The glycogen metabolism via Akt signaling is important for the secretion of enamel matrix in tooth development
The glycogen metabolism via Akt signaling is important for the secretion of enamel matrix in tooth development
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DOI：
10.1016/j.mod.2016.01.002
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发表时间：
2016-02-01
影响因子：
2.6
通讯作者：
Harada, Hidemitsu
中科院分区：
文献类型：
--
作者：
Ida-Yonemochi, Hiroko;Otsu, Keishi;Harada, Hidemitsu
细胞根据不同的分化阶段或不同的环境改变其能量代谢。在连续生长小鼠门牙的成釉细胞分化过程中，我们发现在牙釉质基质分泌开始前，成釉前细胞存在暂时的糖原储存，并探讨了牙釉质基质分泌与糖原代谢的关系。免疫组化结果显示，在成釉前细胞向分泌型成釉细胞过渡阶段，糖原合成酶由无活性变为活性，糖原磷酸化酶表达升高，IGF-1、IGF-1受体及活化Akt水平升高。这些结果表明，通过IGF激活Akt信号与糖原代谢和牙釉质基质沉积的发生有关。在器官培养和成釉细胞系的实验中，IGF-1激活Akt信号通过上调Glut-1、-4和Gsk-3 β以及糖原合成酶的去磷酸化来刺激糖原代谢。随后，它们导致牙釉质基质分泌增加。相反，一些Akt信号和糖原合成/降解抑制剂下调了牙釉质基质的分泌。综上所述，糖原代谢通过Akt信号传导是成釉细胞分化过程中牙釉质基质分泌的重要系统。2016爱思唯尔爱尔兰有限公司版权所有。
Cells alter their energy metabolism depending on the stage of differentiation or various environments. In the ameloblast differentiation of continuous growing mouse incisors, we found temporary glycogen storage in preameloblasts before the start of enamel matrix secretion and investigated the relationship between enamel matrix secretion and glycogen metabolism. Immunohistochemistry showed that in the transitional stage from preameloblasts to secretory ameloblasts, the glycogen synthase changed from the inactive form to the active form, the expression of glycogen phosphorylase increased, and further, the levels of IGF-1, IGF-1 receptor and activated Akt increased. These results suggested that the activation of Akt signaling via IGF is linked to the onset of both glycogen metabolism and enamel matrix deposition. In the experiments using organ culture and ameloblast cell line, the activation of Akt signaling by IGF-1 stimulated glycogen metabolism through the up-regulation of Glut-1,-4 and Gsk-3 beta and the dephosphorylation of glycogen synthase. Subsequently, they resulted in increased enamel matrix secretion. In contrast, some inhibitors of Akt signals and glycogen synthesis/degradation down-regulated enamel matrix secretion. Taking these findings together, glycogen metabolism via Akt signaling is an essential system for the secretion of enamel matrix in ameloblast differentiation. (C) 2016 Elsevier Ireland Ltd. All rights reserved.