Resveratrol suppresses the inflammatory responses of human gingival epithelial cells in a SIRT1 independent manner

BACKGROUND AND OBJECTIVE

In periodontitis, chronic infection by periodontopathic bacteria induces uncontrolled inflammation, which leads to periodontal tissue destruction. Human gingival epithelial cells (HGECs) constitute a critical first line of defense against periodontopathic bacteria, both as a physical barrier and as regulators of inflammation. Resveratrol, a polyphenol found in grapes and red wine, reportedly has anti-inflammatory properties. Therefore, we investigated the effects of resveratrol on the Porphyromonas gingivalis-induced inflammatory responses of HGECs and their mechanism.

MATERIAL AND METHODS

We stimulated the HGEC line, epi 4, with live or heat-killed P. gingivalis in the presence of resveratrol, and analyzed expressions of the interleukin-8, monocyte chemoattractant protein-1 and interleukin-1β genes. We determined the involvement of SIRT1 in the effect of resveratrol using sirtinol (a SIRT1 inhibitor) or SIRT1 knockdown. We also examined whether the effects were mediated by activation of AMP-activated kinase, suppression of reactive oxygen species, or inhibition of nuclear factor-κB (NF-κB).

RESULTS

Resveratrol treatment decreased the expression of inflammatory cytokines and slightly increased the expression of SIRT1. However, neither SIRT1 inhibition nor SIRT1 knockdown counteracted its anti-inflammatory effects. Although resveratrol did not affect AMP-activated kinase activation or reactive oxygen species production, it slightly suppressed NF-κB translocation when cells were stimulated with heat-killed P. gingivalis.

CONCLUSION

Resveratrol suppressed the inflammatory responses of P. gingivalis-stimulated HGECs, probably by inhibiting NF-κB signaling but independent of SIRT1.

Epithelial TRPV1 signaling accelerates gingival epithelial cell proliferation

Transient receptor potential cation channel subfamily V member 1 (TRPV1), a member of the calcium-permeable thermosensitive transient receptor potential superfamily, is a sensor of thermal and chemical stimuli. TRPV1 is activated by noxious heat (> 43°C), acidic conditions (pH < 6.6), capsaicin, and endovanilloids. This pain receptor was discovered on nociceptive fibers in the peripheral nervous system. TRPV1 was recently found to be expressed by non-neuronal cells, such as epithelial cells. The oral gingival epithelium is exposed to multiple noxious stimuli, including heat and acids derived from endogenous and exogenous substances; however, whether gingival epithelial cells (GECs) express TRPV1 is unknown. We show that both TRPV1 mRNA and protein are expressed by GECs. Capsaicin, a TRPV1 agonist, elevated intracellular Ca(2+) levels in the gingival epithelial cell line, epi 4. Moreover, TRPV1 activation in epi 4 cells accelerated proliferation. These responses to capsaicin were inhibited by a specific TRPV1 antagonist, SB-366791. We also observed GEC proliferation in capsaicin-treated mice in vivo. No effects were observed on GEC apoptosis by epithelial TRPV1 signaling. To examine the molecular mechanisms underlying this proliferative effect, we performed complementary (c)DNA microarray analysis of capsaicin-stimulated epi 4 cells. Compared with control conditions, 227 genes were up-regulated and 232 genes were down-regulated following capsaicin stimulation. Several proliferation-related genes were validated by independent experiments. Among them, fibroblast growth factor-17 and neuregulin 2 were significantly up-regulated in capsaicin-treated epi 4 cells. Our results suggest that functional TRPV1 is expressed by GECs and contributes to the regulation of cell proliferation.

Endoplasmic reticulum stress response and bone loss in experimental periodontitis in mice

BACKGROUND AND OBJECTIVE

Endoplasmic reticulum (ER) stress is the cell response that activates the unfolded protein response (UPR) pathway in a variety of conditions, such as inflammation and bone metabolism. The UPR may be associated with the pathogenesis of periodontal disease because the disease is inflammatory in nature, and alveolar bone resorption is a characteristic feature of the disease. However, the relationship between ER stress and alveolar bone resorption observed in periodontal disease remains elusive.

MATERIAL AND METHODS

C57BL/6 mice were orally administered Porphyromonas gingivalis, a representative periodontopathic bacterium, in the presence or absence of a chemical chaperone, 4-phenylbutyrate (4-PBA). The gene expression of UPR-related molecules and cytokines in gingival tissues were analyzed using real-time polymerase chain reaction, and alveolar bone resorption and osteoclast numbers were evaluated histologically. The in vitro effect of 4-PBA on the differentiation of mouse bone marrow cells induced by receptor activator of nuclear factor-κB ligand in the presence of macrophage colony-stimulating factor was analyzed.

RESULTS

The gene expression levels of UPR-related molecules and proinflammatory cytokines and alveolar bone resorption were significantly increased in P. gingivalis-administered mice. UPR-related gene expression and alveolar bone resorption were significantly suppressed by the administration of 4-PBA. However, no effect of 4-PBA was observed for proinflammatory cytokine expression in gingival tissues. Osteoclastic differentiation of bone marrow cells was also suppressed by 4-PBA with a concomitant reduction in the gene expression of cathepsin K and tartrate-resistant alkaline phosphatase genes.

CONCLUSION

ER stress induced by oral administration of P. gingivalis is involved in alveolar bone resorption independent of inflammatory cytokines in mice.

Zur Theorie der Elementarteilchen

The equation is analysed with respect to the following consequences. I the group theoretical structure of the equation is studied. The equation is invariant under a number of continous transformations: the inhomogeneous Lorentzgroup, the transformations of PAULI, GÜRSEY and TOUSCHEK, and the scale transformation [ϰ→η x or ψ → η⅔ψ(ϰη, l η)]. The PAULI-GÜRSEY group is used for the interpretation of the isospin; the γ5-transformation of TOUSCHEK establishes a quantum number IN, and the scale transformation leads to a quantum number IN, which both are connected with the baryonic and the leptonic number. The strangeness s=lN-lQ is suggested to be connected with the discrete groups of the equation and could then be defined and conserved only modulo 4. Of the discrete groups only the well known transformations P, C and T and the reversal of l (l→ - l) are briefly discussed. In II the vacuum expectation values of products of two field operators are studied. These values are considered to be only in a first approximation invariant under the Isospingroup. The deviations from the PAULI-GÜRSEY symmetry in higher approximations are supposed to be due to the replacement of the state “vacuum” by an idealised state “world”, which possesses an infinite isospin; the strange particles are consequently interpreted as states which “borrow” an isospin 1/2 or 1 from the ground state “world”. The concept of “One particle-wavefunctions” is discussed in III. The fermions of finite mass belong to wavefunctions obeying a KLEIN-Gordon-spinor equation instead of a DIRAC equation. The connection with the conventional formalism of the DIRAC equation is treated in detail. The process of ^-conjugation springing from these discussions is used for a variation of the methods of approximation needed later on for the determination of mass values and the pion-nucleon coupling constant. In IV the TAMM-DANCOFF method is applied in two different forms for an estimate of the masses of nucleons and π-mesons. The masses and the symmetry properties of the particles agree qualitatively with the experimental results. The scattering of π-mesons from nucleons is treated in V by a method related more closely to the BETHE-SALPETER theory than to the TAMM-DANCOFF method; the theory leads to a relativistic pseudovector-coupling as the main term and to a value of the coupling constant of the right order of magnitude. In VI the interaction for β-decay is analysed with respect to its symmetry properties. The theory leads to cs =cT= cp=0 and, in the lowest approximation, to cA= -cV, while in higher approximations the ratio cA/cv will be somewhat altered. In VII some mathematical questions are discussed that have been raised by PAULI at the Geneva conference 1958. For the renormalized operators of the Lee model an integro-differential equation is given, that contains only the arbitrarily small time interval Δt. It is further shown in detail why a linear differential equation leads to δ-functions on the light cone for the propagator, while a non linear differential equation can produce there a different kind of singularity.

Sublingual Vaccine with GroEL Attenuates Atherosclerosis

Autoimmune responses to heat-shock protein 60 (HSP60) contribute to the progression of atherosclerosis, whereas immunization with HSP60 may induce atheroprotective responses. We assessed the capacity of an atheroprotective vaccine that targeted a recombinant HSP60 from Porphyromonas gingivalis (rGroEL) to induce a protective mucosal immune response. Female apolipoprotein E-deficient spontaneously hyperlipidemic (Apoeshl) mice received sublingual delivery of rGroEL prior to P. gingivalis 381 injection. The animals were euthanized 16 weeks later. Sublingual immunization with rGroEL induced significant rGroEL-specific serum IgG responses. Antigen-specific cells isolated from spleen produced significantly high levels of IL-10 and IFN-γ after antigen re-stimulation in vitro. Flow cytometric analysis indicated that the frequencies of both IL-10+ and IFN-γ+ CD4+ Foxp3+ cells increased significantly in submandibular glands (SMG). Furthermore, sublingual immunization with rGroEL significantly reduced atherosclerosis lesion formation in the aortic sinus and decreased serum CRP, MCP-1, and ox-LDL levels. These findings suggest that sublingual immunization with rGroEL is associated with the increase of IFNγ+ or IL-10+ Foxp3+ cells in SMG and a systemic humoral response, which could be an effective strategy for the prevention of naturally occurring or P. gingivalis-accelerated atherosclerosis.

Chemistry of odortypes in mice: Fractionation and bioassay

Mice can discriminate samples of urine obtained from two groups of inbred mice that are genetically identical except in their major histocompatibility complex (MHC) haplotype (congenic mice), whereas they cannot distinguish urine samples from two genetically identical groups of mice. Chemical fractions of urine samples obtained from MHC congenic mice were tested in a Y-maze olfactometer using a method modified to accommodate the bioassay to chemical fractions that might differ in sensory properties from the unfractionated urine. Fractions depleted in protein by several methods were consistently discriminable by mice in the Y maze, providing a direct demonstration that the airborne MHC genotype information can be conveyed by volatile compounds alone.

New methods for species and sex determination in three sympatric Mustelids, Mustela itatsi, Mustela sibirica and Martes melampus

We developed novel species and sex determination methods for three Japanese mustelid species. We used DDX3Y to determine sex and generated a primer set to amplify both DDX3X and DDX3Y DNA in Mustela itatsi, M. sibirica and Martes melampus. To determine species and sex simultaneously, we generated fluorescence-labelled primers that give different fragment lengths at D-loop, DDX3X and DDX3Y of these three species using a DNA sequencer.

Selective adsorption of bilirubin against albumin to oxidized single-wall carbon nanohorns

Bilirubin adsorption capacities of single-wall carbon nanohorns (SWNHs) are investigated to develop an efficient adsorbent in plasma apheresis. Pristine, thermally oxidized and H2O2-oxidized SWNHs are examined and it is demonstrated that higher oxidization levels of the SWNHs enhance bilirubin adsorption capacity owing to increase in their dispersibility and formation of nanoscaled holes on the SWNH walls. Under co-existance of albumin molecules, the bilirubin adsorption capacity of the SWNHs increases with the oxidation level whereas the albumin adsorption capacity is kept small. Bilirubin is selectively adsorbed to the SWNHs, especially to the SWNHs with high oxidation levels, against albumin. This selectivity is maintained under high-concentrations of albumin in the near-clinical environment.

Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk of bovine mastitis

The aim of this study was to evaluate the presence of methicillin-resistant Staphylococcus aureus (MRSA) among a (S. aureus) collection (n = 430) isolated from milk of cows suffering from mastitis in Belgium and to compare their genotypic as well as phenotypic characteristics. Pulsed field gel electrophoresis (PFGE) and PCR-based typing techniques (MLST, spa, SCCmec, and agr typing) have been applied and supplemented by capsule serotyping, biofilm production quantification and antimicrobial susceptibility testing. Nineteen MRSA were isolated. Seven distinct ApaI PFGE patterns were observed. All isolates, except one, were identified as ST398 strains. Three spa types (t011, t567 and t108) and two SCCmec types (IV and V) were identified. All isolates belonged to agr type I and capsule type 5 and were Panton-Valentine leukocidin (PVL) negative. All isolates produced biofilm in TSBglc , whereas the majority did not in milk serum. Twelve resistance patterns were observed, with almost two-thirds of the isolates being resistant to at least six antibiotics, including penicillin and tetracycline. Our study confirms that the emerging ST398 LA-MRSA clone has attained Belgian cattle. With regard to genotypic and phenotypic typing, the 19 MRSA isolated in this study form a homogenous group and do not differ much from one another, neither from what has been previously described.

Natural killer T cells mediate alveolar bone resorption and a systemic inflammatory response in response to oral infection of mice with Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

T and B cells are known to be involved in the disease process of periodontitis. However, the role of natural killer T cells in the pathogenesis of periodontitis has not been clarified.

MATERIALS AND METHODS

To examine the role of these cells, C57BL/6J (wild-type), CD1d(-/-) and α-galactosylceramide (αGC)-stimulated wild-type mice were orally infected with Porphyromonas gingivalis strain W83.

RESULTS

Apart from CD1d(-/-) mice, the level of alveolar bone resorption was elevated by the infection and was further accelerated in αGC-stimulated mice. The infection induced elevated levels of serum amyloid A and P. gingivalis-specific IgG in the sera, although the degree of elevation was much smaller in the CD1d(-/-) mice. Infection-induced RANKL elevation was only observed in αGC-stimulated mice. Although the cytokines produced by splenocytes were mainly T-helper 1 type in wild-type mice, those in αGC-stimulated mice were predominantly T-helper 2 type. In the liver, the infection demonstrated no effect on the gene expression for interferon-γ, interleukin-4 and RANKL except αGC-stimulated mice in which the infection upregulated the gene expressions.

CONCLUSION

This study is the first to show that natural killer T cells upregulated systemic and local inflammatory responses induced by oral infection with P. gingivalis, thereby contributing to the progression of alveolar bone resorption.

Hazard Evaluation Support System (HESS) for predicting repeated dose toxicity using toxicological categories

Repeated dose toxicity (RDT) is one of the most important hazard endpoints in the risk assessment of chemicals. However, due to the complexity of the endpoints associated with whole body assessment, it is difficult to build up a mechanistically transparent structure-activity model. The category approach, based on mechanism information, is considered to be an effective approach for data gap filling for RDT by read-across. Therefore, a library of toxicological categories was developed using experimental RDT data for 500 chemicals and mechanistic knowledge of the effects of these chemicals on different organs. As a result, 33 categories were defined for 14 types of toxicity, such as hepatotoxicity, hemolytic anemia, etc. This category library was then incorporated in the Hazard Evaluation Support System (HESS) integrated computational platform to provide mechanistically reasonable predictions of RDT values for untested chemicals. This article describes the establishment of a category library and the associated HESS functions used to facilitate the mechanistically reasonable grouping of chemicals and their subsequent read-across.

Categorization of nitrobenzenes for repeated dose toxicity based on adverse outcome pathways

Adoption of the data-gap filling method for complex endpoints such as repeated dose toxicity (RDT) and reproductive/developmental toxicity is one of the most important issues affecting international chemical management at present. A categorization method based on adverse outcome pathways (AOPs) has recently been investigated for such complex endpoints. In this paper, we report results of the categorization of nitrobenzenes for RDT based on the AOPs obtained by analysing the detailed RDT test reports for 24 different nitrobenzenes already evaluated. In most RDT testing of nitrobenzenes without hydroxyl groups or acid groups, findings related to haemolytic anaemia and liver effects were observed at low dosages. It was, therefore, possible to assume common AOPs for haemolytic anaemia and liver effects induced by these nitrobenzenes. As a result, a group of nitrobenzenes was defined as a single category for both haemolytic anaemia and liver effects, respectively, based on these AOPs.

IFPA Meeting 2012 Workshop Report II: epigenetics and imprinting in the placenta, growth factors and villous trophoblast differentiation, role of the placenta in regulating fetal exposure to xenobiotics during pregnancy, infection and the placenta

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2012 there were twelve themed workshops, four of which are summarized in this report. These workshops related to various aspects of placental biology: 1) epigenetics and imprinting in the placenta; 2) growth factors and villous trophoblast differentiation; 3) role of the placenta in regulating fetal exposure to xenobiotics during pregnancy; 4) infection and the placenta.

Differential carbohydrate expression in tumorigenic vs nontumorigenic prostate cell-lines

Death from prostate cancer is most frequently a result of metastatic disease. A key step in the process of metastasis is the attachment of circulatory tumor cells to target organ endothelium. This process is thought to be mediated by lectins, a class of cell surface proteins that bind two or more carbohydrate groups. Using fluorescent microscopy and fluorescein isothiocyanate (FITC) conjugated lectins, the presence of various carbohydrates was examined in the following tumorigenic and non-tumorigenic cell lines: rat prostate epithelial (EPYP-2, EPYP-1), rat prostate endothelial (YPEN-2, YPEN-1, YPEN-2PV), Dunning rat prostate cancer cell lines (MLL, ML, AT6.3, AT.1, AT2.1, GP9F3), and three tumorigenic human prostate cell lines (LNCaP, PC3, PC3 bone). The lectin Triticum vulgaris (WGA) was found to readily bind the carbohydrates N-acetylglucosamine and sialic acid on the plasma membrane of tumorigenic cell lines. Interestingly, WGA bound carbohydrates located to the nucleus and cytoplasm in non-tumorigenic cell lines, indicating that N-acetylglucosamine and sialic acid residues are preferentially expressed on the cell membrane of prostate cancer cells. Lectin staining patterns in cell lines of varying metastatic potential revealed no significant difference between highly metastatic vs. low metastatic cell lines. Observations revealed an absence of N-acetylgalactosamine and L-fucose in all rat Dunning, epithelial and endothelial cell lines as well as all human prostate cancer cell lines except for the androgen insensitive human prostate cancer cell line PC3, in which L-fucose residues were detected in the nucleus and on the plasma membrane. PC3 bone cells, which metastasized selectively to bone, demonstrated the presence of galactose residues whereas PC3 cells did not, suggesting that preference for target organ endothelium may be influenced by the expression of carbohydrate residues. These data indicate that differential carbohydrate expression may play an important role in prostate cancer biology.

Assessment of the Plasma/Serum IgG Test to Screen for Periodontitis

Chronic periodontitis is a silent infectious disease prevalent worldwide and affects lifestyle-related diseases. Therefore, efficient screening of patients is essential for general health. This study was performed to evaluate prospectively the diagnostic utility of a blood IgG antibody titer test against periodontal pathogens. Oral examination was performed, and IgG titers against periodontal pathogens were measured by ELISA in 1,387 individuals. The cut-off value of the IgG titer was determined in receiver operating characteristic curve analysis, and changes in periodontal clinical parameters and IgG titers by periodontal treatment were evaluated. The relationships between IgG titers and severity of periodontitis were analyzed. The best cut-off value of IgG titer against Porphyromonas gingivalis for screening periodontitis was 1.682. Both clinical parameters and IgG titers decreased significantly under periodontal treatment. IgG titers of periodontitis patients were significantly higher than those of healthy controls, especially in those with sites of probing pocket depth over 4 mm. Multiplied cut-off values were useful to select patients with severe periodontitis. A blood IgG antibody titer test for Porphyromonas gingivalis is useful to screen hitherto chronic periodontitis patients (ClinicalTrials.gov number NCT01658475).

HbA(1c) variability and the development of microalbuminuria in type 2 diabetes: Tsukuba Kawai Diabetes Registry 2

AIMS/HYPOTHESIS

The aim of this study was to examine the association between HbA(1c) variability and the development of microalbuminuria as defined by an albumin/creatinine ratio ≥ 3.4 mg/mmol (≥ 30 mg/g) in at least two of three consecutive urine samples in Japanese patients with type 2 diabetes.

METHODS

HbA(1c) level was measured in 812 serially registered normoalbuminuric adults aged 21-79 years with type 2 diabetes. After registration, a 1-year period to establish baseline values for mean HbA(1c) and HbA(1c) variability (measured as the intrapersonal SD of serially collected HbA(1c)) was decided upon. The association between HbA(1c) variability and the development of microalbuminuria was determined by Cox regression analysis after adjustment for other risk factors for microalbuminuria.

RESULTS

Microalbuminuria occurred in 193 patients during the observation period of (mean ± SD) 4.3 ± 2.7 years. Even after adjustment for mean HbA(1c), HbA(1c) variability was a significant predictor of microalbuminuria independently of the mean HbA(1c); the HR for every 1% (95% CI) increase in mean HbA(1c) was 1.22 (1.06, 1.40) (p = 0.005), and that for HbA(1c) variability was 1.35 (1.05, 1.72) (p = 0.019). The effects of these two variables were quite similar when 1 SD was used; the HR for every 1 SD increase (95% CI) in HbA(1c) was 1.23 (1.07, 1.43) (p = 0.005), and that for HbA(1c) variability was 1.20 (1.03, 1.39) (p = 0.019).

CONCLUSIONS/INTERPRETATION

HbA(1c) variability affects the development of microalbuminuria independently of mean HbA(1c) in type 2 diabetes. Further studies should be performed to evaluate the influence of HbA(1c) variability on other complications and in individuals of other ethnicities with type 2 diabetes.