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，构成了 在我们医院接受治疗的患者比例不断增加，但研究 肌腱愈合的细胞生物学还处于起步阶段。 特别是 肌腱愈合的重要性在于运动及其效果的关系 底层机制。 本研究的目的是探索可能的 机制，负责机械模拟对肌腱的影响 细胞生物学（肌动蛋白聚合和细胞迁移）和生化 响应（第二信使和矩阵适应）。 具体目标是： 1.使肌腱和鞘细胞受到规定的机械变形 振幅、持续时间、频率和应变率分别为 已知； 2. 探究机械运动的机理 转化为生化信号； 3.了解胶原蛋白如何 细胞内的新陈代谢受到规定的循环拉伸的调节 体外。 我的实验室已开发出一种仪器，将使用 对胶原蛋白涂层、柔性底部施加调节的机械应变 支持肌腱细胞粘附和生长的培养板。 一个 细胞对机械响应的数学表达 因子、伸长率、频率和应变率将用于建模 模拟肌腱所经历的身体活动的培养实验 和体内的鞘。 成骨细胞和内皮细胞受到刺激 除以一种循环应变方案，而平滑肌细胞和牙髓 成纤维细胞发育迟缓，而肌腱细胞则难以治愈。 其他 蛋白质合成和胶原代谢改变等反应 具体已注明。 对关键第二信使的检查 信号通路，例如 cAMP、PGE2、二酰基甘油和 磷酸肌醇将使用放射免疫分析法、化学分析法进行 分离和蛋白激酶C 测量。 细胞有丝分裂反应 将通过直接在受刺激的环境中定量 DNA 合成来进行测定 细胞和条件培养基中。 胶原蛋白代谢将通过以下方式监测 mRNA 定量、胶原蛋白合成、交联质量类型和 数量。 模拟物理变形对肌腱细胞的影响 文化可能会产生锻炼方案起作用的定量解决方案 最好在体内产生坚固而灵活的愈合肌腱。