Aim To characterize the odontogenic capability of apical bud and phenotypical change of apical bud cells （ABCs） in different microenvironment.Methodology Incisor apical bud tissues from neonatal SD rat were dissected and transplanted into the renal capsules to determine their odontogenic capability. Meanwhile ABCs were cultured and purified by repeated differential trypsinization. Then ABCs were cultured with conditioned medium from developing apical complex cells （DAC-CM）. Immunocytochemistry, reverse transcriptase polymerase chain reaction （RT-PCR） and scanning electron microscope （SEM） were performed to compare the biolo- gical change of ABC treated with or without DAC-CM. Results First we confirmed the ability of apical bud to form crown-like structure ectopically. Equally important, by using the developing apical complex （DAC） condi- tioned medium, we found the microenvironment created by root could abrogate the ＂crown＂ features of ABCs and promote their proliferation and differentiation. Conclusion ABCs possess odontogenic capability to form crown-like tissues and this property can be affected by root-produced microenvironment.
Jun FangLiang TangXiao-hui LiuLing-ying WenYan Jin
目的:比较牙周炎和2型糖尿病伴牙周炎患者牙周膜干细胞成骨分化能力。方法:体外组织块法和有限稀释法克隆化培养牙周炎患者牙周膜干细胞(P-PDLSCs组)和2型糖尿病伴牙周炎患者牙周膜干细胞(D-PDLSCs组),计算克隆形成率,免疫荧光检测细胞表型分子CD146、STRO-1进行干细胞鉴定,矿化诱导后茜素红染色观察矿化结节形成,实时定量聚合酶链反应(real time PCR)检测成骨相关基因表达。结果:P-PDLSCs组和D-PDLSCs组细胞的克隆形成率分别为(25.6±2.7)%和(17.9±1.7)%(P﹤0.05);P-PDLSCs组CD146和STRO-1表达明显高于D-PDLSCs组;成骨诱导21 d后茜素红染色,2组均出现不同程度的矿化结节,P-PDLSCs组的矿化能力较D-PDLSCs组强;成骨诱导1周后D-PDLSCs组碱性磷酸酶(alkaline phosphatase,ALP)、Runx-2和Ⅰ型胶原蛋白(type-Ⅰcollagen,Col-Ⅰ)的mRNA表达均明显低于P-PDLSCs组(P<0.05)。结论:糖尿病伴牙周炎患者牙周膜干细胞成骨分化能力低于单纯牙周炎患者牙周膜干细胞。
