Circadian rhythms and alcohol in the BMAL1 knockout rat

项目总结 在美国，肝脏疾病是长期大量饮酒导致的头号死因。而当 饮酒剂量和饮酒时间是公认的疾病危险因素，其病因是明确的 酒精相关性肝病(ALD)的发病机制非常复杂，涉及许多尚不清楚的遗传、代谢和 环境因素。这种复杂性也可能解释了为什么治疗的有效疗法如此之少。 ALD.因此，酒精领域的一个主要悬而未决的问题是--还有哪些额外的环境因素， 酒精引起的肝脏病理需要代谢损伤和/或分子紊乱。 消费者？环境刺激、新陈代谢和细胞转录控制的重要时间整合因子 是昼夜节律系统。在细胞水平上，24小时昼夜节律是由转录-翻译驱动的 反馈循环系统。这种分子时钟机制涉及核心时钟基因的激活和许多 转录激活子BMAL1和CLOCK下游的时钟输出基因。这个分子钟 这种机制确保特定的细胞和生物过程在一天中的正确时间发生。积累 有证据表明，昼夜节律紊乱会恶化动物和人类的组织功能和损伤 饮酒。尽管有这些新的发现，但对这种情况如何发生的机械理解非常有限。 这项目前的提案涉及酒精毒性的一个关键靶点--线粒体。即使有多个 研究表明，酒精会严重损害线粒体的功能，目前还没有严格的研究 检测酒精中昼夜节律紊乱对肝脏线粒体功能时间控制的影响 消费者。我们假设昼夜节律紊乱加重了肝脏中与酒精相关的损伤。 线粒体的生物能量功能和增加组织损伤。为了验证这一假设，我们将使用一个令人兴奋的 新的动物模型，BMal1基因敲除大鼠-第一个全球时钟基因敲除的大鼠模型 CRISPR/Cas9基因组编辑技术。在目标1中，我们将确定BMal1在时间控制中的作用 酒精喂养大鼠24小时生理、代谢和分子节律的研究。在目标2中，我们将确定 BMal1与酒精相关的线粒体生物能障碍和肝损伤。成功完成这些任务 研究将提供有关昼夜节律系统和酒精对组织和 线粒体功能和病理学。从这项工作中获得的知识也有能力影响 多个科学领域，促进基于时间疗法的治疗患者的新方法的发展 患有酒精性肝病和其他相关肝病。

PROJECT SUMMARY Liver disease is the number one cause of death from long-term heavy alcohol drinking in the United States. While dose and duration of alcohol consumption are well-accepted risk factors for disease, it is clear that the etiology of alcohol-related liver disease (ALD) is highly complex, involving many still unknown genetic, metabolic, and environmental factors. This complexity also likely explains why there are so few effective therapies for treating ALD. Therefore, a major unanswered question for the alcohol field is – what additional environmental factors, metabolic impairments, and/or molecular disturbances are required for liver pathology to occur in the alcohol consumer? A vital temporal integrator of environmental stimuli, metabolism, and cellular transcriptional control is the circadian system. At the cellular level, 24-h circadian rhythms are driven by a transcriptional-translational feedback loop system. This molecular clock mechanism involves activation of core clock genes and many downstream clock-output genes by the transcriptional activators BMAL1 and CLOCK. This molecular clock mechanism ensures that specific cellular and biological processes occur at the correct time of day. Accumulating evidence shows that circadian rhythm disruption worsens tissue function and injury in animals and humans consuming alcohol. Despite these new findings, the mechanistic understanding of how this occurs is very limited. This current proposal addresses a critical target of alcohol toxicity – the mitochondrion. Even though multiple studies have shown that alcohol severely impairs mitochondrial function, there have not been rigorous studies examining the impact of circadian disruption on temporal control of hepatic mitochondrial function in the alcohol consumer. We hypothesize that circadian disruption worsens alcohol-related impairments in hepatic mitochondrial bioenergetic function and increases tissue injury. To test this hypothesis, we will use an exciting new animal model, the Bmal1 knockout rat – the first rat model of a global clock gene knockout developed with CRISPR/Cas9 genome editing technology. In Aim 1, we will determine the role of Bmal1 in the temporal control of 24-h physiologic, metabolic, and molecular rhythms in alcohol-fed rats. In Aim 2, we will determine the role Bmal1 in alcohol-related mitochondrial bioenergetic dysfunction and liver injury. Successful completion of these studies will provide novel information regarding the interaction of the circadian system and alcohol on tissue and mitochondrial function and pathology. The knowledge gained from this work also has the ability to influence multiple scientific fields and facilitate development of novel chronotherapy-based approaches for treating patients suffering from ALD and other related liver diseases.