This study evaluated the current practices of oral cytology in Japan, focusing on the adoption and clinical impact of liquid-based cytology (LBC) and associated challenges. An anonymous nationwide questionnaire was conducted by the Medical Practice Committee of the Japanese Society of Clinical Oral Pathology. Responses from 28 institutions provided insights into cytology implementation, tools used, Specimen preparation method, and genomic testing. LBC was adopted by 78.6 % of facilities, citing benefits such as improved sample evaluation, cleaner background, and genomic applicability. Seven institutions increased usage post-LBC introduction. However, issues like limited samples, costs, and lack of insurance coverage hinder broader use. Genetic testing was performed in 15 institutions, particularly for salivary gland tumors, though financial and procedural barriers remain. Findings highlight the need for improved reimbursement, national standardization, and education. LBC offers clear diagnostic value and should be integrated into standard oral pathology practices.

Embryonic oral epithelium is a multipotent, ectodermal tissue that gives rise to various organs, including salivary glands, tooth germs, taste buds, and anterior pituitary glands. Although oral epithelium is contiguous posteriorly with endodermal epithelium and anteriorly with surface ectoderm, it exhibits distinct gene expression profiles during development. However, the molecular mechanisms that govern fate specification between oral epithelium and surface ectoderm remain poorly understood. Here, we present a highly efficient protocol for the PITX2-positive oral epithelium induction from human induced pluripotent stem cells (hiPSCs) using a reporter system. Sonic Hedgehog (SHH) signaling activation is essential for the efficient PITX2-positive epithelial cell generation. The induced cells exhibited gene expression profiles resembling those of embryonic oral epithelium and formed epithelial spheres that replicated features of human oral epithelium. This study established a robust platform for investigating human oral epithelial development and provided a valuable foundation for organoid-based research on oral organs.

OBJECTIVES:The junctional epithelium (JE) is a specialized barrier that maintains periodontal tissue homeostasis. Although age-related changes have been reported in other epithelial tissues, the mechanisms underlying age-associated dysfunction in the JE remain largely unknown. In this study, the aims were to determine whether there is cellular senescence in the JE during natural aging, and to elucidate the underlying molecular mechanisms. METHODS:JE was harvested from the maxillae of young (eight-week-old) and aged (72-week-old) male mice, and tissue sections were prepared. To evaluate age-related changes, histological analyses, including hematoxylin-eosin (HE) staining, immunofluorescence staining, and TUNEL assays, as well as bulk RNA sequencing (RNA-seq) for gene expression profiling, were performed. Differentially expressed genes (DEGs) were identified from the RNA-seq data, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. RESULTS:Histological examination revealed no overt morphological differences in the JE between young and aged mice. However, the JE from aged mice had significantly fewer Ki67-positive cells and more TUNEL-positive apoptotic cells. RNA-seq identified DEGs in the JE of aged mice. GO and KEGG analyses indicated significant enrichment of inflammation- and aging-related pathways. RT-qPCR confirmed the increased expression of p16, Lcn2, and Defb3 in the JE of aged mice. Immunostaining also revealed increased numbers of γ-H2AX, p-STAT3, 8-OHdG, and 4-HNE positive cells in the JE of aged mice. CONCLUSIONS:The JE of aged mice had molecular hallmarks of cellular senescence. These findings highlight the role of senescence in the aging of periodontal barrier tissue.

Background The Journal of Oral Biosciences is dedicated to advancing and disseminating fundamental knowledge across the full spectrum of oral biosciences. This editorial features recently published review articles spanning key domains, including “craniofacial biology”; “bone, tooth, and mineral biology”; “periodontal and pulp biology”; “microbiology and immunology”; “pharmacology”; “biomaterials”; “oncology”; “salivary research”; and “regenerative medicine.” Highlight The featured review articles address a diverse range of topics, including buccal bifurcation cysts, mandibular prognathism, glucose metabolism, gingival overgrowth, dextrins, chemokine receptor 5, electrical stimulation, the tumor microenvironment, computer-aided diagnosis, adiponectin, myoepithelial cells, secretory granules, apoptosis, dental regenerative medicine, and three-dimensional in vitro models. Conclusion The review articles featured in the Journal of Oral Biosciences provide comprehensive insights into contemporary research themes and emerging concepts in oral biosciences. This editorial discusses their key findings and underscores their significance in advancing the understanding of oral health and disease.

Neutron beams, being electrically neutral and highly penetrating, offer unique advantages for the irradiation of biological species such as plants, seeds, and microorganisms. We comprehensively investigated the potential of neutron irradiation for inducing genetic mutations by using simulations of spallation, reactor, and compact neutron sources based on J-PARC BL10, the JRR-3 TNRF, and KUANS. We analyzed neutron flux, energy deposition rates, and Linear Energy Transfer (LET) distributions. The KUANS simulation demonstrated the highest dose rate of 17 Gy/h, significantly surpassing that obtained at BL10, due to the large solid angle achieved with optimal sample placement. The findings highlight KUANS’s suitability for efficiently inducing specific genetic mutations and neutron breeding, particularly for inducing targeted mutations in biological samples, also on account of its LET range of 20–70 keV/μm. Our results emphasize the importance of choosing neutron sources based on LET requirements to maximize mutation induction efficiency. This research study shows the potential of compact neutron sources such as KUANS for effective biological irradiation and neutron breeding, offering a viable alternative to larger facilities. The neutron filters used at BL10 and the TNRF effectively exclude low-energy neutrons while keeping the high-LET component. The neutron capture reaction, 14N(n,p)14C, was found to be the main dose contributor under thermal neutron-dominated conditions.

A neutron whispering gallery state is a quantum state localized on a material surface bound by the centrifugal force and the material potential. Precise measurements of such quantum states enable tests of quantum mechanics in noninertial frames, characterization of the surface potential, and searches for hypothetical short-range interactions at the nanometer scale. We observed a neutron whispering gallery state on a SiO2 concave mirror using a pulsed cold neutron beam. The measured results agree with theoretical calculations within 1.9% for the centrifugal acceleration a 7 x 107 m/s2, which is due to unmodeled deviations of the shape of the concave mirror edge from an ideal one. We found that the sensitivity itself was 1 x 10-4, which is two orders of magnitude better than the above agreement.

Objectives The junctional epithelium (JE) plays an important role in maintaining the protective integrity of periodontal tissues by forming an epithelial barrier that impedes bacterial invasion. This study examined the effects of Porphyromonas gingivalis lipopolysaccharide (PG-LPS) on JE-1 cells, a mouse-derived junctional epithelial cell line. Methods JE-1 cells were exposed to PG-LPS, and the effects on cell viability, migration, gene expression, protein expression, and barrier function at various time points were evaluated according to the experimental type. Results PG-LPS (1 μg/mL) did not affect JE-1 cell viability but significantly inhibited migration. Treatment with PG-LPS upregulated inflammatory genes (Il-6, Tlr2, Tlr4, Traf6) and altered the expression of chemokines (increased Cxcl2 and decreased Cxcl10) and protective factors (increased Nfe2l2 and Slpi). Notably, 1 μg/mL of PG-LPS increased permeability and decreased adhesion molecule expression (Cdh1 and Itgb4), whereas 10 μg/mL showed a non-linear response (apparent permeability [cm/s]: 0.868, 0.915, 1.416, 1.728, 1.224, and 1.176 with 0, 0.1, 0.5, 1, 5, and 10 μg/mL respectively), indicating compensatory mechanisms. Conclusions PG-LPS disrupts JE barrier function and alters its immunomodulatory properties, potentially contributing to periodontitis progression. These findings enhance our understanding of the underlying causes of periodontitis and inform targeted treatments to maintain JE defense against periodontopathogenic bacteria.

ZIP14/SLC39A14, a membrane-bound metal transporter, is essential for systemic metal homeostasis and has been implicated in inflammatory and metabolic disorders, including cancer-associated cachexia. Despite its biological and therapeutic significance, no selective inhibitors have been identified. Here, we identify 1-phenyl-8-(2-phenylethyl)-1,3,8-triazaspiro[4.5]decan-4-one (PPTD) as the first selective small-molecule inhibitor of ZIP14. PPTD efficiently blocks ZIP14-mediated uptake of zinc, iron, manganese, and cadmium, while sparing the closely related transporter ZIP8/SLC39A8. Mechanistically, PPTD binds specifically to a pocket formed at the dimer interface of ZIP14, as revealed by AlphaFold3 structural prediction, ligand-interaction profiling, structure-activity analyses, and site-directed mutagenesis, providing direct evidence for a targeted inhibition mechanism. ZIP14-driven metal influx promotes reactive oxygen species and lipid peroxidation, leading to cytotoxicity, which PPTD effectively reverses. In vivo , PPTD ameliorates major features of cancer cachexia in mice, including weight loss, reduced survival, muscle wasting, impaired locomotor activity, and disease progression. PPTD thus provides both a chemical probe to dissect ZIP14 function and a potential therapeutic candidate for cancer cachexia, establishing a foundation for the development of therapies targeting ZIP14-mediated metal dysregulation.

Neutron imaging is a nondestructive and noninvasive inspection technique with a wide range of potential applications. However, the fundamentals of this technique still need to be improved, one of which involves achieving micrometer scale or even better resolution, which is a challenging task. Recently, a high-resolution neutron imaging device based on fine-grained nuclear emulsions was developed. Although these detectors demonstrate exceptionally high resolutions, they have several limitations. Furthermore, these detectors require an additional chemical development process and are thus not reusable. To overcome these limitations, we investigated whether neutron imaging devices based on fluorescent nuclear track detectors were suitable for high-resolution neutron imaging. Fluorescent nuclear track detectors are reusable solid-state detectors that do not require additional chemical processing. A novel technique combining neutron imaging based on fluorescent nuclear track detectors with a neutron converter layer formed using \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$<^>{10}$$\end{document}B\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${_4}$$\end{document}C was developed with unprecedented resolution. The neutron imaging of a gadolinium-based grating with a periodic structure of 9 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{document}m was performed using the proposed fluorescent nuclear track detector-based neutron imaging device, and the grating structure was successfully resolved. The measured resolution was 0.887 +/- 0.009 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu$$\end{document}m, which is the 1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sigma$$\end{document} 10-90% edge response obtained using optical images of the fluorescent nuclear track detectors.

Functional integration of transplanted cells with host tissue remains a major challenge in cell-based therapies for tissue damage in organs with complex structures, such as exocrine glands. In this study, we investigated whether salivary gland organoids derived from human induced pluripotent stem cells (hiPSCs) could be integrated into injured salivary glands using cell sheet engineering. Cell sheet engineering has demonstrated therapeutic potential in a range of organs, including the heart, retina, and lungs. We found that hiPSC-derived salivary gland organoids contain long-term maintainable progenitor cells, and the resulting cell sheets exhibited heterogeneity, including acinar, ductal, and myoepithelial cells. Furthermore, transplantation of the organoid-derived salivary gland cell sheets into immunodeficient mice resulted in partial integration with the host salivary ducts, leading to the formation of structures that included xenogeneic chimeric ducts. These findings suggest that salivary gland cell sheet transplantation represents a promising strategy for functional salivary gland regeneration.

Background The Journal of Oral Biosciences is committed to advancing and disseminating fundamental knowledge across all areas of oral biosciences. This editorial review features review articles covering diverse topics, including the “mandible,” “tooth remineralization,” “dental pulpitis,” “dental implants,” “mesenchymal stem cells,” “microbiota,” “facial pain,” “stomatitis,” “odontogenic tumors,” “oral submucous fibrosis,” “insights on orofacial pain,” “tissue engineering,” “melatonin,” and “regenerative medicine.” Highlight This editorial review focuses on forensic anthropology, calcium sucrose phosphate, pulp biomarkers, zirconia, mesenchymal stem cells, microflora, stomatitis, ameloblastoma, areca nut, orofacial pain, collagen, melatonin, and tooth regeneration. Conclusion The review articles featured in the Journal of Oral Biosciences have significantly contributed to expanding readers’ knowledge across various domains of oral biosciences. The current editorial review discusses the key findings and significance of these review articles.

The displacement-noise-free interferometer (DFI) is designed to eliminate all displacement-induced noise while retaining sensitivity to gravitational wave (GW) signals. Ground-based DFIs suffer from physical arm-length limitations, resulting in poor sensitivity at frequencies below 1 kHz. To address this, previous research introduced a neutron-based DFI, which replaces laser light with neutrons and achieves exceptional sensitivity down to a few hertz. In this study, we conducted a proof-of-principle experiment using a pulsed neutron source at the Japan Proton Accelerator Research Complex (J- PARC). Despite practical constraints that led to deviations from the ideal experimental design, we optimized the setup and developed a novel analysis method that successfully cancels displacement noise while preserving simulated GW signals. This work presents the first successful demonstration of a neutron DFI and a neutron interferometer for GW detection.

Objective This study aimed to evaluate the role of the chromodomain helicase DNA-binding protein 3 (CHD3) in tooth morphogenesis in Chd3 knockout mice. Methods Chd3 knockout mice were generated using the CRISPR-Cas9 method. Mandibular first molars were extracted from the mice and their littermates and morphometrically analyzed. Subsequent histological and immunohistochemical analyses of teeth were performed at each developmental stage. Chd3 knockdown in mesenchymal cells from the dental papilla (mDP) and Hertwig’s epithelial root sheath (HERS) was performed by Chd3 shRNA transduction or a control using an adenoviral vector. These effects were examined using cell proliferation assays and quantitative real-time polymerase chain reaction. Results Narrowing of tooth cervical width was observed in mandibular first molars of Chd3 knockout mice. On postnatal day (PN) 8, the cervical width was narrow before root formation in tooth germs. The number of Ki-67-positive cells decreased in the dental mesenchyme at PN1 and apical papilla at PN8. Chd3 promoted the proliferation of dental mesenchymal cells, but no significant changes were observed in HERS epithelial cells. Chd3 maintained sonic hedgehog (Shh) expression and inhibited that of bone morphogenetic protein (Bmp)4 in dental mesenchymal cells, maintaining Shh and Wnt3a expression and inhibited that of Bmp2 in HERS epithelial cells. Conclusion Chd3 may regulate tooth cervical width during the early growth stage of the apical papilla via Shh, Bmp, and Wnt signaling.

Sjögren's syndrome (SS) is an autoimmune disorder characterized by oral dryness that is primarily attributed to tumor necrosis factor alpha (TNF-α)-mediated reduction in saliva production. In traditional Chinese medicine, goji berries are recognized for their hydrating effect and are considered suitable to address oral dryness associated with Yin deficiency. In the present study, we used goji berry juice (GBJ) to investigate the potential preventive effect of goji berries on oral dryness caused by SS. Pretreatment of human salivary gland cells with GBJ effectively prevented the decrease in aquaporin-5 (AQP-5) mRNA and protein levels induced by TNF-α. GBJ also inhibited histone H4 deacetylation and suppressed the generation of intracellular reactive oxygen species (ROS). Furthermore, GBJ pretreatment reserved mitochondrial membrane potential and suppressed the upregulation of Bax and caspase-3, indicating that GBJ exerted an antiapoptotic effect. These findings suggest that GBJ provides protection against TNF-α in human salivary gland cells and prevents the reduction of AQP-5 expression on the cell membrane. Altogether, these results highlight the potential role of GBJ in preventing oral dryness caused by SS.

The neutron electric dipole moment (EDM) is a sensitive probe for currently undiscovered sources of charge-parity symmetry violation. As part of the TRIUMF Ultracold Advanced Neutron (TUCAN) collaboration, we are developing spin analyzers for ultracold neutrons (UCNs) to be used for a next-generation experiment to measure the neutron EDM with unprecedented precision. Spin-state analysis of UCNs constitutes an essential part of the neutron EDM measurement sequence. Magnetized iron films used as spin filters of UCNs are crucial experimental components, whose performance directly influences the statistical sensitivity of the measurement. To test such iron film spin filters, we propose the use of polarized cold-neutron reflectometry, in addition to conventional UCN transmission experiments. The new method provides information on iron film samples complementary to the UCN tests and accelerates the development cycles. We developed a collaborative effort to produce iron film spin filters and test them with cold and ultracold neutrons available at JRR-3/MINE2 and J-PARC/MLF BL05. In this article, we review the methods of neutron EDM measurements, discuss the complementarity of this new approach to test UCN spin filters, provide an overview of our related activities, and present the first results of polarized cold-neutron reflectometry recently conducted at the MINE2 beamline.

Salivary gland myoepithelial cells regulate saliva secretion and have been implicated in the histological diversity of salivary gland tumors. However, detailed functional analysis of myoepithelial cells has not been determined owing to the few of the specific marker to isolate them. We isolated myoepithelial cells from the submandibular glands of adult mice using the epithelial marker EpCAM and the cell adhesion molecule CD49f as indicators and found predominant expression of the transcription factor FoxO1 in these cells. RNA-sequence analysis revealed that the expression of cell cycle regulators was negatively regulated in FoxO1-overexpressing cells. Chromatin immunoprecipitation analysis showed that FoxO1 bound to the p21/p27 promoter DNA, indicating that FoxO1 suppresses cell proliferation through these factors. In addition, FoxO1 induced the expression of ectodysplasin A (Eda) and its receptor Eda2r, which are known to be associated with X-linked hypohidrotic ectodermal dysplasia and are involved in salivary gland development in myoepithelial cells. FoxO1 inhibitors suppressed Eda/Eda2r expression and salivary gland development in primordial organ cultures after mesenchymal removal. Although mesenchymal cells are considered a source of Eda, myoepithelial cells might be one of the resources of Eda. These results suggest that FoxO1 regulates myoepithelial cell proliferation and Eda secretion during salivary gland development in myoepithelial cells.

This study entailed the successful deployment of a novel neutron interferometer that utilizes multilayer mirrors. The apparatus facilitates a precise evaluation of the wavelength dependence of interference fringes utilizing a pulsed neutron source. Our interferometer achieved an impressive precision of 0.02 rad within a 20-min recording time. Compared to systems using silicon crystals, the measurement sensitivity was maintained even when using a simplified disturbance suppressor. By segregating beam paths entirely, we achieved successful measurements of neutron-nuclear scattering lengths across various samples. The values measured for Si, Al, and Ti were in agreement with those found in the literature, while V showed a disparity of 45%. This discrepancy may be attributable to impurities encountered in previous investigations. The accuracy of measurements can be enhanced further by mitigating systematic uncertainties that are associated with neutron wavelength, sample impurity, and thickness. This novel neutron interferometer enables us to measure fundamental parameters, such as the neutron-nuclear scattering length of materials, with a precision that surpasses that of conventional interferometers.

Objectives This study aimed to investigate the regulatory mechanisms governing dental mesenchymal cell commitment during tooth development, focusing on odontoblast differentiation and the role of epigenetic regulation in this process. Methods We performed single-cell RNA sequencing (scRNA-seq) of dental cells from embryonic day 14.5 (E14.5) mice to understand the heterogeneity of developing tooth germ cells. Computational analyses including gene regulatory network (GRN) assessment were conducted.We validated our findings using immunohistochemistry (IHC) and in vitro loss-of-function analyses using the DNA methyltransferase 1 (DNMT1) inhibitor Gsk-3484862 in primary dental mesenchymal cells (DMCs) isolated from E14.5 mouse tooth germs. Bulk RNA-seq of Gsk-3484862-treated DMCs was performed to identify potential downstream targets of DNMT1. Results scRNA-seq analysis revealed diverse cell populations within the tooth germs, including epithelial, mesenchymal, immune, and muscle cells. Using single-cell regulatory network inference and clustering (SCENIC), we identified Dnmt1 as a key regulator of early odontoblast development. IHC analysis showed the ubiquitous expression of DNMT1 in the dental papilla and epithelium. Bulk RNA-seq of cultured DMCs showed that Gsk-3484862 treatment upregulated odontoblast-related genes, whereas genes associated with cell division and the cell cycle were downregulated. Integrated analysis of bulk RNA-seq data with scRNA-seq SCENIC profiles was used to identify the potential Dnmt1 target genes. Conclusions Dnmt1 may negatively affect odontoblast commitment and differentiation during tooth development. These findings contribute to a better understanding of the molecular mechanisms underlying tooth development and future development of hard-tissue regenerative therapies.

Salivary gland myoepithelial cells regulate salivary secretion and have been implicated in the histological diversity of salivary gland tumors. However, isolation of myoepithelial cells has been difficult owing to a lack of detailed functional analysis and cell surface markers. Therefore, we aimed to isolate myoepithelial cells from adult mouse submandibular glands using the epithelial marker EpCAM and cell adhesion factor CD49f as indicators and characterize them via sphere-forming culture. Functional analysis of specific gene expression in myoepithelial cells is possible via cell transfection experiments using the piggyBac transposon vector system. Here, we describe detailed methods and tips for the isolation and functional analysis of myoepithelial cells.