Suzuki Akito, Takayama Tadahiro, Suzuki Naoto, Sato Michitomo, Fukuda Takeshi, Ito Koichi
Department of Periodontology, Nihon University School of Dentistry, Tokyo, Japan.
Acta Biochim Biophys Sin (Shanghai). 2009 Feb;41(2):108-15. doi: 10.1093/abbs/gmn012.
There were few studies investigating the effects of the mechanical stimulation provided by daily low-intensity pulsed ultrasound (LIPUS) treatment. LIPUS is known to accelerate bone mineralization and regeneration; however, the precise cellular mechanism is unclear.Our purpose was to determine how daily LIPUS treatment affected cell viability, alkaline phosphatase activity, osteogenesis-related gene expression, and mineralized nodule formation in osteoblasts. The typical osteoblastic cell line ROS 17/2.8 cells were cultured in the absence or presence of LIPUS stimulation. Daily LIPUS treatments (1.5 MHz; 20 min) were administered at an intensity of 30 mW/cm(2) for 14 days. Expression of osteogenesis-related genes was examined at mRNA levels using real-time polymerase chain reaction and at protein levels using western blotting analysis. LIPUS stimulation did not affect the rate of cell viability. Alkaline phosphatase activity was increased after 10 days of culture with daily LIPUS stimulation. LIPUS significantly increased the expression of mRNAs encoding Runx2, Msx2, Dlx5, osterix, bone sialoprotein, and bone morphogenetic protein-2, whereas it significantly reduced the expression of mRNA encoding the transcription factor AJ18. Mineralized nodule formation was markedly increased on Day 14 of LIPUS stimulation. LIPUS stimulation directly affected osteogenic cells, leading to mineralized nodule formation. LIPUS is likely to have a fundamental influence on key functional activities of osteoblasts in alveolar bone.
很少有研究调查每日低强度脉冲超声（LIPUS）治疗所提供的机械刺激的效果。已知LIPUS可加速骨矿化和再生；然而，确切的细胞机制尚不清楚。我们的目的是确定每日LIPUS治疗如何影响成骨细胞的细胞活力、碱性磷酸酶活性、成骨相关基因表达和矿化结节形成。在有无LIPUS刺激的情况下培养典型的成骨细胞系ROS 17/2.8细胞。以30 mW/cm²的强度进行每日LIPUS治疗（1.5 MHz；20分钟），持续14天。使用实时聚合酶链反应在mRNA水平以及使用蛋白质印迹分析在蛋白质水平检测成骨相关基因的表达。LIPUS刺激不影响细胞活力率。在每日LIPUS刺激培养10天后，碱性磷酸酶活性增加。LIPUS显著增加了编码Runx2、Msx2、Dlx5、osterix、骨唾液蛋白和骨形态发生蛋白-2的mRNA表达，而显著降低了编码转录因子AJ18的mRNA表达。在LIPUS刺激第14天时，矿化结节形成明显增加。LIPUS刺激直接影响成骨细胞，导致矿化结节形成。LIPUS可能对牙槽骨中成骨细胞的关键功能活动产生根本性影响。
