INTERACTIONA & RESPONSES TO STRESS IN VITRO

互动

• 批准号: 3158418
• 负责人: ALBERT J BANES
• 金额: $ 15.06万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-08-01 至 1993-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3158418
• 关键词: chickens; collagen; crosslink; exercise; fibroblasts; fluorescence microscopy; immobilization of body part; mechanical stress; protein biosynthesis; second messengers; sports injury; synovial fluid; tendon injury; tissue /cell culture; wound healing

Tendon injuries, particularly sports related injuries, constitute an increasing proportion of patients treated at our hospital, yet research in the cell biology of tendon healing is in its infancy. Of particular importance in tendon healing is the relationship of exercise and its underlying mechanism. The objective of this study is to explore possible mechanisms, responsible for the effects of mechanical simulation on tendon cell biologic (actin polymerization and cell migration) and biochemical responses (second messengers and matrix adaptations). Specific aims are: 1. to subject tendon and sheath cells to defined mechanical deformation regiments where the amplitude, duration, frequency and strain rates are known; 2. to investigate the mechanism by which mechanical activity is translated into a biochemical signal; 3. to understand how collagen metabolism is regulated in cells subjected to defined cyclic stretching in vitro. An instrument has been developed in my laboratory that will be used to apply regulated mechanical strain to collagen coated, flexible bottomed culture plates that support tendon cell adherence and growth. A mathematical expression relating a response of a cell to the mechanical factors, elongation, frequency and strain rate will be used to model experiments in culture that mimic physical activity experienced by tendon and sheath in vivo. Osteoblasts and endothelial cells are stimulated to divide by one regimen of cyclic strain whereas smooth muscle cells and pulp fibroblasts are retarded while tendon cells are refractory. Other responses such as alteration in protein synthesis and collagen metabolism specifically have been noted. An examination of key second messenger signalling pathways, such as, cAMP, PGE2, diacylglycerol and phosphoinositides will be performed using radioimmunoassay, chemical separation and protein kinase C measurements. Mitogenic responses of cells will be assayed by quantitation of DNA synthesis directly in stimulated cells and in conditioned medium. Collagen metabolism will be monitored by quantitation of mRNA, collagen synthesis, type an crosslink quality an quantity. Modelling the impact of physical deformation on tendon cells in culture may yield a quantitative solution to which exercise regimens work best in vivo to yield a healed tendon that is strong yet flexible.

肌腱损伤，特别是与运动相关的损伤，构成 在我们医院接受治疗的患者比例越来越高，但研究表明 肌腱愈合的细胞生物学还处于初级阶段。特别的 肌腱愈合中的重要一点是运动和运动之间的关系。 潜在的机制。这项研究的目的是探索 力学模拟对肌腱影响的机理 细胞生物学(肌动蛋白聚合和细胞迁移)和生化 回应(第二信使和矩阵调整)。具体目标是： 1.使肌腱和鞘细胞承受规定的机械变形 波幅、持续时间、频率和应变率 已知；2.研究机械活动的机制 转化为生化信号；3.了解胶原蛋白是如何 新陈代谢在细胞中受到明确的循环伸展的调节 体外培养。我的实验室已经开发出一种仪器，将用于 将调整的机械应变应用于胶原蛋白涂层、柔性底板 支持肌腱细胞黏附和生长的培养板。一个 与细胞对机械的响应有关的数学表达式 将使用因素、伸长率、频率和应变率来建模 模拟肌腱经历的体力活动的培养实验 和鞘在体内。成骨细胞和内皮细胞被刺激以 除以一种循环应变方案，而平滑肌细胞和牙髓 成纤维细胞是迟缓的，而肌腱细胞是难治的。其他 蛋白质合成和胶原代谢改变等反应 特别值得注意的是。对关键第二信使的考察 信号通路，如cAMP、PGE2、二酰甘油和 磷脂酰肌醇将使用放射免疫分析，化学 分离和蛋白激酶C测定。细胞的有丝分裂反应 将通过量化DNA合成直接在刺激后进行检测 细胞和条件培养液中。胶原蛋白代谢将由以下人员监测 信使核糖核酸定量、胶原合成、A型交联性和 数量。物理变形对肌腱细胞影响的模拟研究 文化可能会产生一个量化的解决方案，运动养生法对此有效 最好的在活体内产生一个愈合的肌腱，既强壮又灵活。