Mechanisms of HIF1 alpha mediated dysregulated skeletal muscle proteostasis in alcoholic liver disease

HIF1α介导的酒精性肝病骨骼肌蛋白稳态失调的机制

基本信息

批准号：
10579341
负责人：
Nicole Welch
金额：
$ 17.91万
依托单位：
CLEVELAND CLINIC LERNER COM-CWRU
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-01 至 2026-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10579341
关键词：
Address Adverse effects Alcohol consumption Alcoholic Liver Cirrhosis Alcoholic Liver Diseases Alcohols Ammonia Autophagocytosis Award Biological Assay Biopsy Specimen Career Choice Chromatin Chronic Disease Cirrhosis Citric Acid Cycle Clinical Collaborations Complex Data Degradation Pathway Development Environment Ethanol Exposure to FRAP1 gene Fellowship Foundations Funding Genetic Transcription Goals HIF1A gene Heart failure Hepatic Human Hyperammonemia Hypoxia Hypoxia Inducible Factor Impairment In Vitro Institution Kidney Failure Label Link Liver diseases Mediating Mentors Metabolic Molecular Molecular Target Morbidity - disease rate Mus Muscle Muscle Fibers Muscle Proteins Muscular Atrophy National Institute on Alcohol Abuse and Alcoholism Ohio Outcome Oxygen Patients Phenotype Phosphotransferases Physicians Physiological Pilot Projects Post-Translational Protein Processing Pre-Clinical Model Prevalence Protein Biosynthesis Reporter Reporting Research Research Methodology Research Personnel Research Project Grants Scientist Signal Transduction Signaling Molecule Skeletal Muscle Stress Testing Time Tissues Training Translational Research Transposase United States Validation Work alcohol consequences alcohol exposure alcohol response alcohol testing alcohol use disorder alpha ketoglutarate biobank career development clinical training clinical translation clinically significant effective therapy experimental study gain of function hepatic ureagenesis in vivo inhibitor liver transplantation loss of function lung failure metabolic abnormality assessment mitochondrial dysfunction mortality muscle form muscle strength novel preservation programs proteostasis response sarcopenia skeletal muscle wasting targeted treatment therapeutically effective tissue injury transcription factor uptake

项目摘要

The prevalence of alcohol use disorders and consequent tissue injury, primarily alcoholic liver disease (ALD) continue to increase. Skeletal muscle loss or sarcopenia is a consistent abnormality in patients with ALD and is associated with adverse clinical outcomes that include increased mortality, other complications of liver disease and poor post-liver transplant outcomes. We have recently reported more severe muscle loss and a greater rate of muscle loss in patients with alcoholic cirrhosis compared with those in other causes of cirrhosis. Despite the high clinical significance of sarcopenia in ALD there are no effective therapeutic options because the underlying mechanisms are not well understood. We also reported that ethanol, directly and indirectly via impaired hepatic ammonia disposal and consequent hyperammonemia, results in a sarcopenic phenotype with dysregulated protein homeostasis (proteostasis). In preliminary studies, we have shown mitochondrial dysfunction in response to ethanol and hyperammonemia. We also noted that ethanol results in cataplerosis or loss of tricarboxylic acid (TCA) cycle intermediates, specifically α-ketoglutarate (αKG) an inhibitor of HIF1α. Consistently, unbiased approaches (assay for transposase accessible chromatin sequencing), and targeted experiments showed oxygen independent stabilization of muscle hypoxia inducible factor-1α (HIF1α) with ammonia. In pilot studies, we observed an increased expression of REDD1, a transcriptional target of HIF1α and a negative regulator of the mammalian target of rapamycin complex 1 (mTORC1) that maintains skeletal muscle proteostasis with functional responses. We also noted relative preservation of muscle mass during hyperammonemia in muscle specific deletion of HIF1α mice. These observations formed the basis for our hypothesis that ethanol induced hyperammonemia causes cataplerosis of αKG with oxygen independent stabilization and impaired proteostasis and sarcopenia. We will test this hypothesis by testing if ethanol stabilizes HIF1α in skeletal muscle, and determine the mechanisms of stabilization of muscle HIF1α. Ethanol treatment in vitro in myotubes and in vivo in mice with loss and gain of function of HIF1α and its regulatory molecules will be used for these studies We will also test how metabolic perturbations regulate HIF1α stabilization and consequent molecular and functional responses in our preclinical models. Validation of key observations will be done in human muscle tissue from our biorepository. The proposed studies will enhance our understanding of the mechanisms of sarcopenia in ALD and lay the foundation for targeted therapeutics. This award will provide the support and time for the applicant for a supervised research career development in translational research. The applicant works with NIAAA funded independent investigators in the Northern Ohio Alcohol Center and her mentor developed the field of sarcopenia in liver disease. The institutional environment is highly supportive of her career path towards becoming an independent physician scientist focusing on mechanistic approaches to address unmet clinical needs in patients with alcohol use disorders.

酒精使用障碍和随之而来的组织损伤的患病率，主要是酒精性肝病（ALD）骨骼肌损失或肌肉减少症是 ALD 患者的持续异常。与不良临床结果相关，包括死亡率增加、肝病的其他并发症我们最近报告了更严重的肌肉损失和更大的肝移植后结果。与其他原因的肝硬化患者相比，酒精性肝硬化患者的肌肉损失率。 ALD 中肌肉减少症的高度临床意义目前尚无有效的治疗选择，因为我们还没有直接或间接地报道了乙醇的潜在机制。肝氨处理受损和随之而来的高氨血症，导致肌少症表型在初步研究中，我们发现线粒体存在蛋白质稳态失调。我们还注意到，乙醇会导致瘫痪或高氨血症。三羧酸 (TCA) 循环中间体的损失，特别是 α-酮戊二酸 (αKG)（HIF1α 的抑制剂）。始终如一的、公正的方法（转座酶可及染色质测序的测定）和有针对性的实验表明肌肉缺氧诱导因子 1α (HIF1α) 的氧依赖性稳定在初步研究中，我们观察到 REDD1（HIF1α 的转录靶标）的表达增加。以及维持骨骼健康的哺乳动物雷帕霉素靶标复合物 1 (mTORC1) 的负调节因子我们还注意到肌肉质量的相对保存。 HIF1α 肌肉特异性缺失小鼠的高氨血症这些观察结果构成了我们的基础。假设乙醇诱导的高氨血症导致 αKG 不依赖氧的猝倒症我们将通过测试乙醇是否会导致稳定性和蛋白质稳态受损以及肌肉减少症来检验这一假设。稳定骨骼肌中的 HIF1α，并确定肌肉 HIF1α 的稳定机制。 HIF1α 功能丧失和获得及其调节的体外肌管治疗和小鼠体内治疗分子将用于这些研究我们还将测试代谢扰动如何调节 HIF1α 我们的关键临床前模型的稳定性以及随后的分子和功能反应。将对我们生物样本库中的人体肌肉组织进行观察，拟议的研究将得到加强。我们对 ALD 中肌肉减少症机制的理解为靶向治疗奠定了基础。该奖项将为申请人在监督下的研究职业发展提供支持和时间申请人与 NIAAA 资助的俄亥俄州北部的独立研究人员合作。酒精中心和她的导师开发了肝脏疾病中肌肉减少症领域的机构环境。高度支持她成为一名独立医师科学家的职业道路，专注于解决酒精使用障碍患者未满足的临床需求的机械方法。