纽约州立大学石溪分校骨科生物工程研究实验室主任Yi-Xian Qin领导完成的一项研究表明,中等强度的超声能刺激成骨细胞的流动性,并触发其钙的释放,钙释放促骨细胞的增长。该技术可以提供一种方法来开发非药物治疗骨质疏松症、骨折等涉及骨质流失症状的疾病。
像骨骼、肌肉等组织受到机械负荷和应激如运动等刺激后存在强大的动态平衡状态。Qin医生和石溪分校的同事Shu Zhang、Jiqi Cheng正研究成骨细胞是如何应对机械信号如超声的。
在小鼠细胞实验模型中,研究小组创造了一种新的声辐射力(ARF)的超声形式,只适用于一分钟内单个成骨细胞。他们一致认为ARF通过聚焦超声束诱导细胞骨架重排,促进细胞的活力和流动,加速细胞内钙离子运输和浓度。
Qin医生表示该装置正在开发作为一种新的诊断工具,可以预测早期骨丢失。该项研究项目是由国立卫生研究院、国家空间生物医学研究所部分资助。(生物谷:Bioon.com)
doi:10.1371/journal.pone.0038343
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Mechanobiological Modulation of Cytoskeleton and Calcium Influx in Osteoblastic Cells by Short-Term Focused Acoustic Radiation Force
Shu Zhang1,2, Jiqi Cheng1, Yi-Xian Qin1*
Mechanotransduction has demonstrated potential for regulating tissue adaptation in vivo and cellular activities in vitro. It is well documented that ultrasound can produce a wide variety of biological effects in biological systems. For example, pulsed ultrasound can be used to noninvasively accelerate the rate of bone fracture healing. Although a wide range of studies has been performed, mechanism for this therapeutic effect on bone healing is currently unknown. To elucidate the mechanism of cellular response to mechanical stimuli induced by pulsed ultrasound radiation, we developed a method to apply focused acoustic radiation force (ARF) (duration, one minute) on osteoblastic MC3T3-E1 cells and observed cellular responses to ARF using a spinning disk confocal microscope. This study demonstrates that the focused ARF induced F-actin cytoskeletal rearrangement in MC3T3-E1 cells. In addition, these cells showed an increase in intracellular calcium concentration following the application of focused ARF. Furthermore, passive bending movement was noted in primary cilium that were treated with focused ARF. Cell viability was not affected. Application of pulsed ultrasound radiation generated only a minimal temperature rise of 0.1°C, and induced a streaming resulting fluid shear stress of 0.186 dyne/cm2, suggesting that hyperthermia and acoustic streaming might not be the main causes of the observed cell responses. In conclusion, these data provide more insight in the interactions between acoustic mechanical stress and osteoblastic cells. This experimental system could serve as basis for further exploration of the mechanosensing mechanism of osteoblasts triggered by ultrasound.