INTERACTIONA & RESPONSES TO STRESS IN VITRO

肌腱损伤，特别是运动相关的损伤， 越来越多的病人在我们医院接受治疗，但研究 肌腱愈合的细胞生物学还处于起步阶段。 特别 肌腱愈合的重要性是运动与其 潜在机制 本研究的目的是探索可能的 机制，负责力学模拟对肌腱的影响 细胞生物学（肌动蛋白聚合和细胞迁移）和生物化学 反应（第二信使和矩阵适应）。 具体目标是： 1.使肌腱和鞘细胞经受限定的机械变形 振幅、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 代谢在细胞中受到确定的周期性拉伸的调节， 体外 我的实验室已经开发出一种仪器， 将调节的机械应变施加到胶原蛋白涂层的柔性底部 支持肌腱细胞粘附和生长的培养板。 一 一种数学表达式，将细胞对机械力的反应联系起来， 因素，伸长率，频率和应变率将被用来模拟 模拟肌腱经历的身体活动的培养实验 和鞘管。 成骨细胞和内皮细胞受到刺激， 通过一个周期性应变方案来划分，而平滑肌细胞和牙髓 成纤维细胞发育迟缓，而腱细胞则不应。 其他 反应，如蛋白质合成和胶原代谢的改变 特别注意到。 关键第二信使的研究 信号传导途径，如cAMP、PGE 2、甘油二酯和 磷酸肌醇将使用放射免疫测定法、化学法 分离和蛋白激酶C测量。 细胞的促有丝分裂反应 将通过直接在刺激的细胞中定量DNA合成来测定 细胞和条件培养基中。 胶原蛋白代谢将通过以下方法进行监测： mRNA定量、胶原合成、交联质量和 数量。 模拟物理变形对肌腱细胞的影响， 培养可能会产生一个定量的解决方案， 最好在体内产生一个愈合的肌腱，是强大的，但灵活的。

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.