Cell Biological Study on the Response Against Mechanical Stress on Periodontal Ligament Fibroblasts Derived from Human Deciduous Teeth.

采用Kawase和Saito等报道的体外培养方法，建立了人乳牙和恒牙的牙周膜成纤维细胞。在HPLF-Y和HPLF上研究了机械应力对细胞生长和分化的影响。在有或无维甲酸(RA)和1，25二羟基维生素D_3(D_3)存在或不存在的情况下，使用柔性底培养板和真空系统将这些细胞以5%或10%的伸长率间歇加载10s，然后静息10或50s。拉伸24小时后，测定两种细胞的碱性磷酸酶(ALPase)活性和DNA含量。0.1 mM RA处理8d后，HPLF-Y和HPLF的DNA合成均受到抑制。在培养后期，RA对两种细胞生长的抑制作用均大于D_3或RA和D_3共同作用。…对HPLF-Y细胞碱性磷酸酶活力的影响0.1 mM RA作用8d后，HPLF无明显变化。在培养的第5天，间歇拉伸(5%，3个周期/分钟，24小时)后，HPLF的细胞生长被刺激，而HPLF-Y的细胞生长被抑制。机械应力(5%)可使经D_3或RA和D_3共同作用的HPLF-Y在汇合期ALPase显著升高。RA、D_3单独或与RA、D_3共同作用均能提高HPLF生长期的ALPase活性。这些数据表明，HPLF-Y和HPLF在对RA或机械应力的反应方面存在明显差异。本研究提示，HPLF-Y和HPLF在牙周组织发育过程中具有不同的重塑作用，D3和RA对HPLF和HPLF-Y细胞生长和分化的机械应变反应具有调节作用。较少

Periodontal ligament fibroblasts derived from human deciduous (HPLF-Y) and permanent (HPLF) teeth were established by means of explant method reported by Kawase and Saito. The effects of mechanical stress on cell growth and differentiation were studied on HPLF-Y and HPLF in culture. Those cells were loaded with intermittent mechanical strain at 5 or 10% elongation for 10 second with the resting for 10 or 50 second using the flexible bottomed culture plates and vacuum system in the presence or absence of retinoic acid (RA), 1,25 dihydroxy vitamin D_3 (D_3) or both of them. After the stretching for 24 hours, we measured alkaline phosphatase (ALPase) activity and DNA quantity of both cells. DNA synthesis of HPLF-Y and HPLF were suppressed by treatment with 0.1 mM RA for 8 days. The growth of both cells was more suppressed by RA treatment in the latter half of culture period than by D_3 or by RA and D_3 together. Alkaline phosphatase (ALPase) activity of HPLF-Y was increased by treatment w … More ith 0.1 mM RA for 8 days, however no significant change was observed on HPLF after treatment with RA at the same concentration. After the loading of intermittent stretching (5%, 3 cycle/min., 24 hr) on the day 5 in culture, cell growth of HPlF was stimulated, whereas that of HPLF-Y was suppressed. On the other hand, ALPase synthesis was stimulated on both HPLF-Y and HPLF.The mechanical stress (5%) caused significant increase of ALPase on HPLF-Y treated with D_3 or with RA and D_3 together at confluent phase. ALPase activity was increased by stretching at growth phase of HPLF treated with RA or D_3 separately or with RA and D_3 together. These data demonstrate that there are obvious differences between HPLF-Y and HPLF in terms of the response to RA or mechanical stress. The present study suggests that HPLF-Y and HPLF have different functions in the remodeling of periodontal tissue during development and that D_3 and RA are able to modify of the response to the mechanical strain on the cell growth and differentiation of HPLF and HPLF-Y. Less