釉基质衍生物对脂多糖作用下牙周膜成纤维细胞增殖和凋亡的影响

目的研究釉基质衍生物（enamel matrix derivatives，EMD）对牙龈卟啉单胞菌脂多糖（Porphyromonas gingivalis lipopolysaccharide，Pg-LPS）作用下的人牙周膜成纤维细胞（human periodontal ligament fibroblasts，hPDLFs）增殖和凋亡的影响。方法从正畸治疗需拔除的前磨牙中，分离培养人hPDLFs，传至第4代；实验组培养液中分别加入100μ/mLEMD、10μg／，mL Pg-LPS或者100μ/mL EMD＋10 μg／mL Pg-LPS，对照组不加入刺激物；以四甲基偶氮唑盐3-（4，5-dimethy1-2-thiazolyl）-2，5-diphenyl．2H-tetrazoliumbromide，MTT]法检测hPDLFs的增殖，采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法分析细胞凋亡。结果原代hPDLFs生长良好，加入刺激后第3天时，第4代hPDLFs的Mrrr值由高至低分别是：EMD组、对照组、EMD＋LPS组、LPS组。刺激48h后，LPS组凋亡率（12．10％±2．80％）大于EMD＋LPS组（8．07％±2．04％）、EMD组（3．68％±1．73％）和对照组（3．87％±1．27％）（P〈0．05）。结论EMD能减弱Pg-LPS对hPDLFs增殖的影响，并且降低Pg-LPS所导致的hPDLFs凋亡，可能是其促进牙周组织再生的重要机制。

Effects of enamel matrix derivatives on proliferation and apoptosis in lipopolysaccharide stimulated periodontal ligament fibroblasts

Objective To explore the effects of enamel matrix derivatives （EMD） on proliferation and apoptosis in Porphyromonas gingivalis lipopolysaccharide （Pg-LPS） stimulated periodontal ligament fibroblasts. Methods Human periodontal ligament fibroblasts （hPDLFs） were separated from premolars extracted due to orthodontic treatment, and cul- tured to 4th passage; EMD （100 μg/mL）, Pg-LPS （10 μg/mL） or EMD （100 μg/mL） ＋ Pg-LPS （10 μg/mL） were added into the culture medium in experimental group, whereas no stimulant was added in the blank control group ; growth and proliferation of hPDLFs was evaluated by 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl-2H-tetrazoliumbromide （MTT） method, and apoptosis was detected by TUNEL. Results Three days after stimulation in hPDLFs in 4th passage, MTF value showed a tendency of EMD group 〉 control group 〉 EMD ＋ LPS group 〉 LPS group; 48 h after stimulation, percent- age of apoptotic cells in LPS （ 12.10% ±2.80% ） was larger than EMD ＋ LPS group （ 8.07% ±2.04% ）, EMD group （3.68% ±1.73% ）, and control group （3.87% ±1.27% ）（P〈O. 05）. Conclusion EMD can inhibit effects of Pg- LPS on PDLCs proliferation and decrease apoptosis activated by Pg-LPS, which could be a possible mechanism for perio- dontal regeneration effects of EMD.