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塑中起重要作用，但机械应力刺激下人类成骨细胞的生物学反应尚不清楚。在口腔颌面区域，多种手术后的颌骨缺损均可通过再生骨修复，但目前尚无有效的治疗方法。在本研究中，我们开发了类似声波的新型振动机制，作为临床上适用的机械应力源，并设计了骨再生的研究方案。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，我们研究了COX-2、RANKL、OPG、Cbfa-1、BMP-4和VEGF的产生和/或表达。其次，进行动物实验，对大鼠颅骨缺损进行振动刺激。在体外培养的成骨细胞中加入振动刺激后，COX-2 mRNA的表达量显著增加，反之则不增加蛋白质产量。在培养成纤维细胞中，VEGF mRNA的表达呈时间依赖性增加。而成骨细胞和成纤维细胞中RANKL、OPG、Cbfa-1、BMP-4的蛋白生成和mRNA表达没有变化。在动物实验中，振动刺激对骨重塑没有明显的改变。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，振动刺激对骨再生的影响可能很小。在未来，我们打算从本研究中进行的cDNA微阵列分析结果中确定骨重塑的关键分子。

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.