Small oscillatory accelerations, independent of matrix deformations, increase osteoblast activity and enhance bone morphology.
Small oscillatory accelerations, independent of matrix deformations, increase osteoblast activity and enhance bone morphology.
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DOI：
10.1371/journal.pone.0000653
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发表时间：
2007-07-25
期刊：
影响因子：
3.7
通讯作者：
Judex S
中科院分区：
文献类型：
--
作者：
Garman R;Rubin C;Judex S
一系列组织具有适应机械挑战的能力，这是一种假定通过细胞和/或周围基质的变形来调节的属性。相反，它在这里示出，非常小的振荡加速度，作为不受约束的运动和诱导可忽略的变形，作为一个合成代谢刺激成骨细胞在体内。通过后肢卸载从18只雌性成年小鼠的胫骨中去除习惯性背景负荷。每只小鼠的左侧胫骨以45 Hz的频率受到0.6 g的振荡加速度，持续20 min/d，5 d/周，而右侧胫骨作为对照。假负荷（n = 9）和正常年龄匹配的对照（n = 18）小鼠提供了额外的比较。 与对侧对照组相比，在不负重的情况下施加振荡加速度，导致干骺端骨小梁的骨形成率增加70%，但骨吸收水平相似。骨小梁的数量和质量也因加速度刺激而得到改善，表现为骨体积分数（17%）和连接密度（33%）显著增加，骨小梁间距（−6%）和结构模型指数（−11%）显著减小。这些体内数据表明，常驻骨细胞群的机械感觉元件可以感知和响应加速度信号，并指出一种有效的手段，将强烈的物理信号引入生物系统，而不会使基质处于过载的风险中。回顾过去，与直接的机械变形相反，加速度代表了一种更通用、更安全、也可能是更基本的手段，可以将物理挑战传递给生物体的细胞和组织。
A range of tissues have the capacity to adapt to mechanical challenges, an attribute presumed to be regulated through deformation of the cell and/or surrounding matrix. In contrast, it is shown here that extremely small oscillatory accelerations, applied as unconstrained motion and inducing negligible deformation, serve as an anabolic stimulus to osteoblasts in vivo. Habitual background loading was removed from the tibiae of 18 female adult mice by hindlimb-unloading. For 20 min/d, 5 d/wk, the left tibia of each mouse was subjected to oscillatory 0.6 g accelerations at 45 Hz while the right tibia served as control. Sham-loaded (n = 9) and normal age-matched control (n = 18) mice provided additional comparisons. Oscillatory accelerations, applied in the absence of weight bearing, resulted in 70% greater bone formation rates in the trabeculae of the metaphysis, but similar levels of bone resorption, when compared to contralateral controls. Quantity and quality of trabecular bone also improved as a result of the acceleration stimulus, as evidenced by a significantly greater bone volume fraction (17%) and connectivity density (33%), and significantly smaller trabecular spacing (−6%) and structural model index (−11%). These in vivo data indicate that mechanosensory elements of resident bone cell populations can perceive and respond to acceleratory signals, and point to an efficient means of introducing intense physical signals into a biologic system without putting the matrix at risk of overloading. In retrospect, acceleration, as opposed to direct mechanical distortion, represents a more generic and safe, and perhaps more fundamental means of transducing physical challenges to the cells and tissues of an organism.
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影响因子：
--
作者：
FROST, HM
通讯作者：
FROST, HM
影响因子：
2.8
作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
6.2
作者：
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通讯作者：
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影响因子：
64.8
作者：
Rubin, C;Turner, AS;McLeod, K
通讯作者：
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