Cbfα1 hinders autophagy by DSPP upregulation in odontoblast differentiation
Cbfα1 hinders autophagy by DSPP upregulation in odontoblast differentiation
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DOI：
10.1016/j.biocel.2019.105578
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发表时间：
2019-10-01
影响因子：
4
通讯作者：
Chen, Wei
中科院分区：
文献类型：
--
作者：
Guo, Ting;Cao, Gang;Chen, Wei
成牙本质细胞形成牙本质，作为牙齿的主要硬组织。自噬是一种高度保守的稳态，参与成牙本质细胞的分化。牙本质涎磷蛋白(DSPP)和核心结合因子α1(CBFα1)是牙本质-牙髓复合体成牙本质细胞的典型因子。然而，CBFα1和DSPP之间的关系以及CBFα1在成牙本质细胞分化过程中参与自噬的作用尚不清楚。在这项研究中，我们发现FGF2刺激MDPC-23细胞可以抑制自噬，促进细胞分化。我们发现在FGF2刺激和抑制自噬的情况下，MDPC-23细胞中Cbfα1和DSPP的mRNA和蛋白水平均升高。进一步的结果显示，过量的CBFα1增加了MDPC-23细胞中DSPP的表达，并抑制了自噬。通过荧光素酶报告基因分析和EMSA分析，我们发现Cbfα1通过与DSPP启动子上的5‘-TACCTCA(-3950~-3944)和5’-ACCACA(-3106~-3101)结合而上调DSPP的表达。此外，芯片分析结果表明，FGF2处理增强了Cbfα1与DSPP启动子的结合。信号通路抑制剂筛选进一步显示Cbfα1抑制了参与Wnt I信号转导的自噬。此外，利用siRNA沉默方法敲除CBFα1逆转了FGF2介导的对MDPC-23细胞自噬的抑制。因此，这些发现阐明了一种新的调控机制，CBFα1通过转录增强DSPP的表达，也为CBFα1在自噬中的抑制作用提供了洞察，从而促进了成牙本质细胞在FGF2刺激下的分化。
Odontoblasts forms dentin as the main hard tissue of the tooth. Autophagy is a highly conserved homeostasis involved in odontoblast differentiation. DSPP (Dentin sialophosphoprotein) and Cbf alpha 1 (Core binding factor alpha 1) are typical factors in odontoblasts of the dentin-pulp complex. However, the relationship between Cbf alpha 1 and DSPP as well as the role of Cbf alpha 1 involved in the autophagy during odontoblast differentiation are poorly understood. In this study, we found the stimulation with FGF2 in MDPC-23 cells resulted in the suppression of autophagy and promotion of cell differentiation. We demonstrated that both mRNA and protein levels of Cbf alpha 1 and DSPP were elevated upon FGF2 stimulation coupled with the inhibition of autophagy in MDPC-23 cells. Further results revealed that overdose of Cbf alpha 1 increased the expression of DSPP, and also suppressed autophagy in MDPC-23 cells. Using luciferase reporter assay and EMSA, we illustrated that Cbf alpha 1 upregulated DSPP expression through binding to the specific sites 5'-TACCTCA (-3950 bp to -3944 bp) and 5'-ACCACA (-3106 bp to -3101 bp) in DSPP promoter. Furthermore, ChIP assay results revealed that FGF2 treatment enhanced this binding of Cbf alpha 1 to DSPP promoter. Signaling pathway inhibitor screening further revealed Cbf alpha 1 suppressed autophagy involved in Wnt I signaling. Moreover, knockdown of Cbf alpha 1 using siRNA silencing approach reversed the FGF2-mediated suppression of autophagy in MDPC-23 cells. Thus, these findings illustrate a novel regulatory mechanism by which Cbf alpha 1 transcriptionally enhances DSPP expression, and also provide an insight into the inhibitory action of Cbf alpha 1 in autophagy thereby facilitating odontoblast differentiation upon FGF2 stimulation.