The role of cellular senescence in skeletal muscle loss and dysfunction

细胞衰老在骨骼肌损失和功能障碍中的作用

• 批准号: 10737207
• 负责人: Davis A. Englund
• 金额: $ 10.49万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10737207
• 关键词: Address; Adult; Age; Aging; Anatomy; Bioinformatics; Biology; Cell Aging; Cell Cycle; Cell Cycle Arrest; Cell Nucleus; Cells; Chronology; Clinic; Complement; DNA Damage; Data; Disease; Doxycycline; Drug Targeting; Elderly; Epigenetic Process; Etiology; Fiber; Fibrosis; Foundations; Functional disorder; Funding; Gene Expression Profiling; Giant Cells; Health; Heterogeneity; Human; Image; Individual; Knowledge; Label; Measures; Mediating; Mentors; Methods; Microscopy; Mitotic; Modeling; Molecular; Mononuclear; Mus; Muscle; Muscle Fibers; Muscular Atrophy; Personal Satisfaction; Phase; Phenotype; Physical Function; Population; Positioning Attribute; Predisposition; Prevention; Process; Property; Publishing; Quality of life; Research; Research Personnel; Research Training; Resolution; Role; Skeletal Muscle; Stimulus; Techniques; Testing; Therapeutic; Tissues; Training; Transgenic Mice; Translating; United States National Institutes of Health; Wasting Syndrome; Withdrawal; Work; age related; aged; biomarker validation; blood-based biomarker; career; cell type; clinically relevant; drug discovery; effective therapy; functional improvement; gain of function; health care service utilization; improved; in vivo; insight; loss of function; mitochondrial dysfunction; molecular imaging; mouse model; multiple omics; muscle aging; muscle form; muscle strength; new therapeutic target; novel; oncoprotein p21; overexpression; pharmacologic; postmitotic; programs; response; sarcopenia; satellite cell; senescence; single-cell RNA sequencing; skeletal muscle wasting; skills; synergism; therapeutic target; tool; transcriptome; translational research program

PROJECT SUMMARY/ABSTRACT The objectives of this proposal are to (1) obtain the experimental skills and career training necessary to develop a translational research program investigating mechanisms underlying skeletal muscle wasting and (2) generate the data necessary to determine the feasibility of targeting senescent cells to restore muscle size and function. Sarcopenia is a debilitating age-related skeletal muscle wasting syndrome associated with poor quality of life and high health care utilization. The etiology of sarcopenia is not fully understood, and there are currently no effective treatments. Identifying the processes mediating sarcopenia is critical for developing pharmacologic therapies. Senescent cells accumulate with age and at the anatomical sites of disease. Thus, they are regarded as a logical therapeutic target. Indeed, in mice, the targeted elimination of senescent cells improves function and parameters of health in multiple tissues. Our preliminary data show (1) senescent post- mitotic muscle fibers accumulate in sarcopenic mice, (2) the cyclin-dependent kinase inhibitor p21 is a critical regulator of muscle fiber senescence, and (3) a subset of myonuclei within multi-nucleated muscle fibers are uniquely vulnerable to senescence induction. I will use mouse models that allow for muscle fiber-specific labeling and modulation of p21 to advance our understanding for muscle fiber senescence and examine the direct contribution of senescence to muscle dysfunction. In Aim 1, I will overexpress p21 in muscle fibers in vivo and apply well-validated markers of senescence together with transcriptome-wide analyses to determine the core properties of muscle fiber senescence and identify regulatory processes that may serve as therapeutic targets. In Aim 2, I will use gain-of-function and loss-of-function p21 models and assess measures of muscle health, function, and size to determine the clinical relevance of senescent cell burden in skeletal muscle. In Aim 3, I will use myonuclear identification and isolation techniques together multiomic profiling to examine differences between senescent and non-senescent subsets of myonuclei to gain new insight into the factors regulating myonuclear senescence. The K99 phase will be conducted at Mayo Clinic and will focus on obtaining mentored training in methods required to complete the proposed aims. The R00 phase will be conducted in my independent lab and will focus on analyzing mouse tissues and data, publishing findings, and developing an R01 application based on these results. This proposal synergizes new skills in advanced senescent cell identification, imaging, bioinformatics, and drug target discovery techniques to create a research trajectory that is distinct from my mentors’ foci. This work will produce a robust foundation for an independent research career elucidating cellular mechanisms of skeletal muscle dysfunction with the aim of translating these findings into therapies to improve human health and well-being.

项目摘要/摘要 这项建议的目标是(1)获得必要的实验技能和职业培训 制定一项研究骨骼肌萎缩机制的翻译研究计划，以及(2) 生成必要的数据以确定以衰老细胞为靶点以恢复肌肉大小和 功能。骨质疏松症是一种与年龄相关的骨骼肌衰弱综合征，与贫穷有关 生活质量和高卫生保健利用率。石棺减少症的病因尚不完全清楚，目前有 目前还没有有效的治疗方法。确定调节骨质疏松症的过程对发展至关重要 药物疗法。衰老的细胞随着年龄的增长而积累在疾病的解剖部位。因此， 它们被认为是合理的治疗靶点。事实上，在小鼠中，有针对性地消除衰老细胞 改善多种组织的功能和健康参数。我们的初步数据显示：(1)后衰老 (2)细胞周期蛋白依赖的激酶抑制剂p21是一种关键的 肌肉纤维衰老的调节者，以及(3)多核肌肉纤维内的肌核的一个亚群 特别容易引起衰老。我将使用允许特定于肌肉纤维的小鼠模型 P21的标记和调控，以促进我们对肌肉纤维衰老的理解，并检测 衰老是肌肉功能障碍的直接原因。在目标1中，我将在肌肉纤维中过表达p21 并应用经过充分验证的衰老标记以及转录组分析来确定 肌肉纤维衰老的核心特性，并确定可能起到治疗作用的调节过程 目标。在目标2中，我将使用功能获得和功能丧失的p21模型并评估肌肉的测量 健康、功能和大小，以确定骨骼肌衰老细胞负荷的临床相关性。在……里面 目的3，我将结合肌核鉴定和分离技术结合多组谱分析来检查 肌核衰老亚群与非衰老亚群的差异对相关因素的新认识 调节肌核衰老。K99阶段将在梅奥诊所进行，重点是 获得所需方法的指导培训，以完成提议的目标。R00阶段将是 在我的独立实验室进行，我将专注于分析老鼠组织和数据，发表研究结果，以及 基于这些结果开发一个R01应用程序。此建议将高级课程中的新技能与 衰老细胞识别、成像、生物信息学和药物靶点发现技术创建的研究 这条轨迹与我导师的关注点截然不同。这项工作将为独立的 研究生涯阐明骨骼肌功能障碍的细胞机制，目的是翻译 这些发现被转化为改善人类健康和福祉的疗法。