Regulation of Nutrient Sensing and Muscle Wasting by Alcohol

酒精对营养感应和肌肉消耗的调节

基本信息

批准号：
9320058
负责人：
CHARLES H. LANG
金额：
$ 34.81万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-05 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9320058
关键词：
Acute Address Adult Alcohol abuse Alcoholic Intoxication Alcohols Amino Acids Area Autophagocytosis Binding Biochemical Cells Chronic Complex Data Degradation Pathway Development Doxycycline Electroporation Environment FRAP1 gene Face Female Funding Future Genetic Goals Growth Factor Guanosine Triphosphate Phosphohydrolases Health Hormones Impairment In Vitro Instruction Intoxication Knockout Mice Knowledge Laboratories Leucine Mediating Membrane Methods Modeling Molecular Mus Muscle Muscle Cells Muscle Fibers Muscle Proteins Muscular Atrophy Myopathy Nutrient Nutritional Outcome Pathology Pathway interactions Pharmacology Phase Phosphorylation Phosphotransferases Physiological Postdoctoral Fellow Protein Biosynthesis Protein Phosphatase 2A Regulatory Subunit PR53 Proteins Proteomics Public Health Publications Publishing Raptors Reagent Recruitment Activity Regulation Rehabilitation therapy Research Resistance Seminal Signal Transduction Skeletal Muscle Societies System Time Training Work alcohol availability alcohol effect alcohol research alcohol use disorder alcoholic myopathy base binge drinking chronic alcohol ingestion clinically significant detection of nutrient economic cost experimental study in vivo innovation insight knock-down male mortality mouse model novel overexpression premature protein complex response small hairpin RNA therapeutic target tool trafficking

项目摘要

Muscle wasting is a hallmark of sustained alcohol abuse and the associated weakness represents the most common form of skeletal muscle myopathy. Over the past 4 years we have used genetic, biochemical and pharmacological approaches, both in vivo and in vitro, to generate definitive evidence pertaining to the mechanisms by which acute alcohol intoxication (binge drinking) and chronic alcohol consumption impair muscle protein synthesis under basal postabsorptive conditions and antagonize the anabolic response to amino acids and growth factors. The original 3 aims remain valid with experiments in the first phase of the R37 elucidating the cellular mechanisms by which alcohol down-regulates nutritional signals transduced via mTORC1-dependent and -independent transduction networks producing skeletal muscle myopathy, and comparing these to hormone- and contraction-induced regulation. Exceptional progress was made (27 publications) and the research environment leveraged for the successful training and F32 funding of a post- doctoral fellow who will continue in alcohol-related research. Our publications attest that the original aims have been largely achieved; although our new data also open previously unrecognized avenues of exploration. Unique tools have been developed that will permit us to identify and explore novel mechanisms and thereby validate specific proteins as therapeutic targets. Specific Aim 1 determined whether alcohol-induced changes in Deptor are responsible for the decrease in basal and leucine-stimulated muscle protein synthesis. This aim is now extended to investigate the relative importance of alcohol-induced changes in Deptor under in vivo conditions using our newly developed muscle-specific Deptor knockout mouse. Further, our new data reveal alcohol decreases the previously unrecognized binding of REDD1 with Deptor, a finding that will be expanded upon. Specific Aim 2 delineated the mechanism by which alcohol alters mTOR endosomal trafficking thereby impairing mTORC1 and protein synthesis. This aim will be continued by assessing alcohol-induced changes, with and without leucine, on Sestrin2 phosphorylation and binding with proteins of the GATOR2 complex. The goal of these experiments is to identify new components and modifiers governing the topology of mTORC1. Specific Aim 3 elucidated whether altered MAP4K3 signaling is in part responsible for alcohol-induced decreases mTORC1. These studies will be extended to examine the MAP4K3-dependent phosphorylation of Raptor that can function by mTORC1-dependent and -independent mechanisms. This R37 extension exploits innovative approaches, made possible by the availability of novel reagents and supported by our strong track record. While in vitro studies permit us to define cellular mechanisms and prioritize future work, state-of-the-art in vivo approaches permit us to definitively assign physiological importance – thus filling knowledge gaps. The expected outcomes will contribute translational knowledge on nutrient regulation and provide seminal mechanistic insights into the clinically significant pathology of alcohol-induced muscle disease. RELEVANCE (See instructions): Alcohol excess, both chronic abuse and acute intoxication, exacts a staggering economic cost to society and remains a major public health problem. Alcohol use disorder is associated not only with increased mortality, but also with premature and preventable health concerns, and impaired rehabilitation. Our study focuses on the cellular and molecular mechanisms by which excess alcohol impairs basal skeletal muscle protein synthesis and produces a resistance to the normal beneficial effects of nutrients, thereby leading to the development of alcoholic myopathy, one of the most prominent muscle diseases.

肌肉浪费是持续酒精滥用的标志，相关的弱点最多代表骨骼肌肌病的常见形式。在过去的四年中，我们使用了遗传，生化和在体内和体外的药理方法，以产生与急性酒精中毒（暴饮暴食）和长期饮酒障碍的机制肌肉蛋白质蛋白质在基本的降压条件下，并拮抗合成代谢反应氨基酸和生长因子。最初的3个目标在R37的第一阶段的实验中保持有效阐明酒精通过调节营养信号的细胞机制 MTORC1依赖性和非依赖性转移网络产生骨骼肌肌病，以及将它们与马和合同引起的调节进行比较。取得了出色的进步（27 出版物）和研究环境利用了成功的培训和F32资金博士研究员将继续与酒精有关的研究。我们的出版物证明了最初的目标尽管我们的新数据也开放了以前无法识别的探索途径。已经开发了独特的工具，可以使我们能够识别和探索新颖的机制，从而验证特定蛋白作为治疗靶标。特定目标1确定酒精引起的变化是否变化在DEPTOR中，负责碱性和亮氨酸刺激的肌肉蛋白合成的减少。这个目标现在扩展以调查酒精诱导的体内变化的相对重要性使用我们新开发的肌肉特异性敲除小鼠的条件。此外，我们的新数据揭示了酒精降低了先前未识别的Redd1与Deptor的结合，这一发现将扩大之上。特定目的2描述了酒精会改变MTOR内体贩运的机制损害MTORC1和蛋白质合成。通过评估酒精引起的变化，将继续此目标在有或没有亮氨酸的情况下，在Sestrin2磷酸化上并与Gator2复合物的蛋白质结合。这这些实验的目标是确定有关MTORC1拓扑的新组件和修饰符。特定的目标3阐明了是否改变了MAP4K3信号传导部分原因是酒精引起的减少mTORC1。这些研究将扩展以检查MAP4K3依赖性磷酸化的磷酸化可以通过MTORC1依赖性和非依赖性机制起作用的猛禽。此R37扩展利用创新的方法，通过新型试剂的可用性而成为可能，并在我们的强大轨道上支持记录。尽管体外研究使我们能够定义细胞机制并确定未来的工作，但最新的工作体内方法使我们能够明确地分配身体重要性，从而填补知识空白。这预期的结果将有助于养分调节的转化知识，并提供开创性对酒精引起的肌肉疾病的临床意义病理学的机械洞察力。相关性（请参阅说明）：酗酒超过了长期虐待和急性中毒，这对社会和仍然是一个主要的公共卫生问题。饮酒障碍不仅与死亡率增加有关而且还出于过早和可预防的健康问题，并康复受损。我们的研究重点超过酒精的细胞和分子机制会损害基本的骨骼肌蛋白合成并产生对养分正常有益作用的抵抗力，从而导致酗酒肌病的发展，是最突出的肌肉疾病之一。