Wang Yingxin, Shi Yuanyuan, Wang Lingxiao, Xu Junji, Shan Zhaochen, Gao Zhenhua
Outpatient Department of Oral and Maxillofacial Surgery, School of Stomatology, Capital Medical University, Beijing 100050, China.
Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, School of Stomatology, Capital Medical University, Beijing 100050, China.
Arch Oral Biol. 2023 Nov;155:105795. doi: 10.1016/j.archoralbio.2023.105795. Epub 2023 Aug 20.
Fibroblast growth factors (FGFs) play pivotal roles in mediating interactions between dental epithelium and mesenchyme throughout tooth initiation and morphogenesis. This study aimed to elucidate the roles of FGF4 and FGF10 in the regulation of tooth development.
In this study, we investigated spatiotemporal expression patterns of FGF4 and FGF10 in the third deciduous molars (DM3) of miniature pigs at the cap, early bell, and late bell stages. Pregnant miniature pigs were obtained, and the samples were processed for histological staining. Non-radioactive in situ hybridization, immunohistochemistry, and real-time PCR were used to detect mRNA and protein expression levels of FGF4 and FGF10.
FGF4 was expressed in the dental epithelium and mesenchyme at the cap stage. At the early bell stage, epithelial expression of FGF4 was reduced while mesenchymal expression got stronger. At the late bell stage, the FGF4 expression was restricted to the inner enamel epithelium (IEE) and differentiating odontoblasts. FGF10 was expressed intensely in both epithelium and mesenchyme at the cap stage. The expression of FGF10 was concentrated in the secondary enamel knots and surrounding mesenchyme at the early bell stage. FGF10 was weakly detected in the IEE by the late bell stage.
Our results indicated that FGF4 and FGF10 might have partially redundant functions in regulating epithelium morphogenesis. FGF4 may be involved in regulatory signaling cascades mediating interactions between the epithelium and mesenchyme. In addition, the downregulation of FGF10 expression may be associated with the cessation of mesenchymal cell proliferation and initiation of preodontoblast polarization.
成纤维细胞生长因子（FGFs）在整个牙齿起始和形态发生过程中介导牙上皮和间充质之间的相互作用中发挥关键作用。本研究旨在阐明FGF4和FGF10在牙齿发育调控中的作用。
在本研究中，我们研究了小型猪第三乳磨牙（DM3）在帽状期、早期钟状期和晚期钟状期FGF4和FGF10的时空表达模式。获取怀孕的小型猪，对样本进行组织学染色。采用非放射性原位杂交、免疫组织化学和实时PCR检测FGF4和FGF10的mRNA和蛋白表达水平。
FGF4在帽状期的牙上皮和间充质中表达。在早期钟状期，FGF4的上皮表达减少，而间充质表达增强。在晚期钟状期，FGF4的表达局限于内釉上皮（IEE）和分化中的成牙本质细胞。FGF10在帽状期的上皮和间充质中均强烈表达。在早期钟状期，FGF10的表达集中在继发性釉结和周围的间充质中。在晚期钟状期，在IEE中检测到FGF10的表达较弱。
我们的结果表明，FGF4和FGF10在调节上皮形态发生方面可能具有部分冗余功能。FGF4可能参与介导上皮和间充质之间相互作用的调节信号级联反应。此外，FGF10表达的下调可能与间充质细胞增殖的停止和成牙本质细胞前体极化的起始有关。
