Shear stress inhibits while disuse promotes osteocyte apoptosis
Shear stress inhibits while disuse promotes osteocyte apoptosis
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DOI：
10.1016/j.bbrc.2004.06.056
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发表时间：
2004-08-06
影响因子：
3.1
通讯作者：
Burger, E
中科院分区：
文献类型：
--
作者：
Bakker, A;Klein-Nulend, J;Burger, E
细胞凋亡在生物学上是一种除去除死亡细胞外的一种组织机制。我们最近提出，在骨重建过程中..与整个骨骼的机械负荷有关的骨细胞凋亡引导骨排列[J.生物力学]。36(2003)1453]。在这里，我们提出的证据表明，细胞培养中的骨细胞凋亡是由剪切力调节的。在静态培养条件下，血清饥饿的骨细胞在细胞膜上暴露磷脂酰丝氨酸(PS)的频率是骨膜成纤维细胞的6倍，是成骨细胞的3倍。剪切应力处理使暴露于PS的骨细胞数量减少了90%，但对其他类型的细胞没有影响。流体剪应力呈剂量依赖性地刺激人骨细胞中Bcl2mRNA的表达，而剪应力不改变Bax的表达。这些数据表明，废用促进了骨细胞的凋亡，而流体切应力的机械刺激通过调节Bcl2/Bax的表达比率促进了骨细胞的存活。(C)2004 Elsevier Inc.保留所有权利。
Cell apoptosis operates as an organizing mechanism in biology in addition to removing effete cells. We have recently proposed that during bone remodeling.. osteocyte apoptosis steers osteonal alignment in relation to mechanical loading of the whole bone [J. Biomech. 36 (2003) 1453]. Here we present evidence that osteocyte apoptosis in cell culture is modulated by shear stress. Under static culture conditions, serum starved osteocytes exposed phosphatidylserine (PS) on their cell membrane 6x more often than periosteal fibroblasts and 3x more often than osteoblasts. Treatment with shear stress reduced the number of osteocytes that exposed PS by 90%, but did not affect the other cell types. Fluid shear stress of increasing magnitude, dose-dependently stimulated Bcl-2 mRNA expression in human bone cells, while shear stress did not change Bax expression. These data suggest that disuse promotes osteocyte apoptosis, while mechanical stimulation by fluid shear stress promotes osteocyte survival, by modulating the Bcl-2/Bax expression ratio. (C) 2004 Elsevier Inc. All rights reserved.