Cellular and Physical Function Outcomes Leading to Failed Muscle Recovery After Critical Illness

细胞和身体功能结果导致危重疾病后肌肉恢复失败

基本信息

批准号：
10523782
负责人：
Kirby P Mayer
金额：
$ 14.91万
依托单位：
UNIVERSITY OF KENTUCKY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-08 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10523782
关键词：
Acute respiratory failure Address Adult Applied Research Basic Science Biogenesis Biopsy COVID-19 Cell fusion Cell physiology Cells Characteristics Clinical Clinical Investigator Clinical Sciences Clinical Trials Complex Critical Illness Data Deuterium Oxide Development Disabled Persons Environment Functional disorder Future Gait speed Goals Grant Health Hospitalization Hospitals Human Immunohistochemistry Impairment Inflammatory Intensive Care Units Intervention Knowledge Label Lead Learning Lower Extremity Measures Mechanical ventilation Mentors Mentorship Methodology Microscopy Mitochondria Mitochondrial Proteins Morphology Muscle Muscle Fatigue Muscle Proteins Muscle Weakness Muscle function Muscle satellite cell Outcome Patient-Focused Outcomes Patients Pattern Performance Pharmacology Phase Phenotype Physical Function Physical Rehabilitation Property Protein Biosynthesis Proteins Proteolysis Quality of life RNA Recovery Recovery of Function Regression Analysis Rehabilitation therapy Research Research Training Respiration Ribosomes Sepsis Severity of illness Skeletal Muscle Stable Isotope Labeling Statistical Data Interpretation Survivors Technical Expertise Testing Time Training Translating Walking Western Blotting cell type disability effective therapy experimental study functional disability functional outcomes improved inflammatory milieu longitudinal analysis macrophage muscle form muscle strength novel patient subsets physically handicapped prevent protein degradation proteostasis rehabilitation research rehabilitation strategy satellite cell skeletal muscle wasting skills stem

项目摘要

Project Summary Survival of critical illness such as sepsis and acute respiratory failure is accompanied by serious physical complications with many patients acquiring long-term impairments. Mechanisms and factors that impede the recovery of muscle size and function after hospitalization are not understood. It is unclear if recovery after critical illness leads to a subsequent deficiency in the ability to make new proteins (protein synthesis) or if a catabolic/inflammatory environment persists preventing muscle regrowth which involves muscle stem cell (satellite cell) fusion to myofibers. We will address gaps in knowledge by studying skeletal muscle proteostasis, cellular environment, and RNA and mitochondrial biogenesis after critical illness with closely aligned physical function outcomes. Understanding the cellular environment in the period after hospital release, and how it impacts muscle protein turnover will direct efforts to effective therapies to accelerate muscle regrowth. The overall goal of this application is to identify cellular properties of muscle that may contribute to long-term physical disability in survivors of critical illness. Overall, I hypothesize that aberrant cellular processes in muscle are underlying prolonged functional impairments in patients after critical illness. In Aim 1, we will determine the longitudinal trajectory of muscle and physical function recovery and establish muscle morphological and cellular characteristics in patients after critical illness. We hypothesize that patients with higher severity of illness in the ICU and with longer duration of mechanical ventilation will have the most persistent muscle weakness and deficits in muscle power in recovery. In Aim 2, we will identify cellular mechanisms that contribute to muscle dysfunction after critical illness. We hypothesize that patients with persistent muscle weakness and fatigue have impaired mitochondrial function compared to controls. Moreover, we hypothesize that survivors of critical illness have elevated myofibrillar protein synthesis and ribosome biogenesis in early recovery, but muscle regrowth does not occur due to elevated proteolysis. The overarching goal of this proposal focuses on elucidating the factors that lead to muscle mass dysregulation in recovery and inform why some patients develop persistent disability and others gradually improve. The proposed mentoring team provides the knowledge and training to develop into an independent clinical investigator integrating basic and applied science. The proposed training plan in Aim 1 emphasizes clinical trial methodologies and complex longitudinal analyses. For aim 2, the training focuses on skeletal muscle experiments; specifically, knowledge to assess muscle proteostasis, mitochondrial content and function, and muscle morphology. I will learn the technical skills to examine skeletal muscle including stable isotope labeling, immunohistochemistry, western blot analysis, and microscopy will be gained. Moreover, the proposed research and training plan provides the necessary training and mentorship to translate findings in this proposal into the development of targeted rehabilitation and pharmacological interventions in future R01 studies.

项目概要败血症和急性呼吸衰竭等危重疾病的生存伴随着严重的身体并发症导致许多患者出现长期损伤。机制和因素是否妨碍住院后肌肉大小和功能的恢复尚不清楚。目前还不清楚是否危重病后的康复会导致随后制造新蛋白质（蛋白质）的能力不足合成）或者如果分解代谢/炎症环境持续阻止肌肉再生，这涉及肌肉干细胞（卫星细胞）融合成肌纤维。我们将通过研究骨骼来弥补知识差距危重病后的肌肉蛋白质稳态、细胞环境以及 RNA 和线粒体生物合成紧密结合身体机能结果。了解出院后的细胞环境释放，以及它如何影响肌肉蛋白周转，将指导人们努力寻找有效的治疗方法，以加速肌肉再生。该应用程序的总体目标是识别肌肉的细胞特性，这些特性可能导致危重疾病幸存者长期身体残疾。总的来说，我假设异常肌肉中的细胞过程是危重病患者长期功能损伤的潜在原因。在目标1，我们将确定肌肉和身体功能恢复的纵向轨迹并建立危重病后患者的肌肉形态和细胞特征。我们假设患者 ICU 内病情较严重且机械通气持续时间较长的患者受到的影响最大持续性肌肉无力和恢复过程中肌力不足。在目标 2 中，我们将识别细胞危重病后导致肌肉功能障碍的机制。我们假设患者与对照组相比，持续的肌肉无力和疲劳会损害线粒体功能。而且，我们假设危重疾病的幸存者肌原纤维蛋白合成和核糖体升高恢复早期存在生物发生，但由于蛋白水解作用增强，肌肉不会再生。首要的该提案的目标重点是阐明导致恢复和恢复过程中肌肉质量失调的因素解释为什么有些患者会出现持续性残疾，而另一些患者会逐渐改善。拟议的辅导团队提供知识和培训，以发展成为一名独立的临床研究者，整合基本的和应用科学。目标 1 中提出的培训计划强调临床试验方法和复杂的纵向分析。对于目标2，训练重点是骨骼肌实验；具体来说，知识评估肌肉蛋白质稳态、线粒体含量和功能以及肌肉形态。我将学习检查骨骼肌的技术技能，包括稳定同位素标记、免疫组织化学、西方将获得印迹分析和显微镜检查。此外，拟议的研究和培训计划还提供了必要的培训和指导，以将本提案中的发现转化为有针对性的开发未来 R01 研究中的康复和药物干预。