脂多糖对牙周膜干细胞生物学特性的影响

探讨脂多糖（LPS）对牙周膜干细胞（PDLSCs）生物学特性的影响.方法 分离、培养PDLSCs,并检测其间充质干细胞标志物STRO-1、CD146的表达情况.在含有LPS的培养基中培养PDLSCs,分别进行以下实验：（1）应用甲苯胺蓝染色法和Brdu掺入法分别检测PDLSCs的克隆形成率和细胞增殖率;（2）对PDLSCs进行骨向和脂肪向诱导,采用茜素红染色和油红O染色检测其骨向和脂肪向分化潜能;（3）应用ELISA法测定培养上清中IL-6的浓度;（4） Western blot检测PDLSCs磷酸化ERK1/2的表达情况.结果 PDLSCs表达STRO-1、CD146,阳性率分别为28.6％±2.3％、86.7％±3.9％.LPS对PDLSCs的克隆形成率和细胞增殖率没有影响.在含有LPS的矿化诱导液中,矿化面积明显增多,说明LPS能够促进PDLSCs骨向分化.脂肪向诱导实验发现,LPS组和无LPS组的油红染色阳性面积相近,两组无显著性差异.LPS促进IL-6的分泌和ERK1/2活化,并具有剂量依赖性.结论 LPS改变了PDLSCs的生物学特性,提示炎性状态可能影响PDLSCs介导的牙周组织再生.

Effects of lipopolysaccharide on biological properties of periodontal ligament stem cells

Objective To investigate the effects of lipopolysaccharide （LPS） on the biological properties of periodontal ligament stem ceils （PDLSCs）. Methods PDLSCs were isolated and cultured, and the expressions of mesenchymal stem ceils markers including stromal cell antigen 1 （STRO-1 ） and CD 146 on PDLSCs were examined. PDLSCs were cultured in the a-MEM medium with or without 10 mg/L LPS, and the effects of LPS on colony-forming efficiency and proliferation rate of PDLSCs were determined. Multi-lineage differentiation assays towards osteogenic and adipogenic pathways of PDLSCs in medium with or without 10 mg/L LPS were performed. After 4-week culture, alizarin red staining and oil red O staining were used to evaluate the effects of LPS on osteogenic and adipogenic differentiation of PDLSCs, respectively. PDLSCs were cultured in the a-MEM medium with 0, 1, 5 and 10 mg/L LPS for 3 days, then the concentrations of IL- 6 in the supernatant of medium and the expression of pERK1/2 in PDLSCs were detected by ELISA and Western blotting, respectively. Results The positive rates of STRO-1 and CD146 expression in PDLSCs were 28.6%±2.3% and 86.7%±3.9%, respectively. LPS did not affect the colony-forming efficiency and proliferation rate of PDLSCs （both P〉0.05）. LPS could promote osteogenic （92%±11% vs 64%±9%, P〈 0.05）, but not adipogenie differentiation of PDLSCs （P〉0.05）. Moreover, LPS could promote the secretion of IL-6 and the activation of ERK1/2. Conclusion LPS may alter the biological properties of PDLSCs, suggesting that inflammatory state may influence the PDLSCs-mediated periodontal tissue regeneration.