Project description:Teeth are ectodermal organs that have, throughout their long evolutionary history, retained the capacity for full regeneration and replacement, even in adult stages. Yet, because most mammals (e.g., humans, mice) lack lifelong dental replacement, we do not fully understand its tempo and mode, and we do not have a clear picture of the cell populations and signals that contribute to the process. Here, we used cichlid fishes from Lake Malawi, species that differ in tooth formula (tooth shape and number) but share one-for-one tooth replacement, to (i) explore the tempo of dental replacement after plucking and then (ii) identify the cell populations, gene expression signatures, and interactions between cell populations that change in this plucking paradigm. We observed that cichlid species with divergent dentitions accelerated tooth replacement >3x on the plucked half of the jaw and that dentitions were nearly restored to normal fifteen days after plucking. Then, we used single-nucleus RNA-seq to profile cellular and molecular changes across the first week of post-plucking tooth replacement. This approach allowed us to infer cellular trajectories in dental epithelium and mesenchyme that underlie tooth regeneration. We identifed distinct gene expression profiles and cellular interactions across four time points of accelerated tooth replacement, with divergent involvement of epithelial, mesenchymal and immune cell types. Diferential signaling of Collagen, BMP, MMP, Semaphorin and Slit-Robo pathways was evident after plucking and highlights temporally-sequenced roles of immune response, odontogenesis, vascularization and nerve pathfinding as teeth are constructed anew. Overall, this study provides insight into the trajectory of cellular interactions accompanying whole-tooth replacement and offers a comparative foundation for understanding dental regeneration in vertebrates.
Project description:Tooth regeneration remains an unmet clinical challenge due to the structural complexity of dental tissues and the requirement for precise epithelial–mesenchymal interactions during development. Here, we present a xeno-free, biomimetic strategy for dental organoid engineering by integrating human induced pluripotent stem cell (hiPSC)–derived oral epithelial cells (OECs) and neural crest cells (NCCs) within a biodegradable chitosan–alginate (CA) scaffold. The CA scaffold provides a mechanically compliant and highly porous 3D microenvironment that supports hiPSC maintenance, lineage-specific differentiation, and spatial organization. Recombined OECs and NCCs self-organized into dental organoids that recapitulated key features of early odontogenesis, including coordinated epithelial–mesenchymal interactions, progressive expression of odontogenic markers (DSPP and AMBN), and time-dependent mineral deposition. Transcriptomic profiling revealed activation of gene programs associated with odontogenesis, amelogenesis, and craniofacial morphogenesis. Upon orthotopic implantation into a rat maxillary molar extraction site, cell-laden scaffolds supported cell survival, early tooth-like tissue organization, and localized mineralized matrix formation in vivo. Together, these results establish a xeno-free, scaffold-based platform for dental organoid formation and early tooth regeneration, providing a translational framework for stem cell–based dental tissue engineering and regenerative therapies.
Project description:Background: DNA methylation is an important epigenetic modification critical to the regulation of gene expression during development. To date, little is known about the role of DNA methylation in tooth development in large animal models. Thus, we carried out a comparative genomic analysis of genome-wide DNA methylation profiles in E50 and E60 tooth germ from miniature pigs using methylated DNA immunoprecipitation-sequencing (MeDIP-seq).Results: We observed different DNA methylation patterns during the different developmental stages of pig tooth germ. A total of 2,469 differentially methylated genes were identified. Functional analysis identified several signaling pathways and 104 genes that may be potential key regulators of pig tooth development from E50 to E60.Conclusions: The present study provided a comprehensive analysis of the global DNA methylation pattern of tooth germ in miniature pigs and identified candidate genes that potentially regulate tooth development from E50 to E60.
Project description:The miRNAs expression profile of three different types of teeth include deciduous incisor (QY), deciduous canine (JY) , deciduous premolar (QMY) ,and deciduous molar (MY) in three typical stages of tooth development embryonic day 40 , 50, and 60, which cover the major morphological and physiological changes in pig tooth germ growth and development throughout pregnancy including the bud, cap, and bell stages.
Project description:Tooth extraction triggers a coordinated healing process in which immune responses govern alveolar bone regeneration. However, the cellular and molecular mechanisms underlying bone regeneration within extraction sockets remain unclear. The goal of this study was to characterize the immune landscape of healthy tooth-surrounding tissues in mice, with a particular focus on innate lymphoid cells, using scRNA-seq.
Project description:Tooth extraction triggers a coordinated healing process in which immune responses govern alveolar bone regeneration. However, the cellular and molecular mechanisms underlying bone regeneration within extraction sockets remain unclear. The goal of this study was to characterize the immune landscape of healthy tooth-surrounding tissues in mice, with a particular focus on innate lymphoid cells, using scRNA-seq.
Project description:The miRNAs expression profile of four typical stages of tooth development, embryonic day 35 (E35), E45, E50, and E60, which cover the major morphological and physiological changes in pig tooth germ growth and development throughout pregnancy, including the bud, cap, early bell, and late bell stages.
Project description:The miRNAs expression profile of four typical stages of tooth development, embryonic day 35 (E35), E45, E50, and E60, which cover the major morphological and physiological changes in pig tooth germ growth and development throughout pregnancy, including the bud, cap, early bell, and late bell stages. Four-condition experiment: E35 vs. E45 vs. E50 vs. E60. Biological replicates: 3, independently removed under a microscope. Four replicates per array.
Project description:miRNAs are not well known their expression and function in tooth development. To identify the miRNAs expression during tooth development, tooth germs were dissected from the initiation bud, cap and bell stages.
Project description:The miRNAs expression profile of three different types of teeth include deciduous incisor (QY), deciduous canine (JY) , deciduous premolar (QMY) ,and deciduous molar (MY) in three typical stages of tooth development embryonic day 40 , 50, and 60, which cover the major morphological and physiological changes in pig tooth germ growth and development throughout pregnancy including the bud, cap, and bell stages. twelve-condition experiment, QY40 vs.QY50 vs.QY60 vs. JY40 vs. JY50vs. JY60 vs.QMY40 vs.QMY50 vs.QMY60 vs.MY40.vs.MY50.vs.MY60. Biological replicates: 1 , independently removed under a microscope. Four replicate per array.