Project description:Murine tooth germ development proceeds in continuous and sequential steps with reciprocal interactions between the odontogenic epithelium and the adjacent mesenchyme, and several growth factor signaling and their activation are required for tooth germ development. The expression of ADP-ribosylation factor (Arf)-like 4c (Arl4c) has been shown to induce cell proliferation, thereby involving in epithelial morphogenesis and tumorigenesis. However, other functions of Arl4c except for cellular growth are largely unknown. Although we recently demonstrated the involvement of the upregulated expression of Arl4c in cell proliferation of ameloblastoma, which has the same origin as odontogenic epithelium, its effect on tooth germ development remains unclear. Herein, single-cell RNA sequencing (scRNA-seq) analysis revealed that the expression of Arl4c, among 17 members of the Arf-family members, was specifically detected in odontogenic epithelial cells, such as stratum intermedium, stella reticulum and outer enamel epithelium, of postnatal day 1 (P1) mouse molar. In addition, scRNA-seq analysis showed higher expression of Arl4c in non-ameloblast and inner enamel epithelium, which include immature cells. In the mouse tooth germ rudiments culture, treatment with SecinH3 (an inhibitor of ARNO/Arf6 pathway) reduced the size, width and cusp height and the thickness of eosinophilic layer, which would involve the synthesis of dentin and enamel matrix organization. In addition, loss-of-function experiments using siRNAs and shRNA revealed that Arl4c expression was involved in cell proliferation and osteoblastic cytodifferentiation in odontogenic epithelial cells. Finally, RNA-seq analysis with gene set enrichment analyses (GSEA) and Gene Ontology (GO) analysis showed that osteoblastic differentiation-related gene set and/or GO terms were downregulated in shArl4c expressing odontogenic epithelial cells. These results suggest that the Arl4c-ARNO/Arf6 pathway axis contributes to tooth germ development through osteoblastic differentiation.
Project description:Gene expression profiles were generated from embryonic day 13.5 CD-1 mouse mandibular first molars whole tooth and non-tooth non-bone oral tissue. Three biological replicates from embryonic day 13.5 CD-1 mice were generated from pooled tissues across multiple mice. The tooth germ and non-tooth oral tissues were paired from the same embryos.
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: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: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.
Project description:Odontomas are classified as odontogenic benign tumors, which show disorganized dental mineralized hard tissue formation in the jaw, but mechanisms in the induction of odontomas remain to be clarified. Odontomas are also thought to be developmental anomalies of tooth germ, which frequently occur in patients with familial adenomatous polyposis (FAP) involving activation of Wnt/b-catenin signaling. However, the roles of Wnt/b-catenin signaling in odontomas or odontogenic cells remain to be clarified. The current study was conducted to investigate the expression of b-catenin in odontomas and the function of Wnt/b-catenin signaling in odontogenic epithelial cells and tooth germ development. b-catenin frequently accumulated in the nucleus and/or cellular cytoplasm of remaining odontogenic epithelial cells in human odontoma specimens, immunohistochemically. Activation of Wnt/b-catenin signaling inhibited odontogenic epithelial cell proliferation and mouse tooth germ development, while inducing epithelial bud formation in the novel developed epithelial tooth bud culture system derived from mouse tooth germ. We identified Semaphorin 3A (Sema3A) as a downstream molecule of Wnt/b-catenin signaling using DNA microarray analysis and showed that Wnt/b-catenin signaling-dependent reduction of Sema3A expression resulted in suppression of odontogenic epithelial cell proliferation. Novel developed epithelial tooth bud culture system revealed that Sema3A expression is required in epithelial budding morphogenesis. These results suggest that Wnt/b-catenin signaling negatively regulates odontogenic epithelial cell proliferation and tooth germ development through decreased-Sema3A expression, and aberrant activation of Wnt/b-catenin signaling may be associated with the formation of odontomas.
Project description:Embryologically the tooth is derived from both the ectoderm and neural crest (ectomesenchyme). It is often used as a model to study how epithelialmesenchymal interactions can control differentiation and morphogenesis. During early development organs of ectodermal origin share both a set of signalling molecules and exhibit common morphological features, subsequently proceeding along separate developmental programs.<br><br>Tooth development is a continuous process that can be divided into the initiation -, bud -, cap -, and bell-stages. In mice, tooth development begins at embryonic day 11.5 (E11.5), by thickening of the dental epithelium, while mineralization of enamel and dentin in first molar starts at postnatal day 0 (P0) (5). A multistep and complex process of the gene expression are involved in the early stage of tooth development. So far expression of more than 1300 genes and/or proteins have been detected during tooth germ development by microarrays/immunocytochemistry/in situ hybridization. Studies with mutant mice have identified a number of genes that regulate tooth development and morphology. For example, deficiency of Lef-1 or P63 arrests tooth development at early stages. Deficiency of Msx1 or Pax9 results in arrest of tooth development at the bud stage , while deficiency of Runx2/Cbfa1 or Sp3 inhibits cyto-differentiation of ameloblasts and/or odontoblasts. Shh is required for normal growth and morphogenesis, but is not essential for cyto-differentiation of the ameloblast and odontoblast populations. Ameloblastin and amelogenin knock-out mice develop severe enamel hypoplasia with abnormal ameloblast differentiation. <br><br>Recently, new connections between retinoid metabolism and PPAR responses have been identified. It has also been shown that endogenous retinoic acid is necessary for the initiation of odontogenesis , and that some of the genes that catalyze the oxidation of retinaldehyde into retinoic acid, exhibit distinct patterns of expression in developing murine teeth. Little is known about functions of PPAR-a as regards tooth germs or mature teeth. It is, however, likely that mitochondrial oxidative metabolism well as fatty acid metabolism is enhanced in late odontogenesis. These are metabolic activities which in other tissues are stimulated by PPAR-a agonists.<br><br>For this reason it was of interest to carry out comparative gene expression profiling of the first molar tooth germs of PPAR-a knock-out mouse and of the corresponding wild-type mice. The results suggest marked differences in gene expression, parts of which may be associated with an observed hypomineralization of enamel in the mature PPAR-a knock-out murine tooth.