Recent studies have demonstrated a relationship between oral bacteria and systemic inflammation. Endothelial cells (ECs), which line blood vessels, control the opening and closing of the vascular ...barrier and contribute to hematogenous metastasis; however, the role of oral bacteria‐induced vascular inflammation in tumor metastasis remains unclear. In this study, we examined the phenotypic changes in vascular ECs following Streptococcus mutans (S. mutans) stimulation in vitro and in vivo. The expression of molecules associated with vascular inflammation and barrier‐associated adhesion was analyzed. Tumor metastasis was evaluated after intravenous injection of S. mutans in murine breast cancer hematogenous metastasis model. The results indicated that S. mutans invaded the ECs accompanied by inflammation and NF‐κB activation. S. mutans exposure potentially disrupts endothelial integrity by decreasing vascular endothelial (VE)‐cadherin expression. The migration and adhesion of tumor cells were enhanced in S. mutans‐stimulated ECs. Furthermore, S. mutans‐induced lung vascular inflammation promoted breast cancer cell metastasis to the lungs in vivo. The results indicate that oral bacteria promote tumor metastasis through vascular inflammation and the disruption of vascular barrier function. Improving oral hygiene in patients with cancer is of great significance in preventing postoperative pneumonia and tumor metastasis.
The oral bacterium, Streptococcus mutans (S. mutans) invades endothelial cells (ECs) accompanied by inflammation. S.mutans disrupts endothelial integrity and subsequently promotes tumor cell extravasation and finally promotes breast cancer cell metastasis to the lungs.
Ultrasound stimulation is a type of mechanical stress, and low-intensity pulsed ultrasound (LIPUS) devices have been used clinically to promote fracture healing. However, it remains unclear which ...skeletal cells, in particular osteocytes or osteoblasts, primarily respond to LIPUS stimulation and how they contribute to fracture healing. To examine this, we utilized medaka, whose bone lacks osteocytes, and zebrafish, whose bone has osteocytes, as in vivo models. Fracture healing was accelerated by ultrasound stimulation in zebrafish, but not in medaka. To examine the molecular events induced by LIPUS stimulation in osteocytes, we performed RNA sequencing of a murine osteocytic cell line exposed to LIPUS. 179 genes reacted to LIPUS stimulation, and functional cluster analysis identified among them several molecular signatures related to immunity, secretion, and transcription. Notably, most of the isolated transcription-related genes were also modulated by LIPUS in vivo in zebrafish. However, expression levels of early growth response protein 1 and 2 (Egr1, 2), JunB, forkhead box Q1 (FoxQ1), and nuclear factor of activated T cells c1 (NFATc1) were not altered by LIPUS in medaka, suggesting that these genes are key transcriptional regulators of LIPUS-dependent fracture healing via osteocytes. We therefore show that bone-embedded osteocytes are necessary for LIPUS-induced promotion of fracture healing via transcriptional control of target genes, which presumably activates neighboring cells involved in fracture healing processes.
Development of quantitative analysis software has enabled application of several standardised uptake values (SUV) for bone analysis in single photon emission computed tomography (SPECT). The present ...retrospective study aimed to develop a reliable method of monitoring bone inflammatory activity in antiresorptive agent-related osteonecrosis of the jaw (ARONJ) using SPECT quantitative analysis software. Fifteen ARONJ patients underwent SPECT before and after anti-inflammatory therapy. We calculated the mean maximum SUV (SUVmax) of the bilateral cranial bones using quantitative analysis software and used this as the control C. We attempted to adjust the SUVmax of the lesion L as follows: adjusted SUVmax (aSUVmax) = L - C. The optimum threshold to calculate the metabolic bone volume (MBV) (cm
) was C + 3. The threshold values obtained for each case were input to calculate MBV at each osteomyelitis site. Retrospectively, we compared aSUVmax and MBV of each patient's ARONJ before and after anti-inflammatory therapy. The patients' high aSUVmax or large MBV of the ARONJ reduced rapidly, reflecting individual clinical findings after treatment. Application of SPECT quantitative analysis software to monitor bone inflammatory activity in ARONJ could improve the prognosis-deciding abilities of clinicians and enable them to treat ARONJ effectively.
Osteomyelitis of the jaw is a severe inflammatory disorder that affects bones, and it is categorized into two main types: chronic bacterial and nonbacterial osteomyelitis. Although previous studies ...have investigated the association between these diseases and the oral microbiome, the specific taxa associated with each disease remain unknown. In this study, we conducted shotgun metagenome sequencing (≥10 Gb from ≥66,395,670 reads per sample) of bulk DNA extracted from saliva obtained from patients with chronic bacterial osteomyelitis (N = 5) and chronic nonbacterial osteomyelitis (N = 10). We then compared the taxonomic composition of the metagenome in terms of both taxonomic and sequence abundances with that of healthy controls (N = 5). Taxonomic profiling revealed a statistically significant increase in both the taxonomic and sequence abundance of Mogibacterium in cases of chronic bacterial osteomyelitis; however, such enrichment was not observed in chronic nonbacterial osteomyelitis. We also compared a previously reported core saliva microbiome (59 genera) with our data and found that out of the 74 genera detected in this study, 47 (including Mogibacterium) were not included in the previous meta-analysis. Additionally, we analyzed a core-genome tree of Mogibacterium from chronic bacterial osteomyelitis and healthy control samples along with a reference complete genome and found that Mogibacterium from both groups was indistinguishable at the core-genome and pan-genome levels. Although limited by the small sample size, our study provides novel evidence of a significant increase in Mogibacterium abundance in the chronic bacterial osteomyelitis group. Moreover, our study presents a comparative analysis of the taxonomic and sequence abundances of all genera detected using deep salivary shotgun metagenome data. The distinct enrichment of Mogibacterium suggests its potential as a marker to distinguish between patients with chronic nonbacterial osteomyelitis and chronic bacterial osteomyelitis, particularly at the early stages when differences are unclear.
Abstract
Cetylpyridinium chloride (CPC), a quaternary ammonium compound, which is present in mouthwash, is effective against bacteria, fungi, and enveloped viruses. This study was conducted to ...explore the antiviral effect of CPC on SARS-CoV-2. There are few reports on the effect of CPC against wild-type SARS-CoV-2 at low concentrations such as 0.001%–0.005% (10–50 µg/mL). Interestingly, we found that low concentrations of CPC suppressed the infectivity of human isolated SARS-CoV-2 strains (Wuhan, Alpha, Beta, and Gamma) even in saliva. Furthermore, we demonstrated that CPC shows anti-SARS-CoV-2 effects without disrupting the virus envelope, using sucrose density analysis and electron microscopic examination. In conclusion, this study provided experimental evidence that CPC may inhibit SARS-CoV-2 infection even at lower concentrations.
Objectives
The aim of the present study was to evaluate the effectiveness of platelet-rich fibrin (PRF) as a wound-healing accelerator in patients undergoing oral bisphosphonate therapy and requiring ...tooth extractions.
Materials and methods
A total of 102 patients were divided into a PRF group and control group. The patients received oral bisphosphonate therapy for osteoporosis for an average of 32 months. Blood was collected and PRF was introduced into the socket of the PRF group only. Monitoring of mucosal healing was conducted for 3 months in both groups, and radiographic evaluation in the sockets was performed in the PRF group. Delayed recovery was defined as exposed bone and vulnerable granulation tissue without epithelization after 4 weeks and resolving by 8 weeks.
Results
There were no intraoperative complications, and none of the patients exhibited onset of medication-related osteonecrosis of the jaw (MRONJ). Delayed recovery was observed in 9 out of 73 control patients (12%), whereas 29 PRF patients exhibited complete epithelialization of the socket within 1 month. The prevalence of delayed recovery was significantly higher in the control group than the PRF group (
P
< 0.05). Multivariate logistic regression analysis revealed that risk factors and use of PRF were independent significant factors to relate to delayed recovery (
P
= 0.02).
Conclusions
Early epithelization was confirmed in all PRF patients. Thus, PRF may reduce the risk of delayed recovery in patients undergoing oral bisphosphonate therapy.
Clinical relevance
PRF may be useful in preventing MRONJ in patients receiving oral bisphosphonate (BP).
The basement membrane zone consists of multiple components, including collagen XVII (COL17), which is the target of bullous pemphigoid. To our knowledge, no research has addressed the differences in ...basement membrane zone components between the skin and oral mucosa; therefore, we investigated the basement membrane zone proteins, with a focus on COL17. The mRNA and protein expression levels of COL17 were significantly higher in oral keratinocytes than in skin keratinocytes. Hemidesmosomal COL17 expression was markedly higher in oral keratinocytes than in skin keratinocytes, and its level was associated with adhesion strength. Oral keratinocytes adhered to the extracellular matrix more tightly than did skin keratinocytes in vitro. Based on these results, we attempt to explain the clinical diversity of bullous pemphigoid. COL17 depletion was more prominent in skin keratinocytes than in oral keratinocytes after treatment with COL17-NC16A mAbs, which have in vivo pathogenicity. COL17 C-terminus mAbs, which are not pathogenic, facilitated COL17 depletion in combination treatment with COL17-NC16A mAbs in both types of keratinocytes. In summary, the greater amount of COL17 in oral keratinocytes than in skin keratinocytes is associated with the higher strength of oral keratinocyte hemidesmosomal adhesion at the basement membrane zone. Our results may explain why bullous pemphigoid blistering tends to be more prevalent in the skin than in the oral mucosa.
Introduction
Hypophosphatasia (HPP) is caused by mutations in the
ALPL
gene encoding tissue nonspecific alkaline phosphatase (TNSALP) and inherited in either an autosomal recessive or autosomal ...dominant manner. It is characterized clinically by defective mineralization of bone, dental problems, and low serum ALP levels. In the current report, we demonstrate a novel mutation in the
ALPL
gene (c.244G > A p.Gly82Arg) in a Japanese family with low serum ALP levels.
Materials and methods
The
ALPL
gene analysis using hybridization capture-based next-generation sequencing was performed. The expression plasmids of the wild type and mutated TNSALP were introduced into COS-7 cells. The enzymatic activity of ALP in the cell lysates was measured using p-nitrophenylphosphate as a substrate.
Results
TNSALP with the novel
ALPL
mutation (c.244G > A p.Gly82Arg) completely lost its enzymatic activity and suppressed that of wild-type TNSALP, corroborating its dominant negative effect. The diagnosis of autosomal dominant HPP was confirmed in three members of the family.
Conclusion
Our approach would help to avoid the inappropriate use of bone resorption inhibitors for currently mis- or under-diagnosed HPP, given that the presence of further, yet undetected mutations of the
ALPL
gene are plausible.
The basement membrane zone (BMZ) is framed by hemidesmosomes and extracellular matrix (ECM) including collagen IV (COL4). Hemidesmosomes are multiprotein complexes that include collagen XVII (COL17). ...BMZ proteins can be targeted in autoimmune subepidermal blistering diseases, e.g., pemphigoid targeting COL17. The blistering mechanisms in pemphigoid have not been fully elucidated, especially in mucous membrane pemphigoid (MMP), which mainly affects the mucosa. In this study, we showed that oral lesions in pemphigoid may be attributed to the inhibition of protein–protein interactions by autoantibodies. Using immunoprecipitation, we revealed that COL17 directly binds to COL4 in normal human keratinocytes and normal human oral keratinocytes. In particular, the C-terminus of COL17 is binding site to COL4 in oral keratinocytes. The precise COL4-binding region on COL17 was determined by protein–protein binding assay to be from amino acid Gly1175 to Asp1340 on the C-terminus. MMP-IgG or mAb recognizing the C-terminus hindered the interaction of COL17 with COL4 in oral keratinocytes. Furthermore, keratinocyte adhesion strength to COL4-coated plates was significantly reduced by the treatment of mAb against the C-terminus. In addition, the inflammatory infiltrates around perilesions were significantly less in MMP compared to BP. These results indicate that pemphigoid IgG targeting the C-terminus plays a pathogenic role in blister formation in the oral mucosa to inhibit protein interactions with less inflammation.
Collagen XVII directly binds to collagen IV at the basement membrane zone in both skin and oral mucosa. Mucous membrane pemphigoid autoantibodies targeting the C-terminus of collagen XVII hinder this binding and induce the detachment of basal cells in the oral mucosa. This mechanism leads to oral lesions that show less inflammation than the skin lesions show.
EWS‐FLI1 constitutes an oncogenic transcription factor that plays key roles in Ewing sarcoma development and maintenance. We have recently succeeded in generating an ex vivo mouse model for Ewing ...sarcoma by introducing EWS‐FLI1 into embryonic osteochondrogenic progenitors. The model well recapitulates the biological characteristics, small round cell morphology, and gene expression profiles of human Ewing sarcoma. Here, we clarified the global DNA binding properties of EWS‐FLI1 in mouse Ewing sarcoma. GGAA microsatellites were found to serve as binding sites of EWS‐FLI1 albeit with less frequency than that in human Ewing sarcoma; moreover, genomic distribution was not conserved between human and mouse. Nevertheless, EWS‐FLI1 binding sites within GGAA microsatellites were frequently associated with the histone H3K27Ac enhancer mark, suggesting that EWS‐FLI1 could affect global gene expression by binding its target sites. In particular, the Fox transcription factor binding motif was frequently observed within EWS‐FLI1 peaks and Foxq1 was identified as the cooperative partner that interacts with the EWS portion of EWS‐FLI1. Trib1 and Nrg1 were demonstrated as target genes that are co‐regulated by EWS‐FLI1 and Foxq1, and are important for cell proliferation and survival of Ewing sarcoma. Collectively, our findings present novel aspects of EWS‐FLI1 function as well as the importance of GGAA microsatellites.
GGAA microsatellites and enhancer regions were identified as EWS‐FLI1‐binding loci in a mouse model for Ewing sarcoma. Foxq1 was identified as a cooperative partner of EWS‐FLI1, and interaction between Foxq1 and EWS‐FLI1 was observed. Trib1 and Nrg1 were identified as direct target genes for EWS‐FLI1 and Foxq1 collaboration.
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