Qi Shengcai, Yan Yanhong, Wen Yue, Li Jialiang, Wang Jing, Chen Fubo, Tang Xiaoshan, Shang Guangwei, Xu Yuanzhi, Wang Raorao
Department of Stomatology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
Department of Pediatric Dentistry, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.
Cell Prolif. 2017 Jun;50(3). doi: 10.1111/cpr.12335. Epub 2017 Feb 15.
This study aimed to investigate the functions of delta-like homologue 1 (DLK1) in the proliferation and differentiation of human dental pulp stem cells (hDPSCs).
Immunohistochemical analysis was used to determine the expression of alkaline phosphatase (ALP), dentin sialophosphoprotein (DSPP), DLK1, NOTCH1 and p-ERK1/2 in the mouse first maxillary molar. Recombinant lentivirus was constructed to overexpress DLK1 stably in hDPSCs. The cell viability and proliferation of hDPSCs were examined by CCK8 and EdU incorporation assay respectively. The odontoblastic differentiation of hDPSCs was determined by detection of ALPase activity assay, ALP and alizarin red staining and the expression of mineralization-related genes including ALP, DSPP and dental matrix protein. The mRNA and protein levels of DLK1 and p-ERK1/2 protein expression were detected. ERK inhibitor was used to test the differentiation effect of DLK1 on hDPSCs.
Delta-like homologue 1 was highly expressed on the odontoblasts and dental pulp cells on the first maxillary molar; the expression of p-ERK1/2 is similar with the DLK1 in the same process. The expression level of DLK1 increased significantly after the odontoblastic induction of hDPSCs. DLK1 overexpression increased the proliferation ability of hDPSCs and inhibited odontoblastic differentiation of hDPSCs. The protein level of p-ERK1/2 significantly increased in hDPSCs/dlk1-oe group. ERK signalling pathway inhibitor reversed the odontoblastic differentiation effects of DLK1 on hDPSCs.
The proliferation of hDPSCs was promoted after DLK1 overexpression. DLK1 inhibited the odontoblastic differentiation of hDPSCs, which maybe through ERK signalling pathway.
本研究旨在探讨δ样同源物1（DLK1）在人牙髓干细胞（hDPSCs）增殖和分化中的作用。
采用免疫组织化学分析检测碱性磷酸酶（ALP）、牙本质涎磷蛋白（DSPP）、DLK1、NOTCH1和p-ERK1/2在小鼠上颌第一磨牙中的表达。构建重组慢病毒以在hDPSCs中稳定过表达DLK1。分别通过CCK8和EdU掺入试验检测hDPSCs的细胞活力和增殖情况。通过检测碱性磷酸酶活性测定、ALP和茜素红染色以及包括ALP、DSPP和牙基质蛋白在内的矿化相关基因的表达来确定hDPSCs的成牙本质细胞分化。检测DLK1的mRNA和蛋白水平以及p-ERK1/2蛋白表达。使用ERK抑制剂测试DLK1对hDPSCs的分化作用。
δ样同源物1在上颌第一磨牙的成牙本质细胞和牙髓细胞上高表达；p-ERK1/2在同一过程中的表达与DLK1相似。hDPSCs成牙本质细胞诱导后，DLK1的表达水平显著增加。DLK1过表达增加了hDPSCs的增殖能力并抑制了hDPSCs的成牙本质细胞分化。hDPSCs/dlk1-oe组中p-ERK1/2的蛋白水平显著增加。ERK信号通路抑制剂逆转了DLK1对hDPSCs的成牙本质细胞分化作用。
DLK1过表达后促进了hDPSCs的增殖。DLK1抑制了hDPSCs的成牙本质细胞分化，这可能是通过ERK信号通路实现的。
