Effects of Different Magnitudes of Tension-force on Alkaline Phosphatase Activity in Periodontal Ligament Cells
Effects of Different Magnitudes of Tension-force on Alkaline Phosphatase Activity in Periodontal Ligament Cells
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DOI：
10.1177/00220345960750030501
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发表时间：
1996-03
影响因子：
7.6
通讯作者：
M. Yamaguchi;N. Shimizu;Y. Shibata;Y. Abiko
中科院分区：
文献类型：
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作者：
M. Yamaguchi;N. Shimizu;Y. Shibata;Y. Abiko
碱性磷酸酶(ALP)活性参与了各种矿化组织的钙化过程，其中牙周膜(PDL)的ALP活性明显高于其他结缔组织。由于牙周膜位于硬组织之间，起着缓冲机械应力的作用，如咬合力和正畸力，这种应力可能会调节牙周膜细胞中碱性磷酸酶的活性，进而影响邻近牙槽骨的代谢。本研究的目的是检测周期性张力对人PDL成纤维细胞碱性磷酸酶(ALP)活性及肝/骨/肾(L/B/K)碱性磷酸酶基因表达的影响。将人的PDL细胞培养在柔性底平板上，并放置在Flexpercell应变单元上。细胞以6个周期/分钟(5s应变，5s松弛)在6个拉力水平(表面积增加9%、12%、15%、18%、21%和24%)下弯曲5d。张力组细胞的增殖能力与对照组无明显差异。在低张力(9%)和高张力(24%)下，PDL细胞的ALP活性分别下降10%和42%，且这种下降与张力的大小有关。张力对细胞碱性磷酸酶活性的抑制作用与L/B/K细胞碱性磷酸酶基因表达水平在周期性张力作用下降低的观察结果一致。这些结果表明，张力可能影响PDL的代谢，这取决于ALP的功能作用。
Alkaline phosphatase (ALP) activity is involved in the process of calcification in various mineralizing tissues, and it is found at much higher levels in the periodontal ligament (PDL) than in other connective tissues. Since the PDL lies between hard tissues and functions as a cushion mitigating mechanical stress, such as occlusal and orthodontic forces, this stress may modulate ALP activity in PDL cells, which themselves may affect adjacent alveolar bone metabolism. The objective of this study was to determine the level of ALP activity and the gene expression of liver/bone/kidney (L/B/K) ALP in human PDL fibroblasts in response to cyclic tension-forces. Human PDL cells were cultured on flexible-bottomed plates and placed on a Flexercell Strain Unit. Cells were flexed at 6 cycles/min (5 sec strain, 5 sec relaxation) at 6 levels of tension-force (9%, 12%, 15%, 18%, 21%, and 24% increase in surface area) for 5 days. There was no significant difference in cell proliferation between the cells subjected to the tension-force and the controls. There was a 10% and 42% decrease, respectively, in the ALP activity in PDL cells exposed to low (9%) and high (24%) tension-forces, and these decreases were dependent on the magnitude of the tension-force. The finding of inhibited ALP activity in response to tension-force was consistent with the observation that L/B/K ALP mRNA levels were decreased in response to cyclic tension-force. These results suggest that tension-force may affect PDL metabolism, depending on the functional role of ALP.