High strain mechanical loading rapidly induces tendon apoptosis: an ex vivo rat tibialis anterior model
High strain mechanical loading rapidly induces tendon apoptosis: an ex vivo rat tibialis anterior model
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DOI：
10.1136/bjsm.2004.015164
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发表时间：
2005-05-01
影响因子：
18.4
通讯作者：
Duronio, V
中科院分区：
文献类型：
--
作者：
Scott, A;Khan, KM;Duronio, V
背景：细胞凋亡或程序性细胞死亡在肌腱中的作用最近才被探索。目的：研究大鼠肌腱高应变负荷后细胞凋亡的发展。方法：准备三只大鼠的右侧胫骨前肌腱以进行机械负荷，并以相同的方式制备左侧肌腱作为未负荷对照。使用 1 Hz 纵向正弦波信号对肌腱施加 20% 的应变，持续 6 小时。以下用于评估细胞凋亡：（a）单克隆小鼠抗体（F7-26）来标记单链DNA断裂； (b) 特异性识别 caspase-3 切割形式的兔多克隆抗体。 结果：光学显微镜证实高应变方案诱导拉伸超负荷损伤。对照肌腱显示很少或没有 F7-26 抗体染色，但加载的肌腱显示大量凋亡细胞。负载肌腱中凋亡细胞的百分比 (20%) 显着高于对照肌腱 (1%) (p = 0.000)。标记的细胞与异常的核形态共定位，包括核碎片。针对裂解的 caspase-3 的染色仅在负载肌腱中呈阳性，并且定位于细胞核和细胞质。结论：该实验通过表明细胞凋亡可以响应短期、高应变机械负载而发生，从而扩展了对人类肌腱细胞凋亡的认识。这是完整肌腱机械负荷导致过度细胞凋亡的第一份报告。
Background: The role of apoptosis, or programmed cell death, has only recently been explored in tendon.Objective: To investigate the development of apoptosis after high strain loading of rat tendon.Methods: The right tibialis anterior tendons of three rats were prepared for mechanical loading, and left tendons were prepared identically as non-loaded controls. Tendon was loaded with 20% strain for six hours using a 1 Hz longitudinal sine wave signal. The following were used to assess apoptosis: (a) a monoclonal mouse antibody (F7-26) to label single stranded DNA breaks; (b) a rabbit polyclonal antibody that specifically recognises the cleaved form of caspase-3.Results: Light microscopy confirmed that the high strain protocol induced a stretch overload injury. Control tendons showed little or no staining with the F7-26 antibody, but the loaded tendons displayed numerous apoptotic cells. The percentage of apoptotic cells (20%) in the loaded tendon was significantly greater than in the control tendon (1%) (p = 0.000). The labelled cells colocalised with abnormal nuclear morphology, including nuclear fragmentation. The staining against cleaved caspase-3 was positive in loaded tendons only, and localised both to nucleus and cytoplasm.Conclusion: This experiment extends knowledge of human tendon apoptosis by showing that apoptosis can occur in response to short term, high strain mechanical loading. This is the first report of mechanical loading of intact tendon causing excessive apoptosis.