Unloading-Induced Degradation of the Anisotropic Arrangement of Collagen/Apatite in Rat Femurs
Unloading-Induced Degradation of the Anisotropic Arrangement of Collagen/Apatite in Rat Femurs
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DOI：
10.1007/s00223-016-0200-0
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发表时间：
2017-01-01
影响因子：
4.2
通讯作者：
Nakano, Takayoshi
中科院分区：
文献类型：
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作者：
Wang, Jun;Ishimoto, Takuya;Nakano, Takayoshi
胶原蛋白和生物磷灰石（BAp）的特定取向是骨微组织的各向异性特征；它是各向异性应力下骨机械功能和性能的重要决定因素。然而，当机械环境发生变化时，人们对这种微观结构取向如何改变知之甚少。我们假设胶原蛋白/BAp 的优先取向会随着机械条件的变化而变化，类似于骨量和骨形状变化的方式。在本研究中，我们使用大鼠坐骨神经切除模型研究了卸载（去除各向异性应力）对胶原/BAp 优先取向的影响。与在生理条件下形成的骨组织相比，在无负载条件下形成的骨组织表现出更无序的胶原/BAp取向。巧合的是，卸载骨中的骨细胞表现出球形形态和随机排列。据我们所知，这项研究首次证明了胶原蛋白/BAp 优先取向在卸载条件下会发生降解。总之，我们认为骨材料各向异性的改变是骨对卸载反应的一个重要方面，之前仅针对骨损失进行了检查。
The specific orientation of collagen and biological apatite (BAp) is an anisotropic feature of bone micro-organization; it is an important determinant of bone mechanical function and performance under anisotropic stress. However, it is poorly understood how this microstructure orientation is altered when the mechanical environment changes. We hypothesized that the preferential orientation of collagen/BAp would change in response to changes in mechanical conditions, similar to the manner in which bone mass and bone shape change. In the present study, we investigated the effect of unloading (removal of anisotropic stress) on the preferential orientation of collagen/BAp using a rat sciatic neurectomy model. Bone tissue that formed under unloaded conditions showed a more disordered collagen/BAp orientation than bone tissue that formed under physiological conditions. Coincidentally, osteocytes in unloaded bone displayed spherical morphology and random alignment. To the best of our knowledge, this study is the first to demonstrate the degradation of preferential collagen/BAp orientation in response to unloading conditions. In summary, we identified alterations in bone material anisotropy as an important aspect of the bone's response to unloading, which had previously been examined with regard to bone loss only.