Molecular response of the patellar tendon to fatigue loading explained in the context of the initial induced damage and number of fatigue loading cycles
Molecular response of the patellar tendon to fatigue loading explained in the context of the initial induced damage and number of fatigue loading cycles
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DOI：
10.1002/jor.22059
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发表时间：
2012-08-01
影响因子：
2.8
通讯作者：
Flatow, Evan L.
中科院分区：
文献类型：
--
作者：
Andarawis-Puri, Nelly;Sereysky, Jedd B.;Flatow, Evan L.
肌腱病的发生与亚断裂疲劳损伤的累积有关。我们之前利用大鼠的膝盖腱建立了损伤累积的活体模型。我们的模型允许我们控制输入的加载参数来诱导肌腱的疲劳损伤。尽管有这种精确的控制，但由于不同动物的膝盖腱大小或强度不同，由此造成的损伤可能会有所不同。在这项研究中，我们使用指示诱导损伤的应用循环次数和初始(第0天)参数来评估疲劳加载后7天的分子响应。我们假设，加载和卸载加载和卸载位移曲线的0天滞后、伸长和硬度将预测7天的分子响应。结果表明，7天的分子反应与0天的延伸率和卸载刚度之间存在相关性。此外，负荷导致几个提示适应的细胞外基质基因上调；然而，这些基因中的几个(Col-I、-XII、MMP2和TIMP 3)在诱导高水平的损伤后关闭。我们表明，根据0天伸长率来评估7天的分子轮廓可以提供重要的洞察力，这一点仅通过比较疲劳加载循环的次数就会丢失。我们的数据显示，负荷通常会导致适应性反应。然而，随着损伤的加剧，肌腱的有效反应能力会恶化。(C)2012年骨科研究会。由威利期刊出版公司出版，《矫形外科杂志》2012年版30：13271334
Accumulation of sub-rupture fatigue damage has been implicated in the development of tendinopathy. We previously developed an in vivo model of damage accumulation using the rat patellar tendon. Our model allows us to control the input loading parameters to induce fatigue damage in the tendon. Despite this precise control, the resulting induced damage could vary among animals because of differences in size or strength among their patellar tendons. In this study, we used number of applied cycles and initial (day-0) parameters that are indicative of induced damage to assess the molecular response 7 days after fatigue loading. We hypothesized that day-0 hysteresis, elongation, and stiffness of the loading and unloading loaddisplacement curves would be predictive of the 7-day molecular response. Results showed correlations between the 7-day molecular response and both day-0 elongation and unloading stiffness. Additionally, loading resulted in upregulation of several extracellular matrix genes that suggest adaptation; however, several of these genes (Col-I, -XII, MMP 2, and TIMP 3) shut down after a high level of damage was induced. We showed that evaluating the 7-day molecular profile in light of day-0 elongation provides important insight that is lost from comparing number of fatigue loading cycles only. Our data showed that loading generally results in an adaptive response. However, the tendon's ability to effectively respond deteriorates as greater damage is induced. (C) 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:13271334, 2012