TNF-α对根尖乳头干细胞与牙周膜干细胞增殖活性影响的比较研究

Comparative analysis of the effects of TNF-α on proliferation of stem cells from apical papilla(SCAP) and periodontal ligament stem cells(PDLSCs)

目的:体外培养鼠根尖乳头干细胞和牙周膜干细胞,比较研究肿瘤坏死因子α(TNF-α)对两者增殖活性的影响,以期得出在炎症状态下两者用于牙本质再生的可能性。方法:取幼鼠根尖尚未发育完全的健康下颌牙,用酶消化法获得根尖乳头干细胞和牙周膜干细胞;免疫荧光法鉴定干细胞表面标志物;将含有TNF-α浓度为0、5、10、50 ng/ml的培养液加入两者的第3代细胞中,使用MTT法检测以比较其对两种细胞增殖活性的影响;采用SPSS 11.0软件包对实验组和对照组数据进行单因素方差分析。结果:SCAP与PDLSCs均呈长梭形,形似成纤维细胞;SCAP与PDLSCs均表达干细胞特性;SCAP较PDLSCs具有更强的增殖活性;在10ng/ml和50ng/ml浓度时,TNF-α能促进2种细胞的增殖。结论:与PDLSCs比较,SCAP增殖活性更强,在炎性环境下亦是如此,根尖乳头干细胞可能在年轻恒牙根尖周炎症经适当治疗后牙根继续发育中起到重要作用。

Objective The aim of this study was to culture rat cells from the apical papilla（SCAP） and periodontal ligament stem cells（PDLSCs） in vitro, to investigate the effects of TNF-α on proliferation of these cells and explore the possibility of their dentinogenesis under inflammation. Methods The apical papilla, as well as the periodontal ligament tissues from the mandibular teeth of young rats were digested in Hanks solution including collagenase and dispase. Characteristics of the immunophenotype of SCAP and PDLSCs was detected by immunofluorescence technique. The third passage cells were challenged with different concentration of TNF-α and detected for the proliferation activity by MTT. One-Way ANOVA was conducted using SPSS11.0 software package. Results The apical papilla cells and periodontal ligament stem cells all presented elongated shape. They exhibited fibroblastic characteristics. SCAP and PDLSCs all expressed the characteristic molecules of stem cells.The apical papilla cells had stronger proliferation activity than the dental pulp cells. At the concentration of 10ng/ml and 50ng/ml, TNF-α significantly enhanced the proliferating activity of the two kinds of the cells（P0.05）. ConclusionsStronger proliferation activity of SCAP, especially under inflammation, would possibly be beneficial to continuing development of the root of young permanent tooth with dental pulp necrosis and apical periodontitis after appropriate treatment.