The role of ageing on the regulatory effects of skeletal muscle ECM...

衰老对骨骼肌ECM调节作用的作用...

• 批准号: 7896544
• 负责人: MARK Edwin VAN DYKE
• 金额: $ 15.96万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7896544
• 关键词: Address; Affect; Age; Aging; Aging-Related Process; American; Animal Model; Animals; Apoptosis; Attention; Behavior; Biological; Biological Assay; Bioreactors; Cell Aging; Cell Count; Cell Culture Techniques; Cell Differentiation process; Cell Proliferation; Cell physiology; Cells; Characteristics; Complex; Cues; Data; Development; Disease; Elderly; Environment; Experimental Designs; Exploratory/Developmental Grant; Extracellular Matrix; Foundations; Funding; Future; Gene Expression; Gene Proteins; Genetic; Growth; Health; Homeostasis; Individual; Injury; Institutes; Investigation; Lead; Left; Maintenance; Measures; Mechanics; Mediating; Medical; Methodology; Methods; Modeling; Molecular; Monitor; Morphology; Muscle; Muscle Cells; Muscle Fibers; Muscle function; Muscle satellite cell; Musculoskeletal; NIH Program Announcements; Nature; Normal tissue morphology; Organism; Physiologic Monitoring; Physiological; Play; Population; Predisposition; Process; Quality of life; Rattus; Regenerative Medicine; Relative (related person); Research; Role; Signal Pathway; Skeletal Muscle; Slice; Solid; Specific qualifier value; Stem cells; Stretching; Structure; System; Techniques; Testing; Therapeutic Intervention; Tissue Engineering; Tissue Model; Tissues; United States; Work; Wound Healing; age related; aged; base; cost; design; disability; experience; falls; forest; functional decline; in vitro Model; in vivo; insight; mortality; muscle aging; muscle form; muscle regeneration; myogenesis; novel; novel strategies; prevent; protein expression; public health relevance; regenerative; repaired; response; sarcopenia; satellite cell; scaffold; stem; stem cell population; tissue culture; tissue regeneration; young adult

DESCRIPTION (provided by applicant): This research seeks to determine the role extracellular matrix (ECM) plays in the aging of skeletal muscle. The loss of skeletal muscle mass and strength that occurs during the aging process represents a major health issue facing a growing elderly population. Skeletal muscle homeostasis is the responsibility of the tissue's resident stem/progenitor cell known as the satellite cell or muscle progenitor cell (MPC). With age, the regenerative capacity of MAPCs is diminished. In determining how MPC regenerative capacity is lost, one must consider that both cell-intrinsic and cell-extrinsic changes can impact MPCs. Factors extrinsic to the cell include environmental components such as soluble factors, neighboring cells, and ECM, each of which can experience numerous changes with age. The research described here investigates the impact ECM age has on the ability of MPCs to carry out processes required for the regenerative maintenance of skeletal muscle tissue. We hypothesize that alteration of skeletal muscle ECM during the aging process results in misregulation of the regenerative mechanisms used by MPCs to maintain skeletal muscle homeostasis. This is among the first research to isolate the effects of ECM from cellular and soluble component effects on muscle regeneration as a function of age. In this proposed study, we will utilize ECM and MPCs from different ages of animals to study the interaction between them and the effect ECM has on progenitor cell function, as well as its impact on functional tissue formation. Rats have been chosen as the model organism to minimize genetic variability and gain precise control over the age of both the ECM and the MPCs. Using a method developed in our lab, skeletal muscle tissue from young adult (<12 months) and old rats (>24 months) will be decellularized, a process which removes cellular material while leaving ECM intact. The influence of ECM age on the growth behavior and regenerative capacity of young and old MPCs will be investigated using two in vitro models. In the first, ECM will be extracted from the decellularized tissue and used to coat tissue culture dishes onto which MPCs will be seeded. In the second, slices of decellularized tissue will be used as scaffolds onto which MPCs will be seeded and three-dimensional (3D) tissue will be grown under physiological loading conditions in a bioreactor system. In both culture systems, old or young rat MPCs will be seeded onto plates or scaffolds of old or young ECM in a two-by-two factorial experimental design. In both systems, the impact of ECM age on myogenesis, proliferation, and differentiation of the MPCs will be measured, including monitoring the expression of proteins known to be required for myogenic differentiation. Additionally, global gene expression will be assayed to determine how gene expression of MPCs is altered based on the age of the ECM component of the culture system. Finally, the function of MPC- scaffold constructs will be measured to determine how the formation of functional engineered tissue is affected by the age of the ECM component. When completed, this research will provide significant insight into the role ECM age plays in regulating the regenerative capacity of a stem/progenitor cell population vital to the health of elderly individuals. These data will provide the basis for future investigations of the compositional differences in the cell microenvironment that presents stimulatory and/or inhibitory cues to regenerative muscle cells. PUBLIC HEALTH RELEVANCE: The loss of skeletal muscle mass and strength characteristic of the aging process represents an important health problem facing a growing elderly population. A fundamental question that remains unanswered is the role that age-related changes to the physical microenvironment, or extracellular matrix, of muscle stem cells play in the aging of skeletal muscle. This research is designed to determine how an aging cellular microenvironment affects the regenerative capacity of skeletal muscle progenitor cells and to identify the genes and proteins whose expression and activity is adversely affected by age-related changes to the cell microenvironment.

描述（由申请人提供）：本研究旨在确定细胞外基质（ECM）在骨骼肌衰老中的作用。在衰老过程中发生的骨骼肌质量和力量的丧失是日益增长的老年人口面临的一个主要健康问题。骨骼肌的内稳态是组织的常驻干/祖细胞的责任，称为卫星细胞或肌肉祖细胞（MPC）。随着年龄的增长，MAPCs的再生能力减弱。在确定MPC再生能力如何丧失时，必须考虑细胞内在和细胞外在的变化都可以影响MPC。细胞的外部因素包括环境因素，如可溶性因素、邻近细胞和ECM，每一个都可以随着年龄的增长而经历许多变化。本文描述的研究调查了ECM年龄对MPCs执行骨骼肌组织再生维持所需过程的能力的影响。我们假设在衰老过程中骨骼肌ECM的改变导致MPCs用于维持骨骼肌稳态的再生机制失调。这是首次从细胞和可溶性成分对肌肉再生的影响中分离出ECM对年龄的影响的研究之一。在本研究中，我们将利用来自不同年龄动物的ECM和MPCs来研究它们之间的相互作用，以及ECM对祖细胞功能的影响，以及对功能性组织形成的影响。选择大鼠作为模型生物，以最大限度地减少遗传变异，并对ECM和MPCs的年龄进行精确控制。使用我们实验室开发的方法，将对年轻成年（<12个月）和老年大鼠（bb0 - 24个月）的骨骼肌组织进行脱细胞处理，这一过程可以去除细胞物质，同时保持ECM完整。我们将使用两种体外模型研究体外培养年龄对年轻和老年MPCs生长行为和再生能力的影响。首先，ECM将从脱细胞组织中提取，并用于覆盖组织培养皿，MPCs将被播种。其次，脱细胞组织切片将被用作支架，MPCs将被植入支架上，三维（3D）组织将在生物反应器系统的生理负载条件下生长。在两种培养系统中，采用二乘二因子实验设计，将年老或年轻的大鼠MPCs播种到年老或年轻ECM的板或支架上。在这两种系统中，将测量ECM年龄对MPCs的肌生成、增殖和分化的影响，包括监测肌生成分化所需的已知蛋白质的表达。此外，将检测整体基因表达，以确定MPCs的基因表达如何根据培养系统中ECM成分的年龄而改变。最后，将测量MPC-支架结构的功能，以确定ECM成分的年龄如何影响功能性工程组织的形成。一旦完成，这项研究将为ECM年龄在调节对老年人健康至关重要的干细胞/祖细胞群的再生能力中所起的作用提供重要的见解。这些数据将为未来研究细胞微环境的组成差异提供基础，这些细胞微环境对再生肌肉细胞具有刺激和/或抑制作用。公共卫生相关性：衰老过程中骨骼肌质量和力量的损失是日益增长的老年人口面临的一个重要健康问题。一个尚未解决的基本问题是，与年龄相关的肌肉干细胞的物理微环境或细胞外基质的变化在骨骼肌衰老中所起的作用。本研究旨在确定衰老的细胞微环境如何影响骨骼肌祖细胞的再生能力，并鉴定其表达和活性受到年龄相关的细胞微环境变化不利影响的基因和蛋白质。