Ex vivo rejuvenation and expansion of muscle stem cells from aged mice

衰老小鼠肌肉干细胞的离体再生和扩增

• 批准号: 8354595
• 负责人: Benjamin David Cosgrove
• 金额: $ 8.83万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8354595
• 关键词: Activities of Daily Living; Acute; Adhesions; Aging; Algorithms; Antibodies; Autologous; Biological Assay; Biology; Biomedical Engineering; Biomimetics; Cell Aging; Cell Culture Techniques; Cell physiology; Cellular Mechanotransduction; Cellular Stress; Clinical; Cytometry; Defect; Development; Faculty; Functional disorder; Generations; Homeostasis; Hydrogels; Image; Individual; Injury; Institution; Laboratories; Least-Squares Analysis; Libraries; Life; Longevity; MAPK14 gene; Mentors; Mitogens; Modeling; Modification; Mus; Muscle; Muscle satellite cell; Muscular Atrophy; Natural regeneration; Pathway interactions; Performance; Phase; Phenotype; Phosphoproteins; Physiology; Population; Positioning Attribute; Protein Kinase; Quality of life; Recovery; Rejuvenation; Relative (related person); Research; Signal Transduction; Signaling Molecule; Skeletal Muscle; Stem cells; Surface; System; Systems Biology; Telomerase; Testing; Therapeutic; Tissues; Training; Transplant Recipients; Transplantation; Universities; Work; adult stem cell; age related; aged; attenuation; base; career development; cell age; combinatorial; improved; in vivo; inhibitor/antagonist; injured; innovation; insight; mitogen-activated protein kinase p38; muscle form; muscle regeneration; muscle strength; novel; programs; regenerative; research and development; response; satellite cell; senescence; small molecule; stem cell biology; stem cell fate; stem cell population; stem cell therapy; stemness; symposium; tissue regeneration; wasting

DESCRIPTION (provided by applicant): Muscle stem cells (MuSCs), also known as satellite cells, are essential to muscle regeneration throughout life [1]. In aging, skeletal muscle mass and regenerative capacity after injury progressively decline, leading to diminished quality of life in aged individuals [2]. Efforts to explain the dysfunction of aged skeletal muscle tissue have focused on aging-related changes in tissue microenvironment factors restricting MuSC function [3]. In my postdoctoral research, I have demonstrated, using non-invasive imaging assays of tissue regeneration, that MuSCs prospectively isolated from old mice have a marked reduction in regenerative capacity relative to young MuSCs, revealing a previously undetected intrinsic stem cell defect in old MuSCs. Further, I have identified a novel ex vivo strategy to overcome the regenerative dysfunction of old MuSCs; treatment of old MuSCs maintained on a soft biomimetic hydrogel platform [4] with a small molecule inhibitor of p38 mitogen- associated protein kinase yields an expansion in absolute numbers of functional stem cells and restores their function in regeneration to that of young MuSCs. This approach offers promise for rejuvenating and increasing the numbers of MuSCs and could enable localized autologous stem cell therapy for muscle wasting in aged individuals, for which there are no pharmacologic treatments in clinical use. I propose to merge prior training in bioengineering and stem cell biology with new training in muscle physiology and systems biology to further investigate the regenerative dysfunction of MuSCs in aging and its rescue ex vivo. In Aim 1 (K99 phase), I will evaluate whether ex vivo-treated old MuSCs can rescue defective muscle regeneration and increase muscle strength in old mice and are capable of long-term rejuvenated function in response to successive regenerative demands. In Aim 2 (bridging K99/R00 phases), I will elucidate whether defective regenerative function is a homogeneous or heterogeneous phenotype in old MuSCs by combining multi-parameter mass cytometry (CyTOF) [5] and SPADE algorithm [6] analysis with sensitive transplantation assays to identify and compare the regenerative functions of MuSC sub-populations isolated from young and old mice. In Aim 3 (R00 phase), I will elucidate dysregulated signaling network mechanisms underlying the stem cell dysfunction of old MuSCs for improved therapeutic treatment using signaling network- level systems biology approaches [7]. This Transition to Independence proposal describes research and career development activities, including conference attendance and course training that will establish me as a competitive candidate for an independent faculty position and aid my development of an innovative, successful research program in the biology and treatment of stem cell aging. These activities will be mentored by Drs. Helen Blau (primary), Scott Delp (co-mentor), and Garry Nolan (co-mentor) at Stanford University, which is a world-class stem cell biology research institution. PUBLIC HEALTH RELEVANCE: Skeletal muscle is maintained and regenerated through the action of adult stem cells that reside in muscle tissue throughout the lifespan of an individual. I aging, muscle atrophies and does not regenerate from injury efficiently, diminishing quality of life, due to a reduced regenerative capacity of muscle stem cells. This proposal focuses on gaining insights and developing strategies towards providing therapy to defective muscle stem cells from aged individuals.

描述（申请人提供）：肌肉干细胞（MuSC），也称为卫星细胞，对整个生命中的肌肉再生至关重要[1]。随着年龄的增长，骨骼肌质量和损伤后的再生能力逐渐下降，导致生活质量下降 老年人[2]。解释老年骨骼肌组织功能障碍的努力集中在限制MuSC功能的组织微环境因素中的衰老相关变化[3]。在我的博士后研究中，我已经证明，使用非侵入性组织再生成像分析，从老年小鼠中前瞻性分离的MuSC相对于年轻的MuSC具有明显的再生能力降低，揭示了老年MuSC中以前未检测到的内在干细胞缺陷。此外，我已经确定了一种新的体外策略来克服旧MuSC的再生功能障碍;用p38有丝分裂原相关蛋白激酶的小分子抑制剂处理维持在软仿生水凝胶平台上的旧MuSC [4]，产生了功能性干细胞绝对数量的扩增，并将其再生功能恢复到年轻MuSC的功能。这种方法为恢复和增加MuSC的数量提供了希望，并且可以使局部自体干细胞治疗老年人的肌肉萎缩，临床上没有药物治疗。 我建议将生物工程和干细胞生物学的先前培训与肌肉生理学和系统生物学的新培训相结合，以进一步研究MuSCs在衰老中的再生功能障碍及其体外拯救。在目标1（K99阶段）中，我将评估体外处理的老年MuSC是否可以挽救老年小鼠中有缺陷的肌肉再生并增加肌肉力量，并且能够响应连续的再生需求而长期恢复功能。在目标2（桥接K99/R 00期）中，我将通过将多参数质谱细胞术（CyTOF）[5]和SPADE算法[6]分析与敏感的移植试验相结合，以鉴定和比较分离自年轻和老年小鼠的MuSC亚群的再生功能，阐明再生功能缺陷在老年MuSC中是同质还是异质表型。在目标3（R 00阶段）中，我将阐明旧MuSC干细胞功能障碍的信号网络失调机制，以使用信号网络水平的系统生物学方法改善治疗[7]。 这个过渡到独立的建议描述了研究和职业发展活动，包括会议出席和课程培训，将建立我作为一个独立的教师职位的竞争力的候选人，并帮助我在生物学和干细胞衰老的治疗创新，成功的研究计划的发展。这些活动将由世界一流的干细胞生物学研究机构斯坦福大学的Helen Blau博士（主要）、Scott Delp博士（共同导师）和Garry Nolan博士（共同导师）指导。 公共卫生相关性：骨骼肌是通过成体干细胞的作用来维持和再生的，成体干细胞在个体的整个生命周期中都存在于肌肉组织中。随着年龄的增长，肌肉萎缩，不能有效地从损伤中再生，由于肌肉干细胞的再生能力降低，生活质量下降。该提案的重点是获得见解和制定策略，为老年人有缺陷的肌肉干细胞提供治疗。