alleviate negative emotions despite negative consequences. Better understanding the underlying neurocircuitries and molecular mechanisms of negative emotion processing associated with alcohol addiction, including genetic and epigenetic contributors, is crucial for the development of novel interventions and effective prevention strategies. To investigate this, our sections human clinical protocol 15-AA-0127: (Epi)Genetic modulators of fear extinction in alcohol dependence was developed and is actively recruiting. This protocol aims to investigate underlying neurobiology and neurocircuitries of fear extinction in individuals with AUD with and without ELS.

我们使用来自独立队列的样本对AUD的全基因组甲基化变异进行了跨组织和跨表型分析，这些样本涉及死后脑、血液、肝组织以及各种临床和神经影像学表型，目的是鉴定疾病相关的甲基化DNA变异。结果表明，编码前蛋白转化酶枯草杆菌蛋白酶/Kexin 9（PCSK 9）的基因是数据集中与AUD相关的表观遗传变化的主要靶点（Lohoff et al，2018）。PCSK 9主要在肝脏中表达，在肝脏中合成和分泌。它靶向肝细胞中的低密度脂蛋白胆固醇受体（LDL-R），并干扰血液中LDL胆固醇（LDL-C）的调节。饮酒对PCSK 9表达的表观遗传调节是解释重度饮酒患者脂质代谢异常的一种潜在机制。我们继续并扩大了与PCSK 9相关的研究，并与L. Vendruscolo，G博士。Koob，B博士。Gao和P. Pacher博士。这些合作导致了一种新型的液体酒精暴露动物模型的开发，该模型更接近于人类的酒精使用。此外，已进行并正在进行各种分子表征。目前正在开展多项人体临床研究。 在临床检查中，患有AUD的人往往比规定的年龄大，这表明过量饮酒可能会加速衰老。研究表明，患有AUD的个体比健康对照组死亡早，并且全因死亡率的风险显着增加130，131。鉴于AUD在衰老过程中的潜在作用，在分子和表观遗传水平上理解这种关系是很重要的。为了更好地评估生物年龄，Hannum和Horvath开发了与实足年龄密切相关的表观遗传时钟132，133。这些时钟是采用特定CpG位点甲基化水平的加权平均值来计算DNA甲基化年龄（DNA年龄）的算法，该年龄与实际年龄高度相关。鉴于我们对AUD的表观遗传调控的兴趣，我们假设AUD个体具有加速的生物/表观遗传年龄。为了验证这一假设，我们利用了现有的数据集，并与表观遗传时钟的发明者Steve Horvath博士（加州大学洛杉矶分校）合作。我们在五个独立的队列中探索了这个问题，包括来自血液（n=129，n=329），肝脏（n=92; n=49）和死后前额皮质（n=46）数据集的DNA甲基化数据。ALC患者的一个血液数据集和一个肝脏组织数据集显示出正的年龄加速（分别为p<0.0001和p=0.0069），而其他血液和肝脏组织数据集都显示出不显著的正的年龄加速趋势（分别为p=0.83和p=0.57）。前额叶皮层组织表现出负年龄加速的趋势（p=0.19）134。这些结果需要进一步研究慢性重度饮酒在更大样本中的衰老过程中的作用，同时控制潜在的混淆，如种族，性别和血细胞组成（全血）。 CGET的另一个兴趣是研究负性情感状态的分子机制以及它们如何促进成瘾循环。负面情绪状态会导致成瘾周期恶化，并增加复发风险（Ahmed和Koob，1998;乔治et al，2014; Koob，2015）。人类的退缩/负面情绪阶段通常以慢性易怒、身体疼痛、情绪疼痛、不适、烦躁不安、快感缺乏、绝望和失去自然奖励的动机的症状为特征。据推测，大脑试图通过激活应激反应系统来克服这种状态（Koob和Le Moal，2008），如所有主要滥用药物引起的HPA轴和CRF失调所证明的。此外，有强有力的证据表明，焦虑样反应的发生受到CRF的调节（Koob，2015）。 关于这个成瘾阶段的情绪认知过程知之甚少，关于情绪学习作为负强化的结果的数据有限。参与负面情绪处理和学习的大脑区域往往位于内侧前额叶皮层（mPFC），并且可能重叠，如之前的神经成像研究所示（Lissek et al，2014; Lohoff et al，2014; Mickey et al，2011; Phelps et al，2004）。一种假设是，有创伤/早期生活压力（ELS）史的人可能更难忘记消极的情绪状态，包括情绪低落和焦虑。因此，酒精最初提供了暂时的缓解。然而，随着成瘾周期的进展，个体会经历更多与戒断相关的负面情绪，他们无法忘记，因此继续饮酒以减轻负面情绪，尽管会产生负面后果。更好地了解与酒精成瘾相关的负面情绪处理的潜在神经回路和分子机制，包括遗传和表观遗传因素，对于开发新型干预措施和有效的预防策略至关重要。为了研究这一点，我们开发了人类临床方案15-AA-0127：（Epi）酒精依赖中恐惧消退的遗传调节剂，并正在积极招募。该方案旨在研究伴有和不伴有ELS的AUD个体中恐惧消退的潜在神经生物学和神经回路。