Basic and clinical study aimed for the regenerative medicine of jaw bone by vibratory stimulation system

机械应力被认为在骨重建中起重要作用，但机械应力刺激的人成骨细胞的生物学反应尚不清楚。在口腔颌面部，几种手术后的颌骨缺损区均可用再生骨修复，但目前尚无有效的治疗方法。在这项研究中，我们开发了类似声波的新的振动机制，这是临床上适用的机械应力源，并设计了骨再生的研究计划。首先，我们阐明了振动刺激对成骨细胞和/或成纤维细胞的影响，我们检测了COX-2、RANKL、OPG、CBFA-1、BMP-4和VEGF的产生和/或表达。其次，我们进行了动物实验，在大鼠颅骨缺损处加入振动刺激，对培养的成骨细胞施加振动刺激，COX-2mRNA的表达明显增加，而蛋白质的产量没有增加。在培养的成纤维细胞中，血管内皮生长因子mRNA的表达呈时间依赖性增加。成骨细胞和成纤维细胞RANKL、OPG、CBFA-1、BMP-4的蛋白产量和mRNA表达无明显变化。在动物实验中，振动刺激对骨重建的影响不明显，我们认为振动刺激是一种经济有效的方法，适合临床应用，但与其他机械应力加载方法相比，它对骨再生的影响可能较小。在未来，我们打算从本研究中进行的基因芯片分析的结果中确定骨重建的关键分子。

Mechanical stress is thought to play an important role in bone remodeling, but the biological responses of human osteoblasts stimulated by mechanical stress are not well clarified. In oral maxillofacial region, the jaw bone defect after several types of surgery should be recovered by regenerated bone, however, there are no effective treatment methods available yet. In this research, we have developed new vibratory mechanism as like sound wave, that is clinically applicable source of mechanical stress, and designed research plan for bone regeneration. First, we clarifies the effect of vibratory stimulation on osteoblasts and/or fibroblasts, we investigated the production and/or the expression of COX-2,RANKL,OPG,Cbfa-1,BMP-4 and VEGF. Secondly, we carry out experiments on animals, adding vibratory stimulation on defect in the rat skull.Adding vibratory stimulation on cultured osteoblasts, the expression of COX-2 mRNA was significantly increased, otherwise the protein production was not increased. In cultured fibroblasts, the expression of VEGF mRNA was increased in time-dependent manner. However, the protein production and mRNA expression of RANKL,OPG, Cbfa-1,BMP-4 was not changed in osteoblasts and fibroblasts. In animal experiments, vibratory stimulation had no appreciable change in bone remodeling.We conclude that vibratory stimulation was cost-effective method as well as suitable for clinical application, however, it's effects on bone regeneration may be rather small compared to other mechanical stress loading methods. In the future, we intend to identify key molecule of bone remodeling from the results of cDNA microarray analysis performed in this study.