Epithelial-derived interleukin-23 promotes oral mucosal immunopathology.

At mucosal surfaces, epithelial cells provide a structural barrier and an immune defense system. However, dysregulated epithelial responses can contribute to disease states. Here, we demonstrated that epithelial cell-intrinsic production of interleukin-23 (IL-23) triggers an inflammatory loop in the prevalent oral disease periodontitis. Epithelial IL-23 expression localized to areas proximal to the disease-associated microbiome and was evident in experimental models and patients with common and genetic forms of disease. Mechanistically, flagellated microbial species of the periodontitis microbiome triggered epithelial IL-23 induction in a TLR5 receptor-dependent manner. Therefore, unlike other Th17-driven diseases, non-hematopoietic-cell-derived IL-23 served as an initiator of pathogenic inflammation in periodontitis. Beyond periodontitis, analysis of publicly available datasets revealed the expression of epithelial IL-23 in settings of infection, malignancy, and autoimmunity, suggesting a broader role for epithelial-intrinsic IL-23 in human disease. Collectively, this work highlights an important role for the barrier epithelium in the induction of IL-23-mediated inflammation.

Neutrophils and neutrophil extracellular traps in oral health and disease.

Neutrophils perform essential functions in antimicrobial defense and tissue maintenance at mucosal barriers. However, a dysregulated neutrophil response and, in particular, the excessive release of neutrophil extracellular traps (NETs) are implicated in the pathology of various diseases. In this review, we provide an overview of the basic concepts related to neutrophil functions, including NET formation, and discuss the mechanisms associated with NET activation and function in the context of the prevalent oral disease periodontitis.

Dissociation of murine oral mucosal tissues for single cell applications.

Single-cell RNA sequencing and flow cytometry approaches have been instrumental in understanding cellular states within various tissues and organs. However, tissue dissociation methods can potentially alter results and create bias due to preferential recovery of particular cell types. Here we present efforts to optimize methods for dissociation of murine oral mucosal tissues and provide three different protocols that can be utilized to isolate major cell populations in the oral mucosa. These methods can be used both in health and in states of inflammation, such as periodontitis. The optimized protocols use different enzymatic approaches (collagenase II, collagenase IV and the Miltenyi whole skin dissociation kit) and yield preferential recovery of immune, stromal and epithelial cells, respectively. We suggest choosing the dissociation method based on the cell population of interest to study, while understanding the limitations of each approach.

Neutrophil extracellular traps and extracellular histones potentiate IL-17 inflammation in periodontitis.

Neutrophil infiltration is a hallmark of periodontitis, a prevalent oral inflammatory condition in which Th17-driven mucosal inflammation leads to destruction of tooth-supporting bone. Herein, we document that neutrophil extracellular traps (NETs) are early triggers of pathogenic inflammation in periodontitis. In an established animal model, we demonstrate that neutrophils infiltrate the gingival oral mucosa at early time points after disease induction and expel NETs to trigger mucosal inflammation and bone destruction in vivo. Investigating mechanisms by which NETs drive inflammatory bone loss, we find that extracellular histones, a major component of NETs, trigger upregulation of IL-17/Th17 responses, and bone destruction. Importantly, human findings corroborate our experimental work. We document significantly increased levels of NET complexes and extracellular histones bearing classic NET-associated posttranslational modifications, in blood and local lesions of severe periodontitis patients, in the absence of confounding disease. Our findings suggest a feed-forward loop in which NETs trigger IL-17 immunity to promote immunopathology in a prevalent human inflammatory disease.

Dexmedetomidine and LPS co-treatment attenuates inflammatory response on WISH cells via inhibition of p38/NF-κB signaling pathway.

Background: Inflammatory dental diseases that occur during pregnancy can cause preterm labor and/or intrauterine growth restriction. Therefore, proactive treatment of dental diseases is necessary during pregnancy. Dexmedetomidine (DEX) is a widely used sedative in the dental field, but research on the effect of DEX on pregnancy is currently insufficient. In this study, we investigated the effects of co-treatment with DEX and lipopolysaccharide (LPS) on inflammatory responses in human amnion-derived WISH cells. Methods: Human amnion-derived WISH cells were treated with 0.001, 0.01, 0.1, and 1 µg/mL DEX with 1 µg/mL LPS for 24 h. Cytotoxicity of WISH cells was evaluated by 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. The protein expression of cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), p38, and nuclear factor kappa B (NF-κB) was examined by western blot analysis. The mRNA expression of pro-inflammatory cytokines such as interleukin (IL)-1ß and tumor necrosis factor (TNF)-α was analyzed by real-time quantitative polymerase chain reaction. Results: Co-treatment with DEX and LPS showed no cytotoxicity in the WISH cells. The mRNA expression of IL-1ß and TNF-α decreased after co-treatment with DEX and LPS. DEX and LPS co-treatment decreased the protein expression of COX-2, PGE2, phospho-p38, and phospho-NF-κB in WISH cells. Conclusion: Co-treatment with DEX and LPS suppressed the expression of COX-2 and PGE2, as well as pro-inflammatory cytokines such as IL-1ß and TNF-α in WISH cells. In addition, the anti-inflammatory effect of DEX and LPS co-treatment was mediated by the inhibition of p38/NF-κB activation.

Palliative percutaneous stabilization of lower extremity for bone metastasis using flexible nails and bone cement.

OBJECTIVE: Percutaneous stabilization (PS; percutaneous flexible nailing and intramedullary bone cement injection) was performed at lower extremity long bones in patients with multiple bone metastases with short life expectancy to get mechanical stability and local tumor control. We evaluated the usefulness of PS by clinical status, F-18-FDG PET-CT and bone scintigraphy (BS). METHODS: Patients comprised 15 patients (total 20 sites) who had undergone PS for the metastatic bone tumors of lower extremity long bones (femur and tibia). After percutaneous flexible nailing, bone cement was injected (mean amount=15.5±6.4 ml). Patients' clinical status was evaluated by visual analog scale (VAS). Qualitative assessment of PET-CT and BS was categorized by improved, stable and aggravated states of PS lesion. Quantitative assessment of PET-CT was performed by maximum and mean standardized uptake value (SUVmax and SUVmean). RESULTS: PS was performed in all of the patients without complication, and showed significant pain improvement of VAS (7.2±0.2 vs. 2.8±0.3, P<0.001). PS lesion showed improved state in 65% (13/20) and stable state in 35% (7/20). However, naive bony metastatic lesion showed mostly aggravated state in 90% (19/20) in the same patients, which was significantly different compared with PS lesion (P<0.001). In PS lesion, SUVmax (10.1±6.9 vs. 7.1±5.2, P=0.008) and SUVmean (6.2±4.8 vs. 4.6±3.7, P=0.008) showed significantly decreased uptake after PS. CONCLUSION: By PS in lower extremity long bones, patients can reduce regional pain, and has the possibility of local tumor control. PS can be performed for lower extremity bone metastasis in poor general condition to perform conventional intramedullary nailing.