Assessing lineage decisions of musculoskeletal progenitor cells with aging

评估肌肉骨骼祖细胞随衰老的谱系决定

• 批准号: 7288835
• 负责人: David W. Rowe
• 金额: $ 37.94万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7288835
• 关键词: Adipocytes; Adult; Affect; Age; Aging; Animals; Appearance; Back; Bioinformatics; Bone Marrow; Breeding; Bromodeoxyuridine; Cartilage; Cell physiology; Cells; Characteristics; Chromosome Mapping; Clinical; Color; Commit; Cultured Cells; Deterioration; Development; Disruption; Environment; Event; Fatty acid glycerol esters; Fluorescence; Foundations; Frail Elderly; Future; Generations; Genes; Genetic; Genetic Models; Genotype; Grant; Green Fluorescent Proteins; Health; Immunohistochemistry; In Situ; In Vitro; Inflammatory; Invaded; Label; Mature Bone; Mediator of activation protein; Microarray Analysis; Microscopy; Modeling; Molecular; Mus; Muscle; Muscle Cells; Muscle Fibers; Musculoskeletal; Musculoskeletal System; Myofibroblast; Osteoblasts; Osteogenesis; Osteoporosis; Pathway interactions; Pattern; Phenotype; Population; Primary Cell Cultures; Process; Production; Quantitative Trait Loci; Regulation; Relative (related person); Reporter; Research Personnel; Resistance; Signal Transduction; Skeletal Muscle; Skeletal system; Smooth Muscle; Smooth Muscle Actin Staining Method; Speed; Stem cells; Structure; Techniques; Testing; Time; Tissues; Transcription Factor AP-2 Alpha; Transplantation; Validation; age related; aged; base; bone; cell type; concept; congenic; cytokine; design; digital; fiber cell; fluorescence imaging; functional loss; in vivo; indexing; lipid biosynthesis; muscle strength; myogenesis; novel strategies; progenitor; programs; research study; sarcopenia; second harmonic; time use; tool

DESCRIPTION (provided by applicant): The deterioration of the musculoskeletal system with age that leads to sarcopenia and osteoporosis is a multi-factorial reality that has significant clinical limitations for muscle strength, mobility and loss of functional independence in frail older adults. Murine models may provide a window into the environmental and genetic factors that contribute to the process. This grant will test two independent yet converging hypothesis: one model based on lineage regulation that focuses on a common progenitor cell with the ability to develop into the myogenic, osteogenic or adipogenic lineages, and a second model in which invading adipocytes adversely influence the immunological and contractile status of mature muscle tissue. The first model envisions that age-related changes in gene activity result in a disruption of lineage progression from its primary or default direction (bone and muscle) to a secondary alternative direction (fat). To test this model, GFP-reporter constructs that mark specific levels of cellular differentiation (Col3.6, bone; AP2, fat; myoD, muscle; smooth muscle actin.SMA, myofibroblast) will be introduced in to C57BI/6 (affected) and 129 P3/J (resistant) mice and the animals will be aged to 10 and 24 months. By combining reporter constructs with complementary colors, the ability of the lineage to progress from a progenitor to fully mature bone or muscle cells, or the branch point of the progenitor to select the primary or adipocytic lineage will be assessed in a primary cell culture model. The tempo and extent of differentiation will be assess in real time using repetitive fluorescence imaging of the same culture well, and the proportion of cells at a defined levels of development will be obtained by FAC analysis. In vitro analysis will suggest levels of differentiation that are particularly sensitive to genetic and age-related factors and the potential genetic mediators of the effect will be examined by microarray analysis of the FAC isolated cell populations. In vivo validation of the culture results will be performed by progenitor transplantation experiments into young and aged hosts, and by a BrdU labeling study that assesses lineage choices of the endogenous progenitor cells. To test the second model of in-situ tissue disruption by adipocytes, the two experimental groups will be phenotyped for appearance of GFP positive fat cells in bone and muscle and for a spatial correlation of adipocytes with disorganized microstructure within muscle fiber cells. The tools, techniques and molecular concepts that are developed in this grant will provide a foundation for future QTL studies in mice designed to map genetic factors that contribute to age-related changes in skeletal health.

描述（由申请人提供）：随着年龄的增长，肌肉骨骼系统的恶化，导致肌肉减少症和骨质疏松症是一种多因素现实，它具有严重的临床限制，使肌肉力量，迁移率和脆弱的老年人功能独立性丧失。鼠模型可以为有助于该过程的环境和遗传因素提供一个窗口。该赠款将检验两个独立但融合的假设：一个基于谱系调节的模型，该模型的重点是具有发展为肌生成，成骨或脂肪生成谱系的通用祖细胞，并为第二个模型，其中侵入脂肪细胞不利地影响了免疫学和免疫学和。成熟肌肉组织的收缩状态。第一个模型设想，基因活性与年龄相关的变化会导致谱系从其主要或默认方向（骨和肌肉）到次级替代方向（FAT）的谱系进展。为了测试该模型，将标记特定水平的细胞分化水平（Col3.6，Bone; ap2，fat； myod，肌肉；平滑肌肌动蛋白。SMA，肌纤维细胞）的GFP重复蛋白构建。和129 p3/j（抗性）小鼠，动物的年龄为10和24个月。通过将报告基因构建体与互补的颜色相结合，谱系从祖细胞到完全成熟的骨骼或肌肉细胞的能力，或祖细胞的分支点选择主要或脂肪细胞谱系的分支点。通过对同一培养物的重复荧光成像，将实时评估分化的节奏和程度，并且通过FAC分析将获得定义开发水平的细胞比例。体外分析将表明分化水平对遗传和年龄相关的因素特别敏感，并且该作用的潜在遗传介体将通过对FAC分离细胞群体的微阵列分析来检查。培养结果的体内验证将通过祖细胞移植实验和老年宿主进行，以及评估内源性祖细胞的谱系选择的BRDU标记研究。为了测试脂肪细胞的第二个原位组织破坏模型，将对两个实验组进行表型，以表现出骨骼和肌肉中GFP阳性脂肪细胞的出现，以及在肌肉纤维细胞中与杂有的微观结构的脂肪细胞的空间相关性。该赠款中开发的工具，技术和分子概念将为旨在绘制遗传因素的QTL研究提供基础，以绘制有助于年龄相关的骨骼健康变化。