Response to mechanical strain in an immortalized pre-osteoblast cell is dependent on ERK1/2
Response to mechanical strain in an immortalized pre-osteoblast cell is dependent on ERK1/2
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DOI：
10.1002/jcp.20581
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发表时间：
2006-05-01
影响因子：
5.6
通讯作者：
Rubin, J
中科院分区：
文献类型：
--
作者：
Fan, M;Rahnert, JA;Rubin, J
机械菌株通过调节成骨细胞功能抑制破骨细胞生成：我们已经表明，菌株抑制nf - κ B配体受体激活因子（RANKL）表达，并通过ERK1/2信号通路增加内皮型一氧化氮合酶（eNOS）和一氧化氮水平。原代基质培养系统虽然有助于理解微环境如何调节骨重塑，但在生化分析和其他骨祖细胞对机械应变反应的研究中受到限制：基质细胞增殖不良，在培养相对较短的时间后失去应变反应的方面。在这项研究中，我们使用了已建立的小鼠成骨细胞系，条件永生化小鼠颅骨（CIMC-4），该细胞系来自于通过插入SV40大T抗原（TAg）温度敏感突变基因编码而条件永生化的小鼠颅骨，并支持破骨细胞的发生。机械应变（0.5-2%，10个周期/分钟，等双轴）导致RANKL表达的幅度依赖性下降，低于未应变培养的50%。通过RT-PCR检测，2%的过夜菌株也使osterix （OSX）和RUNX2的表达增加了近两倍。重要的是，ERK1/2抑制剂PD98059完全消除了菌株效应，使RANKL、OSX和RUNX2基因表达完全恢复到控制水平。这些数据表明，菌株对CIMC-4细胞的影响需要激活ERK1/2通路。因此，CIMC-4细胞系是一种有用的体外模型，它有效地概括了原代基质细胞的各个方面，并增加了在机械活性环境中研究成骨细胞对骨重塑的控制的扩展能力。
Mechanical strain inhibits osteoclastogenesis by regulating osteoblast functions: We have shown that strain inhibits receptor activator of NF-kappa B ligand (RANKL) expression and increases endothelial nitric oxide synthase (eNOS) and nitric oxide levels through ERK1/2 signaling in primary bone stromal cells. The primary stromal culture system, while contributing greatly to understanding of how the microenvironment regulates bone remodeling is limited in use for biochemical assays and studies of other osteoprogenitor cell responses to mechanical strain: Stromal cells proliferate poorly and lose aspects of the strain response after a relatively short time in Culture. In this study, we used the established mouse osteoblast cell line, conditionally immortalized murine calvarial (CIMC-4), harvested from mouse calvariae conditionally immortalized by insertion of the gene coding for a temperature-sensitive mutant of SV40 large T antigen (TAg) and Support osteoclastogenesis. Mechanical strain (0.5-2%, 10 cycles per min, equibiaxial) caused magnitude-dependent decreases in RANKL expression to less than 50% those of unstrained cultures. Overnight strains of 2% also increased osterix (OSX) and RUNX2 expression by nearly twofold as measured by RT-PCR. importantly, the ERK1/2 inhibitor, PD98059, completely abrogated the strain effects bringing RANKL, OSX, and RUNX2 gene expression completely back to control levels. These data indicate that the strain effects on CIMC-4 cells require activation of ERK1/2 pathway. Therefore, the CIMC-4 cell line is a useful alternative in vitro model which effectively recapitulates aspects of the primary stromal cells and adds an extended capacity to study osteoblast control of bone remodeling in a mechanically active environment.