Control of Muscle Stem Cells to Enhance Regeneration

控制肌肉干细胞以增强再生

• 批准号: 10346767
• 负责人: Helen M Blau
• 金额: $ 48.53万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10346767
• 关键词: 3' Untranslated Regions; Affect; Age; Aging; American; Architecture; Biological Assay; Blocking Antibodies; CD36 Antigens; CD47 gene; Cell Count; Cell physiology; Cell surface; Cells; Censuses; Cyclic AMP; Cytometry; Data; Defect; Detection; Elderly; Exhibits; Functional disorder; Generations; Genetic Transcription; Goals; Heterogeneity; Homeostasis; Impairment; Incidence; Injury; Institutionalization; Investigation; Kinetics; Knowledge; Lead; Long-Term Care; Maps; Measurement; Molecular; Movement; Mus; Muscle; Muscle function; Muscle satellite cell; Muscular Atrophy; Natural regeneration; Outcome; Phenotype; Polyadenylation; Population; Population Heterogeneity; Post-Transcriptional Regulation; Proteins; Public Health; Quality of life; Regenerative capacity; Regenerative response; Research; Resolution; Series; Signal Transduction; Skeletal Muscle; Surface; THBS1 gene; Technology; Therapeutic; Therapeutic Intervention; Thrombospondin 1; Tissue imaging; Tissues; Transcript; Up-Regulation; age related; age-related muscle loss; aged; data integration; falls; frailty; improved; in vivo; in vivo evaluation; indexing; innovation; insight; muscle aging; muscle form; muscle regeneration; muscle strength; neutralizing antibody; novel; novel strategies; novel therapeutic intervention; novel therapeutics; p38 Mitogen Activated Protein Kinase; paracrine; prevent; prospective; receptor; regeneration model; regenerative; repaired; sarcopenia; self-renewal; single cell technology; single-cell RNA sequencing; skeletal muscle wasting; stem cell aging; stem cell expansion; stem cell function; stem cell niche; stem cell population; tool; transcriptome sequencing

PROJECT SUMMARY According to the most recent U.S. Census, the elderly population will more than double to 80 million, encompassing 1 in 5 Americans by 2050. Aging is characterized by a decline in tissue function and regenerative capacity. Sarcopenia, also known as age-dependent loss of skeletal muscle mass and strength, is a major public- health problem that affects 15% of the elderly, leading to loss of mobility and diminished quality of life. Age- related muscle loss is paralleled by a loss in the function of muscle stem cells (MuSCs), key players in muscle homeostasis and regeneration. However, the mechanisms responsible for age-associated MuSC dysfunction remain elusive. Two major barriers to gaining mechanistic insights into MuSC aging are (1) the heterogeneity of the aged MuSC population, which renders standard bulk analysis ineffective, and (2) the lack of tools to resolve this heterogeneity, underscoring the need for single-cell studies. We previously demonstrated that aged MuSCs are a heterogeneous population comprised of functional and dysfunctional subsets. This key observation suggests a therapeutic strategy to regenerate muscle - boosting the activity of resilient functional MuSCs. Here we explore this possibility using a specific cell surface marker and a series of innovative single-cell technologies required to resolve MuSC subsets. Our preliminary data iden- tify CD47 as a cell surface marker whose expression level, not presence or absence, distinguishes functional CD47lo and dysfunctional CD47hi MuSC subsets. Known widely as a receptor for SIRPα, CD47 is also a receptor for thrombospondin-1 (THBS1). We found that CD47hi MuSCs accumulate in aged muscle and aberrantly ex- press THBS1. We hypothesize that during aging the accumulation of CD47hi MuSCs impairs the proliferation of CD47lo MuSCs through secretion of THBS1, hindering regeneration and contributing to sarcopenia. Here, our specific aims are to (1) determine how CD47 signaling goes awry in aging, (2) elucidate how post-transcriptional regulation of CD47 is altered during aging leading to the accumulation of dysfunctional CD47hi MuSCs, and (3) determine the effects of aberrant THBS1 secretion in the aged MuSC niche on regeneration. We capitalize on cutting-edge single-cell technologies, including multidimensional single-cell mass cytometry (CyTOF) and multi- plexed tissue imaging (CO-Detection by indexing (CODEX)). These technologies allow us to track simultane- ously 40+ distinct cell and signaling phenotypes in CD47lo and CD47hi MuSCs (CyTOF) and resolve how spatial changes in the architecture of the multicellular niche lead to MuSC dysfunction in aging (CODEX). We combine this knowledge with in vivo investigation of regenerative capacity and strength in aged mice. Finally, we perturb CD47 signaling in vivo using blocking antibodies to surmount the regenerative deficits in aged mice. The pro- posed analyses of newly identified aged MuSC subsets that can be prospectively isolated will provide fresh mechanistic insights into aging and inform therapeutic strategies to augment endogenous muscle repair.

项目摘要 根据最近的美国人口普查，最古老的人口将两倍多到8000万 到2050年，包括5分之一的美国人。衰老的特征是组织功能下降和再生 容量。肌肉减少症，也称为年龄依赖性骨骼肌质量和力量的损失，是主要的公众 影响较早的15％的健康问题，导致流动性丧失和生活质量下降。年龄- 相关的肌肉损失与肌肉干细胞功能（MUSC）的功能，肌肉的主要参与者相似 稳态和再生。但是，导致与年龄相关的MUSC功能障碍的机制 保持难以捉摸。获得MUSC衰老的机理见解的两个主要障碍是（1） 老年MUSC人群，这使标准批量分析无效，以及（2）缺乏解决的工具 这种异质性，强调了单细胞研究的需求。 我们先前证明，老化的MUSC是功能的异质种群 和功能失调的子集。该关键观察结果提出了再生肌肉的治疗策略 - 增强肌肉 弹性功能性MUSC的活性。在这里，我们使用特定的细胞表面标记探索这种可能性 以及解决MUSC子集所需的一系列创新的单细胞技术。我们的初步数据 将CD47视为一种细胞表面标记，其表达水平而不是存在或不存在，可以区分功能 CD47LO和功能障碍CD47HI MUSC子集。 CD47被称为SIRPα的受体，也是受体 用于血小板传播1（THBS1）。我们发现CD47HI MUSC积聚在老年肌肉中，异常地 按THBS1。我们假设在衰老中CD47HI MUSC的积累会损害 CD47LO MUSC通过THBS1分泌，阻碍再生并为肌肉减少症做出贡献。在这里，我们的 具体目的是（1）确定CD47信号在衰老中的出现方式，（2）阐明转录后如何 在衰老过程中，CD47的调节发生了变化，导致CD47HI MUSC的积累，（3） 确定异常THBS1分泌在老年MUSC生态裂市场中的影响。我们大写 尖端的单细胞技术，包​​括多维单细胞质量细胞术（Cytof）和多层次 悬式组织成像（通过索引（codex）共检测）。这些技术使我们能够跟踪同时 在CD47LO和CD47HI MUSC（cytof）中，有40多个不同的细胞和信号表型，并解决空间的方式 多细胞生态位的体系结构的变化导致衰老（codex）的MUSC功能障碍。我们结合了 这种知识是在老年小鼠中对再生能力和力量的体内投资的知识。最后，我们扰动 CD47在体内信号传导使用阻断抗体来刺激老年小鼠的再生防御。专业人士 对新鉴定的老年MUSC子集的ESTED分析可以被期望隔离 对衰老的机械洞察力，并为治疗策略提供了增强内源性肌肉修复的信息。