Fascicular elastin within tendon contributes to the magnitude and modulus gradient of the elastic stress response across tendon type and species
Fascicular elastin within tendon contributes to the magnitude and modulus gradient of the elastic stress response across tendon type and species
复制标题
肌腱内的束状弹性蛋白有助于跨肌腱类型和物种的弹性应力响应的幅度和模量梯度
DOI：
10.1016/j.actbio.2022.03.025
复制
发表时间：
2023
影响因子：
9.7
通讯作者：
Lake, Spencer P.
中科院分区：
文献类型：
--
作者：
Eekhoff, Jeremy D.;Abraham, James A.;Schott, Hayden R.;Solon, Lorenzo F.;Ulloa, Gabriella E.;Zellers, Jennifer A.;Cannon, Paul C.;Lake, Spencer P.
弹性蛋白是弹性纤维的主要成分，已通过弹性蛋白降解研究和弹性病态小鼠模型证明对肌腱力学有显著影响。然而，目前尚不清楚先前的结果在物种和功能不同的肌腱之间有何不同，特别是结果如何转化为人类肌腱。束和束间弹性蛋白在功能上的差异也尚未完全阐明。因此，本研究评估了不同物种功能不同肌腱中弹性蛋白的数量、结构和力学贡献。具有储能功能的肌腱的弹性蛋白含量略高于具有定位功能的肌腱，而人类肌腱的弹性蛋白含量至少是其他物种的两倍。虽然观察到肌束和肌束间基质在弹性纤维的组织结构上的差异，但不同物种和肌腱类型之间弹性蛋白网络结构排列的差异是有限的。力学测试结合酶诱导的弹性蛋白降解被用来评估弹性蛋白对肌腱力学的贡献。在所有肌腱中，弹性蛋白降解通过降低应力值而影响弹性应力响应，同时增加应力-应变曲线的模数梯度。只有弹性蛋白对粘弹性性质的贡献因肌腱类型和种类的不同而不同，其中人肌腱和储能肌腱受影响更大。这些数据表明，束状弹性纤维对肌腱的拉伸机械反应有贡献，可能是通过调节负荷下的胶原结合来实现的。结果补充了先前的发现，并为更多地从机械上理解弹性纤维在肌腱中的作用提供了证据。有意义的陈述先前已表明，弹性蛋白影响肌腱的机械性能，由衰老或疾病引起的弹性蛋白网络的退化或异常可能导致疼痛和受伤风险的增加。然而，以前的工作还没有完全确定弹性蛋白对不同功能需求的肌腱以及肌腱不同区域的不同作用。本研究确定了弹性蛋白降解对具有不同功能需求、分级结构和弹性蛋白含量的肌腱的拉伸弹性和粘弹性反应的影响。此外，体积成像和蛋白质定量被用来彻底描述每个不同肌腱中的弹性蛋白网络。本文提出的结果可以为特定肌腱的策略提供参考，以维持或恢复弹性蛋白降解组织的固有属性。
Elastin, the main component of elastic fibers, has been demonstrated to significantly influence tendon mechanics using both elastin degradation studies and elastinopathic mouse models. However, it remains unclear how prior results differ between species and functionally distinct tendons and, in particular, how results translate to human tendon. Differences in function between fascicular and interfascicular elastin are also yet to be fully elucidated. Therefore, this study evaluated the quantity, structure, and mechanical contribution of elastin in functionally distinct tendons across species. Tendons with an energy-storing function had slightly more elastin content than tendons with a positional function, and human tendon had at least twice the elastin content of other species. While distinctions in the organization of elastic fibers between fascicles and the interfascicular matrix were observed, differences in structural arrangement of the elastin network between species and tendon type were limited. Mechanical testing paired with enzyme-induced elastin degradation was used to evaluate the contribution of elastin to tendon mechanics. Across all tendons, elastin degradation affected the elastic stress response by decreasing stress values while increasing the modulus gradient of the stress-strain curve. Only the contributions of elastin to viscoelastic properties varied between tendon type and species, with human tendon and energy-storing tendon being more affected. These data suggest that fascicular elastic fibers contribute to the tensile mechanical response of tendon, likely by regulating collagen engagement under load. Results add to prior findings and provide evidence for a more mechanistic understanding of the role of elastic fibers in tendon.Statement of significanceElastin has previously been shown to influence the mechanical properties of tendon, and degraded or abnormal elastin networks caused by aging or disease may contribute to pain and an increased risk of injury. However, prior work has not fully determined how elastin contributes differently to tendons with varying functional demands, as well as within distinct regions of tendon. This study determined the effects of elastin degradation on the tensile elastic and viscoelastic responses of tendons with varying functional demands, hierarchical structures, and elastin content. Moreover, volumetric imaging and protein quantification were used to thoroughly characterize the elastin network in each distinct tendon. The results presented herein can inform tendon-specific strategies to maintain or restore native properties in elastin-degraded tissue.