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Koji Naruishi,1,2 Akiko Kunita,3 Katsuyuki Kubo,1,2 Toshihiko Nagata,4 Shogo Takashiba,2,5 Seiji Adachi1 1Division of Local Care Center, Tottori Municipal Hospital, Tottori, Japan; 2Department of Periodontics and Endodontics, Okayama University Hospital, Okayama, Japan; 3Division of Rehabilitation, Tottori Municipal Hospital, Tottori, Japan; 4Department of Periodontology and Endodontology, Institute of Health Biosciences, Tokushima University Graduate School, Tokushima, Japan; 5Department of Pathophysiology-Periodontal Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan Purpose: The number of elderly inpatients has been steadily increasing worldwide. However, the ability to predict the degree of improvement of functional capacity after comprehensive examination of elderly inpatients is still lacking. The purpose of this study was to investigate the predictors of improved functional outcome after rehabilitation of elderly inpatients.Methods: We performed a retrospective cohort study with 1,079 patients (age

Salivary glands (SGs) are very important for maintaining the physiological functions of the mouth. When SGs regenerate and repair from various damages, including mechanical, radiological, and immune diseases, acinar and granular duct cells originate from intercalated duct cells. However, the recovery is often insufficient because of SGs' limited self-repair function. Furthermore, the precise repair mechanism has been unclear. Here, we focused on CD49f, one of the putative stem cell markers, and characterized CD49f positive cells (CD49f+ cells) isolated from male murine SGs. CD49f+ cells possess self-renewal ability and express epithelial and pluripotent markers. Compared to CD49f negative cells, freshly isolated CD49f+ cells highly expressed inhibin beta A and beta B, which are components of activin that has anti-proliferative effects. Notably, an inhibitor of activin, follistatin was expressed in mechanically-damaged SGs, meanwhile no follistatin was expressed in normal SGs in vivo. Moreover, sub-cultured CD49f+ cells highly expressed both Follistatin and a series of proliferative genes, expressions of which were decreased by Follistatin siRNA. These findings indicated that the molecular interaction between activin and follistatin may induce CD49f+ cells proliferation in the regeneration and repair of mouse SGs. [ABSTRACT FROM AUTHOR]

Background/aim: Malignant melanoma is a tumor with a poor prognosis that can metastasize distally at an early stage. Terrein, a metabolite produced by Aspergillus terreus, suppresses the expression of angiogenin, an angiogenic factor. However, the pharmacological effects of natural terrein have not been elucidated, because only a small amount of terrein can be extracted from large fungal cultures. In this study, we investigated the antineoplastic effects of terrein on human malignant melanoma cells and its underlying mechanisms., Materials and Methods: Human malignant melanoma cell lines were cultured in the presence of terrein and analyzed. Angiogenin production was evaluated using ELISA. Ribosome biosynthesis was evaluated using silver staining of the nucleolar organizer region. Intracellular signaling pathways were analyzed using western blotting. Malignant melanoma cells were transplanted subcutaneously into the backs of nude mice. The tumors were removed at 5 weeks and analyzed histopathologically., Results: Terrein inhibited angiogenin expression, proliferation, migration, invasion, and ribosome biosynthesis in malignant melanoma cells. Terrein was shown to inhibit tumor growth and angiogenesis in animal models., Conclusion: This study demonstrated that terrein has anti-tumor effects against malignant melanoma. Furthermore, chemically synthesized non-natural terrein can be mass-produced and serve as a novel potential anti-tumor drug candidate., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Introduction: Vital pulp therapy (VPT) is performed to preserve dental pulp. However, the biocompatibility of the existing materials is of concern. Therefore, novel materials that can induce pulp healing without adverse effects need to be developed. Resolvin D2 (RvD2), one of specialized pro-resolving mediators, can resolve inflammation and promote the healing of periapical lesions. Therefore, RvD2 may be suitable for use in VPT. In the present study, we evaluated the efficacy of RvD2 against VPT using in vivo and in vitro models., Methods: First molars of eight-week-old male Sprague-Dawley rats were used for pulpotomy. They were then divided into three treatment groups: RvD2, phosphate-buffered saline, and calcium hydroxide groups. Treatment results were assessed using radiological, histological, and immunohistochemical (GPR18, TNF-α, Ki67, VEGF, TGF-β, CD44, CD90, and TRPA1) analyses. Dental pulp-derived cells were treated with RvD2 in vitro and analyzed using cell-proliferation and cell-migration assays, real-time PCR ( Gpr18 , Tnf-α , Il-1β , Tgf-β , Vegf , Nanog , and Trpa1 ), ELISA (VEGF and TGF-β), immunocytochemistry (TRPA1), and flow cytometry (dental pulp stem cells: DPSCs)., Results: The formation of calcified tissue in the pulp was observed in the RvD2 and calcium hydroxide groups. RvD2 inhibited inflammation in dental pulp cells. RvD2 promoted cell proliferation and migration and the expression of TGF-β and VEGF in vitro and in vivo . RvD2 increased the number of DPSCs. In addition, RvD2 suppressed TRPA1 expression as a pain receptor., Conclusion: RvD2 induced the formation of reparative dentin, anti-inflammatory effects, and decreased pain, along with the proliferation of DPSCs via the expression of VEGF and TGF-β, on the pulp surface in pulpotomy models., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Zulema Arias reports financial support was provided by 10.13039/501100001691Japan Society for the Promotion of Science. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Periodontal disease is highly prevalent in both humans and dogs. Although there have been reports of cross-infection of periodontopathic bacteria, methods for assessing it have yet to be established. The actual status of cross-infection remains to be seen. The purpose of this study was to evaluate the utility of bacterial DNA and serum immunoglobulin G (IgG) antibody titer assays to assess infection of human-pathogenic and dog-pathogenic Porphyromonas species in dogs. Four experimental beagles were used for establishing methods. Sixty-six companion dogs at veterinary clinics visiting for treatment and prophylaxis of periodontal disease were used and divided into healthy, gingivitis, and periodontitis groups. Periodontal pathogens such as Porphyromonas gingivalis and Porphyromonas gulae were investigated as target bacteria. DNA levels of both bacteria were measured using species-specific primers designed for real-time polymerase chain reaction (PCR). Serum IgG titers of both bacteria were measured by enzyme-linked immunosorbent assay (ELISA). PCR primers were confirmed to have high sensitivity and specificity. However, there was no relationship between the amount of bacterial DNA and the severity of the periodontal disease. In addition, dogs with periodontitis had higher IgG titers against both bacteria compared to dogs in the healthy and gingivitis groups; there was cross-reactivity between the two bacteria. Receiver operating characteristic (ROC) analysis of IgG titers against both bacteria showed high sensitivity (>90 %) and specificity (>75 %). Since both bacteria were distinguished by DNA assays, the combination of these assays may be useful in the evaluation of cross-infection., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

Background: Plasminogen serves as the precursor to plasmin, an essential element in the fibrinolytic process, and is synthesized primarily in the liver. Plasminogen activation occurs through the action of plasminogen activator, converting it into plasmin. This conversion greatly enhances the fibrinolytic system within tissues and blood vessels, facilitating the dissolution of fibrin clots. Consequently, congenital deficiency of plasminogen results in impaired fibrin degradation. Patients with plasminogen deficiency typically exhibit fibrin deposits in various mucosal sites throughout the body, including the oral cavity, eyes, vagina, and digestive organs. Behcet's disease is a chronic recurrent systemic inflammatory disease with four main symptoms: aphthous ulcers of the oral mucosa, vulvar ulcers, skin symptoms, and eye symptoms, and has been reported worldwide. This disease is highly prevalent around the Silk Road from the Mediterranean to East Asia. We report a case of periodontitis in a patient with these two rare diseases that worsened quickly, leading to alveolar bone destruction. Genetic testing revealed a novel variant characterized by a stop-gain mutation, which may be a previously unidentified etiologic gene associated with decreased plasminogen activity., Case Presentation: This case report depicts a patient diagnosed with ligneous gingivitis during childhood, originating from plasminogen deficiency and progressing to periodontitis. Genetic testing revealed a suspected association with the PLG c.1468C > T (p.Arg490*) stop-gain mutation. The patient's periodontal condition remained stable with brief intervals of supportive periodontal therapy. However, the emergence of Behçet's disease induced acute systemic inflammation, necessitating hospitalization and treatment with steroids. During hospitalization, the dental approach focused on maintaining oral hygiene and alleviating contact-related pain. The patient's overall health improved with inpatient care and the periodontal tissues deteriorated., Conclusions: Collaborative efforts between medical and dental professionals are paramount in comprehensively evaluating and treating patients with intricate complications from rare diseases. Furthermore, the PLG c.1468C > T (p.Arg490*) stop-gain mutation could contribute to the association between plasminogen deficiency and related conditions., (© 2023. The Author(s).)

Dental caries are an oral infectious disease that can affect human health both orally and systemically. It remains an urgent issue to establish a novel antibacterial method to prevent oral infection for a healthy life expectancy. The aim of this study was to evaluate the inhibitory effects of novel iron chelators, super-polyphenols (SPs), on the cariogenic bacterium Streptococcus mutans , in vitro. SPs were developed to reduce the side effects of iron chelation therapy and were either water-soluble or insoluble depending on their isoforms. We found that SP6 and SP10 inhibited bacterial growth equivalent to povidone-iodine, and viability tests indicated that their effects were bacteriostatic. These results suggest that SP6 and SP10 have the potential to control oral bacterial infections such as Streptococcus mutans .

We herein elucidate the function of SARS-CoV-2derived 5'UTR in the human cells. 5'UTR bound host cellular RNAs were immunoprecipitated by gRNA-dCas13 (targeting luciferase RNA fused to SARS-CoV-2 5'UTR) in HEK293T and A549 cells. The 5'UTR bound RNA extractions were predominantly enriched for regulating lipid metabolism. Overexpression of SARS-CoV-2 5'UTR RNA altered the expression of factors involved in the process of the human Mevalonate pathway. In addition, we found that HMG-CoA reductase inhibitors were shown to suppress SARS-CoV-2 5'UTR-mediated translation activities. In conclusion, we deduce the array of host RNAs interacting with SARS-CoV-2 5'UTR that drives SARS-CoV-2 translation and influences host metabolic pathways., (© 2023. The Author(s).)

Apical periodontitis is an inflammatory response caused by pulp infection. It induces bone resorption in the apical and periapical regions of the tooth. The most conservative approach to treat this condition is nonsurgical endodontic treatment. However, clinical failure has been reported with this approach; thus, alternative procedures are required. This review highlights recent literature regarding advanced approaches for the treatment of apical periodontitis. Various therapies, including biological medications, antioxidants, specialized pro-resolving lipid mediators, and stem cell therapy, have been tested to increase the success rate of treatment for apical periodontitis. Some of these approaches remain in the in vivo phase of research, while others have just entered the translational research phase to validate clinical application. However, a detailed understanding of the molecular mechanisms that occur during development of the immunoinflammatory reaction in apical periodontitis remains unclear. The aim of this review was to summarize advanced approaches for the treatment of apical periodontitis. Further research can confirm the potential of these alternative nonsurgical endodontic treatment approaches.

The curriculum at the Department of Pathophysiology in the Periodontal Sciences program at Okayama University includes normative preclinical training (NPT) using phantoms. NPT is given to the whole class of 5 th year students divided in groups of 8 students/instructor. In 2019, an innovative personalized preclinical training (PPT) pilot study was implemented for this group of students whereby two students, each with their own dental unit, were coached by one instructor. The main topics covered were dental ergonomics and endodontics. We aimed to evaluate the effectiveness of PPT in dental ergonomics and endodontics toward increasing the knowledge and future clinical skills of students who had already undergone NPT. A test on endodontics was taken before and after PPT. A questionnaire was completed to assess their perception of improvement regarding the above-mentioned topics. Test scores and questionnaire results both showed that the students' level of knowledge and awareness of future clinical skills was significantly higher after PPT. This pilot study demonstrated that PPT increased the students' knowledge and future clinical skills. As preclinical training forms the foundation for clinical practice, investment in future research regarding this personalized approach is likely to enhance students' understanding and clinical performance., Competing Interests: No potential conflict of interest relevant to this article was reported.

Dental anterior fractures are common injuries, especially in those who practice extreme sports. This report describes a 25-year-old Bolivian patient who attended our private dental clinic in La Paz, Bolivia after experiencing an accident during downhill mountain biking. An intraoral examination revealed a fracture line on the buccal side in the middle third of the coronal portion of the right central maxillary incisor which extended towards the proximal and lingual sides. Multidisciplinary treatment, including crown lengthening, osteotomy, root canal treatment, fiberglass post insertion, and reattachment of the fracture segment was performed. A follow-up examination at 10 months later revealed that the tooth was completely reestablished both functionally and esthetically and that there was no periapical pathosis or discomfort. This outcome suggests that if a patient seeks a dental consultation soon after a complex crown-root fracture has occurred, and if the broken tooth segment is available, then reattachment offers an economical and simple treatment option which will allow immediate restoration of functionality and esthetic standards. Continued follow-up should form part of such a treatment plan to allow long-term pulp vitality and periodontal health status to be monitored.

Current periodontal treatment focuses on the mechanical removal of the source of infection, such as bacteria and their products, and there is no approach to control the host inflammatory response that leads to tissue destruction. In order to control periodontal inflammation, we have previously reported the optimization of (+)-terrein synthesis methods and the inhibitory effect of (+)-terrein on osteoclast differentiation in vitro. However, the pharmacological effect of (+)-terrein in vivo in the periodontitis model is still unknown. In this study, we investigated the effect of synthetic (+)-terrein on inflammatory bone resorption using a ligature-induced periodontitis mouse model. Synthetic (+)-terrein (30 mg/kg) was administered intraperitoneally twice a week to the mouse periodontitis model. The control group was treated with phosphate buffer. One to two weeks after the induction of periodontitis, the periodontal tissues were harvested for radiological evaluation (micro-CT), histological evaluation (HE staining and TRAP staining), and the evaluation of inflammatory cytokine production in the periodontal tissues and serum (quantitative reverse-transcription PCR, ELISA). The synthetic (+)-terrein-treated group suppressed alveolar bone resorption and the number of osteoclasts in the periodontal tissues compared to the control group ( p < 0.05). In addition, synthetic (+)-terrein significantly suppressed both mRNA expression of TNF-α in the periodontal tissues and the serum concentration of TNF-α (both p < 0.05). In conclusion, we have demonstrated that synthetic (+)-terrein abrogates alveolar bone resorption via the suppression of TNF-α production and osteoclast differentiation in vivo. Therefore, we could expect potential clinical effects when using (+)-terrein on inflammatory bone resorption, including periodontitis.

The major active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D3), is known for its wide bioactivity in periodontal tissues. Although the exact mechanisms underlying its protective action against periodontitis remain unclear, recent studies have shown that 1,25D3 regulates autophagy. Autophagy is vital for intracellular pathogen invasion control, inflammation regulation, and bone metabolic balance in periodontal tissue homeostasis, and its regulation could be an interesting pathway for future periodontal studies. Since vitamin D deficiency is a worldwide health problem, its role as a potential regulator of autophagy provides new insights into periodontal diseases. Based on this premise, this narrative literature review aimed to investigate the possible connection between 1,25D3 and autophagy in periodontitis. A comprehensive literature search was conducted on PubMed using the following keywords (e.g., vitamin D, autophagy, periodontitis, pathogens, epithelial cells, immunity, inflammation, and bone loss). In this review, the latest studies on the protective action of 1,25D3 against periodontitis and the regulation of autophagy by 1,25D3 are summarized, and the potential role of 1,25D3-activated autophagy in the pathogenesis of periodontitis is analyzed. 1,25D3 can exert a protective effect against periodontitis through different signaling pathways in the pathogenesis of periodontitis, and at least part of this regulatory effect is achieved through the activation of the autophagic response. This review will help clarify the relationship between 1,25D3 and autophagy in the homeostasis of periodontal tissues and provide perspectives for researchers to optimize prevention and treatment strategies in the future., (© 2023. The Author(s).)

The failure of endodontic treatment is directly associated with microbial infection in the root canal or periapical areas. An endodontic sealer that is both bactericidal and biocompatible is essential for the success of root canal treatments. This is one of the vital issues yet to be solved in clinical dental practice. This in vitro study assessed the effectiveness of graphene oxide (GO) composites GO-CaF2 and GO-Ag-CaF2 as endodontic sealer materials. Dentin slices were coated with either the GO-based composites or commonly used root canal sealers (non-eugenol zinc oxide sealer). The coated slices were treated in 0.9% NaCl, phosphate-buffered saline (PBS), and simulated body fluid (SBF) at 37˚C for 24 hours to compare their sealing effect on the dentin surface. In addition, the radiopacity of these composites was examined to assess whether they complied with the requirements of a sealer for good radiographic visualization. Scanning electron microscopy showed the significant sealing capability of the composites as coating materials. Radiographic images confirmed their radiopacity. Mineral deposition indicated their bioactivity, especially of GO-Ag-CaF2, and thus it is potential for regenerative application. They were both previously shown to be bactericidal to oral microbes and cytocompatible with host cells. With such a unique assemblage of critical properties, these GO-based composites show promise as endodontic sealers for protection against reinfection in root canal treatment and enhanced success in endodontic treatment overall., Competing Interests: No potential conflict of interest relevant to this article was reported.

Introduction: Periodontal disease is associated with nonalcoholic fatty liver disease (NAFLD). We evaluated periodontal treatment efficacy in patients with NAFLD and periodontal disease., Methods: This multicenter, 2-arm, randomized study recruited adult patients with NAFLD and periodontitis, alanine aminotransferase levels ≥40 U/L, and equivalent steatosis grade ≥1. Forty eligible patients (18 men and 22 women) were randomly assigned to 2 groups (scaling and root planning [SRP; n = 20] and tooth brushing [n = 20] groups) stratified by age and sex. The primary and secondary endpoints were changes in alanine aminotransferase levels and serum Porphyromonas gingivalis IgG antibody titers from baseline to 12 weeks, respectively. Efficacy analysis was performed using an intention-to-treat approach ( t test). This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000022079)., Results: We observed a significantly higher decrease in absolute alanine aminotransferase levels and P. gingivalis IgG antibody titers in the SRP group than in the tooth brushing group (-12 vs 1 U/L; mean difference [δ], -12; 95% confidence interval [CI], -20 to -5; P = 0.002). The decrease in P. gingivalis IgG antibody titer was significantly higher in the SRP group than in the tooth brushing group (FDC381, -1.6 [2.5]; δ, -1.6; 95% CI, -2.7 to -0.4; P = 0.0092; SU63, -1.7 [2.0]; δ, -1.7; 95% CI, -2.7 to -0.7). No life-threatening events or treatment-related deaths occurred., Discussion: Periodontal treatment induced significant short-term and mid-term reductions in liver enzyme levels and antibody titers. Further research is warranted to clearly define SRP efficacy and tolerability in patients with NAFLD and periodontitis., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

The risk factors for non-alcoholic fatty liver disease (NAFLD) progression are not completely known. Porphyromonas gingivalis infection is a risk factor for systemic diseases. We investigated the association of P. gingivalis infection with the risk of non-alcoholic steatohepatitis progression. Here, hematological tests, periodontal examination, and saliva collection were performed for 164 patients with NAFLD. P. gingivalis was identified in saliva using polymerase chain reaction. Hepatic steatosis and stiffness were evaluated using vibration-controlled transient elastography (VCTE) and magnetic resonance imaging. In patients with NAFLD, P. gingivalis positivity (P. gingivalis ratio ≥ 0.01%) in saliva correlated with liver stiffness determined using magnetic resonance elastography (MRE; p < 0.0001). A P. gingivalis ratio of 0.01% corresponds to 100,000 cells/mL and indicates the proportion of P. gingivalis in the total number of bacteria in the oral cavity. Patients with NAFLD and advanced fibrosis on MRE showed significantly elevated endotoxin activity; those who had > 10 periodontal pockets with depths ≥ 4 mm had significantly increased hepatic stiffness on both VCTE and MRE., (© 2022. The Author(s).)

Recent studies have shown that periodontitis is associated with rheumatoid arthritis (RA) and periodontal bacteria, such as Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) are involved in the pathogenesis of RA via citrullinated proteins. Smoking has also been shown to be involved in the pathogenesis of RA; however, the extent of this involvement is still poorly understood. In addition, RA and polymyalgia rheumatica (PMR) are sometimes difficult to differentiate; however, the relationship between PMR and the factors from smoking and periodontal bacteria is unclear. The aim of this study was to clarify the relationship between periodontal pathogenic bacterial infections and smoking in patients with RA or PMR. This case-control study included 142 patients with untreated RA or PMR. This study evaluated the serum antibody titers against periodontal pathogenic bacterial antigens and an anti-citrullinated peptide antibody (ACPA). In patients with RA, the relationship between antibody titers and disease activity of RA and response after 3 months of treatment was also investigated. Additionally, the effects of smoking were evaluated. Although there was no significant difference in serum antibody titer against periodontal pathogenic bacteria between the ACPA-positive RA group and the ACPA-negative PMR group, we found an association between the elevated antibody titer against Pg and the degree of ACPA value, especially between negative group and high-value positive group (≥ 100 U/mL). The antibody titers against Aa and Pg did not differ depending on disease activity score 28 (DAS28) at baseline; however, patients with high antibody titers had poor RA therapeutic response as judged by DAS28 after 3 months. We could not find any association between smoking and any of these parameters. Periodontal pathogenic bacteria, especially Pg, are associated with elevated ACPA levels. Our findings suggest that Pg and Aa infections interfere with the therapeutic response of RA., (© 2022. The Author(s).)

Periodontal disease is a chronic inflammatory condition caused by periodontal pathogens in the gingival sulcus. Short-chain fatty acids (SCFAs) produced by causal bacteria are closely related to the onset and progression of periodontal disease and have been reported to proliferate in the periodontal sulcus of patients experiencing this pathology. In such patients, propionic acid (C3), butyric acid (C4), isobutyric acid (IC4), valeric acid (C5), isovaleric acid (IC5), and caproic acid (C6), henceforth referred to as [C3-C6], has been reported to have a detrimental effect, while acetic acid (C2) exhibits no detrimental effect. In this study, we established an inexpensive and simple enzymatic assay that can fractionate and measure these acids. The possibility of applying this technique to determine the severity of periodontal disease by adapting it to specimens collected from humans has been explored. We established an enzyme system using acetate kinase and butyrate kinase capable of measuring SCFAs in two fractions, C2 and [C3-C6]. The gingival crevicular fluid (GCF) and saliva of 10 healthy participants and 10 participants with mild and severe periodontal disease were measured using the established enzymatic method and conventional gas chromatography-mass spectrometry (GC-MS). The quantification of C2 and [C3-C6] in human GCF and saliva was well correlated when using the GC-MS method. Furthermore, both C2 and [C3-C6] in the GCF increased with disease severity. However, while no significant difference was observed between healthy participants and periodontal patients when using saliva, [C3-C6] significantly differed between mild and severe periodontal disease. The enzymatic method was able to measure C2 and [C3-C6] separately as well as using the GC-MS method. Furthermore, the C2 and [C3-C6] fractions of GCF correlated with disease severity, suggesting that this method can be applied clinically. In contrast, the quantification of C2 and [C3-C6] in saliva did not differ significantly between healthy participants and patients with periodontal disease. Future studies should focus on inflammation rather than on tissue destruction., Competing Interests: The authors have declared that no competing interests exist.

Periodontal disease often develops in patients with diabetes, and further exacerbated with diabetic complications. It would be clinically important to clarify the relationship between diabetic microvascular diseases and periodontal disease. This study aimed to evaluate the association between periodontal disease and diabetic complications in patients with type 2 diabetes with poor glycemic control. A total of 447 patients with type 2 diabetes hospitalized at Rakuwakai Otowa Hospital, Japan, were initially recruited in this study. After excluding 134 patients who lacked clinical data or were edentulous, 312 were included in our study. The severity of periodontal disease was evaluated based on the average bone resorption rate. Patients with diabetic nephropathy developed severe periodontal disease (multivariate-adjusted odds ratio, 3.00 [95% CI 1.41-5.19]). Diabetic neuropathy was positively associated with the severity of periodontal disease; the multivariate-adjusted odds ratio (95% CI) was 1.62 (0.87‒2.99) for moderate and 4.26 (2.21‒8.20) for severe periodontal disease. In contrast, diabetic retinopathy was linked with moderate periodontal disease (multivariate-adjusted odds ratio 2.23 [95% CI 1.10-4.10]), but not with severe conditions (multivariate-adjusted odds ratio 0.92 [95% CI 0.67-3.07]). In conclusion, periodontal disease, evaluated by average bone resorption rate, was associated with diabetic nephropathy and neuropathy., Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-022-00591-0., Competing Interests: Conflict of interestAll authors declare no conflict interest associated with this manuscript., (© The Japan Diabetes Society 2022.)

The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression., Competing Interests: All authors declare that they have no conflicts of interests., (© 2022 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd.)

Background: Periodontal disease is the most common dental disease in dogs. Although the systemic effects of periodontal disease have not been clarified in veterinary science, it is necessary to evaluate the effects of periodontal disease in clinical trials in the future. There have been a few clinical attempts made, however, to assess the severity of periodontal inflammation and its impact on the systemic health of dogs. Meanwhile, in the field of dentistry for humans, the periodontal inflamed surface area (PISA) and periodontal epithelial surface area (PESA) have been used to quantitatively assess the degree of periodontal disease affecting a single tooth as well as the overall extent of periodontitis. Recent studies have also suggested the use of these assessments to examine the relationship between periodontal inflammation and systemic health., Results: The estimation formula for a dog's periodontal pocket surface area (PPSA), an alternative to PISA and PESA in humans, was established using body weight and periodontal pocket depth. Actual values were measured using extracted teeth from various dog breeds and sizes (2.3-25.0 kg of body weight) to obtain universal regression equations for PPSA. Altogether, 625 teeth from 73 dogs of 16 breeds were extracted and subsequently analyzed for morphological information. PPSA was measured in 61 dogs of 10 breeds with periodontal disease using the established estimation formulas, and the correlation between PPSA and preoperative blood chemistry data was analyzed accordingly. A strong correlation was found between PPSA and serum globulin (r = 0.71) while moderate correlations were found for C-reactive protein (r = 0.54) and serum albumin (r = -0.51)., Conclusions: Estimation formulas using body weight and the 6-point probing depth were established for determining PPSA. Direct correlations between PPSA and several blood test results were observed in the study sample. Taken together, these results suggest that PPSA could be useful for evaluating the effects of periodontitis on systemic conditions in dogs., (© 2021. The Author(s).)

Osteoporosis is a common disease characterized by a systemic impairment of bone mass and microarchitecture that results in fragility fractures. Severe bone loss due to osteoporosis triggers pathological fractures and consequently decreases the daily life activity and quality of life. Therefore, prevention of osteoporosis has become an important issue to be addressed. We have reported that the fungal secondary metabolite (+)-terrein (TER), a natural compound derived from Aspergillus terreus , has shown receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation by suppressing nuclear factor of activated T-cell 1 (NFATc1) expression, a master regulator of osteoclastogenesis. TER has been shown to possess extensive biological and pharmacological benefits; however, its effects on bone metabolism remain unclear. In this study, we investigated the effects of TER on the femoral bone metabolism using a mouse-ovariectomized osteoporosis model (OVX mice) and then on RANKL signal transduction using mouse bone marrow macrophages (mBMMs). In vivo administration of TER significantly improved bone density, bone mass, and trabecular number in OVX mice ( p < 0.01). In addition, TER suppressed TRAP and cathepsin-K expression in the tissue sections of OVX mice ( p < 0.01). In an in vitro study, TER suppressed RANKL-induced phosphorylation of PKCα/βII, which is involved in the expression of NFATc1 ( p < 0.05). The PKC inhibitor, GF109203X, also inhibited RANKL-induced osteoclastogenesis in mBMMs as well as TER. In addition, TER suppressed the expression of osteoclastogenesis-related genes, such as Ocstamp , Dcstamp , Calcr , Atp6v0d2 , Oscar , and Itgb3 ( p < 0.01). These results provide promising evidence for the potential therapeutic application of TER as a novel treatment compound against osteoporosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Sakaida, Omori, Nakayama, Mandai, Nakagawa, Sako, Kamei, Yamamoto, Kobayashi, Ishii, Ono, Ibaragi, Yamashiro, Yamamoto, Suga and Takashiba.)

Oral health is closely related to subjective general health and systemic diseases. This cross-sectional study aimed to identify the factors related to oral symptoms and their worsening in relation to psychosocial factors after the Great East Japan Earthquake. In this study, 64,186 residents aged 15-101 years old, who experienced the earthquake on 11 March 2011, were surveyed regarding their oral symptoms; psychological factors, such as post-traumatic reactions and psychological distress; and social factors such as evacuation, work change, and loss of a close person; history of systemic diseases; and lifestyle. Binomial logistic regression analysis was used to calculate odds ratios, and 95% confidence intervals were established for each factor associated with prevalent and exacerbated oral symptoms. The proportions of participants with prevalent and exacerbated oral symptoms were 10.3% and 1.6%, respectively. The multivariate odds ratios and 95% CI of psychosocial factors associated with exacerbated oral symptoms were as follows: post-traumatic stress disorder symptoms, 2.24 (1.64-3.06); work changes, 1.88 (1.34-2.65); history of dyslipidemia, 1.74 (1.27-2.39); and subjective current poor health condition, 2.73 (2.00-3.75). Psychological factors, social factors, and physical factors were associated with both prevalent and exacerbated oral symptoms., Competing Interests: The authors declare no conflict of interest.

Periodontal disease is a chronic inflammatory disease of the periodontal tissue. The periodontal inflamed surface area (PISA) is a proposed index for quantifying the inflammatory burden resulting from periodontitis lesions. This study aimed to investigate longitudinal changes in the periodontal status as evaluated by the PISA following the active periodontal treatment. To elucidate the prognostic factors of PISA, mixed-effect modeling was performed for clinical parameters, tooth-type, and levels of periodontal pathogens as independent variables. One-hundred-twenty-five patients with chronic periodontitis who completed the active periodontal treatment were followed-up for 24 months, with evaluations conducted at 6-month intervals. Five-times repeated measures of mean PISA values were 130+/-173, 161+/-276, 184+/-320, 175+/-417, and 209+/-469 mm 2 . Changes in clinical parameters and salivary and subgingival periodontal pathogens were analyzed by mixed-effect modeling. Plaque index, clinical attachment level, and salivary levels of Porphyromonas gingivalis were associated with changes in PISA at the patient- and tooth-level. Subgingival levels of P. gingivalis and Prevotella intermedia were associated with changes in PISA at the sample site. For most patients, changes in PISA were within 10% of baseline during the 24-month follow-up. However, an increase in the number of bleeding sites in a tooth with a deep periodontal pocket increased the PISA value exponentially.

The periodontal inflamed surface area (PISA) is a useful index for clinical and epidemiological assessments, since it can represent the inflammation status of patients in one contentious variable. However, calculation of the PISA is difficult, requiring six point probing depth measurements with or without bleeding on probing on 28 teeth, followed by data input in a calculation program. More simple methods are essential for screening periodontal disease or in epidemiological studies. In this study, we tried to establish a convenient partial examination method to estimate PISA. Cross-sectional data of 254 subjects who completed active periodontal therapy were analyzed. Teeth that represent the PISA value were selected by an item response theory approach. The maxillary second molar, first premolar, and lateral incisor and the mandibular second molar and lateral incisor were selected. The sum of the PISAs of these teeth was significantly correlated with the patient's PISA (R 2 = 0.938). More simply, the sum of the maximum values of probing pocket depth with bleeding for these teeth were also significantly correlated with the patient's PISA (R 2 = 0.6457). The simple model presented in this study may be useful to estimate PISA.

This case report highlights the importance of using a dental operating microscope (DOM) and ultrasonic endodontic tips (UETs) to locate all root canals in the lower first premolar. A 53-year-old woman presented to our clinic with pain in the lower right first premolar. After a detailed search using a DOM and UETs, three root canals were found, prepared with rotary HyFlex endodontic files, and obturated using the lateral condensation technique. At the five-year follow-up after treatment, the tooth was completely restored and fulfilling its function, with no signs or symptoms of any post-treatment flare-up., Competing Interests: No potential conflict of interest relevant to this article was reported.

Periodontal examination data have a complex structure. For epidemiological studies, mass screenings, and public health use, a simple index that represents the periodontal condition is necessary. Periodontal indices for partial examination of selected teeth have been developed. However, the selected teeth vary between indices, and a justification for the selection of examination teeth has not been presented. We applied a graded response model based on the item response theory to select optimal examination teeth and sites that represent periodontal conditions. Data were obtained from 254 patients who participated in a multicenter follow-up study. Baseline data were obtained from initial follow-up. Optimal examination sites were selected using item information calculated by graded response modeling. Twelve sites-maxillary 2nd premolar (palatal-medial), 1st premolar (palatal-distal), canine (palatal-medial), lateral incisor (palatal-central), central incisor (palatal-distal) and mandibular 1st premolar (lingual, medial)-were selected. Mean values for clinical attachment level, probing pocket depth, and bleeding on probing by full mouth examinations were used for objective variables. Measuring the clinical parameters of these sites can predict the results of full mouth examination. For calculating the periodontal index by partial oral examination, a justification for the selection of examination sites is essential. This study presents an evidence-based partial examination methodology and its modeling.

High mobility group box 1 (HMGB1) is a non-histone DNA-binding protein of about 30 kDa. It is released from a variety of cells into the extracellular milieu in response to inflammatory stimuli and acts on specific cell-surface receptors, such as receptors for advanced glycation end-products (RAGE), Toll-like receptor (TLR)2, TLR4, with or without forming a complex with other molecules. HMGB1 mediates various mechanisms such as inflammation, cell migration, proliferation, and differentiation. On the other hand, HMGB1 enhances chemotaxis acting through the C-X-C motif chemokine ligand (CXCL)12/C-X-C chemokine receptor (CXCR)4 axis and is involved in regeneration. In the oral cavity, high levels of HMGB1 have been detected in the gingival tissue from periodontitis and peri-implantitis patients, and it has been shown that secreted HMGB1 induces pro-inflammatory cytokine expression, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, which prolong inflammation. In contrast, wound healing after tooth extraction or titanium dental implant osseointegration requires an initial acute inflammation, which is regulated by secreted HMGB1. This indicates that secreted HMGB1 regulates angiogenesis and bone remodeling by osteoclast and osteoblast activation and promotes bone healing in oral tissue repair. Therefore, HMGB1 can prolong inflammation in the periodontal tissue and, conversely, can regenerate or repair damaged tissues in the oral cavity. In this review, we highlight the role of HMGB1 in the oral cavity by comparing its function and regulation with its function in other diseases. We also discuss the necessity for further studies in this field to provide more specific scientific evidence for dentistry., (Copyright © 2020 Yamashiro, Ideguchi, Aoyagi, Yoshihara-Hirata, Hirai, Suzuki-Kyoshima, Zhang, Wake, Nishibori, Yamamoto and Takashiba.)

The prevention of nosocomial infections is an imperative task. The dental chair unit (DCU) is an indispensable device used in dental treatment. However, it is known that the dental unit water line (DUWL) can become contaminated with biofilm, consisting mainly of heterotrophic bacteria (HB). Recently, the International Organization for Standardization specified the methods for testing DUWL contamination management. On these grounds, a simulator reproducing DUWL was prepared to standardize the examination method of the DUWL contamination., Objectives: To evaluate the reproducibility of the DUWL simulator, monitor the DUWL contamination states, and test the efficacy of a commercial decontaminant for DUWL., Methods: The DUWL simulator was assembled by a DCU manufacturing company. The simulator's DUWL was filled with tap water (TW), and left for approximately one year. Neutral electrolyzed water (NEW) was used as a decontaminant for DUWL. Both TW and NEW were passed through DUWL in a timely manner simulating daily dental treatment. Water was sampled from the air turbine hand piece weekly for 4 weeks and used for HB culture. Contamination status was evaluated by measuring bacterial adenosine triphosphate release and by culturing on Reasoner's 2A medium., Results: The DUWL released contaminated water had a bacterial count of over 6 × 10 4 cfu/mL. After passing NEW through DUWL for 1 week, the count drastically decreased to its basal level and remained steady for 4 weeks. However, TW showed no effect on DUWL decontamination throughout the examination periods., Conclusions: The DUWL simulator could be useful to examine the efficacy of the decontaminant for DUWL and development of new methods in DUWL contamination management., (© 2020 The Author(s).)

Chronic periodontitis is an inflammatory disease caused by the formation of oral microbial biofilms. Periodontitis is associated with general health and not only oral diseases. Porphyromonas gingivalis is a well-known keystone pathogen for periodontitis and is associated with several systemic diseases, such as diabetes mellitus and Alzheimer's disease. We previously developed a system for screening periodontitis using P. gingivalis -specific serum immunoglobulin G (IgG) in an enzyme-linked immunosorbent assay with a sensitivity of 0.774 and a specificity of 0.586 and an area under the receiver operating characteristic curve of 0.708. However, the antigens elicited non-specific responses, since they were obtained from whole extracts of sonicated cultured bacteria. The purpose of this study was to identify antigens ideal for a sensitive and specific serum test. We identified the specific antigens using immunoaffinity columns immobilized with IgG antibodies from periodontitis patients. Liquid chromatography-tandem mass spectrometry identified 29 antigens from the elutes. Recombinant proteins for these candidates were synthesized using the wheat germ cell-free translation system and screened by dot blot analysis with serum from the columns. Three of the 16 candidates that reacted showed strongest affinities upon dot blot analysis; they included outer membrane protein 28, cysteine proteases, lysine gingipain Kgp, and arginine gingipain RgpA. Outer membrane protein 28 was not suitable for screening P. gingivalis infection because of its high false-negative rates. Kgp and RgpA were unstable antigens since they underwent self-digestion. They were made stable by substituting the active cysteine residues in Kgp and RgpA with alanine using site-directed mutagenesis. Using the modified antigens, we demonstrated that the patient serum IgG level against RgpA was the highest among all the antigens expressed in P. gingivalis . Moreover, the N-terminus of recombinant RgpA was excellent in differentiating between diseased and non-diseased states (with sensitivity of 0.85, specificity of 0.9, and area under the curve of 0.915). Although dot blot analysis was the only experiment used, the N-terminus of RgpA is an excellent antigen to immunologically test for P. gingivalis infection, especially for estimating the risks for periodontitis-associated systemic diseases. In conclusion, we have developed a P. gingivalis antigen for screening periodontitis., (Copyright © 2020 Hirai, Yamaguchi-Tomikawa, Eguchi, Maeda and Takashiba.)

Background: We report the first protocol for a multicenter, randomized comparison study to compare the efficacies of periodontal scaling and root-planing treatment against that of tooth-brushing treatment for nonalcoholic fatty liver disease (NAFLD) (PERION: PERIOdontal treatment for NAFLD). Nonalcoholic steatohepatitis (NASH) is an advanced form of NAFLD, which can progress to cirrhosis and hepatocellular carcinoma. Increased endotoxemia is associated with the progression of NAFLD. Periodontal bacteria possess endotoxins; Porphyromonas gingivalis is well-known as a major pathogenic bacterium in periodontitis, and serum antibody levels for P. gingivalis are high in patients with periodontitis. Several reports have indicated that P. gingivalis is related to NAFLD. This study aims to investigate the effect of periodontal treatment for liver damage, P. gingivalis infection, and endotoxemia on patients with NAFLD., Methods: We will include adult patients (20-85 years old) with NAFLD, alanine aminotransferase (ALT) ≥ 40 IU/L, and equivalent steatosis grade ≥ 1 (target sample size, n = 40 patients; planned number of patients with outcome data, n = 32). Participants will be randomly assigned to one of two groups: a scaling and root-planing group or tooth-brushing as the usual group. The primary outcome will be the change in ALT levels from baseline to 12 weeks; the key secondary outcome will be the change in the serum immunoglobulin G (IgG) antibody titer for P. gingivalis at 12 weeks., Discussion: This study should determine whether periodontal treatment decreases liver damage, P. gingivalis infection, and endotoxemia in patients with NAFLD., Trial Registration: University Hospital Medical Information Network (UMIN) Clinical Trials Registry, ID: UMIN000022079.

We report a case of acute prevertebral abscess caused by traumatic tooth fractures in a 77-year-old Japanese man. After being transferred to our hospital the patient was initially diagnosed with a neck hematoma; however, blood culture showed Streptococcus parasanguinis, an oral bacterium, and an MRI examination suggested prevertebral abscesses. Tooth fractures, severe periodontitis, and peri-implantitis with Streptococcus parasanguinis were observed. Antibiotics were administered and fractured teeth were extracted. The patient's condition then gradually improved. We concluded that bacteremia caused by traumatic tooth fractures induced the acute prevertebral abscesses., Competing Interests: No potential conflict of interest relevant to this article was reported.

Contamination of dental unit waterlines (DUWL) with heterotrophic bacteria can cause problems in immune compromised patients (aged, tumor and organ transplantation-patients). We focused on the use of low-concentrated ozonized water (OZW) as the biofilm formation restraint system for DUWL. Here, we examined the effects of low-concentrated OZW on the growth of bacteria and related biofilm formation and harmfulness to dental unit components (DUCs) in vitro ., Objectives: To evaluate the bactericidal effects of OZW on biofilms in DUWL and DUC in vitro ., Methods: Low-concentrated OZW (0.4 mg/L) was generated using an OZS-PTDX generator. Heterotrophic bacterial biofilms in old DUWL tubes and Candia albicans solution (control microbe) were treated with OZW for 1 h with gentle agitation before static culturing for 96 h in Reasoner's 2A liquid media. The control solutions were 0.1% cetylpyridinium chloride (CPC), chlorinated tap water (TW), and phosphate-buffered saline (PBS). Adenosine triphosphate (ATP) amounts of the microbes were measured and the biofilms of these microbes were observed using scanning electron microscopy (SEM). Moreover, surfaces of DUC soaked in OZW and TW were observed by SEM., Results: The OZW reduced ATP levels in microbes to 50% compared to TW and PBS treatment, although CPC reduced it below detection limits. SEM observation revealed deformation of microbes cultured with OZW, whereas no changes were seen on DUC surfaces., Conclusions: Low-concentrated OZW is bactericidal against heterotrophic bacteria biofilms and it is not harmful to DUC, suggesting that it might be useful in preventing DUWL contamination.

The periodontal pathogen Porphyromonas gingivalis shows colonial pigmentation on blood agar and produces gingipains (Kgp, RgpA, and RgpB), cysteine proteases involved in an organism's virulence and pigmentation. We showed previously that deletion of the PGN&#95;0300 gene abolished the pigmentation activity and reduced the proteolytic activity of gingipains. The role of the PGN&#95;0297 gene, which consists of an operon with the PGN&#95;0300 gene, is unclear. Herein we examined the effect of PGN&#95;0297 gene deletion on the pigmentation and proteolytic activities and transcriptional levels of gingipains. A PGN&#95;0297 gene deletion mutant (ΔPGN&#95;0297) did not exhibit the pigmentation. The proteolytic activity of the gingipains was decreased in the culture supernatant and on the cell surface of ΔPGN&#95;0297. The mutant ΔPGN&#95;0297 failed to attenuate Akt phosphorylation at Thr308 and Ser473, but both phosphorylations were attenuated in the wild-type and its complementation strain. The deletion of PGN&#95;0297 gene did not substantially affect the transcriptional levels of the gingipain genes kgp, rgpA, and rgpB. Taken together, these results indicate that PGN&#95;0297 is closely involved in the secretion and maturation of gingipains., Competing Interests: No potential conflict of interest relevant to this article was reported.

Taste alteration is one of the complications of severe diabetes. It is important in diabetes treatment to assess taste alteration and perform dietary counseling, therapeutic exercise, and oral care. In this case, multidisciplinary clinical approach by medical staff was successful for a severely diabetic patient with dysgeusia., Competing Interests: The authors state that they have no conflict of interest.

Periapical periodontitis results from pulpal infection leading to pulpal necrosis and resorption of periapical bone. The current treatment is root canal therapy, which attempts to eliminate infection and necrotic tissue. But, in some cases periapical inflammation doesn't resolve even after treatment. Resolvins belongs to a large family of specialized pro-resolving lipid mediators that actively resolves inflammation signaling via specific receptors. Resolvin D2 (RvD2), a metabolite of docosahexaenoic acid (DHA), was tested as an intracanal medicament in rats in vivo . Mechanism was evaluated in rat primary dental pulp cells (DPCs) in vitro . The results demonstrate that RvD2 reduces inflammatory cell infiltrate, periapical lesion size, and fosters pulp like tissue regeneration and healing of periapical lesion. RvD2 enhanced expression of its receptor, GPR18, dentin matrix acidic phosphoprotein 1 (DMP1) and mineralization in vivo and in vitro . Moreover, RvD2 induces phosphorylation of Stat3 transcription factor in dental pulp cells. We conclude that intracanal treatment with RvD2 resolves inflammation and promoting calcification around root apex and healing of periapical bone lesions. The data suggest that RvD2 induces active resolution of inflammation with pulp-like tissue regeneration after root canal infection and thus maybe suitable for treating periapical lesions.

The recruitment of tissue-resident stem cells is important for wound regeneration. Periodontal ligament cells (PDL cells) are heterogeneous cell populations with stemness features that migrate into wound sites to regenerate periodontal fibres and neighbouring hard tissues. Cell migration is regulated by the local microenvironment, coordinated by growth factors and the extracellular matrix (ECM). Integrin-mediated cell adhesion to the ECM provides essential signals for migration. We hypothesized that PDL cell migration could be enhanced by selective expression of integrins. The migration of primary cultured PDL cells was induced by platelet-derived growth factor-BB (PDGF-BB). The effects of blocking specific integrins on migration and ECM adhesion were investigated based on the integrin expression profiles observed during migration. Up-regulation of integrins α3, α5, and fibronectin was identified at distinct localizations in migrating PDL cells. Treatment with anti-integrin α5 antibodies inhibited PDL cell migration. Treatment with anti-integrin α3, α3-blocking peptide, and α3 siRNA significantly enhanced cell migration, comparable to treatment with PDGF-BB. Furthermore, integrin α3 inhibition preferentially enhanced adhesion to fibronectin via integrin α5. These findings indicate that PDL cell migration is reciprocally regulated by integrin α3-mediated inhibition and α5-mediated promotion. Thus, targeting integrin expression is a possible therapeutic strategy for periodontal regeneration., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Control of bacterial infection-induced inflammatory responses is one of the effective therapeutic approaches of periodontal diseases. Natural products such as lipid mediators and metabolites from microorganisms have been used for decreasing inflammation. We previously reported that (+)-terrein inhibited activation of STAT3 and ERK1/2 in interleukin-6 (IL-6) signaling cascade, leading to prevent vascular endothelial growth factor (VEGF) secretion in human gingival fibroblasts (HGFs). However, little is still known about the role of (+)-terrein on inflammatory responses. In this study, we provided the possibility of novel action that (+)-terrein inhibits activation of Janus-activated kinase 1 (JAK1), which has a central function in IL-6 signaling cascade, and alters expression of mRNAs and proteins induced by IL-6/soluble IL-6 receptor (sIL-6R) stimulation in HGFs. First, we performed PCR array to examine IL-6/sIL-6R-induced mRNA expression, and then expression of mRNA and protein of colony stimulating factor-1 (CSF1) and VEGF were clearly determined by quantitative RT-PCR and ELISA, respectively. Treatment with (+)-terrein suppressed expression of mRNA and protein of CSF1 and VEGF by IL-6/sIL-6R stimulation. Next, to test the effect of (+)-terrein on IL-6/sIL-6R signaling cascade, we demonstrated whether (+)-terrein affects phosphorylation of JAK1 and its downstream proteins, Akt and SHP-2. Western blotting revealed that (+)-terrein inhibited IL-6/sIL-6R-induced phosphorylation of JAK1, Akt, and SHP-2. Therefore, (+)-terrein suppresses IL-6/sIL-6R-induced expression of CSF1 and VEGF via inhibition of JAK1, Akt, and SHP-2. Based on our results, we suggest that (+)-terrein is a candidate compound for anti-inflammatory effect associated with IL-6 signaling.

High mobility group box 1 (HMGB1) is a non-histone DNA-binding protein that is secreted into the extracellular milieu in response to inflammatory stimuli. The secreted HMGB1 mediates various inflammatory diseases, including periodontitis; however, the underlying mechanisms of HMGB1-induced periodontal inflammation are not completely understood. Here, we examined whether anti-HMGB1 neutralizing antibody inhibits periodontal progression and investigated the molecular pathology of HMGB1 in vitro and in vivo. In vitro analysis indicated that HMGB1, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-1β (IL-1β) were secreted in response to tumor necrosis factor-α (TNF-α) stimuli in human gingival epithelial cells (HGECs) and human monocytic leukemia cells (THP-1) treated with phorbol myristate acetate. Increased levels of GM-CSF and IL-1β were observed in the conditioned media from TNF-α-stimulated HGECs and THP-1 in vitro Simultaneous stimulation with TNF-α and anti-HMGB1 antibody significantly decreased TNF-α-induced inflammatory cytokine secretion. Experimental periodontitis was induced in mice using Porphyromonas gingivalis -soaked ligatures. The extracellular translocation was confirmed in gingival epithelia in the periodontitis model mice by immunofluorescence analysis. Systemic administration of anti-HMGB1 neutralizing antibody significantly inhibited translocation of HMGB1. The anti-HMGB1 antibody inhibited periodontal inflammation, expression of IL-1β and C-X-C motif chemokine ligand 1 (CXCL1), migration of neutrophils, and bone resorption, shown by bioluminescence imaging of myeloperoxidase activity, quantitative reverse transcription-PCR (RT-PCR), and micro-computed tomography analysis. These findings indicate that HMGB1 is secreted in response to inflammatory stimuli caused by periodontal infection, which is crucial for the initiation of periodontitis, and the anti-HMGB1 antibody attenuates the secretion of a series of inflammatory cytokines, consequently suppressing the progression of periodontitis., (Copyright © 2018 American Society for Microbiology.)