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

• 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
• 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

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.

酒精使用障碍的患病率和随之而来的组织损伤，原发性酒精肝病（ALD） 继续增加。骨骼肌损失或肌肉减少症是ALD患者的一致异常，IS 与不良临床结果有关，包括增加死亡率，其他并发症的肝病 和肝后移植结果不良。我们最近报告了更严重的肌肉损失和更大的 与肝硬化的其他原因相比，酒精性肝硬化患者的肌肉损失率。尽管 肌肉减少症在ALD中的临床意义很高，没有有效的治疗选择 基本机制尚不清楚。我们还报告了乙醇直接或间接地通过 肝氨处置受损和随之而来的高症血症，导致肌肉减少型表型与 蛋白质稳态（蛋白质的）失调。在初步研究中，我们显示了线粒体 响应乙醇和高症血症的功能障碍。我们还注意到乙醇会导致催化或 三核酸（TCA）循环中间体的丧失，特别是α-酮戊二酸（αkg）HIF1α的抑制剂。 一致地，无偏的方法（用于转座酶可访问的染色质测序的测定），并针对目标 实验表明，肌肉缺氧诱导因子-1α（HIF1α）的氧气独立稳定 氨。在试点研究中，我们观察到Redd1的表达增加，Redd1是HIF1α的转录靶标的 雷帕霉素复合物1（MTORC1）的哺乳动物靶标的负调节剂保持骨骼 具有功能反应的肌肉蛋白抑制剂。我们还注意到在 HIF1α小鼠的肌肉特异性缺失中的高氨血症。这些观察构成了我们的基础 假设乙醇诱导的高症会导致αkg的催化性与氧无关 稳定和蛋白质症和肌肉减少症受损。我们将通过测试乙醇来检验该假设 稳定HIF1α在骨骼肌中，并确定肌肉HIF1α稳定的机制。乙醇 在肌管中的体外治疗肌管和体内在小鼠中的体外治疗，而HIF1α及其调节的功能损失和功能 分子将用于这些研究，我们还将测试代谢扰动如何调节HIF1α 在我们的临床前模型中，稳定以及随之而来的分子和功能响应。键的验证 观察将在我们的生物疗法中在人类肌肉组织中进行。拟议的研究将增强 我们对ALD肌肉减少症机制的理解，并为有针对性的治疗奠定了基础。 该奖项将为申请人提供监督研究职业发展的支持和时间 翻译研究。申请人与NIAAA资助的独立调查员合作 酒精中心和她的心理发展了肝病中肌肉减少症领域。机构环境 高度支持她的职业道路，成为一名专注于独立的物理科学家 解决酒精使用障碍患者未满足临床需求的机械方法。