Developmental plasticity of epithelial stem cells in tooth and taste bud renewal

In Cichlids, replacement teeth (RT) share a continuous band of epithelium with adjacent taste buds (TB) and both organs co-express stem cell factors in subsets of label-retaining cells. In the mouse and other mammals, the tongue inter molar eminence (IE) oral papillae of Follistatin (Fat, BMP antagonist) mutants exhibited dysmorphic invagination. By using NGS-derived transcriptome profiling (RNAseq) analysis, we compared differential gene expression in the mouse tongue tissue in Follistatin (Fst) mutants mice with the wild type controls. Our results demonstrated ectopic expression of dental markers in tongue IE indicating that vertebrate oral epithelium retains inherent plasticity to form tooth and taste-like cell types mediated by BMP, therefore revealed under appreciated epithelial cell populations with promising potential in bioengineering and dental therapeutics.

在慈鲷（Cichlids）中，替换齿（RT）与邻近的味蕾（TB）共享连续的上皮带，且两种组织在标记滞留细胞（label-retaining cells）的亚群中共同表达干细胞因子。在小鼠及其他哺乳动物体内，卵泡抑素（Follistatin，又称Fat，骨形态发生蛋白（Bone Morphogenetic Protein，BMP）拮抗剂）突变体的舌部磨牙间隆起（IE）区域的口腔乳头呈现形态异常的内陷。本研究采用基于下一代测序（Next Generation Sequencing，NGS）的转录组分析（RNA-seq）手段，对比了卵泡抑素（Fst）突变型小鼠与野生型对照小鼠的舌组织差异基因表达情况。研究结果证实，舌部磨牙间隆起区域出现了牙源性标记基因的异位表达，这表明脊椎动物口腔上皮保留了固有可塑性，能够形成由BMP介导的牙齿及味觉样细胞类型，由此揭示了此前未被充分认知的上皮细胞群，其在生物工程与牙科治疗领域具备极具前景的应用潜力。