The influence of mechanical stress on the gene expression related to the differentiation and the growth of bone cell

机械应力对骨细胞分化和生长相关基因表达的影响

• 批准号: 12470433
• 负责人: KIMURA Hiroto
• 金额: $ 8.96万
• 依托单位: Hirosaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12470433/
• 关键词: Osteoblast; Mechanical stress; Cyclic tensile strain; Quantitative RT-PCR; Nitric oxide; MAP kinase; sRANKL; Osteoprotegerin; Osteoprotegerin; 定量PCR法; TAクローニング; 機械的刺激; インターロイキン6

To study the influence of physical stimulus 6n bone remodeling, using a model of mechanical stress on osteoblasts, we investigated the production of NO and the expression and/or activation of NOS, Cox-2, and MAPKs. Furthermore, the synthesis of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) were investigated by ELISA.Results were as follows.1. Mechanical stress (cyclic tensile strain) against osteoblasts induced the NO production and the expression for iNOS mRNA.2. By the quantitative RT-PCR method, mechanical stress increased the expression for Cox-2 mRNA. But the expression of mRNA of cytokine and cytokine-receptors were not changed.3. The p38 MAPK was activated just after starting to add mechanical stress, on the contrary, ERK1/2 and JNK were not activated. Mechanical stress for 3 days, p38 MAPK activation was kept and ERK1/2 activation was down-regulated day by day.4. Adding mechanical stress at 4 hrs a day for 3days, sRANKL release was decreased and OPG synthesis was increased, simultaneously.These results suggested that p38 MAPK in osteoblasts was activated by adding mechanical stress. It was revealed consequently that mechanical stress activated osteoblasts to induce NO production, expression for Cox-2 mRNA and OPG through p38 MAPK activation. It was suggested that mechanical stress might enhance the function of osteoblasts to form new bone.

为了研究物理刺激对骨重塑的影响，我们利用成骨细胞的机械应力模型，研究了NO的产生以及NOS、Cox-2和MAPKs的表达和/或激活。此外，ELISA法检测了NF-κB配体受体激活剂（RANKL）和骨保护素（OPG）的合成。结果如下：成骨细胞的机械应力（循环拉伸应变）诱导NO的产生和iNOS mrna的表达。通过定量RT-PCR方法，机械应力增加了Cox-2 mRNA的表达。细胞因子和细胞因子受体mRNA的表达无明显变化。p38 MAPK在开始施加机械应力后才被激活，而ERK1/2和JNK则未被激活。机械应力作用3 d后，p38 MAPK活性保持不变，ERK1/2活性逐日下调。每天施加4 h机械应力，连续3d， sRANKL释放减少，OPG合成增加。这些结果表明，成骨细胞中的p38 MAPK通过增加机械应力而被激活。结果表明，机械应力激活成骨细胞，通过激活p38 MAPK诱导NO的产生、Cox-2 mRNA和OPG的表达。提示机械应力可能增强成骨细胞形成新骨的功能。