Yang Kun, Wang Yingying, Ju Yingxin, Li Gang, Liu Chang, Liu Junyu, Liu Qi, Wen Xiujie, Liu Lu Chuan
Department of Stomatology, Daping Hospital of the Third Military Medical University, Chongqing, China.
Department of Stomatology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Cell Prolif. 2017 Feb;50(1). doi: 10.1111/cpr.12290. Epub 2016 Sep 27.
The aim of this study was to investigate whether p75NTR (p75 neurotrophin receptor) regulates differential mineralization capacity of rEMSCs (rat ectomesenchymal stem cells) and underlying mechanisms associated with Mage-D1 (melanoma-associated antigens-D1).
Immunohistochemical staining of p75NTR in developing tooth germs was performed on E12.5d (embryonic 12.5 days) and E19.5d (embryonic 19.5 days). E12.5d EMSCs and E19.5d EMSCs were isolated in the same pregnant Sprague-Dawley rats from embryonic maxillofacial processes and tooth germs. p75NTR small-interfering RNA, p75NTR overexpression plasmid, Mage-D1 small-interfering RNA and recombined rat NGF were used to transfect cells.
p75NTR was expressed in epithelial-mesenchymal interaction areas at E12.5d and E19.5d tooth germ development stages. E19.5d EMSCs had higher p75NTR expression levels and differential mineralization capacity but lower levels of cell proliferation. Under induction by mineralized culture medium, the potential of differential mineralization had identical trends in regulation of p75NTR in EMSCs; Mage-D1 did not fluctuate and TrkA was not expressed. Binding of p75NTR and Mage-D1 were detected. Mage-D1 knockdown significantly down-regulated expression of related genes, which NGF could not rescue.
p75NTR participated in tooth germ development stages and mediated differential mineralization of EMSCs. p75NTR played a critical role in regulating the potential of differential mineralization of EMSCs. Mage-D1 seemed to act as a bridge in the underlying mechanism of effects of p75NTR.
本研究旨在探究p75神经营养因子受体（p75NTR）是否调控大鼠外胚间充质干细胞（rEMSCs）的差异化矿化能力以及与黑素瘤相关抗原-D1（Mage-D1）相关的潜在机制。
在胚胎第12.5天（E12.5d）和胚胎第19.5天（E19.5d）对发育中的牙胚进行p75NTR的免疫组织化学染色。从同一怀孕的斯普拉格-道利大鼠的胚胎颌面突和牙胚中分离出E12.5d的EMSCs和E19.5d的EMSCs。使用p75NTR小干扰RNA、p75NTR过表达质粒、Mage-D1小干扰RNA和重组大鼠神经生长因子（NGF）转染细胞。
在E12.5d和E19.5d牙胚发育阶段，p75NTR在上皮-间充质相互作用区域表达。E19.5d的EMSCs具有更高的p75NTR表达水平和差异化矿化能力，但细胞增殖水平较低。在矿化培养基诱导下，EMSCs中p75NTR的调控在差异化矿化潜能方面具有相同趋势；Mage-D1无波动，且未检测到TrkA表达。检测到p75NTR与Mage-D1结合。Mage-D1基因敲低显著下调相关基因的表达，NGF无法挽救这种下调。
p75NTR参与牙胚发育阶段并介导EMSCs的差异化矿化。p75NTR在调节EMSCs的差异化矿化潜能中起关键作用。Mage-D1似乎在p75NTR作用的潜在机制中起桥梁作用。
