ELECTRIC FIELD ATTENUATION OF OSTEOCLAST FORMATION

刺激骨吸收的全身激素信号受到调节 以特定于场地的方式受当地因素影响。其中最重要的是 骨骼动态平衡的局部调节器是物理刺激。一 提出的骨骼对负荷反应的机制是局部的 机械刺激产生一个电场，它可以被 骨组织作为骨调节因子。事实上，时变电场 已经成功地用于预防动物的废用性骨质疏松症。 因此，我们假设破骨细胞的形成， 骨吸收的细胞效应物，是由局部电调制的 菲尔德。在前期工作中，使用了独特的电磁系统 能够在体外产生均匀且可量化的电场， 我们已经证明，时变的电场会衰减 1，25(OH)2D诱导小鼠破骨细胞样细胞的形成 骨髓培养系统。我们建议扩大这些观察结果， 定义负责以下任务的本地字段的特征 破骨细胞生成的衰减，并研究相互作用 骨吸收的激素调节领域。 在这项为期四年的研究中，一系列系统的体外实验 建议在招聘过程中施加电场 小鼠骨髓模型系统中的破骨细胞。1，25(OH)2D驱动 破骨细胞的形成将通过破骨细胞样计数来评估 细胞和TRAP含量的测定/培养8天后良好。 在方井培养皿中电镀的细胞将放置在实验范围内 由产生时变磁场引起的电场 在螺线管线圈内。假暴露的细胞将受到 螺线管接收器内类似的振动和温度变化 产生零磁场的恒定电流。我们 将研究电场的哪些分量负责 破骨细胞形成的抑制、测试频率和强度 特征以及每天所需的小时数 最大衰减。电场的能力(使用最多的 有效场)抑制骨髓细胞集落增殖 在半固体介质中由M-CSF、GM-CSF或IL-3支持 检查以表明在招聘过程中的哪个时间点 调节破骨细胞的形成。然后我们将考察一下 这些领域以减弱因子对破骨细胞的招募 (除1，25(OH)2D外)在破骨细胞中起重要作用 分化：M-CSF、GM-CSF、IL-6。要减弱的场效应 通过骨髓培养产生的这些因子的分泌也将被研究。 使用标准生物测定来评估田间处理过的介质。 这些实验应该提供对正常站点的独特见解 骨转换的特效控制。此外，通过确定那些 调节破骨细胞形成的电场--一种新的 用于高危地区局部治疗的治疗方案 更年期的骨丢失成为可能。

Systemic hormonal signals which stimulate bone resorption are modulated in a site specific manner by local factors. Among the most important local regulators of skeletal homeostasis are physical stimuli. One proposed mechanism for the response of bone to loading is that local mechanical stimuli generate an electric field which can be sensed by bone tissue as osteoregulatory. Indeed, time varying electric fields have been used with success to prevent disuse osteoporosis in animals. Therefore, we have hypothesized that the formation of osteoclasts, the cell effectors of bone resorption, is modulated by the local electric field. In preliminary work, using a unique electromagnetic system capable of inducing uniform and quantifiable electric fields in vitro, we have shown that time varying electric fields attenuate the 1,25(OH)2D-driven formation of osteoclast-like cells from the murine marrow culture system. We propose to extend these observations, defining the characteristics of the local field responsible for attenuation of osteoclastogenesis, and investigating interactions of the field with hormone regulators of bone resorption. In this four year study a systematic series of in vitro experiments is proposed which involves applying electric fields during recruitment of osteoclasts from the murine marrow model system. 1,25(OH)2D-driven osteoclast formation will be assessed by counting of osteoclast-like cells and assay of TRAP content/well after an 8 day culture period. Cells plated in square well dishes will be placed within experimental electric fields induced by creating a time varying magnetic field within a solenoid coil. Sham exposed cells will be subjected to similar vibrational and thermal variations within a solenoid receiving a constant electric current, which induces a null magnetic field. We will examine which components of the electric field are responsible for inhibition of osteoclast formation, testing frequency and intensity characteristics as well as the number of hours per day required for maximal attenuation. The ability of electric fields (using the most efficacious field) to inhibit marrow cell colony proliferation supported by M-CSF, GM-CSF or IL-3 in semisolid media will then be examined to indicate at which point during recruitment the field modulates osteoclast formation. We will then examine the ability of these fields to attenuate the recruitment of osteoclasts by factors (besides 1,25(OH)2D) known to be important in osteoclast differentiation: M-CSF, GM-CSF and IL-6. Field effects to diminish secretion by the marrow culture of these factors will also be studied using standard bioassays to assess field treated media. These experiments should provide unique insights into the normal, site specific control of bone turnover. Further, by identifying those electric fields which modulate osteoclast formation, a novel therapeutic regimen for the local treatment of areas at high risk of involutional bone loss becomes possible.