Mechano-Regulation of Trabecular Bone Adaptation Is Controlled by the Local in vivo Environment and Logarithmically Dependent on Loading Frequency.
Mechano-Regulation of Trabecular Bone Adaptation Is Controlled by the Local in vivo Environment and Logarithmically Dependent on Loading Frequency.
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DOI：
10.3389/fbioe.2020.566346
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发表时间：
2020
影响因子：
5.7
通讯作者：
Müller R
中科院分区：
文献类型：
--
作者：
Scheuren AC;Vallaster P;Kuhn GA;Paul GR;Malhotra A;Kameo Y;Müller R
众所周知，周期性而非静态的机械负荷对骨具有合成代谢作用。然而，描述加载频率和骨适应量之间关系的函数仍不清楚。采用实验和计算相结合的方法，本研究旨在研究松质骨的机械调节是否由局部体内环境中的机械信号控制，并依赖于加载频率。具体而言，通过结合在体内的微型计算机断层扫描（micro-CT）成像与微型有限元（micro-FE）分析，我们监测的变化，以及在体内环境的机械[应变能密度（SED）和SED梯度]的小鼠尾椎在4周的周期性负载在不同的频率为2，5，或10 Hz，分别，或静态负载。局部组织水平上较高的SED和SED梯度值导致骨小梁形成的概率增加和骨小梁吸收的概率降低。在所有载荷组中，与SED相比，SED梯度在确定局部骨形成和吸收事件方面具有上级优势。循环加载诱导积极的净（重）建模率相比，假和静态加载，主要是由于矿化表面的增加和减少侵蚀表面。因此，在2、5和10 Hz下，骨体积分数随时间增加（+15%、+21%和+24%，p ≤ 0.0001），而静态载荷导致骨体积分数降低（-9%，p ≤ 0.001）。此外，回归分析显示，在4周的观察期内，负荷频率与骨体积分数的净变化之间存在对数关系（R2 = 0.74）。总之，这些结果表明，骨小梁适应调节的机械信号在局部的体内环境，此外，机械调节是动力学依赖于加载频率低于一定的阈值具有分解代谢的影响，和那些以上的合成代谢的影响。因此，这项研究提供了有价值的见解，更好地了解机械信号影响骨小梁形成和吸收在当地的体内环境。
It is well-established that cyclic, but not static, mechanical loading has anabolic effects on bone. However, the function describing the relationship between the loading frequency and the amount of bone adaptation remains unclear. Using a combined experimental and computational approach, this study aimed to investigate whether trabecular bone mechano-regulation is controlled by mechanical signals in the local in vivo environment and dependent on loading frequency. Specifically, by combining in vivo micro-computed tomography (micro-CT) imaging with micro-finite element (micro-FE) analysis, we monitored the changes in microstructural as well as the mechanical in vivo environment [strain energy density (SED) and SED gradient] of mouse caudal vertebrae over 4 weeks of either cyclic loading at varying frequencies of 2, 5, or 10 Hz, respectively, or static loading. Higher values of SED and SED gradient on the local tissue level led to an increased probability of trabecular bone formation and a decreased probability of trabecular bone resorption. In all loading groups, the SED gradient was superior in the determination of local bone formation and resorption events as compared to SED. Cyclic loading induced positive net (re)modeling rates when compared to sham and static loading, mainly due to an increase in mineralizing surface and a decrease in eroded surface. Consequently, bone volume fraction increased over time in 2, 5, and 10 Hz (+15%, +21% and +24%, p ≤ 0.0001), while static loading led to a decrease in bone volume fraction (−9%, p ≤ 0.001). Furthermore, regression analysis revealed a logarithmic relationship between loading frequency and the net change in bone volume fraction over the 4 week observation period (R2 = 0.74). In conclusion, these results suggest that trabecular bone adaptation is regulated by mechanical signals in the local in vivo environment and furthermore, that mechano-regulation is logarithmically dependent on loading frequency with frequencies below a certain threshold having catabolic effects, and those above anabolic effects. This study thereby provides valuable insights toward a better understanding of the mechanical signals influencing trabecular bone formation and resorption in the local in vivo environment.
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影响因子：
2.5
作者：
Carrieroa A;Pereirab AF;Wilson AJ;Castagno S;Javaheri B;Pitsillides AA;Marenzana M;Shefelbine SJ
通讯作者：
Shefelbine SJ
影响因子：
2.8
作者：
Goodship, Allen E.;Lawes, Timothy J.;Rubin, Clinton T.
通讯作者：
Rubin, Clinton T.
影响因子：
4.1
作者：
Lambers, Floor M.;Schulte, Friederike A.;Mueller, Ralph
通讯作者：
Mueller, Ralph
影响因子：
3.2
作者：
Levchuk, Alina;Schneider, Philipp;Mueller, Ralph
通讯作者：
Mueller, Ralph
影响因子：
4.6
作者：
Betts, Duncan C. Tourolle ne;Wehrle, Esther;Muller, Ralph
通讯作者：
Muller, Ralph