Journal of Oral Biosciences最新文献

{"title":"Acknowledgement of Reviewers","authors":"","doi":"10.1016/j.job.2026.100744","DOIUrl":"10.1016/j.job.2026.100744","url":null,"abstract":"","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100744"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147395211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oral SARS-CoV-2 inoculation leads to distinct viral distribution compared to nasal inoculation in a Syrian hamster model","authors":"Nao Gojo ,&nbsp;Yu Usami ,&nbsp;Katsutoshi Hirose ,&nbsp;Satoru Toyosawa ,&nbsp;Shintaro Shichinohe ,&nbsp;Tokiko Watanabe ,&nbsp;Chikako Ono ,&nbsp;Tsuyoshi Inoue ,&nbsp;Takayoshi Sakai","doi":"10.1016/j.job.2026.100746","DOIUrl":"10.1016/j.job.2026.100746","url":null,"abstract":"<div><h3>Objectives</h3><div>The nose and mouth are the primary entry points for upper respiratory severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; however, the influence of different entry routes on viral spread remains unclear. Oral and nasal infection routes in terms of viral distribution and presence of inflammation were compared.</div></div><div><h3>Methods</h3><div>Syrian hamsters were inoculated with SARS-CoV-2 via three routes: nasal inoculation (NI), simulating conventional upper respiratory infection; lingual (supra-lingual) inoculation (LI), simulating exposure during speaking and eating; and sublingual inoculation (SI), simulating exposure to the salivary glands. After three days, the lungs, submandibular glands, nasal turbinates, liver, and brain were examined histologically and immunohistochemically. To assess direct access to the lungs, India ink was administered via each route and analyzed after tissue clearing.</div></div><div><h3>Results</h3><div>NI resulted in infection in the nasal olfactory sensory epithelium of the nasal cavity and in the lungs. India ink studies suggest that the virus is likely to have infected the nasal mucosa first, followed by secondary infection of the lungs. LI resulted in marked infection of the submandibular glands with vascular involvement. In the LI and SI groups, no viral antigen was detected in the lungs; however, there was inflammation of the lungs, suggesting cytokine-mediated effects.</div></div><div><h3>Conclusion</h3><div>Different upper respiratory entry routes produced distinct pathological patterns. While nasal infection is well recognized, our findings indicate that salivary gland infection via SI may suggest an alternative pathway for systemic viral dissemination.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100746"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mandibular morphogenesis: Genetic insights into malocclusion from EVC perspective","authors":"Nikta Gholampour ,&nbsp;Amin Kalmari ,&nbsp;Abasalt Hosseinzadeh Colagar ,&nbsp;Valiollah Arash","doi":"10.1016/j.job.2025.100711","DOIUrl":"10.1016/j.job.2025.100711","url":null,"abstract":"<div><h3>Objectives</h3><div>To investigate the association between an <em>EVC</em> gene single nucleotide polymorphism (rs1383180; G &gt; A; R &gt; Q) and mandibular skeletal malocclusion in the Mazandaran people of Northern Iran.</div></div><div><h3>Methods</h3><div>At the Arash Orthodontic Clinic in Babol, Iran, 393 individuals (148 controls, 119 with mandibular prognathism, and 126 with mandibular retrognathism) were screened for this case-control study. Cephalometric analysis, using Steiner parameters and “Wits” appraisal, verified skeletal relationships. Genomic DNA, extracted from gingival blood samples, was genotyped for rs1383180 using polymerase chain reaction-restriction fragment length polymorphism and validated using Sanger sequencing. Bioinformatics tools, including MUpro, iStable, DynaMut2, INPS-MD, SWISS-MODEL, ConSurf, PhD-SNPg, and Cscape, predicted the impact of the variant on protein function.</div></div><div><h3>Results</h3><div>The AA genotype of rs1383180 was significantly associated with mandibular prognathism (<em>p</em> = 0.036) and the mutant allele (A) trended towards significance (<em>p</em> = 0.081). There was no association with mandibular retrognathism. Bioinformatics analysis predicted that the G &gt; A transition may disrupt the structure and stability of EVC protein. ConSurf indicated moderate evolutionary conservation and PhD-SNPg and Cscape identified rs1383180 as pathogenic and oncogenic.</div></div><div><h3>Conclusion</h3><div>The AA genotype of rs1383180 was associated with an increased risk of skeletal Class III malocclusion due to mandibular prognathism. As this genotype may disrupt Hedgehog signaling, this pathway may be influencing mandibular development.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100711"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145580405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultracentrifuged serum fractions reveal promotion of dental epithelial proliferation by lactoferrin","authors":"Yoshihito Yamakawa ,&nbsp;Kimiko Yamaguchi-Ueda ,&nbsp;Asuna Sugimoto ,&nbsp;Yuki Akazawa ,&nbsp;Tomokazu Hasegawa ,&nbsp;Yumiko Nakashima ,&nbsp;Rika Kurogoushi ,&nbsp;Manami Tanaka ,&nbsp;Muhammad Dhiaulfikri Nauval Hadiana ,&nbsp;Nodoka Ato ,&nbsp;Akihito Yamamoto ,&nbsp;Tomonori Iwasaki ,&nbsp;Tsutomu Iwamoto","doi":"10.1016/j.job.2025.100728","DOIUrl":"10.1016/j.job.2025.100728","url":null,"abstract":"<div><h3>Objectives</h3><div>Serum is an essential supplement of basal cell culture media, providing growth factors, adhesion molecules, hormones, lipids, and minerals that support cell survival and function. This study was conducted to investigate the effects of ultracentrifugation-separated fractions of fetal bovine serum (FBS) on the proliferation and differentiation of dental epithelial cells with the aim of identifying the key serum-derived factors that regulate cellular activities.</div></div><div><h3>Methods</h3><div>FBS was fractionated by ultracentrifugation at 100,000×<em>g</em> for 18 h at 4 °C into three layers, designated as the FBS-1st (top), -2nd (middle), and 3rd (bottom) fractions. Each fraction was added at 10 % (v/v) to the culture medium of rat dental epithelial HAT-7 cells. Cell proliferation was assessed by cell counting and 5-bromo-2′-deoxyuridine incorporation, and differentiation was evaluated by ameloblastin immunostaining. The involvement of lactoferrin and its receptors was examined using recombinant protein stimulation, reverse transcription polymerase chain reaction, small interfering RNA knockdown, and western blotting.</div></div><div><h3>Results</h3><div>FBS-3rd significantly promoted cell proliferation, whereas FBS-1st and -2nd inhibited it. Ameloblastin staining revealed no significant differences between FBS-1st and the control; however, it was suppressed in the FBS-2nd and -3rd. Proteomic analysis identified lactoferrin as the most abundant protein in FBS-3rd, and exogenous lactoferrin enhanced HAT-7 cell proliferation. The lactoferrin receptor, low-density lipoprotein receptor-related protein 1 (Lrp1), was expressed in HAT-7 cells, and <em>Lrp1</em> knockdown stopped lactoferrin-induced proliferation. Lactoferrin induced phosphorylation of extracellular signal-regulated kinase 1/2, but not Akt serine/threonine kinase, and mitogen-activated protein kinase kinase inhibition with U0126 suppressed the proliferative effect of lactoferrin.</div></div><div><h3>Conclusion</h3><div>Lactoferrin, which was enriched in the FBS-3rd fraction, may contribute to the proliferation of dental epithelial cells via the Lrp1-ERK signaling pathway.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100728"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Periostin deficiency leads to age-dependent craniofacial, dental, and skeletal morphological alterations in mice","authors":"Akihiko Fujita ,&nbsp;Masahiro Chatani ,&nbsp;Yurie Sato ,&nbsp;Natsuhiro Takahashi ,&nbsp;Yuki Azetsu ,&nbsp;Akiko Karakawa ,&nbsp;Nobuhiro Sakai ,&nbsp;Shugo Haga ,&nbsp;Haruhisa Nakano ,&nbsp;Masamichi Takami","doi":"10.1016/j.job.2026.100734","DOIUrl":"10.1016/j.job.2026.100734","url":null,"abstract":"<div><h3>Objectives</h3><div>Periostin is an extracellular matrix protein that is highly expressed in hard tissue-associated regions, including the periosteum and periodontal ligament, where it is essential for bone formation and craniofacial development. In this study, the aim was to clarify its functions in skeletal maintenance during aging by comparing periostin-deficient (<em>Postn</em>^−/−) and wild-type (<em>Postn</em>^+/+) mice.</div></div><div><h3>Methods</h3><div>Comprehensive micro-computed tomography analyses were performed on <em>Postn</em>^−/− and <em>Postn</em>^+/+ mice at 18 and 62 weeks of age to assess age-related changes in craniofacial and femoral morphologies.</div></div><div><h3>Results</h3><div>At 18 weeks, there were craniofacial abnormalities in <em>Postn</em>^−/− mice, including the absence of the foramen-like structure on the ventral mandible, increased incisor curvature, and a reduction in pulp cavity size. With age, these alterations became more pronounced, with significant differences in the angulation of the upper incisors, vertical height of the mandibular body, progressive enamel defects that expanded across the surface of the maxillary and mandibular incisors, and further narrowing of the pulp cavity. Additionally, in <em>Postn</em>^+/+ mice, there was an expected age-dependent reduction in bone volume fraction in the femur, but not in <em>Postn</em>^−/− mice at 18 or 62 weeks, suggesting suppression of age-related trabecular deterioration. In contrast, aged <em>Postn</em>^−/− mice had ectopic bone formation in the distal femur and around the knee joint, indicating aberrant ossification in the absence of periostin.</div></div><div><h3>Conclusions</h3><div>Periostin deficiency induces alterations in craniofacial, dental, and skeletal morphologies during aging. Periostin is also required for normal trabecular remodeling. These findings underscore its essential role in skeletal integrity and provide insights into bone biology and aging-related tissue remodeling.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100734"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of Mfa5-2 as a structural component of Mfa1 fimbriae in Porphyromonas gingivalis","authors":"Naoyoshi Miwa ,&nbsp;Makoto Hirohata ,&nbsp;Yui Yoshimura ,&nbsp;Akihiro Oishi ,&nbsp;Ayaka Kato ,&nbsp;Yoshikazu Naiki ,&nbsp;Kiyoshi Nishikawa ,&nbsp;Hiroyuki Nawa ,&nbsp;Yoshiaki Hasegawa","doi":"10.1016/j.job.2026.100753","DOIUrl":"10.1016/j.job.2026.100753","url":null,"abstract":"<div><h3>Objectives</h3><div>The periodontal pathogen <em>Porphyromonas gingivalis</em> produces Mfa1 fimbriae, which play an important role in biofilm formation and bacterial colonization. In <em>P. gingivalis</em> ATCC 33277, Mfa1 fimbriae are composed of the major Mfa1 subunit and the accessory proteins Mfa3, Mfa4, and Mfa5. Some <em>P. gingivalis</em> strains harbor an additional Mfa5-related gene (<em>mfa5-2</em>). However, <em>mfa5-2</em> presence in the genome of <em>P. gingivalis</em> EM3 and 1439 and Mfa5-2 incorporation into the Mfa1 fimbriae in both strains remain unclear. Therefore, this study investigated <em>mfa5-2</em> presence in the genomes of the two bacterial strains and assessed Mfa5-2 incorporation into the Mfa1 fimbriae.</div></div><div><h3>Methods</h3><div>The genomic regions downstream of <em>mfa5</em> in <em>P. gingivalis</em> EM3 and 1439 were sequenced. Subsequently, Mfa1 fimbriae were purified and analyzed using sodium dodecyl-sulfate polyacrylamide gel electrophoresis, followed by mass spectrometry and immunoblotting with an Mfa5-2-specific peptide antibody. Fimbrial morphology was examined using transmission electron microscopy.</div></div><div><h3>Results</h3><div>Sequencing results revealed that <em>mfa5-2</em> was located immediately downstream of <em>mfa5-1</em> in both strains. The purified fimbrial fractions contained Mfa1, Mfa3, Mfa4, Mfa5, and a protein of approximately 250 kDa, identified as Mfa5-2. Transmission electron microscopy showed that fimbrial architecture remained unchanged despite Mfa5-2 incorporation.</div></div><div><h3>Conclusions</h3><div>Mfa5-2 is expressed as a high-molecular-weight component and integrated into the Mfa1 fimbriae in <em>P. gingivalis</em> EM3 and 1439. These findings revealed previously unknown structural diversity of Mfa1 fimbriae.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100753"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inflammatory characteristics induced by cellular senescence in the junctional epithelium of aged mice","authors":"Masaru Sunaga ,&nbsp;Akane Yukimori ,&nbsp;Junichi Tanaka ,&nbsp;Ryo Aizawa ,&nbsp;Koki Okada ,&nbsp;Daisuke Saito ,&nbsp;Kenji Mishima ,&nbsp;Matsuo Yamamoto","doi":"10.1016/j.job.2026.100748","DOIUrl":"10.1016/j.job.2026.100748","url":null,"abstract":"<div><h3>Objectives</h3><div>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.</div></div><div><h3>Methods</h3><div>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.</div></div><div><h3>Results</h3><div>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 <em>p16</em>, <em>Lcn2</em>, and <em>Defb3</em> 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.</div></div><div><h3>Conclusions</h3><div>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.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100748"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early senescence in salivary glands: A multimodal analysis across parotid, submandibular, and sublingual glands","authors":"Koichi Shibagaki ,&nbsp;Kiyomi Ogawa ,&nbsp;Tetsuro Horie ,&nbsp;Ken-ichiro Kikuchi","doi":"10.1016/j.job.2025.100717","DOIUrl":"10.1016/j.job.2025.100717","url":null,"abstract":"<div><h3>Objectives</h3><div>To elucidate the early-stage mechanisms of aging in salivary glands by focusing on the epigenetic regulator Jmjd3, proliferation marker proliferating cell nuclear antigen (PCNA), and senescence marker p16^INK4a in adult and middle-aged mice of both sexes.</div></div><div><h3>Methods</h3><div>Male and female C57BL/6JJcl mice at 18 weeks (adult) and 48 weeks (middle-aged) of age (n ≥ 5 per group) were used. The parotid, submandibular, and sublingual glands were collected, weighed, and analyzed by histology (hematoxylin and eosin, Alcian blue, periodic acid–Schiff staining), immunohistochemistry (for Jmjd3, PCNA, and p16^INK4a), quantitative image analysis, and real-time polymerase chain reaction. Statistical analysis was performed using analysis of variance or Kruskal–Wallis with appropriate post hoc tests (α = 0.05).</div></div><div><h3>Results</h3><div>Body weight increased with age, but the salivary gland weight relative to body weight remained unchanged. Histologically, at 48 weeks, the parotid and submandibular glands exhibited lymphocytic infiltration, whereas the sublingual glands did not. Jmjd3 was mainly localized in the acinar and striated duct cells and decreased with age in the parotid gland. PCNA-positive cells (acinar and ductal) were abundant at 18 weeks, but decreased after 48 weeks. p16^INK4a expression increased from 18 to 48 weeks, with initial staining in ductal cells and extension to some acinar cells by 48 weeks. p16^INK4a levels were higher in females than in males across all three glands.</div></div><div><h3>Conclusions</h3><div>By middle age, salivary glands exhibit early senescent changes, senescent cell accumulation, altered proliferative capacity, and shifts in Jmjd3-mediated epigenetic regulation, which occur in parallel with histological changes.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100717"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145624589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proteomic analysis of fibroblasts exposed to Bis-GMA","authors":"Yohann Flottes ,&nbsp;Elisabeth Dursun","doi":"10.1016/j.job.2026.100737","DOIUrl":"10.1016/j.job.2026.100737","url":null,"abstract":"<div><h3>Objective</h3><div>To investigate the dose-dependent effects of Bisphenol A-glycidyl methacrylate (Bis-GMA), a monomer released from dental resin composites, on the proteome of human gingival fibroblasts.</div></div><div><h3>Methods</h3><div>Primary human gingival fibroblasts were exposed to different concentrations of Bis-GMA (0.002 mM, 0.02 mM, and 0.2 mM) for 72 h, and protein extracts were analyzed using two-dimensional electrophoresis coupled with liquid chromatography-tandem mass spectrometry. Differentially abundant proteins were identified and functionally classified using STRING and Gene Ontology enrichment analysis.</div></div><div><h3>Results</h3><div>A total of 45 proteins were differentially abundant across the three exposure conditions. At 0.002 mM, there were indicators of an adaptive response, with upregulation of proteins related to mitochondrial function and cytoskeletal integrity. At 0.02 mM, there were indicators of cellular stress, including alterations in nuclear transport, cytoskeletal disorganization, and energy metabolism. At 0.2 mM, there was a marked shift towards protein underabundance, which may indicate disruption of proteostasis, oxidative stress, and endoplasmic reticulum stress. The proteomic profiles reflect the progressive loss of homeostasis, culminating in a cellular state compatible with apoptosis or senescence.</div></div><div><h3>Conclusions</h3><div>These findings raise concerns regarding low-level exposure to Bis-GMA, which is often encountered after dental restorations. These results support the necessity to adopt clinical procedures that minimize release of monomers and to develop safer monomers.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100737"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of the binding affinity between osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) utilizing Gaussia luciferase in living cells","authors":"Yuto Shibata ,&nbsp;Hisayo Nishida-Fukuda ,&nbsp;Hironao Nakayama ,&nbsp;Yudai Izumi ,&nbsp;Reina Suzuki ,&nbsp;Satoru Yokawa ,&nbsp;Takuma Sato ,&nbsp;Tadahide Furuno ,&nbsp;Mamoru Matsubara ,&nbsp;Ken Miyazawa ,&nbsp;Shinji Fukuda ,&nbsp;Takahiro Suzuki","doi":"10.1016/j.job.2025.100727","DOIUrl":"10.1016/j.job.2025.100727","url":null,"abstract":"<div><h3>Objectives</h3><div>The interaction between osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) regulates osteoclast differentiation and bone resorption. Although their binding affinity has been analyzed using purified proteins in biochemical assays, including surface plasmon resonance, measurements under living-cell conditions remain limited. In this study, a bioluminescence-based assay using <em>Gaussia</em> luciferase (GLase/GLuc) was adapted to quantify the binding affinity between OPG and RANKL in living cells.</div></div><div><h3>Methods</h3><div>OPG and OPG–GLase fusion proteins (OPG-GLase) were purified from conditioned media of 293T cells. Osteoclast differentiation assays were performed to determine whether OPG-GLase retained the biological activity of OPG. Purified proteins were then incubated with CHO–K1 cells expressing RANKL, and saturation binding assays were performed to calculate dissociation constants (Kd). The same assay was performed using pgsD-677 cells, a CHO–K1 mutant line that lacks heparan sulfate proteoglycan synthesis.</div></div><div><h3>Results</h3><div>Immunofluorescence and blocking experiments confirmed that OPG-GLase specifically binds to RANKL on the surface of CHO–K1 cells. OPG-GLase retained the ability to inhibit osteoclast differentiation to a similar extent as OPG. Saturation binding assays and non-linear regression analysis yielded a Kd of 11.0 nM in CHO–K1 cells. A parallel assay using pgsD-677 cells produced a comparable Kd of 12.6 nM, indicating that heparan sulfate proteoglycans contributed minimally to OPG–RANKL affinity under the experimental conditions used in this study.</div></div><div><h3>Conclusions</h3><div>This bioluminescence-based method provides a simple and accessible platform for evaluating interactions between soluble and membrane-bound proteins in living cells, with potential application in the development of drugs targeting the RANKL–RANK–OPG axis.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100727"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}