The Sonic Hedgehog-Patched-Gli Signaling Pathway Maintains Dental Epithelial and Pulp Stem/Progenitor Cells and Regulates the Function of Odontoblasts
The Sonic Hedgehog-Patched-Gli Signaling Pathway Maintains Dental Epithelial and Pulp Stem/Progenitor Cells and Regulates the Function of Odontoblasts
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Sonic Hedgehog-Patted-Gli信号通路维持牙上皮细胞和牙髓干/祖细胞并调节成牙本质细胞的功能
DOI：
10.3389/fdmed.2021.651334
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发表时间：
2021-04-14
影响因子：
--
通讯作者：
Ohshima, Hayato
中科院分区：
文献类型：
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作者：
Ishikawa, Yuko;Ida-Yonemochi, Hiroko;Ohshima, Hayato
本研究旨在阐明Sonic hedgehog（Shh）-Patched（Ptch）-Gli信号通路在维持牙本质上皮细胞和牙髓干/祖细胞以及调节成牙本质细胞功能中的作用。多西环素（Doxycycline，dox）诱导的组蛋白2B（H2 B）-绿色荧光蛋白（GFP）转基因小鼠在出生前胚胎14.5或15.5天摄入dox，并在出生后第1天（P1）至第3周（P3 W）收集其后代。Gli 1，Ptch 1，Ptch 2和原位杂交Shh和Ptch 1进行免疫组化。将出生后第2天的H2 B-GFP转基因小鼠和野生型小鼠的下颌切牙在含有Shh抗体的营养培养基中培养4天，随后进行Sox 2的免疫组织化学处理。在磨牙中，致密的H2 B-GFP-label-retaining cells（H2 B-GFP-LRCs）密集分布在整个牙髓在P1至出生后第2周（P2 W），并在出生后P3 W的数量减少，而致密的H2 B-GFP-LRCs在subodontoblastic层中的数量在P2 W的数量增加。Gli 1（+）和Pthc 1（+）细胞分布于整个成釉器和牙髓，包括成牙本质细胞层和亚成牙本质细胞层。Shh mRNA表达于内釉上皮，牙本质形成后，Shh mRNA向成牙本质细胞转移。Ptch 1 mRNA于P1时在内釉上皮和牙尖牙髓组织中表达，从出生后1周到P3周表达强度逐渐减弱。在切牙中，顶芽含有H2 B-GFP-LRC、Gli 1（+）细胞和Ptch 1（+）细胞。Shh抗体的加入诱导了Sox 2（+）细胞数量的减少，这是由于顶芽中凋亡细胞的增加。因此，Shh-Ptch-Gli信号通路在维持静止的成体干细胞和调节成牙本质细胞的功能中起作用。
This study aimed to elucidate the role of the Sonic hedgehog (Shh)-Patched (Ptch)-Gli signaling pathway in maintaining dental epithelial and pulp stem/progenitor cells and regulating the function of odontoblasts. Doxycycline (dox)-inducible histone 2B (H2B)-green fluorescent protein (GFP) transgenic mice ingested dox at prenatal embryonic days 14.5 or 15.5 and their offspring were collected from postnatal day 1 (P1) to week 3 (P3W). Immunohistochemistry for Gli1, Ptch1, and Ptch2 and in situ hybridization for Shh and Ptch1 were conducted. Mandibular incisors of postnatal day 2 H2B-GFP transgenic and wild-type mice were cultivated in a nutrient medium with Shh antibody for 4 days and subsequently processed for immunohistochemistry for Sox2. In molars, dense H2B-GFP-label-retaining cells (H2B-GFP-LRCs) were densely distributed throughout the dental pulp during P1 to postnatal week 2 (P2W) and decreased in number by postnatal P3W, whereas the number of dense H2B-GFP-LRCs in the subodontoblastic layer increased in number at P2W. Gli1(+) and Pthc1(+) cells were distributed throughout the enamel organ and dental pulp, including the odontoblast and subodontoblastic layers. Shh mRNA was expressed in the inner enamel epithelium and shifted into odontoblasts after dentin deposition. Ptch1 mRNA was expressed in the inner enamel epithelium and cuspal pulpal tissue on P1 and decreased in intensity from postnatal week 1 to P3W. In incisors, the apical bud contained H2B-GFP-LRCs, Gli1(+) cells, and Ptch1(+) cells. The addition of Shh antibody to explants induced a decrease in the number of Sox2(+) cells due to the increase in apoptotic cells in the apical bud. Thus, the Shh-Ptch-Gli signaling pathway plays a role in maintaining quiescent adult stem cells and regulating the function of odontoblasts.