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Background: Psychological stress is associated with changes in salivary flow and composition. However, studies to show the effect of psychological stress on the transcriptome of the salivary gland are limited. This study aims to perform a transcriptomic analysis of the submandibular gland under psychological stress using a chronic restraint stress model of rats. Methods: Sprague‐Dawley rats were divided into stress groups and control groups. Psychological stress was induced in the stress group rats by enclosing them in a plastic tube for 4 h daily over 6 weeks. RNA sequencing was performed on RNA extracted from the submandibular gland. The differentially expressed genes were identified, and the genes of interest were further validated using qRT‐PCR, immunofluorescence, and western blot. Results: A comparison between control and stress groups showed 45 differentially expressed genes. The top five altered genes in RNA sequencing data showed similar gene expression in qRT‐PCR validation. The most downregulated gene in the stress group, FosB, was a gene of interest and was further validated for its protein‐level expression using immunofluorescence and western blot. The genesets for gene ontology cellular component, molecular function, and KEGG showed that pathways related to ribosome biosynthesis and function were downregulated in the stress group compared to the control. Conclusion: Psychological stress showed transcriptomic alteration in the submandibular gland. The findings may be important in understanding stress‐related oral diseases. [ABSTRACT FROM AUTHOR]

Objective and Background: Heated tobacco products have recently become commercially available. These products, as well as combustible cigarettes, produce aerosols; the risk of various diseases associated with heated tobacco products may be the same or higher than that with combustible cigarettes. In this study, we examined the effect of Ploom TECH+ extract on gingival epithelial cells. Methods: Tobacco leaves from Ploom TECH+ tobacco capsules and water were mixed and heated; the supernatant subsequently collected was the heated tobacco product (HTP; control: HTP not added). Normal human gingival epithelial progenitors were cultured alternately with or without HTP for a total of 1 month. Subsequently, RNA, DNA, and proteins were isolated from these samples and comprehensively analyzed using RNA sequencing (RNA‐seq), reduced representation bisulfite sequencing (RRBS), and western blotting, respectively. Results: RNA‐seq revealed that 284 genes showed a twofold increase and 145 genes showed a twofold decrease in gene expression. A heat map showed genetic differences between the control and HTP groups. A principal component analysis plot showed a clear genetic distribution between the control and HTP. Gene Ontology (GO) analysis showed that genes related to seven GO terms, including cornification and keratinization, were induced by long‐term HTP stimulation. By contrast, GO pathways with a significant decrease in component expression were not detected. RRBS revealed that CpG island methylation increased more than twofold in 158 genes and decreased to less than twofold in 171 genes. Methylation of these CpG islands was not correlated with changes in gene expression levels. HTP treatment increased S100A7 expression. Conclusion: Long‐term HTP stimulation affected epithelial differentiation and keratinization of gingival epithelial cells. Thus, habitual use of Ploom TECH+ may be a risk factor for tobacco‐related oral mucosal diseases. [ABSTRACT FROM AUTHOR]

Background and Objective: The translocation of oral bacteria, including Porphyromonas gingivalis, to the gut has been shown to alter gut microbiome. However, the effect of P. gingivalis on gut microbiome in relation to aging has not been demonstrated. We hypothesize that P. gingivalis has more detrimental effect on gut environment with increased age. The objective of this study is to investigate the effect of P. gingivalis on gut environment using aged mice. Materials and Methods: C57BL/6J mice aged 4 weeks (young) or 76 weeks (old) were divided into four groups: control‐young, control‐old, P. gingivalis‐administered young, and P. gingivalis‐administered old. P. gingivalis was orally administered thrice weekly for 5 weeks. At 30 days after the last P. gingivalis administration, 16S rRNA sequencing was performed to study the gut microbiome. The mRNA and protein expression of intestinal junctional barrier molecules and the levels of the inflammatory cytokines IL‐1β and TNF‐α in the serum were evaluated. Results: Significant differences in the gut microbiomes between the groups, in terms of taxonomic abundance, bacterial diversity, and predicted metagenome function, were observed. A significant reduction in the alpha diversity and in the abundance of beneficial bacteria, such as Akkermansia and Clostridiaceae, in the P. gingivalis‐administered old mice was observed. The mRNA and protein levels of Claudin‐1 and Claudin‐2 in the intestine were significantly elevated, while E‐cadherin was significantly downregulated in the P. gingivalis‐administered old mice, as were the serum levels of IL‐1β and TNF‐α. Conclusion: The effect of P. gingivalis on the gut environment is more pronounced in old mice than in young mice. [ABSTRACT FROM AUTHOR]

Objectives: Epigenetic phenomena are changes in gene expression not involving the DNA sequence. DNA methylation is a major occurrence underlying epigenetic changes in human cells. Although aberrant DNA methylation is well documented in malignant lesions, limited information has been shown on the involvement of DNA methylation in oral lichen planus and oral lichenoid lesions (OLP). The present study aimed to investigate DNA methylation of E‐cadherin and p16 in OLP, and compare the findings with those in non‐inflamed gingiva (Non), radicular cyst (RC), and oral squamous cell carcinoma (SCC). Materials and methods: Paraffin‐embedded surgical biopsy specimens were sliced, DNA was extracted, bisulfite treatment was applied, and methylation‐specific polymerase chain reaction was performed. Immunohistochemistry was performed to observe the relative expression patterns of these genes. Results: E‐cadherin was hypermethylated in OLP (p < 0.01), SCC (p < 0.01), and RC (p < 0.05), when compared with Non; DNA hypermethylation was confirmed in OLP and SCC when compared to Non and RC. Hypermethylation of p16ink4a was observed only in SCC (p < 0.01). Conclusion: DNA methylation levels of E‐cadherin and p16ink4a were significantly higher in OLP than in normal tissues, and may be associated with the pathogenesis and progression of the disease. [ABSTRACT FROM AUTHOR]

Dear Editors, Skin barrier functions such as transepidermal water loss (TWEL), water content of the skin stratum corneum (WCSC), and thickness of the skin stratum corneum (TSSC) are recognized as being affected by skin diseases including atopic dermatitis (AD).1 The challenge of measuring TEWL is that its variables are typically affected by the environment. Skin barrier dysfunction measured by transepidermal water loss at 2 days and 2 months predates and predicts atopic dermatitis at 1 year. [Extracted from the article]

Objective: Burning mouth syndrome (BMS) is a chronic intraoral burning sensation with no identifiable causes. In this study, we aim to demonstrate the effectiveness of treatment strategy using ethyl loflazepate monotherapy or in combination with milnacipran or amitriptyline. Method: A hospital‐based, retrospective study was conducted in 86 patients. The patients were divided into remission group and non‐remission group. The remission group comprised patients who were satisfied with their pain relief within a year of treatment initiation and did not require any follow‐up treatment. The treatment was considered effective if the patient got remission within 1 year or was able to reduce the visual analogue scale (VAS) score to <20, in the absence of remission. Results: The treatment strategy was effective in 76.7% of the patients. Significant reductions (p <.05) in VAS scores from 73.5 ± 14.2 at first visit to 14.7 ± 8.7 at last visit in the remission group, and from 79.7 ± 14.3 at first visit to 33.4 ± 23.7 after 1 year of treatment in the non‐remission group were noted. Conclusion: The treatment strategy using ethyl loflazepate monotherapy or in combination with milnacipran or amitriptyline can be very effective in reducing pain in BMS patients. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we compared the performance of ChatGPT-3.5 to that of ChatGPT-4o in the context of the Japanese National Dental Examination, which assesses clinical reasoning skills and dental knowledge, to determine their potential usefulness in dental education., Methods: ChatGPT's performance was assessed using 1399 (55% of the exam) of 2520 questions from the Japanese National Dental Examinations (111-117). The 1121 excluded questions (45% of the exam) contained figures or tables that ChatGPT could not recognize. The questions were categorized into 18 different subjects based on dental specialty. Statistical analysis was performed using SPSS software, with McNemar's test applied to assess differences in performance., Results: A significant improvement was noted in the percentage of correct answers from ChatGPT-4o (84.63%) compared with those from ChatGPT-3.5 (45.46%), demonstrating enhanced reliability and subject knowledge. ChatGPT-4o consistently outperformed ChatGPT-3.5 across all dental subjects, with significant improvements in subjects such as oral surgery, pathology, pharmacology, and microbiology. Heatmap analysis revealed that ChatGPT-4o provided more stable and higher correct answer rates, especially for complex subjects., Conclusions: This study found that advanced natural language processing models, such as ChatGPT-4o, potentially have sufficiently advanced clinical reasoning skills and dental knowledge to function as a supplementary tool in dental education and exam preparation., (© 2024 American Dental Education Association.)

Objective and Background: Heated tobacco products have recently become commercially available. These products, as well as combustible cigarettes, produce aerosols; the risk of various diseases associated with heated tobacco products may be the same or higher than that with combustible cigarettes. In this study, we examined the effect of Ploom TECH + extract on gingival epithelial cells., Methods: Tobacco leaves from Ploom TECH + tobacco capsules and water were mixed and heated; the supernatant subsequently collected was the heated tobacco product (HTP; control: HTP not added). Normal human gingival epithelial progenitors were cultured alternately with or without HTP for a total of 1 month. Subsequently, RNA, DNA, and proteins were isolated from these samples and comprehensively analyzed using RNA sequencing (RNA-seq), reduced representation bisulfite sequencing (RRBS), and western blotting, respectively., Results: RNA-seq revealed that 284 genes showed a twofold increase and 145 genes showed a twofold decrease in gene expression. A heat map showed genetic differences between the control and HTP groups. A principal component analysis plot showed a clear genetic distribution between the control and HTP. Gene Ontology (GO) analysis showed that genes related to seven GO terms, including cornification and keratinization, were induced by long-term HTP stimulation. By contrast, GO pathways with a significant decrease in component expression were not detected. RRBS revealed that CpG island methylation increased more than twofold in 158 genes and decreased to less than twofold in 171 genes. Methylation of these CpG islands was not correlated with changes in gene expression levels. HTP treatment increased S100A7 expression., Conclusion: Long-term HTP stimulation affected epithelial differentiation and keratinization of gingival epithelial cells. Thus, habitual use of Ploom TECH + may be a risk factor for tobacco-related oral mucosal diseases., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)