Journal of Oral Biosciences最新文献

{"title":"Study on the mechanism of radioactive salivary gland injury: a relatively comprehensive statement","authors":"Yixin Hu ,&nbsp;Teng Xu ,&nbsp;Chenfei Wang ,&nbsp;Guijuan Feng","doi":"10.1016/j.job.2026.100747","DOIUrl":"10.1016/j.job.2026.100747","url":null,"abstract":"<div><h3>Background</h3><div>Radiation-induced salivary gland dysfunction (RSGD) is a common complication of radiotherapy in patients with head and neck cancers that leads to xerostomia and related oral complications. It reduces treatment tolerance and quality of life, while current clinical interventions only alleviate superficial symptoms and fail to restore salivary gland function. This highlights the necessity to explore the pathogenesis of RSGD and to identify targets; existing studies have focused on DNA damage, oxidative stress, and fibrosis, but lack insights into emerging mechanisms such as ferroptosis, and therapies require improvement.</div></div><div><h3>Conclusions</h3><div>Based on models of radiation-induced salivary gland injury, this review had two core tasks: 1) to systematically explore multi-dimensional injury mechanisms, including existing and latest findings, and 2) to summarize current RSGD-related clinical drug regimens and stem cell/exosome-mediated therapies. The aims were to clarify core molecular mechanisms and potential targets, provide theoretical/practical references for novel effective therapies, overcome limitations in symptomatic treatment, and provide insights into how to improve outcomes and quality of life for patients with RSGD.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100747"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090691","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":"Ninjin'yoeito enhances saliva secretion in aged mice via nutritional, immune, anti-inflammatory, and anti-aging effects","authors":"Tomoki Kurakata,&nbsp;Yusuke Kondo,&nbsp;Akihiro Nakamura,&nbsp;Yui Hirata Obikane,&nbsp;Tomotaka Nodai,&nbsp;Takashi Munemasa,&nbsp;Taro Mukaibo,&nbsp;Ryuji Hosokawa,&nbsp;Chihiro Masaki","doi":"10.1016/j.job.2026.100739","DOIUrl":"10.1016/j.job.2026.100739","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aimed to evaluate the effects of long-term administration of Ninjin'yoeito, a traditional Japanese Kampo medicine, on age-related salivary hypofunction in mice.</div></div><div><h3>Methods</h3><div>Male senescence-accelerated mice (SAMP1) were divided into two groups and fed either a control diet, or a diet containing 3 % Ninjin'yoeito extract for four months. Salivary gland function was assessed by measuring the flow rate after muscarinic stimulation of the submandibular glands perfused ex vivo. Additional analysis included histological and immunohistochemical evaluations, blood tests, and real-time PCR to investigate gland morphology, immune cell profiles, gene expression, and inflammation/aging markers.</div></div><div><h3>Results</h3><div>Long-term Ninjin'yoeito administration significantly increased salivary secretion after stimulation and decreased the number of vacuoles in acinar cells as compared to the controls. Ninjin'yoeito improved the plasma albumin levels and increased the lymphocyte ratio in the white blood cell count. Furthermore, real-time PCR revealed decreased levels of inflammatory cytokine and senescence-associated genes. No significant changes were detected in the expression or localization of the main salivary secretion-related channels, such as transmembrane protein 16A and aquaporin 5.</div></div><div><h3>Conclusions</h3><div>Ninjin'yoeito enhances salivary secretion from the submandibular glands of aged mice by improving nutritional status, modulating immune function, suppressing chronic inflammation, and attenuating cellular aging. These results suggest that Ninjin'yoeito has potential applications as a complementary therapy for age-related dry mouth.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100739"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976126","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":"Choline acetyltransferase as a marker for Merkel cells in mucosal and skin tissues","authors":"Ranhui Xi ,&nbsp;Jiaxin Liu ,&nbsp;Shahd Almasswary ,&nbsp;Xin Xu ,&nbsp;Marco Tizzano","doi":"10.1016/j.job.2025.100722","DOIUrl":"10.1016/j.job.2025.100722","url":null,"abstract":"<div><h3>Objectives</h3><div>To investigate the expression of choline acetyltransferase (<em>ChAT</em>), the enzyme responsible for acetylcholine (ACh) synthesis, in Merkel cells in hairy and glabrous skin, including whiskers, palms, and oral mucosa, and to evaluate whether <em>ChAT</em> is a general molecular marker for Merkel cells that could indicate a potential cholinergic role in mechanosensory signaling.</div></div><div><h3>Methods</h3><div>Immunofluorescence staining was performed on skin and oral epithelial tissues of <em>ChAT</em>-<em>tau</em>-enhanced green fluorescent protein (<em>ChAT</em>-eGFP) transgenic mice. Co-expression of <em>ChAT</em>-eGFP and the Merkel cell marker, keratin 8 (KRT8<em>)</em>, was analyzed to identify <em>ChAT</em>⁺ Merkel cells. Their spatial organization and association with nerve endings were examined, and age-related changes in the Merkel cell count in the palate were quantified.</div></div><div><h3>Results</h3><div>Merkel cells consistently co-expressed <em>ChAT</em>-eGFP and KRT8 in skin and mucosal tissues, and they were organized into characteristic clusters, closely associated with nerve fibers. There was also <em>ChAT</em> expression in taste-related structures and cholinergic epithelial cells. In aged mice, Merkel cell count in the palate was significantly reduced, particularly in anterior rugae.</div></div><div><h3>Conclusions</h3><div>This study identified <em>ChAT</em> as a novel and general marker for Merkel cells in skin and oral tissues, revealing a previously unrecognized cholinergic component of Merkel cell signaling. These findings suggest a potential role of ACh in mechanotransduction and tactile sensation. By establishing <em>ChAT</em> as a Merkel cell marker, this study provides new insights into somatosensory biology and provides a molecular framework for exploring cholinergic mechanisms in tactile perception. These findings may inform therapeutic strategies for sensory disorders of skin and oral mucosa.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100722"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747946","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":"RANKL enhances the expression of PEPT1/SLC15A1 and PEPT2/SLC15A2 in RAW264.7 cells","authors":"Mana Shintani ,&nbsp;Wakana Sugimoto ,&nbsp;Hiroshi Inoue ,&nbsp;Nagako Sougawa ,&nbsp;Seiji Goda ,&nbsp;Aki Nishiura","doi":"10.1016/j.job.2025.100724","DOIUrl":"10.1016/j.job.2025.100724","url":null,"abstract":"<div><h3>Objectives</h3><div>Muramyl dipeptide (MDP), a bacterial cell wall component, is recognized by NOD2 and vital in innate immune responses, including inflammatory cytokine production. MDP is transported into the cells via PEPT1/SLC15A1 and PEPT2/SLC15A2, which are members of the proton-coupled oligopeptide transporter family within the SLC15 solute carrier group. Although the effects of RANKL stimulation on certain transporters are known, its effects on the SLC15 family remain unclear. This study aimed to clarify the effects of RANKL stimulation on PEPT1/SLC15A1 and PEPT2/SLC15A2 in RAW264.7 cells and determine their role in osteoclast differentiation.</div></div><div><h3>Methods</h3><div>RAW264.7 cells were stimulated with RANKL and MDP. Expression levels of NOD2, PEPT1/SLC15A1, PEPT2/SLC15A2, cathepsin K, and NFATc1 were analyzed via Western blotting. Osteoclast differentiation was evaluated using a tartrate-resistant acid phosphatase (TRAP) activity assay.</div></div><div><h3>Results</h3><div>RANKL stimulation increased NOD2, PEPT1/SLC15A1, and PEPT2/SLC15A2 expression in RAW264.7 cells. Colistin and polymyxin B, which are PEPT1 and PEPT2 inhibitors, respectively, did not affect the stimulation of cells with RANKL alone. However, RANKL and MDP co-stimulation suppressed the RANKL/MDP-induced increase in TRAP activity and cathepsin K and NFATc1 expression.</div></div><div><h3>Conclusions</h3><div>RANKL stimulation increased PEPT1/SLC15A1 and PEPT2/SLC15A2 levels in RAW264.7 cells, suggesting an increase in the intracellular uptake of MDP. This may promote osteoclast differentiation, potentially through NOD2activation or NOD2-independent mechanisms.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100724"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145796678","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":"The Runx2-SMOC axis in skeletal development: Expanding roles of Smoc1 and Smoc2 in development and disease","authors":"Yoshifumi Takahata ,&nbsp;Mitsuki Urushizaki ,&nbsp;Kanta Wakamori ,&nbsp;Miho Kakiuchi ,&nbsp;Tomohiko Murakami ,&nbsp;Maiko Omi-Sugihara ,&nbsp;Kenji Hata ,&nbsp;Riko Nishimura","doi":"10.1016/j.job.2026.100738","DOIUrl":"10.1016/j.job.2026.100738","url":null,"abstract":"<div><h3>Background</h3><div>Secreted modular calcium-binding proteins (SMOCs), including SMOC1 and SMOC2, are secreted protein acidic and rich in cysteine family matricellular proteins that regulate cell–matrix interactions and growth factor signaling across development and disease. Recent studies positioned SMOC1 and SMOC2 as direct downstream targets of Runt-related transcription factor 2 (Runx2), the master transcription factor for osteoblast differentiation, and revealed dose-dependent modulation of bone morphogenetic protein 2 (BMP2) signaling by SMOC2.</div></div><div><h3>Highlight</h3><div>SMOC1/2 exhibit distinct yet complementary roles in skeletal morphogenesis, extracellular matrix assembly, and mineralization. At lower concentrations, SMOC2 enhances BMP2 signaling, whereas at higher concentrations, it inhibits receptor engagement, explaining context-dependent effects on osteogenesis. Genetic evidence from mouse models and human variants (e.g., SMOC2 Leu359Arg) links disrupted SMOC–ECM interactions to growth-plate defects, delayed ossification, and craniofacial phenotypes. Beyond the skeleton, SMOC proteins participate in angiogenesis, ocular development, kidney and testis biology, and platelet thrombin responses.</div></div><div><h3>Conclusion</h3><div>The Runx2–SMOC axis provides a mechanistic bridge between transcriptional programs and matricellular control of BMP2 signaling and ECM dynamics. Clarifying isoform-specific functions and ECM anchoring mechanisms will inform therapeutic strategies for skeletal disorders and broader pathologies in which SMOC proteins are implicated.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100738"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938326","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":"Impaired PD-1 expression in tumor-infiltrating senescent CD8+ T cells is reversed by PD-L1 blockade in a murine squamous cell carcinoma model","authors":"Yi Lu ,&nbsp;Yuya Su ,&nbsp;Yuto Nagatomo ,&nbsp;Chenyang Zhang ,&nbsp;Shigenori Nagai ,&nbsp;Naoto Nishii ,&nbsp;Hiroyuki Harada ,&nbsp;Peiya Lin ,&nbsp;Sayaka Katagiri ,&nbsp;Miyuki Azuma","doi":"10.1016/j.job.2025.100730","DOIUrl":"10.1016/j.job.2025.100730","url":null,"abstract":"<div><h3>Objectives</h3><div>Aging induces senescence-related immune changes that affect antitumor immunity and treatment efficacy. Immune checkpoint inhibitors (ICIs) targeting programmed cell death-1 (PD-1) are approved for recurrent and metastatic head and neck squamous cell carcinoma (SCC). We aimed to investigate how aging alters the tumor immune microenvironment and modulates ICI efficacy in a murine SCC model.</div></div><div><h3>Methods</h3><div>We analyzed SCCVII tumor growth and phenotypes of tumor-draining lymph node (TDLN) cells and tumor-infiltrating leukocytes in young, middle-aged, and aged mice. We examined the effects of antibodies against PD-1 ligand-1 (PD-L1) in young and aged mice.</div></div><div><h3>Results</h3><div>Tumor growth accelerated with age and was accompanied with increased CD206⁺ M2-like tumor-associated macrophage (TAM) accumulation. In intact LNs and TDLNs, CD8⁺ T cells (CD8T), interferon (IFN)-γ, and PD-1 expression increased with age. The CD8T phenotype in the tumor microenvironment (TME) differed between young and aged mice; however, CD8T and regulatory T cells preferentially recruited to the TME across all age groups. PD-1 expression was significantly impaired in TME of aged mice. PD-1⁻IFN-γ⁻ CD8T predominated in aged mice, whereas PD-1⁺IFN-γ⁻ CD8T predominated in young mice. Anti-PD-L1 treatment in aged mice enhanced antitumor immunity, but preferentially increased PD-1⁺ CD8T in both TDLNs and TME.</div></div><div><h3>Conclusions</h3><div>In the SCCVII model, aging impaired the antitumor immune responses, associated with early recruitment of M2-like TAMs. PD-1 expression in aged TME CD8T was impaired, but the PD-L1 blockade increased PD-1 expression, suggesting that the site of action for PD-L1 blockade differs between young and aged mice.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100730"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145938310","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":"Broad-range 16S rDNA sequencing and quantitative bacteriome profiling: a small-cohort feasibility study in orthodontic patients with early gingivitis","authors":"Tadaharu Yokogawa ,&nbsp;Keiji Nagano ,&nbsp;Hiroshi Miyakawa ,&nbsp;Mari Fujita ,&nbsp;Chen-Hsuan Chiu ,&nbsp;Masahiro Iijima","doi":"10.1016/j.job.2025.100732","DOIUrl":"10.1016/j.job.2025.100732","url":null,"abstract":"<div><h3>Objectives</h3><div>Many bacteriome studies employing next-generation sequencing (NGS) have focused on the partial sequencing of the 16S rRNA gene (rDNA). This limits both species-level resolution and quantitative interpretation of bacterial abundance, which have been addressed in this study.</div></div><div><h3>Methods</h3><div>Nanopore sequencing was used to analyze nearly the entire 16S rDNA sequence for species-level classification, and quantitative PCR for bacterial quantification. This approach was applied in a small-cohort feasibility study to investigate oral bacterial changes in orthodontic patients. Saliva samples were collected from 10 patients before and 1, 3, and 6 months after the initiation of orthodontic treatment.</div></div><div><h3>Results</h3><div>Dental caries was not detected during the study, and periodontal pockets ≥4 mm were rarely observed. However, all patients exhibited changes in bleeding on probing (BOP), which is indicative of early stage gingivitis. Although the compositional analysis did not reveal any significant association between specific bacterial species and BOP changes, the quantitative analysis showed a positive correlation between BOP changes and two bacterial species in the phyla Candidatus <em>Saccharibacteria</em>: Candidatus <em>Saccharimonas aalborgensis</em> and Candidatus <em>Saccharibacteria</em> bacterium oral taxon TM7x. No correlation was observed with representative periodontal disease-associated bacteria.</div></div><div><h3>Conclusions</h3><div>These findings support the feasibility of species-level and quantitative bacteriome analysis in a small cohort and highlight the bacterial species potentially linked to early stage gingivitis.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100732"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883337","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":"Evaluation of anesthetic effects of remimazolam using mouse model with jugular vein cannulation","authors":"Aoi Ikuse-Oshio ,&nbsp;Yuki Azetsu ,&nbsp;Aiko Hirayama ,&nbsp;Akiko Karakawa ,&nbsp;Masahiro Chatani ,&nbsp;Akiko Nishimura ,&nbsp;Rikuo Masuda ,&nbsp;Masamichi Takami","doi":"10.1016/j.job.2026.100741","DOIUrl":"10.1016/j.job.2026.100741","url":null,"abstract":"<div><h3>Objective</h3><div>Remimazolam, a novel ultra-short-acting benzodiazepine anesthetic, provides rapid recovery with minimal circulatory depression, making it a promising agent for procedural sedation. However, differences in regulatory approvals and safety requirements across countries limit its clinical use. Therefore, its pharmacological properties and safety should be clarified in further studies. In this study, jugular vein-cannulated model mice were administered intravenous anesthetic, and the sedative effects of remimazolam were compared with those of midazolam and propofol.</div></div><div><h3>Methods</h3><div>Following jugular vein cannulation, each mouse was administered a single intravenous dose of remimazolam or midazolam, and changes in sedation levels were assessed using a sedation scale. In another test, continuous infusion of propofol or remimazolam was administered using a precise microflow pump and sedation scale scores, defensive reflexes, and vital signs were analyzed.</div></div><div><h3>Results</h3><div>The sedation scale score increased after a single administration of remimazolam or midazolam in a concentration-dependent manner, followed by gradual recovery, whereas continuous administration caused a gradual increase that stabilized over time. Continuous remimazolam administration (30 mg/kg/h) produced sedation comparable to that produced by propofol administration (120 mg/kg/h), although with much smaller decreases in heart and breathing rates. Defensive reflex reactivity in mice administered remimazolam exhibited a shorter time to reflex extinction than in those administered propofol, with repeated extinction and recovery cycles.</div></div><div><h3>Conclusions</h3><div>Our findings suggest that the jugular vein-cannulated mouse model is useful for evaluating time-dependent sedative effects. Continuous remimazolam administrationmaintained stable sedation with minimal vital depression and faster defensive reflex suppression than propofol administration.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100741"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037234","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":"Effect of differences in food texture on swallowing-related muscle activity in older people","authors":"Yi-Ying Hsieh ,&nbsp;Chun-Jung Lin ,&nbsp;Chia-Li Chi ,&nbsp;Kuan-Yu Lin","doi":"10.1016/j.job.2026.100749","DOIUrl":"10.1016/j.job.2026.100749","url":null,"abstract":"<div><h3>Objectives</h3><div>In this study, the effect of different rice-flour mixtures,used to modify steamed-bread texture, on swallowing-related muscle activity in older people, was explored. The objective was to identify the texture associated with reduced swallowing-related muscular activation accompanied by reduced bread hardness.</div></div><div><h3>Methods</h3><div>Sixty-eight community-dwelling people aged ≥65 years were recruited. Swallowing ability was assessed using the eating assessment tool 10 (EAT-10) swallowing screening tool, and each participant consumed 5 g of steamed bread containing 0 %, 10 %, 20 %, or 30 % rice flour in a randomized order. Suprahyoid muscle activity during swallowing was recorded using surface electromyography (sEMG), and peak swallowing-related EMG amplitude, extracted from the swallowing-related burst, was analyzed.</div></div><div><h3>Results</h3><div>Bread containing 20 % rice flour had the lowest hardness (199 × 10³ N/m²) and required the least suprahyoid muscle activation (F = 4.26, p = 0.007). Regression analysis confirmed that rice-flour percentage was significantly associated with peak swallowing-related EMG amplitude (β = 0.41, p = 0.01; adjusted R² = 0.717). Among participants with an EAT-10 score ≥3, the Wilcoxon signed-rank test indicated a significant reduction in peak swallowing-related EMG amplitude when consuming 20 % rice-flour bread (p = 0.01).</div></div><div><h3>Conclusions</h3><div>A 20 % rice-flour substitution provided a favorable steamed-bread texture associated with reduced swallowing-related muscular activation in older people. This simple dietary modification may facilitate safer swallowing by lowering the demand for muscle activation.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100749"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090690","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":"Effects of pharyngolaryngeal injury on nociceptive swallowing reflexes","authors":"Naoyuki Mitarai ,&nbsp;Chihiro Nakatomi ,&nbsp;Chia-Chien Hsu ,&nbsp;Hiroka Yasuda ,&nbsp;Mari Fukuzaki ,&nbsp;Tomoki Shimada ,&nbsp;Ai Orimoto ,&nbsp;Chiaki Kitamura ,&nbsp;Kentaro Ono","doi":"10.1016/j.job.2026.100736","DOIUrl":"10.1016/j.job.2026.100736","url":null,"abstract":"<div><h3>Objectives</h3><div>Although pharyngolaryngeal injury impairs water-evoked swallowing, its influence on nociceptive swallowing reflexes remains unclear. Therefore, this study aimed to determine the effects of pharyngolaryngeal injury on nociceptive receptor-dependent swallowing reflexes.</div></div><div><h3>Methods</h3><div>Adult male rats underwent endoscopic evaluation of swallowing under anesthesia. The number, latency, and swallowing intervals were quantified. Distilled water, capsaicin (TRPV1 agonist), and allyl isothiocyanate (AITC, TRPA1 agonist) were infused onto the pharyngolaryngeal surface via a syringe pump at a constant flow for 10 s. Blue-dyed water confirmed gastric delivery. Pharyngolaryngeal injury was induced by topical application of 10 % acetic acid. The nodose and petrosal/jugular-complex ganglia were analyzed for TRPV1 and TRPA1 gene expression using quantitative RT-PCR.</div></div><div><h3>Results</h3><div>Gastric delivery from the pharyngolaryngeal region was confirmed with blue-dyed water, although aspiration was observed, indicating the reliability of the endoscopic swallowing evaluation. Pharyngolaryngeal injury significantly suppressed water-evoked swallowing, consistent with previous findings. Contrastingly, capsaicin robustly evoked swallowing post-injury, with attenuated desensitization upon repeated stimulation. AITC did not change the number of swallows but prolonged latency. Quantitative RT-PCR revealed significant upregulation of TRPV1 gene expression in the petrosal/jugular-complex ganglia, whereas TRPA1 expression remained unchanged in both ganglia.</div></div><div><h3>Conclusion</h3><div>Nociceptive stimuli elicit swallowing via mechanisms that are distinct from those activated by water. Reduced desensitization of capsaicin-evoked swallowing after pharyngolaryngeal injury suggests facilitation through TRPV1-dependent pathways, potentially driven by increased TRPV1 expression in petrosal/jugular-complex afferents.</div></div>","PeriodicalId":45851,"journal":{"name":"Journal of Oral Biosciences","volume":"68 1","pages":"Article 100736"},"PeriodicalIF":2.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145976192","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}