The Three-Dimensional In Vitro Cell Culture Models in the Study of Oral Cancer Immune Microenvironment.

The onset and progression of oral cancer are accompanied by a dynamic interaction with the host immune system, and the immune cells within the tumor microenvironment play a pivotal role in the development of the tumor. By exploring the cellular immunity of oral cancer, we can gain insight into the contribution of both tumor cells and immune cells to tumorigenesis. This understanding is crucial for developing effective immunotherapeutic strategies to combat oral cancer. Studies of cancer immunology present unique challenges in terms of modeling due to the extraordinary complexity of the immune system. With its multitude of cellular components, each with distinct subtypes and various activation states, the immune system interacts with cancer cells and other components of the tumor, ultimately shaping the course of the disease. Conventional two-dimensional (2D) culture methods fall short of capturing these intricate cellular interactions. Mouse models enable us to learn about tumor biology in complicated and dynamic physiological systems but have limitations as the murine immune system differs significantly from that of humans. In light of these challenges, three-dimensional (3D) culture systems offer an alternative approach to studying cancer immunology and filling the existing gaps in available models. These 3D culture models provide a means to investigate complex cellular interactions that are difficult to replicate in 2D cultures. The direct study of the interaction between immune cells and cancer cells of human origin offers a more relevant and representative platform compared to mouse models, enabling advancements in our understanding of cancer immunology. This review explores commonly used 3D culture models and highlights their significant contributions to expanding our knowledge of cancer immunology. By harnessing the power of 3D culture systems, we can unlock new insights that pave the way for improved strategies in the battle against oral cancer.

The Lysyl Oxidase G473A Polymorphism Exacerbates Oral Cancer Development in Humans and Mice.

Oral cancer is primarily squamous-cell carcinoma with a 5-year survival rate of approximately 50%. Lysyl oxidase (LOX) participates in collagen and elastin maturation. The propeptide of LOX is released as an 18 kDa protein (LOX-PP) in the extracellular environment by procollagen C-proteinases and has tumor-inhibitory properties. A polymorphism in the propeptide region of LOX (rs1800449, G473A) results in a single amino acid substitution of Gln for Arg. Here we investigated the frequency of rs1800449 in OSCC employing TCGA database resources and determined the kinetics and severity of precancerous oral lesion development in wildtype and corresponding knockin mice after exposure to 4-nitroquinoline oxide (4 NQO) in drinking water. Data show that the OSCC is more common in humans carrying the variant compared to the wildtype. Knockin mice are more susceptible to lesion development. The immunohistochemistry of LOX in mouse tissues and in vitro studies point to a negative feedback pathway of wildtype LOX-PP on LOX expression that is deficient in knockin mice. Data further demonstrate modulations of T cell phenotype in knockin mice toward a more tumor-permissive condition. Data provide initial evidence for rs1800449 as an oral cancer susceptibility biomarker and point to opportunities to better understand the functional mechanism of LOX-PP cancer inhibitory activity.

Prevalence, General and Periodontal Risk Factors of Gastroesophageal Reflux Disease in China.

Purpose: There is insufficient information about the prevalence and risk factors of gastroesophageal reflux disease (GERD) in the Chinese adult population. We aimed to assess the prevalence and identify the risk factors of GERD in China. Methods: We collected data from a nationally representative sample (50,991 subjects) of Chinese adults from a large nation-wide cross-sectional survey. GERD was diagnosed by a standardized Chinese-language GERD questionnaire with a score of ≥ 8. The demographic characteristics, comorbidities and periodontal factors of all participants were collected. Results: Fifty-thousands-one-hundred-eighty-three participants were finally included in this study. The overall prevalence of GERD was 5.6% (95% CI, 5.4-5.8%) among the general Chinese population aged 20 years or older. Women, smokers, and people with older age, BMI ≥ 25.0 kg/m2, urban residence, lower education level or comorbidities were more prevalent with GERD (p < 0.001). Symptoms of severe periodontitis (OR = 1.40, 95% CI 1.28-1.52, p < 0.001) and lower frequency of tooth brushing (OR = 2.01, 95% CI 1.76-2.29, p < 0.001) were significantly associated with risk of GERD. Conclusion: Symptom-based GERD is highly prevalent in the Chinese population. Overweight and smoking are major preventable risk factors for GERD. Periodontal factors are novel potential risk factors for GERD and should be given more attention in GERD prevention.

Group 1 and 3 innate lymphoid cells are increased in oral lichen planus and oral lichenoid lesions.

OBJECTIVES: Innate lymphoid cells (ILCs) are vital innate immune cells cooperating with T cells. While their phenotypes and functions in oral mucosa kept unclear yet. In the present study, the relative proportions and distribution of different ILC subsets in oral mucosa of oral lichen planus (OLP), oral lichenoid lesions (OLL), and controls were compared. SUBJECTS AND METHODS: Oral mucosal samples were collected from control (n = 29), OLP (n = 20), and OLL (n = 22) donors. ILCs subsets were characterized in single-cell suspensions by flow cytometry. Immunohistochemistry was performed to locate the CD127+ cells in situ. RESULTS: ILCs were present in healthy and increased infiltration in OLP/OLL (p = 0.0092, p = 0.0216). Infiltration of ILC1 increased in OLP/OLL mucosa (p = 0.0225, p = 0.0399), as did the infiltration of ILC3 increase in OLL mucosa (p = 0.0128). The ILC2/ILCs ratio was significantly reduced in OLP and OLL (p = 0.0124, p = 0.0346). CD127+ cells were mainly located closely at the basement membrane. CONCLUSIONS: The results of increased ILC1, decreased ILC2, and increased ILC3 suggested that changes of ILC distributions in oral mucosa may be relevant to persistent inflammation in local tissues, by promoting immune factors and weakening repair capacity.

Saliva Microbiome Changes in Patients With Periodontitis With and Without Chronic Obstructive Pulmonary Disease.

Objective: The oral microbiota plays a key part in the initial colonization by pathogens and the chronic inflammatory reaction of the host. We measured variations in the salivary microbiota and evaluated their potential associations with periodontitis and chronic obstructive pulmonary disease (COPD). Methods: We investigated the salivary microbiota of patients with COPD and periodontitis (n = 21) compared with that in patients with periodontitis alone (n = 36) and with healthy controls (HCs; n = 14), using pyrosequencing of polymerase chain reaction-amplified 16s rRNA genes. Results: Bacterial richness and diversity were significantly higher in patients suffering from COPD, and the bacterial family Lachnospiraceae was observed frequently only among patients with COPD and periodontitis. Veillonella, Rothia, Actinomyces, and Fusobacterium were the core bacterial genera that showed significant differences among patients with coincident COPD and periodontitis, patients with periodontitis alone, and HCs (p < 0.05). Veillonella, Rothia, and Actinomyces were observed much more frequently in patients with COPD and periodontitis, compared with that in HCs. All tested populations were divided into subgroups based on sex, smoking, or periodontitis index. In the subgroup with a bleeding index >2, Rothia was significantly different in periodontitis with and without COPD groups compared with HCs. In the subgroup with a plaque index >2.5, Rothia and Veillonella showed significant differences in periodontitis with and without COPD groups compared with HCs. Conclusion: Variations in salivary microbiota may be associated with COPD and periodontitis.

Toll-Like Receptor Signaling and Immune Regulatory Lymphocytes in Periodontal Disease.

Periodontitis is known to be initiated by periodontal microbiota derived from biofilm formation. The microbial dysbiotic changes in the biofilm trigger the host immune and inflammatory responses that can be both beneficial for the protection of the host from infection, and detrimental to the host, causing tissue destruction. During this process, recognition of Pathogen-Associated Molecular Patterns (PAMPs) by the host Pattern Recognition Receptors (PRRs) such as Toll-like receptors (TLRs) play an essential role in the host-microbe interaction and the subsequent innate as well as adaptive responses. If persistent, the adverse interaction triggered by the host immune response to the microorganisms associated with periodontal biofilms is a direct cause of periodontal inflammation and bone loss. A large number of T and B lymphocytes are infiltrated in the diseased gingival tissues, which can secrete inflammatory mediators and activate the osteolytic pathways, promoting periodontal inflammation and bone resorption. On the other hand, there is evidence showing that immune regulatory T and B cells are present in the diseased tissue and can be induced for the enhancement of their anti-inflammatory effects. Changes and distribution of the T/B lymphocytes phenotype seem to be a key determinant of the periodontal disease outcome, as the functional activities of these cells not only shape up the overall immune response pattern, but may directly regulate the osteoimmunological balance. Therefore, interventional strategies targeting TLR signaling and immune regulatory T/B cells may be a promising approach to rebalance the immune response and alleviate bone loss in periodontal disease. In this review, we will examine the etiological role of TLR signaling and immune cell osteoclastogenic activity in the pathogenesis of periodontitis. More importantly, the protective effects of immune regulatory lymphocytes, particularly the activation and functional role of IL-10 expressing regulatory B cells, will be discussed.

TLR4 mediates alveolar bone resorption in experimental peri-implantitis through regulation of CD45+ cell infiltration, RANKL/OPG ratio, and inflammatory cytokine production.

BACKGROUND: The present study was to determine the role of Toll-like receptor 4 (TLR4) signaling in inflammation and alveolar bone resorption using a murine model of Porphyromonas gingivalis-associated ligature-induced peri-implantitis. METHODS: Smooth surface titanium implants were placed in the left maxilla alveolar bone 6 weeks after extraction of first and second molars in Wild-type (WT) and TLR4-/- (TLR4 KO) mice. Silk ligatures immersed with P. gingivalis were tied around the implants 4 weeks after the implant placement and confirmation of osteointegration. Two weeks after the ligation, bone resorption, osteoclastogenesis, cellular inflammatory responses, and gingival mRNA expression levels of cytokines were assessed by micro-computed tomography, tartrate-resistant acid phosphatase (TRAP) staining, immunobiological examination and Real-time quantitative polymerase chain reaction, respectively. RESULTS: In both WT and TLR4 KO mice, the bone resorption around implants was significantly increased in the P. gingivalis/ligation group compared with control group. In P. gingivalis/ligation group, the levels of bone resorption, TRAP+ cell formation, and gingival CD3+ and CD45+ cell infiltration were significantly decreased in TLR4 KO mice compared with that in WT mice. Receptor activator of nuclear factor-kappa B ligand /osteoprotegerin (RANKL/OPG) ratio was significantly increased after P. gingivalis/ligation treatment in WT mice not in TLR4 KO mice. When comparing the P. gingivalis/ligation group with the respective control group, gingival mRNA expressions of IL-1ß, IFN-γ, and 1L-17 were significantly increased in TLR4 KO mice. CONCLUSION: This study suggests that TLR4 mediates alveolar bone resorption in P. gingivalis associated ligature-induced peri-implantitis through regulation of immune B cell infiltration, RANKL/OPG expression ratio, and differential inflammatory cytokine production.

Periodontal health: A national cross-sectional study of knowledge, attitudes and practices for the public oral health strategy in China.

AIM: To assess the status of periodontal health knowledge, attitudes and practices (KAP) among Chinese adults. MATERIALS AND METHODS: A cross-sectional study was conducted in a nationally representative sample of adults (N = 50,991) aged 20 years or older from ten provinces, autonomous regions, and municipalities. Percentages of Chinese adults with correct periodontal knowledge, positive periodontal attitudes, and practices were estimated. Multiple logistic regression analyses were used to examine the related factors. RESULTS: Less than 20% of Chinese adults were knowledgeable about periodontal disease. Very few (2.6%) of Chinese adults use dental floss ≥once a day and undergo scaling ≥once a year and visit a dentist (6.4%) in the case of gingival bleeding. Periodontal health KAP was associated with gender, age, body mass index, marital status, place of residence, education level, income, smoking status, and history of periodontal disease. CONCLUSIONS: Periodontal health KAP are generally poor among the Chinese adult population. Community-based health strategies to improve periodontal health KAP need to be implemented. Increasing knowledge of periodontal disease, the cultivation of correct practices in response to gingival bleeding, and the development of good habits concerning the use of dental floss and regular scaling should be public oral health priorities.

A novel prognostic model for tongue squamous cell carcinoma based on the characteristics of tumour and its microenvironment: iBD score.

AIMS: Tumour budding and invasive depth can predict survival of patients with tongue squamous cell carcinoma (TSCC), while the prognostic value of tumour microenvironment (TME) remains unknown. Here, both characteristics of the tumour and its microenvironment were examined and a novel prognostic model has been proposed. METHODS AND RESULTS: A total of 246 patients with TSCC were included. Using H&E-stained sections, pathological parameters of tumour and the TME were assessed. Inflammatory response (i), tumour budding (B) and invasive depth (D) were combined as iBD score. The association between these variables and the patient survival was determined. Both tumour budding and inflammatory status were independent variables for predicting overall survival (OS) and disease-free survival (DFS) of TSCC patients. Invasive depth was correlated with differentiation, T classification, lymph node metastasis, clinical stage and recurrence (P < 0.05). The novel iBD model was strongly correlated with T classification, lymph node metastasis, clinical stage and recurrence, and showed clear distinction of scores 0, 1 and 2. High iBD score had a strong association with reduced OS and DFS (P < 0.01). CONCLUSIONS: The iBD scoring model is strongly associated with lymph node metastasis and recurrence in TSCC and could be a promising survival predictor for TSCC patients.

Cytidine-phosphate-guanosine oligodeoxynucleotides in combination with CD40 ligand decrease periodontal inflammation and alveolar bone loss in a TLR9-independent manner.

Local administration of toll-like receptor 9 (TLR9), agonist cytidine-phosphate-guanosine oligodeoxynucleotide (CpG ODNs), and CD40 ligand (CD40L) can decrease ligature-induced periodontal inflammation and bone loss in wild type (WT) mouse. OBJECTIVE: This study aimed to explore whether such effect is dependent on TLR9 signaling. MATERIAL AND METHODS: Purified spleen B cells isolated from WT C57BL/6J mice and TLR9 knockout (KO) mice were cultured for 48 hours under the following conditions: CD40L, CpG+CD40L, CpG at low, medium and high doses. We determined B cell numbers using a hemocytometer at 24 h and 48 h. Percentages of CD1dhiCD5+ B cells were detected by flow cytometry. Interleukin-10 (IL-10) mRNA expression and protein secretion were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and by ELISA, respectively. The silk ligature was tied around the maxillary second molars for 14 days, during which the CpG+CD40L mixture or PBS was injected into palatal gingiva on days 3, 6, and 9. RESULTS: For both WT and TLR9 KO mice, CpG significantly induced B cell proliferation, increased IL-10 mRNA expression and protein secretion of IL-10 but reduced CD1dhiCD5+ B cells population; local injection of CpG+CD40L mixture significantly decreased alveolar bone loss and the number of TRAP-positive cells adjacent to the alveolar bone surface, and significantly increased the gingival mRNA expression of IL-10 and decreased RANKL and IFN-γ mRNA expression. CONCLUSIONS: These results indicated that CpG plus CD40L decreased periodontal inflammation and alveolar bone loss in a TLR9-independent manner in ligature-induced experimental periodontitis.

OC-STAMP promotes osteoclast fusion for pathogenic bone resorption in periodontitis via up-regulation of permissive fusogen CD9.

Cell fusion-mediated formation of multinuclear osteoclasts (OCs) plays a key role in bone resorption. It is reported that 2 unique OC-specific fusogens [ i.e., OC-stimulatory transmembrane protein (OC-STAMP) and dendritic cell-specific transmembrane protein (DC-STAMP)], and permissive fusogen CD9, are involved in OC fusion. In contrast to DC-STAMP-knockout (KO) mice, which show the osteopetrotic phenotype, OC-STAMP-KO mice show no difference in systemic bone mineral density. Nonetheless, according to the ligature-induced periodontitis model, significantly lower level of bone resorption was found in OC-STAMP-KO mice compared to WT mice. Anti-OC-STAMP-neutralizing mAb down-modulated in vitro: 1) the emergence of large multinuclear tartrate-resistant acid phosphatase-positive cells, 2) pit formation, and 3) mRNA and protein expression of CD9, but not DC-STAMP, in receptor activator of NF-κB ligand (RANKL)-stimulated OC precursor cells (OCps). While anti-DC-STAMP-mAb also down-regulated RANKL-induced osteoclastogenesis in vitro, it had no effect on CD9 expression. In our mouse model, systemic administration of anti-OC-STAMP-mAb suppressed the expression of CD9 mRNA, but not DC-STAMP mRNA, in periodontal tissue, along with diminished alveolar bone loss and reduced emergence of CD9+ OCps and tartrate-resistant acid phosphatase-positive multinuclear OCs. The present study demonstrated that OC-STAMP partners CD9 to promote periodontal bone destruction by up-regulation of fusion during osteoclastogenesis, suggesting that anti-OC-STAMP-mAb may lead to the development of a novel therapeutic regimen for periodontitis.-Ishii, T., Ruiz-Torruella, M., Ikeda, A., Shindo, S., Movila, A., Mawardi, H., Albassam, A., Kayal, R. A., Al-Dharrab, A. A., Egashira, K., Wisitrasameewong, W., Yamamoto, K., Mira, A. I., Sueishi, K., Han, X., Taubman, M. A., Miyamoto, T., Kawai, T. OC-STAMP promotes osteoclast fusion for pathogenic bone resorption in periodontitis via up-regulation of permissive fusogen CD9.

Increased infiltration of CD11 c+/CD123+ dendritic cell subsets and upregulation of TLR/IFN-α signaling participate in pathogenesis of oral lichen planus.

OBJECTIVE: Investigation of dendritic cell (DC) subsets and expression patterns of Toll-like receptors (TLRs) was conducted to understand the pathogenesis in oral lichen planus (OLP). STUDY DESIGN: Blood, OLP lesion, and control samples were collected. Four DC subsets (CD11c+CD123-myeloid DC1 [mDC1], CD141+mDC2, CD11c-CD123+plasmacytoid DC [pDC], and CD1a+CD207+Langerhans cells [LC]) were investigated via flow cytometry (FCM) and immunohistochemical staining. Expression patterns of TLRs and their downstream molecules were analyzed via quantitative real-time polymerase chain reaction and immunohistochemistry in situ. RESULTS: Thirty-two samples were collected (9 controls and 23 OLP patients). FCM results found that the percentages of LC, mDC1, mDC2, and pDC in situ were 0.0119 ± 0.0251%, 0.0064 ± 0.0134%, 0.0005 ± 0.0011%, and 0.0022 ± 0.0019% in control mucosa, respectively. The mDC1 (0.0300 ± 0.0276%) and pDC (0.0204 ± 0.0186%) subsets were significantly increased in OLP lesions (P < .01). No marked differences were evident, when comparing all 4 DC subsets from blood, between control and OLP groups. Significant upregulation of TLR7, TLR8, and TLR9 were disclosed in OLP (P < .01), along with their downstream interferon-α (IFN-α) signaling molecules (IRF7 and IFN-α, P < .01). CONCLUSION: Our findings of increased infiltration of pDC and mDC1, along with upregulation of TLR/IFN-α signaling, provide valuable information for further understanding the immunity in OLP.

Differential expression of STAT-3 in subtypes of oral lichen planus: a preliminary study.

OBJECTIVE: This study aimed to examine the expression of signaling transduction proteins and their possible correlation with different clinical subtypes of oral lichen planus (OLP). STUDY DESIGN: We examined the immunoexpression and phosphorylation status of 21 signaling transduction proteins of OLP (n = 10) and normal groups (n = 8) using PathScan analysis. Using immunohistochemistry, we detected expression of STAT-3 and p38 MAPK in tissues of OLP (n = 40) and normal controls (n = 10). RESULTS: PathScan analysis showed that STAT-3 (Ser727) expression in normal control (N), reticular OLP (R-OLP) and erosive OLP (E-OLP) group was gradually elevated (R-OLP vs N, P = .001; E-OLP vs N, P < .001; E-OLP vs R-OLP, P = .002). Immunohistochemistry showed that STAT-3 expression in the epithelium of normal control, reticular OLP and erosive OLP was consistent with PathScan analysis (R-OLP vs N, P < .001; E-OLP vs N, P < .001; E-OLP vs R-OLP, P = .036). Both PathScan (P = .012) and immunohistochemistry (P < .001) showed that, p38 MAPK expression was significantly higher in OLP compared with normal controls. However, a significant difference was not seen between the reticular OLP and erosive OLP groups. CONCLUSIONS: Our results indicate that STAT-3 may be involved in OLP development and progression and account for different clinical manifestations.

Cytidine-phosphate-guanosine oligodeoxynucleotides in combination with CD40 ligand decrease periodontal inflammation and alveolar bone loss in a TLR9-independent manner

Abstract Local administration of toll-like receptor 9 (TLR9), agonist cytidine-phosphate-guanosine oligodeoxynucleotide (CpG ODNs), and CD40 ligand (CD40L) can decrease ligature-induced periodontal inflammation and bone loss in wild type (WT) mouse. Objective: This study aimed to explore whether such effect is dependent on TLR9 signaling. Material and Methods: Purified spleen B cells isolated from WT C57BL/6J mice and TLR9 knockout (KO) mice were cultured for 48 hours under the following conditions: CD40L, CpG+CD40L, CpG at low, medium and high doses. We determined B cell numbers using a hemocytometer at 24 h and 48 h. Percentages of CD1dhiCD5+ B cells were detected by flow cytometry. Interleukin-10 (IL-10) mRNA expression and protein secretion were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and by ELISA, respectively. The silk ligature was tied around the maxillary second molars for 14 days, during which the CpG+CD40L mixture or PBS was injected into palatal gingiva on days 3, 6, and 9. Results: For both WT and TLR9 KO mice, CpG significantly induced B cell proliferation, increased IL-10 mRNA expression and protein secretion of IL-10 but reduced CD1dhiCD5+ B cells population; local injection of CpG+CD40L mixture significantly decreased alveolar bone loss and the number of TRAP-positive cells adjacent to the alveolar bone surface, and significantly increased the gingival mRNA expression of IL-10 and decreased RANKL and IFN-γ mRNA expression. Conclusions: These results indicated that CpG plus CD40L decreased periodontal inflammation and alveolar bone loss in a TLR9-independent manner in ligature-induced experimental periodontitis.

Different engagement of TLR2 and TLR4 in Porphyromonas gingivalis vs. ligature-induced periodontal bone loss.

This study was conducted to investigate the roles of different Toll-like receptor (TLR) signaling in Porphyromonas gingivalis (P. gingivalis)-induced and ligature-induced experimental periodontal bone resorption in mice. Wild-type (WT), TLR2 knockout (KO), TLR4KO, and TLR2&4 KO mice with C57/BL6 background were divided into three groups: control, P. gingivalis infection, and ligation. Live P. gingivalis or silk ligatures were placed in the sulcus around maxillary second molars over a 2-week period. Images were captured by digital stereomicroscopy, and the bone resorption area was measured with ImageJ software. The protein expression level of gingival RANKL was measured by ELISA. The gingival mRNA levels of RANKL, IL-1ß, TNF-α, and IL-10 were detected by RT-qPCR. The results showed that P. gingivalis induced significant periodontal bone resorption in WT mice and TLR2 KO mice but not in TLR4 KO mice or TLR2&4 KO mice. For all four types of mice, ligation induced significant bone loss compared with that in control groups, and this bone loss was significantly higher than that in the P. gingivalis infection group. RANKL protein expression was significantly increased in the ligation group compared with that in the control group for all four types of mice, and in the P. gingivalis infection group of WT, TLR2 KO, and TLR4 KO mice. Expression patterns of RANKL, IL-1ß, TNF-α, and IL-10 mRNA were different in the P. gingivalis infection group and the ligation group in different types of mice. In summary, P. gingivalis-induced periodontal bone resorption is TLR4-dependent, whereas ligation-induced periodontal bone resorption is neither TLR2- nor TLR4-dependent.

IL-21/anti-Tim1/CD40 ligand promotes B10 activity in vitro and alleviates bone loss in experimental periodontitis in vivo.

IL-10-expressing regulatory B cells (B10) play an essential role in immune system balance by suppressing excessive inflammatory responses. In this study, we investigated induction of B 10 cell's IL-10 competency in vitro and its effect on ligature-induced experimental periodontitis in vivo. Spleen B cells were isolated from C57BL/6J mice and cultured for 48h under the following conditions: control, CD40L, IL-21, anti-Tim1, CD40L+IL-21, CD40L+anti-Tim1, CD40L+IL-21+anti-Tim1. Silk ligatures were tied around both maxillary second molars of C57BL/6J mice for two weeks. Optimized combination of CD40L, IL-21 and anti-Tim1 and vehicle were injected into contralateral side of palatal gingiva on days 3, 6 and 9. The palatal gingival tissues and maxillary bone were collected on day 14 to determine expressions of IL-10 and periodontal bone resorption respectively. Our results demonstrated that IL-10 expressions of cultured spleen B cells were significantly increased in the presence of CD40L, IL-21 and anti-Tim1 combination when compared with control groups. Gingival IL-10 mRNA and protein expressions were significantly increased after injection of CD40L, IL-21 and anti-Tim1 combination, when compared to the control side. The gingival RANKL expression and periodontal bone loss were significantly decreased on the combination treatment side, as compared to the control side. These results suggest that combination of IL-21, anti-Tim1 and CD40L treatment induced B10 cell's IL-10 competency in vitro and inhibited periodontal bone loss in ligature-induced experimental periodontitis.

B10 Cells Alleviate Periodontal Bone Loss in Experimental Periodontitis.

B10 cells can regulate inflammatory responses in innate immunity. Toll-like receptors (TLRs) play an important role in B cell-mediated immune responses in periodontal disease. This study aimed to determine the effects of TLR-activated B10 cells on periodontal bone loss in experimental periodontitis. Spleen B cells isolated from C57BL/6J mice were cultured with Porphyromonas gingivalis lipopolysaccharide (LPS) and cytosine-phospho-guanine (CpG) oligodeoxynucleotides for 48 h. B10-enriched CD1dhi CD5+ B cells were sorted by flow cytometry and were adoptively transferred to recipient mice through tail vein injection. At the same time, P. gingivalis-soaked ligatures were placed subgingivally around the maxillary second molars and remained there for 2 weeks before the mice were euthanized. Interleukin-10 (IL-10) production and the percentage of CD1dhi CD5+ B cells were significantly increased with treatment with P. gingivalis LPS plus CpG compared to those in mice treated with P. gingivalis LPS or CpG alone. Mice with CD1dhi CD5+ B cell transfer demonstrated reduced periodontal bone loss compared to the no-transfer group and the group with CD1dlo CD5- B cell transfer. Gingival IL-10 mRNA expression was significantly increased, whereas expressions of receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG), tumor necrosis factor alpha (TNF-α), and IL-1ß were significantly inhibited in the CD1dhi CD5+ B cell transfer group. The percentages of CD19+ IL-10+ cells, CD19+ CD1dhi CD5+ cells, and P. gingivalis-binding CD19+ cells were significantly higher in recovered mononuclear cells from gingival tissues of the CD1dhi CD5+ B cell transfer group than in tissues of the no-transfer group and the CD1dlo CD5- B cell transfer group. This study indicated that the adoptive transfer of B10 cells alleviated periodontal inflammation and bone loss in experimental periodontitis in mice.

Interplay between ΔNp63 and miR-138-5p regulates growth, metastasis and stemness of oral squamous cell carcinoma.

TP63 acts as a master regulator in epithelia development and in the progression of various cancers, but its role in oral cancer pathogenesis remains unknown. This study aimed to explore the role of TP63 in the progression of oral squamous cell carcinoma (OSCC). This study shows that ΔNp63, the predominant isoform of TP63, is significantly upregulated in OSCC tissues and cell lines compared with their normal counterparts, and its expression is closely correlated with pathological differentiation, lymph node metastasis and clinical stage in patients with OSCC. The overexpression of ΔNp63 promotes growth, metastasis and stem-like properties in OSCC cells, and ΔNp63 depletion significantly represses OSCC cellular phenotypes in vitro and in vivo. The ΔNp63 isoform transcriptionally suppresses miR-138-5p expression; restoration of miR-138-5p expression partially abolishes the effect of upregulating ΔNp63. This study also demonstrates that miR-138-5p directly targets ΔNp63, resulting in crosstalk with ΔNp63. The correlation between ΔNp63 and miR-138-5p was further validated in OSCC tissues and was found to be significantly associated with the prognosis of patients with OSCC. Therefore, our data reveal that the interplay between ΔNp63 and miR-138-5p promotes OSCC progression by regulating cell growth, metastasis and stemness.

Phosphoglycerol dihydroceramide, a distinctive ceramide produced by Porphyromonas gingivalis, promotes RANKL-induced osteoclastogenesis by acting on non-muscle myosin II-A (Myh9), an osteoclast cell fusion regulatory factor.

Among several virulence factors produced by the periodontal pathogen Porphyromonas gingivalis (Pg), a recently identified novel class of dihydroceramide lipids that contains a long acyl-chain has the potential to play a pathogenic role in periodontitis because of its higher level of tissue penetration compared to other lipid classes produced by Pg. However, the possible impact of Pg ceramides on osteoclastogenesis is largely unknown. In the present study, we report that the phosphoglycerol dihydroceramide (PGDHC) isolated from Pg enhanced osteoclastogenesis in vitro and in vivo. Using RAW264.7 cells, in vitro assays indicated that PGDHC can promote RANKL-induced osteoclastogenesis by generating remarkably larger TRAP+ multinuclear osteoclasts compared to Pg LPS in a TLR2/4-independent manner. According to fluorescent confocal microscopy, co-localization of non-muscle myosin II-A (Myh9) and PGDHC was observed in the cytoplasm of osteoclasts, indicating the membrane-permeability of PGDHC. Loss- and gain-of-function assays using RNAi-based Myh9 gene silencing, as well as overexpression of the Myh9 gene, in RAW264.7 cells showed that interaction of PGDHC with Myh9 enhances RANKL-induced osteoclastogenesis. It was also demonstrated that PGDHC can upregulate the expression of dendritic cell-specific transmembrane protein (DC-STAMP), an important osteoclast fusogen, through signaling that involves Rac1, suggesting that interaction of PGDHC with Myh9 can elicit the cell signal that promotes osteoclast cell fusion. Taken together, our data indicated that PGDHC is a Pg-derived, cell-permeable ceramide that possesses a unique property of promoting osteoclastogenesis via interaction with Myh9 which, in turn, activates a Rac1/DC-STAMP pathway for upregulation of osteoclast cell fusion.

Local Induction of B Cell Interleukin-10 Competency Alleviates Inflammation and Bone Loss in Ligature-Induced Experimental Periodontitis in Mice.

Interleukin-10 (IL-10)-producing B cells (B10 cells) play a critical role in the immune system balance by negatively regulating inflammatory responses. This study was conducted to determine the effect of local B10 cell induction on periodontal inflammation and bone loss in ligature-induced experimental periodontitis in vivo Purified spleen B cells from C57BL/6J mice (8 to 10 weeks old) were cultured with CD40 ligand (CD40L) and the Toll-like receptor 9 (TLR9) agonist cytidine-phosphate-guanosine oligodeoxynucleotide (CpG) to determine effective IL-10 induction in vitro Silk ligatures (size 7-0) were tied around the mouse maxillary second molars on day 0, followed by the injection of CD40L and CpG into the palatal gingiva on days 3, 6, and 9. All the mice were sacrificed, and samples were collected on day 14. CD40L and CpG significantly increased the level of IL-10 production by B cells in vitro, although the frequencies of CD1dhi CD5+ and IL-10-producing (IL-10+) CD45+ cells were decreased. IL-10 was predominantly produced by the CD1dhi CD5+ subpopulation of B cells. In vivo, both IL-10 mRNA expression and the number of IL-10+ CD45+ cells were significantly increased after gingival injection of CD40L and CpG. Periodontal bone loss was significantly decreased and the gingival expression of IL-1ß, tumor necrosis factor alpha, and RANKL was significantly reduced. The number of multinucleated tartrate-resistant acid phosphatase-positive cells along the alveolar bone surface was significantly decreased after gingival injection of CD40L and CpG. This study indicates for the first time that the local induction of B10 cell activity could inhibit periodontal inflammation and bone loss.