Omics-Based Mathematical Modeling Unveils Pathogenesis of Periodontitis in an Experimental Murine Model.

Periodontitis is a multifactorial disease that progresses via dynamic interaction between bacterial and host-derived genetic factors. The recent trend of omics analyses has discovered many periodontitis-related risk factors. However, how much the individual factor affects the pathogenesis of periodontitis is still unknown. This article aims to identify multiple key factors related to the pathogenesis of periodontitis and quantitatively predict the influence of each factor on alveolar bone resorption by omics analysis and mathematical modeling. First, we induced periodontitis in mice (n = 3 or 4 at each time point) by tooth ligation. Next, we assessed alveolar bone resorption by micro-computed tomography, alterations in the gene expression by RNA sequencing, and the microbiome of the gingivae by 16S ribosomal RNA sequencing during disease pathogenesis. Omics data analysis identified key players (bacteria and molecules) involved in the pathogenesis of periodontitis. We then constructed a mathematical model of the pathogenesis of periodontitis by employing ordinary differential equations that described the dynamic regulatory interplay between the key players and predicted the alveolar bone integrity as output. Finally, we estimated the model parameters using our dynamic experimental data and validated the model prediction of influence on alveolar bone resorption by in vivo experiments. The model predictions and experimental results revealed that monocyte recruitment induced by bacteria-mediated Toll-like receptor activation was the principal reaction regulating alveolar bone resorption in a periodontitis condition. On the other hand, osteoblast-mediated osteoclast differentiation had less impact on bone integrity in a periodontitis condition.

Signature of spin-phonon coupling driven charge density wave in a kagome magnet.

The intertwining between spin, charge, and lattice degrees of freedom can give rise to unusual macroscopic quantum states, including high-temperature superconductivity and quantum anomalous Hall effects. Recently, a charge density wave (CDW) has been observed in the kagome antiferromagnet FeGe, indicative of possible intertwining physics. An outstanding question is that whether magnetic correlation is fundamental for the spontaneous spatial symmetry breaking orders. Here, utilizing elastic and high-resolution inelastic x-ray scattering, we observe a c-axis superlattice vector that coexists with the 2[Formula: see text]2[Formula: see text]1 CDW vectors in the kagome plane. Most interestingly, between the magnetic and CDW transition temperatures, the phonon dynamical structure factor shows a giant phonon-energy hardening and a substantial phonon linewidth broadening near the c-axis wavevectors, both signaling the spin-phonon coupling. By first principles and model calculations, we show that both the static spin polarization and dynamic spin excitations intertwine with the phonon to drive the spatial symmetry breaking in FeGe.

Oxidative Stress Inhibits Endotoxin Tolerance and May Affect Periodontitis.

Periodontal disease is caused by dysbiosis of the dental biofilm and the host inflammatory response. Various pathogenic factors, such as proteases and lipopolysaccharides (LPSs) produced by bacteria, are involved in disease progression. Endotoxin tolerance is a function of myeloid cells, which sustain inflammation and promote tissue regeneration upon prolonged stimulation by endotoxins such as LPS. The role of endotoxin tolerance is gaining attention in various chronic inflammatory diseases, but its role in periodontal disease remains elusive. Oxidative stress, one of the major risk factors for periodontal disease, promotes disease progression through various mechanisms, of which only some are known. The effect of oxidative stress on endotoxin tolerance has not yet been studied, and we postulated that endotoxin tolerance regulation may be an additional mechanism through which oxidative stress influences periodontal disease. This study aimed to reveal the effect of oxidative stress on endotoxin tolerance and that of endotoxin tolerance on periodontitis progression. The effect of oxidative stress on endotoxin tolerance was analyzed in vitro using peritoneal macrophages of mice and hydrogen peroxide (H2O2). The results showed that oxidative stress inhibits endotoxin tolerance induced by Porphyromonas gingivalis LPS in macrophages, at least partially, by downregulating LPS-elicited negative regulators of Toll-like receptor (TLR) signaling. A novel oxidative stress mouse model was established using SMP30KO mice incapable of ascorbate biosynthesis. Using this model, we revealed that oxidative stress impairs endotoxin tolerance potential in macrophages in vivo. Furthermore, gingival expression of endotoxin tolerance-related genes and TLR signaling negative regulators was decreased, and symptoms of ligature-induced periodontitis were aggravated in the oxidative stress mouse model. Our findings suggest that oxidative stress may contribute to periodontitis progression through endotoxin tolerance inhibition.

Matrix Vesicle-Mediated Mineralization and Potential Applications.

Hard tissues, including the bones and teeth, are a fundamental part of the body, and their formation and homeostasis are critically regulated by matrix vesicle-mediated mineralization. Matrix vesicles have been studied for 50 y since they were first observed using electron microscopy. However, research progress has been hampered by various technical barriers. Recently, there have been great advancements in our understanding of the intracellular biosynthesis of matrix vesicles. Mitochondria and lysosomes are now considered key players in matrix vesicle formation. The involvement of mitophagy, mitochondrial-derived vesicles, and mitochondria-lysosome interaction have been suggested as potential detailed mechanisms of the intracellular pathway of matrix vesicles. Their main secretion pathway may be exocytosis, in addition to the traditionally understood mechanism of budding from the outer plasma membrane. This basic knowledge of matrix vesicles should be strengthened by novel nano-level microscopic technologies, together with basic cell biologies, such as autophagy and interorganelle interactions. In the field of tissue regeneration, extracellular vesicles such as exosomes are gaining interest as promising tools in cell-free bone and periodontal regenerative therapy. Matrix vesicles, which are recognized as a special type of extracellular vesicles, could be another potential alternative. In this review, we outline the recent significant progress in the process of matrix vesicle-mediated mineralization and the potential clinical applications of matrix vesicles for tissue regeneration.

Outcomes with durvalumab after chemoradiotherapy in stage IIIA-N2 non-small-cell lung cancer: an exploratory analysis from the PACIFIC trial.

BACKGROUND: The phase III PACIFIC trial (NCT02125461) established consolidation durvalumab as standard of care for patients with unresectable, stage III non-small-cell lung cancer (NSCLC) and no disease progression following chemoradiotherapy (CRT). In some cases, patients with stage IIIA-N2 NSCLC are considered operable, but the relative benefit of surgery is unclear. We report a post hoc, exploratory analysis of clinical outcomes in the PACIFIC trial, in patients with or without stage IIIA-N2 NSCLC. MATERIALS AND METHODS: Patients with unresectable, stage III NSCLC and no disease progression after ≥2 cycles of platinum-based, concurrent CRT were randomized 2 : 1 to receive durvalumab (10 mg/kg intravenously; once every 2 weeks for up to 12 months) or placebo, 1-42 days after CRT. The primary endpoints were progression-free survival (PFS; assessed by blinded independent central review according to RECIST version 1.1) and overall survival (OS). Treatment effects within subgroups were estimated by hazard ratios (HRs) from unstratified Cox proportional hazards models. RESULTS: Of 713 randomized patients, 287 (40%) had stage IIIA-N2 disease. Baseline characteristics were similar between patients with and without stage IIIA-N2 NSCLC. With a median follow-up of 14.5 months (range: 0.2-29.9 months), PFS was improved with durvalumab versus placebo in both patients with [HR = 0.46; 95% confidence interval (CI), 0.33-0.65] and without (HR = 0.62; 95% CI 0.48-0.80) stage IIIA-N2 disease. Similarly, with a median follow-up of 25.2 months (range: 0.2-43.1 months), OS was improved with durvalumab versus placebo in patients with (HR = 0.56; 95% CI 0.39-0.79) or without (HR = 0.78; 95% CI 0.57-1.06) stage IIIA-N2 disease. Durvalumab had a manageable safety profile irrespective of stage IIIA-N2 status. CONCLUSIONS: Consistent with the intent-to-treat population, treatment benefits with durvalumab were confirmed in patients with stage IIIA-N2, unresectable NSCLC. Prospective studies are needed to determine the optimal treatment approach for patients who are deemed operable.

Giant phonon anomalies in the proximate Kitaev quantum spin liquid α-RuCl3.

The Kitaev quantum spin liquid epitomizes an entangled topological state, for which two flavors of fractionalized low-energy excitations are predicted: the itinerant Majorana fermion and the Z2 gauge flux. It was proposed recently that fingerprints of fractional excitations are encoded in the phonon spectra of Kitaev quantum spin liquids through a novel fractional-excitation-phonon coupling. Here, we detect anomalous phonon effects in α-RuCl3 using inelastic X-ray scattering with meV resolution. At high temperature, we discover interlaced optical phonons intercepting a transverse acoustic phonon between 3 and 7 meV. Upon decreasing temperature, the optical phonons display a large intensity enhancement near the Kitaev energy, JK~8 meV, that coincides with a giant acoustic phonon softening near the Z2 gauge flux energy scale. These phonon anomalies signify the coupling of phonon and Kitaev magnetic excitations in α-RuCl3 and demonstrates a proof-of-principle method to detect anomalous excitations in topological quantum materials.

Radial Spin Texture in Elemental Tellurium with Chiral Crystal Structure.

The chiral crystal is characterized by a lack of mirror symmetry and inversion center, resulting in the inequivalent right- and left-handed structures. In the noncentrosymmetric crystal structure, the spin and momentum of electrons are expected to be locked in the reciprocal space with the help of the spin-orbit interaction. To reveal the spin textures of chiral crystals, we investigate the spin and electronic structure in a p-type semiconductor, elemental tellurium, with the simplest chiral structure by using spin- and angle-resolved photoemission spectroscopy. Our data demonstrate that the highest valence band crossing the Fermi level has a spin component parallel to the electron momentum around the Brillouin zone corners. Significantly, we have also confirmed that the spin polarization is reversed in the crystal with the opposite chirality. The results indicate that the spin textures of the right- and left-handed chiral crystals are hedgehoglike, leading to unconventional magnetoelectric effects and nonreciprocal phenomena.

Total tumour volume as a prognostic factor in patients with resectable colorectal cancer liver metastases.

BACKGROUND: Although total tumour volume (TTV) may have prognostic value for hepatic resection in certain solid cancers, its importance in colorectal liver metastases (CRLM) remains unexplored. This study investigated its prognostic value in patients with resectable CRLM. METHOD: This was a retrospective review of patients who underwent hepatic resection for CRLM between 2008 and 2017 in a single institution. TTV was measured from CT images using three-dimensional construction software; cut-off values were determined using receiver operating characteristic (ROC) curve analyses. Potential prognostic factors, overall survival (OS) and recurrence-free survival (RFS) were determined using multivariable and Kaplan-Meier analyses. RESULTS: Some 94 patients were included. TTV cut-off values for OS and RFS were 100 and 10 ml respectively. Right colonic primary tumours, primary lymph node metastasis and bilobar liver metastasis were included in the multivariable analysis of OS; a TTV of 100 ml or above was independently associated with poorer OS (hazard ratio (HR) 6·34, 95 per cent c.i. 2·08 to 17·90; P = 0·002). Right colonic primary tumours and primary lymph node metastasis were included in the RFS analysis; a TTV of 10 ml or more independently predicted poorer RFS (HR 1·90, 1·12 to 3·57; P = 0·017). The 5-year OS rate for a TTV of 100 ml or more was 41 per cent, compared with 67 per cent for a TTV below 100 ml (P = 0·006). Corresponding RFS rates with TTV of 10 ml or more, or less than 10 ml, were 14 and 58 per cent respectively (P = 0·009). A TTV of at least 100 ml conferred a higher rate of unresectable initial recurrences (12 of 15, 80 per cent) after initial hepatic resection. CONCLUSION: TTV was associated with RFS and OS after initial hepatic resection for CRLM; TTV of 100 ml or above was associated with a higher rate of unresectable recurrence.

ANTECEDENTES: Aunque el volumen total del tumor (total tumour volume, TTV) puede tener valor pronóstico tras la resección hepática (hepatic resection, HR) en algunas neoplasias sólidas, no se conoce su importancia en las metástasis hepáticas de cáncer colorrectal (colorectal liver metastases, CRLMs). Este estudio analizó el valor pronóstico del TTV en pacientes con CRLMs resecables. MÉTODOS: Revisión retrospectiva de pacientes a los que se realizó una HR por CRLMs entre 2008 y 2017 en un solo centro. El TTV se estimó a partir de imágenes de tomografía computarizada utilizando un programa de reconstrucción 3D; se determinaron los valores de corte mediante un análisis de las características operativas del receptor. Se identificaron los posibles factores pronósticos y se calcularon la supervivencia global (overall survival, OS) y la supervivencia libre de recidiva (recurence-free survival, RFS) mediante análisis multivariados y de Kaplan-Meier. RESULTADOS: Se incluyeron 94 pacientes. Los valores de corte del TTV para la OS y la RFS fueron de 100 mL y 10 mL, respectivamente. En el análisis multivariable para la OS, se incluyeron los tumores del colon derecho, las metástasis linfáticas primarias y la metástasis hepática bilobar; un TTV ≥ 100 mL se asoció de forma independiente con una peor OS (cociente de riesgos instantáneos, hazard ratio, HR, 6,34, i.c. del 95% 2,08-17,9; P = 0,002). En el anáisis para la RFS, se incluyeron tumores primarios de colon derecho y las metástasis linfáticas primarias; un TTV ≥ 10 mL predijo de forma independiente una peor RFS (HR 1,90, i.c. del 95% 1,12-3,57; P = 0,017). Las tasas de OS a los 5 años con TTVs ≥ 100 mL versus < 100 mL fueron del 41% versus 67% (P = 0,006); las tasas de RFS respecto a TTVs ≥ 10 mL versus < 10 mL fueron del 14% versus 58% (P = 0,009). Un TTV ≥ 100 mL conllevó una tasa más elevada (80%) de recidivas no resecables después de la HR inicial. CONCLUSIÓN: El TTV se asoció con la RFS y la OS tras la HR por CRLMs; unos valores ≥ 100 mL conllevan una tasa más elevada de recidiva irresecable.

Outcomes with durvalumab by tumour PD-L1 expression in unresectable, stage III non-small-cell lung cancer in the PACIFIC trial.

BACKGROUND: In the PACIFIC trial, durvalumab significantly improved progression-free and overall survival (PFS/OS) versus placebo, with manageable safety, in unresectable, stage III non-small-cell lung cancer (NSCLC) patients without progression after chemoradiotherapy (CRT). We report exploratory analyses of outcomes by tumour cell (TC) programmed death-ligand 1 (PD-L1) expression. PATIENTS AND METHODS: Patients were randomly assigned (2:1) to intravenous durvalumab 10 mg/kg every 2 weeks or placebo ≤12 months, stratified by age, sex, and smoking history, but not PD-L1 status. Where available, pre-CRT samples were tested for PD-L1 expression (immunohistochemistry) and scored at pre-specified (25%) and post hoc (1%) TC cut-offs. Treatment-effect hazard ratios (HRs) were estimated from unstratified Cox proportional hazards models (Kaplan-Meier-estimated medians). RESULTS: In total, 713 patients were randomly assigned, 709 of whom received at least 1 dose of study treatment durvalumab (n = 473) or placebo (n = 236). Some 451 (63%) were PD-L1-assessable: 35%, 65%, 67%, 33%, and 32% had TC ≥25%, <25%, ≥1%, <1%, and 1%-24%, respectively. As of 31 January 2019, median follow-up was 33.3 months. Durvalumab improved PFS versus placebo (primary-analysis data cut-off, 13 February 2017) across all subgroups [HR, 95% confidence interval (CI); medians]: TC ≥25% (0.41, 0.26-0.65; 17.8 versus 3.7 months), <25% (0.59, 0.43-0.82; 16.9 versus 6.9 months), ≥1% (0.46, 0.33-0.64; 17.8 versus 5.6 months), <1% (0.73, 0.48-1.11; 10.7 versus 5.6 months), 1%-24% [0.49, 0.30-0.80; not reached (NR) versus 9.0 months], and unknown (0.59, 0.42-0.83; 14.0 versus 6.4 months). Durvalumab improved OS across most subgroups (31 January 2019 data cut-off; HR, 95% CI; medians): TC ≥ 25% (0.50, 0.30-0.83; NR versus 21.1 months), <25% (0.89, 0.63-1.25; 39.7 versus 37.4 months), ≥1% (0.59, 0.41-0.83; NR versus 29.6 months), 1%-24% (0.67, 0.41-1.10; 43.3 versus 30.5 months), and unknown (0.60, 0.43-0.84; 44.2 versus 23.5 months), but not <1% (1.14, 0.71-1.84; 33.1 versus 45.6 months). Safety was similar across subgroups. CONCLUSIONS: PFS benefit with durvalumab was observed across all subgroups, and OS benefit across all but TC <1%, for which limitations and wide HR CI preclude robust conclusions.

Isotope Effect on Energy Confinement Time and Thermal Transport in Neutral-Beam-Heated Stellarator-Heliotron Plasmas.

The isotope effect on energy confinement time and thermal transport has been investigated for plasmas confined by a stellarator-heliotron magnetic field. This is the first detailed assessment of an isotope effect in a stellarator heliotron. Hydrogen and deuterium plasmas heated by neutral beam injection on the Large Helical Device have exhibited no significant dependence on the isotope mass in thermal energy confinement time, which is not consistent with the simple gyro-Bohm model. A comparison of thermal diffusivity for dimensionally similar hydrogen and deuterium plasmas in terms of the gyroradius, collisionality, and thermal pressure has clearly shown robust confinement improvement in deuterium to compensate for the unfavorable mass dependence predicted by the gyro-Bohm model.

The effects of resection of the peripheral branches of the posterior nasal nerves in the inferior turbinate, with special focus on olfactory dysfunction.

OBJECTIVE: There are few detailed studies about peripheral branch resection of the posterior nasal nerves in the inferior turbinate; thus, this study aimed to investigate this. METHODS: Patients who underwent submucosal turbinoplasty with or without resection of the peripheral branches of posterior nasal nerves in the inferior turbinate were included. RESULTS: The resection of the posterior nasal nerves with turbinoplasty significantly reduced detection and recognition thresholds on olfactory testing. The rhinorrhoea severity, detection threshold and recognition threshold were significantly lower after resection of the posterior nasal nerves with turbinoplasty than after turbinoplasty alone, although there were no significant differences between the two groups before surgery. CONCLUSION: This is the first study to show that the resection of the peripheral branches of the posterior nasal nerves in the inferior turbinate with turbinoplasty more effectively inhibits allergic symptoms compared with turbinoplasty alone. It also showed that the resection of the peripheral branches of the posterior nasal nerves can inhibit olfactory dysfunction.

Measurements of radial profile of hydrogen and deuterium density in isotope mixture plasmas using bulk charge exchange spectroscopy.

A bulk charge exchange spectroscopy system has been applied to measure the radial profiles of the hydrogen (H) and deuterium (D) density ratio in the isotope mixture plasma in a large helical device. Charge exchange lines of Hα and Dα are fitted by 4 Gaussian of H and D cold components and H and D hot components with 5 parameters by combining the measurement of plasma toroidal rotation velocity with carbon charge exchange spectroscopy. The radial profiles of the relative density of hydrogen and deuterium ions are derived from H and D hot components measured and the beam density calculated from beam attenuation calculation. A proof-of-principle experiment is performed by the H pellet and the D pellet injections into the H-D mixture plasma.

Effects of paraoxonase 1 on the cytodifferentiation and mineralization of periodontal ligament cells.

BACKGROUND AND OBJECTIVE: Single nucleotide polymorphisms (SNPs) of paraoxonase 1 (PON1) are known to be associated with the pathogenesis of osteoporosis and periodontitis. However, the effects of PON1 on the osteoblastic differentiation of periodontal ligament (PDL) cells are unclear. In this study, we examined the effects of PON1 on the osteoblastic differentiation of PDL cells, and analysed the role of PON1 SNPs on the pathogenesis of aggressive periodontitis (AgP) in the Japanese population. MATERIAL AND METHODS: Human PDL (HPDL) cells were exposed to the PON1 plasmid and PON1 inhibitor, 2-hydroxyquinoline, and cultured in mineralization medium. Expression of calcification-related genes and calcified nodule formation were assessed by real-time PCR, an alkaline phosphatase (ALPase) activity assay and Alizarin red staining. Sanger sequencing was performed to evaluate whether PON1 SNPs are associated with the pathogenesis of AgP in Japanese people. RESULTS: During osteoblastic differentiation of HPDL cells, expression of PON1 mRNA increased in a time-dependent manner. PON1 stimulated an increase in expression of mRNA for calcification-related genes, as well as ALPase activity. In contrast, 2-hydroxyquinoline clearly inhibited the expression of calcification-related genes, ALPase activity and calcified nodule formation in HPDL cells. Moreover, there was a statistically significant difference in the minor allele frequency of PON1 SNP rs854560 between the Japanese control database and patients with AgP in the Japanese population (P = .0190). CONCLUSION: PON1 induced cytodifferentiation and mineralization of HPDL cells, and PON1 SNP rs854560 may be associated with the pathogenesis of AgP in the Japanese population.

IL-11 contribution to tumorigenesis in an NRF2 addiction cancer model.

The interaction between cancer cells and their microenvironment is an important determinant of the pathological nature of cancers, particularly their tumorigenic abilities. The KEAP1-NRF2 system, originally identified as a critical defense mechanism against oxidative stress, is often dysregulated in various human cancers forming solid tumors, resulting in the aberrant activation of NRF2. Increased accumulation of NRF2 in cancers is strongly associated with the poor prognoses of cancer patients, including those with lung and breast cancers. Multiple lines of evidence suggest that aberrantly activated NRF2 in cancer cells drives their malignant progression and that the cancer cells consequently develop 'NRF2 addiction.' Although the downstream effectors of NRF2 that are responsible for cancer malignancy have been extensively studied, mechanisms of how NRF2 activation contributes to the aggressive tumorigenesis remains to be elucidated. In this study, we found a significant correlation between NRF2 and IL-11 status in breast cancer patients. Based on a recent report demonstrating that IL-11 is induced downstream of NRF2, we examined the significance of IL-11 in NRF2-driven tumorigenesis with a newly established NRF2 addiction cancer model. Expression of Il11 was elevated during the tumorigenesis of the NRF2 addiction cancer model, but intriguingly, it was hardly detected when the cancer model cells were cultured in vitro. These results imply that a signal originating from the microenvironment cooperates with NRF2 to activate Il11. To the best of our knowledge, this is the first report showing the influence of the microenvironment on the NRF2 pathway in cancer cells and the contribution of NRF2 to the secretory phenotypes of cancers. Disruption of Il11 in the NRF2 addiction cancer model remarkably inhibited the tumorigenesis, suggesting an essential role of IL-11 in NRF2-driven tumorigenesis. Thus, this study suggests that IL-11 is a potential therapeutic target for NRF2-addicted breast cancers.

Sinonasal organised haematoma: clinical features and successful application of modified transnasal endoscopic medial maxillectomy.

OBJECTIVE: Although organised haematoma often induces bone thinning and destruction similar to malignant diseases, the aetiology of organised haematoma and the optimal treatment remain unclear. This paper presents the clinical features of individuals with organised haematoma, and describes cases in which a novel modified approach was successfully applied for resection of organised haematoma in the maxillary sinus. METHOD: Pre-operative examination data were evaluated retrospectively. Modified transnasal endoscopic medial maxillectomy was employed. RESULTS: Fourteen patients with organised haematoma were treated. Contrast-enhanced computed tomography showed heterogeneous enhancement in all patients. Eight patients underwent modified transnasal endoscopic medial maxillectomy, without complications such as facial numbness, tooth numbness, facial tingling, lacrimation and eye discharge. Dissection of the apertura piriformis and anterior maxillary wall was not necessary for any of these eight patients. No recurrence was observed. CONCLUSION: Pre-operative examinations can be helpful in determining the likelihood of organised haematoma. Modified transnasal endoscopic medial maxillectomy appears to be a safe and effective method for organised haematoma resection.

Sphingomyelin Phosphodiesterase 3 Enhances Cytodifferentiation of Periodontal Ligament Cells.

Sphingomyelin phosphodiesterase 3 ( Smpd3), which encodes neutral sphingomyelinase 2 (nSMase2), is a key molecule for skeletal development as well as for the cytodifferentiation of odontoblasts and alveolar bone. However, the effects of nSMase2 on the cytodifferentiation of periodontal ligament (PDL) cells are still unclear. In this study, the authors analyzed the effects of Smpd3 on the cytodifferentiation of human PDL (HPDL) cells. The authors found that Smpd3 increases the mRNA expression of calcification-related genes, such as alkaline phosphatase (ALPase), type I collagen, osteopontin, Osterix (Osx), and runt-related transcription factor (Runx)-2 in HPDL cells. In contrast, GW4869, an inhibitor of nSMase2, clearly decreased the mRNA expression of ALPase, type I collagen, and osteocalcin in HPDL cells, suggesting that Smpd3 enhances HPDL cytodifferentiation. Next, the authors used exome sequencing to evaluate the genetic variants of Smpd3 in a Japanese population with aggressive periodontitis (AgP). Among 44 unrelated subjects, the authors identified a single nucleotide polymorphism (SNP), rs145616324, in Smpd3 as a putative genetic variant for AgP among Japanese people. Moreover, Smpd3 harboring this SNP did not increase the sphingomyelinase activity or mRNA expression of ALPase, type I collagen, osteopontin, Osx, or Runx2, suggesting that this SNP inhibits Smpd3 such that it has no effect on the cytodifferentiation of HPDL cells. These data suggest that Smpd3 plays a crucial role in maintaining the homeostasis of PDL tissue.

Decreased expression of E-cadherin by Porphyromonas gingivalis-lipopolysaccharide attenuates epithelial barrier function.

BACKGROUND AND OBJECTIVE: The gingival epithelium is a first line of defense against bacterial challenge. E-cadherin (E-cad) plays an important role in cell-cell adhesion as a barrier in the epithelium. Recently, a decrease in the expression of E-cad has been observed in inflamed gingival tissue. The aims of this study were to clarify the changes in E-cad expression and barrier function in human gingival epithelial cells stimulated with Porphyromonas gingivalis-lipopolysaccharide (P. gingivalis-LPS) and to evaluate the influence of these changes on the inflammatory reaction. Furthermore, to clarify the mechanism of the E-cad changes induced by P. gingivalis-LPS, we focused on reactive oxygen species (ROS) that are reported to induce a decrease in E-cad expression. MATERIAL AND METHODS: Human gingival epithelial cells were incubated in Humedia-KG2 in the presence or absence of P. gingivalis-LPS and antioxidants to analyze ROS involvement in P. gingivalis-LPS-induced E-cad changes. E-cad protein expression was analyzed by immunofluorescence staining. To investigate barrier function and inflammatory changes, we performed transport and cytokine assays using gingival epithelial cells and macrophages co-culture model in transwell plates. Medium containing 10 µg/mL P. gingivalis-LPS (transport substance) was added to the upper compartment, which harvested gingival epithelial cells, and medium without P. gingivalis-LPS was added to the lower compartment, which harvested macrophages. In the transport assay, P. gingivalis-LPS penetration was analyzed using the Limulus amebocyte lysate test. In the cytokine assay, we examined the change in tumor necrosis factor-α (TNF-α) production from the macrophages in the lower compartment using enzyme-linked immunosorbent assay. RESULTS: Expression of E-cad in human gingival epithelial cells was decreased by P. gingivalis-LPS, and the decrease in E-cad accelerated the penetration of P. gingivalis-LPS through the monolayer. In addition, the concentration of TNF-α was higher under the E-cad reduced monolayer. Antioxidants, particularly vitamin E and l-ascorbic acid 2-phosphate magnesium salt, inhibited the decrease in E-cad expression, penetration of P. gingivalis-LPS and increase in TNF-α. CONCLUSION: These results suggest that the decrease in E-cad caused by P. gingivalis-LPS leads to destruction of the epithelial barrier function in human gingival epithelial cells, and finally accelerates the inflammatory reaction under the barrier. Antioxidants, particularly vitamin E and l-ascorbic acid 2-phosphate magnesium salt, may restore the impaired function by scavenging ROS, which are related to the decrease in E-cad expression by P. gingivalis-LPS.

Hypoxia-inducible factor-1α inhibits interleukin-6 and -8 production in gingival epithelial cells during hypoxia.

BACKGROUND AND OBJECTIVE: Hypoxia has been widely studied in inflammatory diseases as it can modulate the inflammatory response, mainly via the hypoxia-inducible factor (HIF). However, little is known about the effects of hypoxia and the role of HIF in the inflammatory responses to periodontitis. In this study, we focused on the gingival epithelium that is exposed to relatively low levels of oxygen. We investigated whether hypoxic conditions have an impact on inflammatory responses in human gingival epithelial cells (HGECs). MATERIAL AND METHODS: Pimonidazole HCl, which accumulates in hypoxic cells, was administered intraperitoneally to C57BL/6 mice with or without Porphyromonas gingivalis infection. Immunohistochemistry was then performed to detect the hypoxic cells in periodontal tissue. Immortalized HGECs were cultured under hypoxic conditions with or without interleukin (IL)-1ß, and the expression levels of IL-6 and IL-8 were measured by real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. HIF-1α expression was detected by western blotting. The DNA-binding activity of HIF-1α was determined by a DNA-binding enzyme-linked immunosorbent assay. The involvement of HIF-1α in the hypoxic response was examined by transfection with HIF-1α siRNA. RESULTS: Immunohistochemistry revealed pimonidazole HCl accumulation in the gingival epithelium of both normal and P. gingivalis-infected mice, with a slightly stronger signal in the P. gingivalis-infected mice than in the normal mice. The IL-1ß-induced IL-6 and IL-8 production by HGECs was suppressed under hypoxic conditions. HIF-1α accumulated during hypoxia, and this accumulation was further enhanced by IL-1ß treatment. The hypoxia-dependent suppression of IL-6 and IL-8 expression was reversed by treating the cells with HIF-1α siRNA. CONCLUSION: Our results suggest that the gingival epithelium is exposed to low oxygen tension in periodontal tissue and that this hypoxic condition modulates the local inflammatory response of gingival epithelial cells in an HIF-1α-dependent manner.

Yes-associated protein mediates immune reprogramming in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a high degree of inflammation and profound immune suppression. Here we identify Yes-associated protein (Yap) as a critical regulator of the immunosuppressive microenvironment in both mouse and human PDAC. Within Kras:p53 mutant pancreatic ductal cells, Yap drives the expression and secretion of multiple cytokines/chemokines, which in turn promote the differentiation and accumulation of myeloid-derived suppressor cells (MDSCs) both in vitro and in vivo. Pancreas-specific knockout of Yap or antibody-mediated depletion of MDSCs promoted macrophage reprogramming, reactivation of T cells, apoptosis of Kras mutant neoplastic ductal cells and pancreatic regeneration after acute pancreatitis. In primary human PDAC, YAP expression levels strongly correlate with an MDSC gene signature, and high expression of YAP or MDSC-related genes predicts decreased survival in PDAC patients. These results reveal multifaceted roles of YAP in PDAC pathogenesis and underscore its promise as a therapeutic target for this deadly disease.