Xing Yongjun, Nie Xin, Chen Guoqing, Wen Xiujie, Li Gang, Zhou Xia, Tian Weidong, Liu Luchuan
Department of Stomatology, Daping Hospital & Research Institute of Surgery, Third Military Medical University, Chongqing, 400038, China.
Affiliated Stomatological Hospital, PLA General Hospital of Chengdu Military Region, Chengdu, 610083, China.
Cell Prolif. 2016 Apr;49(2):185-94. doi: 10.1111/cpr.12248. Epub 2016 Mar 31.
The aim of this study was to investigate differences of odonto-differentiation between P75 -neurotrophin receptor (P75 -NTR)-positive ectomesenchymal stem cells (P75+EMSCs) and P75 -NTR-negative ectomesenchymal stem cells (P75-EMSCs), and their underlying mechanisms.
Primary cranial neural crest-derived cells (CNC) were isolated from the first branchial arches, and P75+EMSCs and P75-EMSCs were sorted by fluorescence-activated cell sorting. Differentiation of P75+EMSCs or P75-EMSCs into odontoblast-like cells was induced by dental epithelial cells in vitro or in vivo. Differential gene expression profiles between P75+EMSCs and P75-EMSCs were analysed by microarray assay. Smad4-specific small interfering RNA and activator kartogenin were used to treat the cells, to evaluate effects of Smad4 in odonto-differentiation of P75+EMSCs or P75-EMSCs.
Under induction of dental epithelium conditioned medium, P75+EMSCs had more mineralized node formation and higher expression of Dmp1 and Dspp compared to P75-EMSCs. In our in vivo study, graft of P75+EMSCs recombination with dental epithelium showed higher expression of DMP1 and DSP. Knock-down of Smad4 in P75+EMSCs significantly downregulated expression of DMP1 and DSP, while activation of Smad4 in P75-EMSCs by the activator kartogenin, significantly increased DSP and DMP1 expression.
P75+EMSCs showed more odonto-differentiation potential than P75-EMSCs both in vivo and in vitro. Smad4 played a critical role in determination of odonto-differentiation potential of CNC-derived EMSCs.
本研究旨在探讨P75神经营养因子受体（P75 -NTR）阳性外胚间充质干细胞（P75+EMSCs）与P75 -NTR阴性外胚间充质干细胞（P75-EMSCs）在成牙本质分化方面的差异及其潜在机制。
从第一鳃弓分离出原代颅神经嵴来源细胞（CNC），通过荧光激活细胞分选法分选P75+EMSCs和P75-EMSCs。P75+EMSCs或P75-EMSCs在体外或体内被牙上皮细胞诱导分化为成牙本质样细胞。通过微阵列分析检测P75+EMSCs和P75-EMSCs之间的差异基因表达谱。使用Smad4特异性小干扰RNA和激活剂卡托金处理细胞，以评估Smad4在P75+EMSCs或P75-EMSCs成牙本质分化中的作用。
在牙上皮条件培养基诱导下，与P75-EMSCs相比，P75+EMSCs形成更多矿化结节，Dmp1和Dspp表达更高。在我们的体内研究中, P75+EMSCs与牙上皮重组移植显示DMP1和DSP表达更高。P75+EMSCs中Smad4基因敲低显著下调DMP1和DSP的表达，而激活剂卡托金激活P75-EMSCs中的Smad4则显著增加DSP和DMP1的表达。
P75+EMSCs在体内和体外均显示出比P75-EMSCs更强的成牙本质分化潜能。Smad4在决定CNC来源的EMSCs成牙本质分化潜能中起关键作用。
