Investigation of action of shear stress, which is produced by Mechanical loading applied to the skeleton, on osteodast formation and bone-resorbing activity

研究由施加到骨骼的机械载荷产生的剪切应力对破骨细胞形成和骨吸收活性的作用

• 批准号: 17591922
• 负责人: HAKEDA Yoshiyuki
• 金额: $ 2.24万
• 依托单位: Meikai University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17591922/
• 关键词: bone; fluid shear stress; osteoblasts; osteoclastogenesis; bone resorption; RANKL; prostaglandin; OPG; 破骨細胞文化

Background : Mechanical loading applied to the skeleton is crucial to the development and maintenance of bone integrity and architecture. A decrease in the mechanical loading due to prolonged immobilization or weightlessness in space reduces the bone formation rate, resulting in bone loss. On the other hand, an increase in mechanical loading causes a gain in bone density. Thus, bone tissue is sensitive to mechanical stimulation. Mechanical loading on bone generates extracellular matrix deformation and fluid flow, and the mechanical stimuli are translated to mechanical signals such as mechanical strain and fluid shear stress, respectively. Evidence obtained from in vitro studies indicates that osteocytes embedded in the lacunae/canaliculi system and osteoblasts and bone cells lining the bone surface are mechanosensors that detect load-derived mechanical stimuli. By these bone-forming cells, the mechanical stimuli are translated into cellular signaling factors. However, normal bone metab … More olism is achieved by bone remodeling on balance between bone-forming cells and bone-resorbing cells. To date, the effect of fluid shear stress on osteoblasts has been extensively investigated ; however, the action on osteoclasts responsible for bone resorption remains to be elucidated. Therefore, the aim of this study is to elucidate the effect of fluid shear stress on osteoclastogenesis and osteoclast function directly or indirectly via osteoblasts.Methods : We isolated osteoblastic cells from mouse calvaria, and loaded fluid shear stress on these cells with a single flow-through system. In the case of study on osteoclast formation, we employed in vitro culture system of M-CSF dependent bone marrow cells-derived osteoclast progenitors for osteoclast formation dependent on RANKL. Results and Discussion : Isolated mouse calvalia-derived osteoblasts were capable of forming nodules and calcifing in a long-term culture. When the osteoblasts were exposed to fluid shear stress, expression of Cox-2 and RANKL mRNAs was increased as early as 2h after the start of exposure. In addition, gene expression of OPG, a soluble decoy receptor of RANKL, was also increased by the fluid shear stress in the cells ; however, the increase was less than that of RANKL expression. Conditioned medium obtained from the culture of shear stress-loading osteoblasts increased osteoclast formation induced by low concentration of RANKL, whereas the conditioned medium from the stress-unloading osteoblasts did not stimulated the formation. Short-term shear stress loading was sufficient for induction of RANKL gene expression, and the induction maintained even after freeing the loading. The shear stress-induced RANKL expression was dependent on the activation of Erk, but independent of prostaglangin induced by the shear stress. Finally, fluid shear stress directly stimulated the osteoclast formation from osteoclast precursors that were treated with M-CSF and low doses of RANKL. Taken together, fluid shear stress stimulates osteoclastogenesis directly or indirectly via inducing RANKL expression in osteoblasts. Less

背景：施加到骨骼上的机械载荷对于骨骼完整性和结构的发育和维持至关重要。 A decrease in the mechanical loading due to prolonged immobilization or weightlessness in space reduces the bone formation rate, resulting in bone loss.另一方面，机械负荷的增加会导致骨密度增加。 Thus, bone tissue is sensitive to mechanical stimulation. Mechanical loading on bone generates extracellular matrix deformation and fluid flow, and the mechanical stimuli are translated to mechanical signals such as mechanical strain and fluid shear stress, respectively. Evidence obtained from in vitro studies indicates that osteocytes embedded in the lacunae/canaliculi system and osteoblasts and bone cells lining the bone surface are mechanosensors that detect load-derived mechanical stimuli.通过这些骨形成细胞，机械刺激被转化为细胞信号因子。 However, normal bone metab … More olism is achieved by bone remodeling on balance between bone-forming cells and bone-resorbing cells.迄今为止，流体剪切应力对成骨细胞的影响已被广泛研究。 however, the action on osteoclasts responsible for bone resorption remains to be elucidated. Therefore, the aim of this study is to elucidate the effect of fluid shear stress on osteoclastogenesis and osteoclast function directly or indirectly via osteoblasts.Methods : We isolated osteoblastic cells from mouse calvaria, and loaded fluid shear stress on these cells with a single flow-through system. In the case of study on osteoclast formation, we employed in vitro culture system of M-CSF dependent bone marrow cells-derived osteoclast progenitors for osteoclast formation dependent on RANKL.结果与讨论：分离的小鼠颅骨来源的成骨细胞能够在长期培养中形成结节并钙化。 When the osteoblasts were exposed to fluid shear stress, expression of Cox-2 and RANKL mRNAs was increased as early as 2h after the start of exposure.此外，细胞内流体剪切应力也增加了 RANKL 的可溶性诱饵受体 OPG 的基因表达。然而，增加幅度小于 RANKL 表达的增加幅度。 Conditioned medium obtained from the culture of shear stress-loading osteoblasts increased osteoclast formation induced by low concentration of RANKL, whereas the conditioned medium from the stress-unloading osteoblasts did not stimulated the formation. Short-term shear stress loading was sufficient for induction of RANKL gene expression, and the induction maintained even after freeing the loading.剪切应力诱导的 RANKL 表达依赖于 Erk 的激活，但与剪切应力诱导的前列腺素无关。 Finally, fluid shear stress directly stimulated the osteoclast formation from osteoclast precursors that were treated with M-CSF and low doses of RANKL.总之，流体剪切应力通过诱导成骨细胞中的 RANKL 表达直接或间接刺激破骨细胞生成。较少的

项目成果

PGC7/Stella protects against DNA demethylation in early embryogenesis

• DOI: 10.1038/ncb1519
• 发表时间: 2007-01-01
• 期刊: NATURE CELL BIOLOGY
• 影响因子: 21.3
• 作者: Nakamura, Toshinobu;Arai, Yoshikazu;Nakano, Toru
• 通讯作者: Nakano, Toru

Action of glucocorticoid on bone-forming and bone-resorbing cells.

糖皮质激素对骨形成和骨吸收细胞的作用。

• 发表时间: 2006
• 期刊: Clin Calcium 16(11)
• 作者: Nakamura;T.;Arai;Y.;Umehara;H.;Masuhara;M.;Kimura;T.;Taniguchi;H.;Sekimoto;T.;Ikawa;M.;Yoneda;Y.;Okabe;M.;Tanaka;S.;Shiota;K.;Nakano;T.;羽毛田慈之;Ozaki A;Hakeda Y.
• 通讯作者: Hakeda Y.

Production of IL-7 is increased in ovariectomized mice, but not RANKL mRNA expression by osteoblasts/stromal cells in bone, and IL-7 enhances generation of osteoclast precursors in vitro

• DOI: 10.1007/s00774-006-0723-y
• 发表时间: 2007-01-01
• 期刊: JOURNAL OF BONE AND MINERAL METABOLISM
• 影响因子: 3.3
• 作者: Sato, Takuya;Watanabe, Ken;Hakeda, Yoshiyuki
• 通讯作者: Hakeda, Yoshiyuki

グルココルチコイドの骨形成系・骨吸収系細胞に対する作用

糖皮质激素对成骨细胞和骨吸收细胞的影响

• 发表时间: 2006
• 期刊: Cinical Calcium 16
• 作者: Nakamura;T.;Arai;Y.;Umehara;H.;Masuhara;M.;Kimura;T.;Taniguchi;H.;Sekimoto;T.;Ikawa;M.;Yoneda;Y.;Okabe;M.;Tanaka;S.;Shiota;K.;Nakano;T.;羽毛田慈之
• 通讯作者: 羽毛田慈之