Anatomy and Cell Biology, Uniklinik RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany.
Institute of Neuroanatomy, Uniklinik RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany.
Int J Mol Sci. 2020 Apr 22;21(8):2925. doi: 10.3390/ijms21082925.
The effects of mechanical stress on cells and their extracellular matrix, especially in gliding sections of tendon, are still poorly understood. This study sought to compare the effects of uniaxial stretching on both gliding and traction areas in the same tendon. Flexor digitorum longus muscle tendons explanted from rats were subjected to stretching in a bioreactor for 6, 24, or 48 h, respectively, at 1 Hz and an amplitude of 2.5%. After stimulation, marker expression was quantified by histological and immunohistochemical staining in both gliding and traction areas. We observed a heightened intensity of scleraxis after 6 and 24 h of stimulation in both tendon types, though it had declined again 48 h after stimulation. We observed induced matrix metalloproteinase-1 and -13 protein expression in both tendon types. The bioreactor produced an increase in the mechanical structural strength of the tendon during the first half of the loading time and a decrease during the latter half. Uniaxial stretching of flexor tendon in our set-up can serve as an overloading model. A combination of mechanical and histological data allows us to improve the conditions for cultivating tendon tissues.
机械应力对细胞及其细胞外基质的影响，尤其是在滑行段的肌腱中，仍知之甚少。本研究旨在比较在同一肌腱的滑行区和牵引区施加单向拉伸的效果。从大鼠中取出的屈趾长肌腱在生物反应器中以 1 Hz 的频率和 2.5%的幅度分别拉伸 6、24 或 48 h。刺激后，通过组织学和免疫组织化学染色在滑行区和牵引区定量标记物表达。我们观察到在两种肌腱类型中，刺激 6 和 24 h 后，硬蛋白的强度增加，但刺激 48 h 后又下降。我们观察到两种肌腱类型中基质金属蛋白酶-1 和 -13 蛋白表达的诱导。生物反应器在加载时间的前半段增加了肌腱的机械结构强度，在后半段则降低了。我们的实验装置中对屈肌腱的单向拉伸可以作为一种过载模型。机械和组织学数据的结合可以改善培养肌腱组织的条件。
