Advanced glycation end products increase expression of S100A8 and A9 via RAGE-MAPK in rat dental pulp cells

OBJECTIVE

Advanced glycation end products (AGE) are involved in the progression of diabetic complications. Although our previous reports show that AGE increased dental pulp calcification, AGE accumulation is also associated with inflammation. This study examined AGE effect on the expression of inflammation factors using rat dental pulp tissues and cell cultures.

MATERIALS AND METHODS

Receptor for AGE (RAGE), S100A8, S100A9, and interleukin (IL)-1β were selected as inflammation parameters. Rat dental pulp cells were cultured and treated with AGE, and the effects were determined by real-time PCR. An anti-RAGE antibody or MAPK pathway inhibitors (PD98059, SB203580, and SP60012) were used to investigate AGE signaling pathway.

RESULTS

The mRNA levels of RAGE, S100A8, S100A9, and IL-1β were higher in diabetic pulp tissues. AGE increased mRNA expressions of S100A8, S100A9, and IL-1β in cultured dental pulp cells. In the presence of anti-RAGE antibody, AGE did not increase in S100A8 or S100A9 expressions. The AGE-induced increases in S100A8 and S100A9 were inhibited by PD98059 and SB203580, respectively.

CONCLUSIONS

Advanced glycation end products increased mRNA expression of S100A8, S100A9, and IL-1β under diabetic pulp conditions, and AGE-induced increases in S100A8 and S100A9 expressions may be associated with the RAGE-MAPK signaling pathway.

Type 1 Pili Enhance the Invasion ofSalmonella braenderupandSalmonella typhimuriumto HeLa Cells

The relationship between type 1 pili-associated adhesion and invasion to HeLa cells by Salmonella braenderup and S. typhimurium was studied. When the clinical isolates of these strains were grown in L-broth, they showed both type 1 pili formation and mannose-sensitive adhesion to HeLa cells. On the other hand, the type 1 pili-defective mutants, which were obtained either by repeated subcultures on L-agar plates or by the transposon Tn1-insertion mutagenesis of the S. braenderup and S. typhimurium strains, concomitantly lost mannose-sensitive adhesion to HeLa cells. When the HeLa cells were incubated with Salmonella, the type 1 piliated strains invaded the HeLa cells with much higher infection rate than did the type 1 pili-defective strains. The invasion of type 1 piliated strains to HeLa cells was markedly inhibited in the presence of D-mannose. The infectivity of the strain, which lost type 1 pili but still had mannose-resistant adhesion, was slightly higher than that of the strains defective in both mannose-sensitive and mannose-resistant adhesion. These results suggested that type 1 pili have a role in enhancing the invasion of S. braenderup and S. typhimurium to HeLa cells.

Flavonoids as potential anti-hepatocellular carcinoma agents: recent approaches using HepG2 cell line

Numerous studies have documented that in cancer therapy flavonoids extracted from traditional Chinese medicine have anti-tumor activity or can enhance efficiency of chemotherapy in combination with chemotherapeutics. Thus, an awareness of flavonoids is needed by physicians and medical researchers. This review provides evidence about anti-hepatocellular carcinoma activity of flavonoids. First, as a common employed in vitro model, profile of HepG2 is shown. Second, the intracellular signaling pathways induced by flavonoids which inhibit the HepG2 cell line are summarized. Third, study situation of anti-HBV/HCV activity of flavonoids is shown. Our review is aimed at providing an understanding of anti-HBV/HCV activity and anti-HCC mechanisms of flavonoids, and an outlook on flavonoids application on cancer therapy.

The expression and function of Toll-like receptors 3 and 9 in human colon carcinoma

Toll-like receptors (TLRs) are pattern-recognition receptors that are important in immune signaling. TLR recognition of various viral components including double-stranded RNA (TLR3) and unmethylated CpG-DNA (TLR9) plays a crucial role in cell survival. However, TLR expression and function in colon carcinoma cells are not well clarified. We investigated the expression of TLR3 and TLR9 in colon carcinoma cells using immunohistochemical methods. The function of TLR3 and TLR9 signaling in carcinoma cell lines was studied by direct cell stimulation with, or by cell transfection of, polyinosinic-polycytidylic acid (Poly I:C), a synthetic form of dsRNA, and by cell stimulation with CpG-oligodeoxynucleotides (ODNs), respectively. Positive TLR3 and TLR9 immunohistochemical staining was observed in 91 and 86% of human hepatocellular carcinoma (HCC) tissues, respectively. Cell surface stimulation of TLR3 with Poly I:C did not affect cell viability but it did activate NF-κB activity. By contrast, stimulation of intracellular TLRs with transfected Poly I:C significantly induced apoptosis. Cell surface stimulation of TLR9 with CpG-ODNs promoted cell proliferation, and, furthermore, these CpG-ODN TLR9 agonists reduced the cytotoxicity of the anticancer drug adriamycin. Cell surface expression of TLR3 and TLR9 in colon carcinoma cells plays an important role in cell survival. In addition, the proapoptotic activity of intracellularly expressed TLR3 may provide the possibility of using TLR3 agonists as novel clinical cytotoxic agents against colon carcinoma cells.

Efficacy and immunomodulatory actions of ONO-4641, a novel selective agonist for sphingosine 1-phosphate receptors 1 and 5, in preclinical models of multiple sclerosis

ONO-4641 is a next-generation sphingosine 1-phosphate (S1P) receptor agonist selective for S1P receptors 1 and 5. The objective of the study was to characterize the immunomodulatory effects of ONO-4641 using preclinical data. ONO-4641 was tested in both in-vitro pharmacological studies as well as in-vivo models of transient or relapsing-remitting experimental autoimmune encephalomyelitis (EAE). In vitro, ONO-4641 showed highly potent agonistic activities versus S1P receptors 1 and 5 [half maximal effective concentration (EC(50) ) values of 0·0273 and 0·334 nM, respectively], and had profound S1P receptor 1 down-regulating effects on the cell membrane. ONO-4641 decreased peripheral blood lymphocyte counts in rats by inhibiting lymphocyte egress from secondary lymphoid tissues. In a rat experimental autoimmune encephalomyelitis (EAE) model, ONO-4641 suppressed the onset of disease and inhibited lymphocyte infiltration into the spinal cord in a dose-dependent manner at doses of 0·03 and 0·1 mg/kg. Furthermore, ONO-4641 prevented relapse of disease in a non-obese diabetic mouse model of relapsing-remitting EAE. These observations suggest that ONO-4641 may provide therapeutic benefits in the treatment of multiple sclerosis.

Sorafenib and TRAIL have synergistic effect on hepatocellular carcinoma

A multi-kinase inhibitor, sorafenib, was recently approved and is currently recommended for the treatment of advanced hepatocellular carcinoma (HCC). However, HCC treatment outcomes are still poor and necessitate improvement. Therefore, we investigated the influence of sorafenib in combination with each of cytotoxic chemotherapy agents, hypoxia or tumor necrosis factor (TNF)-related apoptosis‑inducing ligand (TRAIL), on cytotoxicity to determine which is the better adjuvant. Additive cytotoxicity of sorafenib to chemotherapy agents, hypoxia and TRAIL, to HCC cells was assessed using cell viability assay. Intracellular levels of anti-apoptotic proteins were determined using western blot analysis. Activation of Wnt/β-catenin signaling was assessed using a luciferase reporter gene assay. Sorafenib significantly and synergistically enhanced the cytotoxicity of TRAIL to HCC cells and 4',6-diamidino-2-phenylindole (DAPI) staining showed increased apoptosis among cells treated with sorafenib and TRAIL. This augmentation in cytotoxicity was derived from sorafenib-mediated downregulation of anti-apoptotic proteins. However, sorafenib did not enhance the cytotoxicity of chemotherapy agents (cisplatin, 5-FU or doxorubicin) or hypoxic treatment to HCC. Moreover, hypoxic treatment induced Wnt/β-catenin signaling activation. Our data showed that in combination TRAIL and sorafenib had a synergistic cytokilling effect on HCC cells and that this effect derived from sorafenib-mediated downregulation of anti-apoptotic proteins.

c-Met: A potential therapeutic target for hepatocellular carcinoma

The approval of receptor tyrosine kinase (RTK) targeted agent sorafenib as the first effective drug for the systemic treatment of advanced hepatocellular carcinoma (HCC) represents a milestone in the treatment of this disease. A better understanding of HCC pathogenesis will lead to development of novel targeted treatments. As a typical member of the RTK family, c-Met represents an intriguing target for cancer therapy. The c-Met signaling pathway has been shown to be deregulated and to correlate with poor prognosis in a number of major human cancers. This review discusses the possibility of c-Met as a target in HCC treatment from the following respects: i) c-Met expression and activation profile in HCC, ii) relationship between c-Met and clinicopathologic state and prognosis of HCC, iii) role of c-Met signaling activity in HCC genesis and progression, and iv) strategy of c-Met pathway targeting therapy in HCC treatment.

Diffusion of Technetium in Compacted Bentonites in the Reducing Condition with Corrosion Products of Iron

In the vicinity of a high-level waste repository, corrosion of carbon steel overpacks will create a reducing environment. Reducing conditions are expected to retard the migration of redox-sensitive radionuclides such as technetium.

The apparent diffusion coefficients of technetium were measured in compacted bentonites (Kunigel VI® and Kunipia F®, JAPAN) in contact with carbon steel and its corrosion products under reducing conditions or without carbon steel under oxidizing conditions for comparison. The apparent diffusion coefficients measured were 10-12 to 10-13 m2/s under oxidizing conditions and 10-12 to 10-13 m2/s under reducing conditions. There were significant effects of redox condition, dry density (0.2 to 2.3 g / cm3) and montmorillonite content (50% for Kunigel VI or 100% for Kunipia F) on the apparent diffusion coefficients. Montmorillonite density could be a good index to explain density dependence of the diffusion coefficients under both reducing and oxidizing conditions.

Invasion of carcinoma cells into reconstituted type I collagen gels: visual real-time analysis by time-lapse microscopy

Stromal-epithelial interactions play a critical role in promoting tumorigenesis and invasion. To obtain detailed information on cancer cell behaviors on the stroma and kinetics of cell migration, which cannot be observed by conventionally-used Boyden chamber assays, this study was aimed at analyzing the cell invasion process in vitro using time-lapse microscopic observation. Serum-free conditions and reconstituted type I collagen gels which provided a basal membrane-stroma-like microenvironment were used to first establish a basal condition. Time-lapse microscopic observation for 30 h of cell invasion into the collagen gel revealed kinetic parameters and individualistic behavior of cancer cells. Of breast cancer MDA-MB-231 or MCF-7 cells and colon cancer LS180 or HT29 cells examined, MDA-MB-231 cells most rapidly disappeared from the collagen gel surface under basal conditions. Estrogen-dependent MCF-7 cells disappeared at a rate approximately two times slower than that of MDA-MB-231 cells under serum- and phenol red-free conditions. By the addition of 10 nM β-estradiol to the basal medium, MCF-7 cell invasion was facilitated to a rate similar to that of MDA-MB-231 cells. Microscopic analyses of collagen gel-sections demonstrated that most of the MDA-MB-231 and MCF-7 cells remained within 60 μm from the gel top under basal conditions, which is consistent with the observation obtained using Boyden chambers that no cells could cross the collagen I gel barrier unless 1% fetal calf serum was added to basal conditions. In summary, this study demonstrated future applicability of this method to understand the initial phase of cancer cell invasion processes.

Microstructure of Simulated High-Level Waste Glass Doped with Short-Lived Actinides, 238Pu and 244Cm

The microstructural changes of a simulated waste glass irradiated with doping of 238pu and 244Cm were observed by use of a preshadowed carbon replica technique in combination with scanning electron microscopy (SEM). The irradiated glass was annealed and its microstructural changes after annealing were observed by use of the sametechnique.

In the glass irradiated at a dose of 2.75x1025 α-decays/m3, bubbles with a radius from 0.15μrm to 0.35μm were observed. The average bubble radius and the bubble density were 0.23μm and 1x1017 bubbles/m3, respectively. Using these observed values, the volume change of the glass resulting from the bubble formation was estimated to be + 0.51 %. This valuoof + 0.51 % was close to the volume change of the irradiated glass measured in our previous study, which suggests a large portion of the volume change by α-irradiation results from bubble formation. In the glass annealed after irradiation the average bubbleradius was observed to decrease with annealing time. The bubble radius as a function of annealing time was analyzed on the basis of the helium diffusion model with two chemicalprocesses, i.e. trapping at bubbles and re-solution from bubbles into glass matrix. The values of the diffusion coefficient of helium, the trapping parameter and the re-solution parameter, which had been obtained experimentally in our previous study on the helium release, were applied to the calculation. The calculated curve was in good agreement with the observed data.

Diffusion of Uranium in Compacted Bentonite in the Presence of Carbon Steel

In a high-level waste repository, a carbon steel overpack will be corroded by consuming oxygen trapped in the repository after closure. This will create a reducing environment in the vicinity of repository. Reducing conditions are expected to retard the migration of redox-sensitive radionuclides such as uranium.

The apparent diffusivities of uranium were measured in compacted bentonite (Kunigel VI®, Japan) in contact with carbon steel under reducing conditions or without carbon steel under oxidizing conditions for comparison. The apparent diffusivities of uranium were 3.5 × 10-14 to 1.1 × 10-13 m2/s under reducing conditions and 9.0 × 10-13 to 1.4 × 10-12 m2/s under oxidizing conditions. There was no significant effect of dry density (1.6 to 1.8 g/cm3) and silica sand (0 or 40%) on the apparent diffusivities.

Since the bentonite pore water would be buffered at a pH between 8 and 9, uranium in the bentonite pore water would probably exist as a neutral hydroxide complex under reducing conditions and as an anioníc carbonate or hydroxide complex under oxidizing conditions. The anion exclusion theory cannot explain the difference of diffusivities between the two conditions. The uranium concentrations in bentonite under oxidizing conditions were one order of magnitude higher than those under the reducing conditions. The uranium concentration in the bentonite pore water under the reducing condition is estimated to be two orders of magnitude lower than that under the oxidizing conditions under the assumption of diffusion in porous media.

Diffusion of Uranium in Compacted Bentonites in the Reducing Condition with Corrosion Products of Iron

In high-level waste repository, a carbon steel overpack will be corroded after closure. This will create a reducing environment in the vicinity of the repository. Reducing conditions are expected to retard the migration of redox-sensitive radionuclides such as uranium.

The apparent diffusion coefficients of uranium were measured in compacted bentonites (Kunigel VI® and Kunipia F®, JAPAN) in contact with carbon steel and its corrosion products under reducing conditions or without carbon steel under oxidizing conditions for comparison. The apparent diffusion coefficients measured were 10-12 to 10-14 m2/s under oxidizing conditions and 10-13 to 10-14 m2/s under reducing conditions. There were significant effects of redox conditions, dry density (0.8 to 2.0 g/cm3) and montmorillonite contents (60% for Kunigel VI or 100% for Kunipia F) on the apparent diffusion coefficients. The sorption of uranium on corrosion products of iron was smaller than that on montmorillonite. Montmorillonite density could be a good index to explain density dependence of the diffusion coefficients under the reducing conditions. Uranium would diffuse in free pore water with diffusion coefficients greater than 10-13 m2/s in low density bentonites under both redox conditions because the diffusion coefficients depended on sorption coefficients. Since diffusion coefficients were independent of sorption coefficients in high density bentonites where free pore water is scarce, surface diffusion might occur with coefficients were of about 10-13 m2/s.

Sorption Behavior of Uranium(VI) on a Biotite Mineral

Biotite has the most important role for the sorption of radionuclides in granitic rocks. Experiments on the sorption of uranium (VI) on biotite were conducted to understand the fundamental controls on uranium sorption on biotite mineral, including the effects of pH and uranium concentration in solution. Biotite powder (mesh 32 – 60) were washed with 1N HC1 for a week and were rinsed twice with deionized water for a week. This HC1 treatment was necessary to avoid the effects by other minerals. The agreement between surface adsorption coefficient, Ka, of both biotites with and without HC1 treatment was within one order of magnitude. The peak Ka value was in the range of 0.1 to 0.01 cm3/cm2 around pH 6. A comparison of aqueous uranium speciations and sorption results indicates that neutral uranyl hydroxide could be an important species sorbed on the biotite.

Sequential desorption experiments with KC1 and HC1 solutions were also carried out after sorption experiments to investigate sorption forms of uranium. Approximately 20 % of uranium in solution were sorbed on the biotite as an exchangeable ion. The fraction of exchangeable uranium had a little dependence on pH. The other uranium could not be extracted even by 6N HC1 solution. It is possible that most of the uranium could be precipitated as U(IV) via Fe(II) reduction on the biotite surface.

Measurement of initial dissolution rate of P0798 simulated HLW glass by using micro-reactor flow-through test method

We applied a new type of flow-through test method using micro-reactor consisting of a simple test apparatus with compact size to measurement of the dissolution rate of a Japanese type of simulated waste glass (P0798 glass). In this test method, a solution flows through a micro-channel (20 mm length, 2 mm width, 0.16 mm depth) in contact with a face of coupon shaped glass specimen, and the output solution is retrieved at certain intervals to be analyzed for determination of the glass dissolution rate. By using this test method the initial dissolution rate of glass matrix or forward dissolution rate was measured as a function of pH (3 to 11) and temperature (25°C to 90°C). The present test results indicated that the initial dissolution rate has ‘V-shaped’ pH dependence, and the effect of pH on the dissolution rate decreases with increase in temperature similar to the results measured by using the Single-pass flow-through (SPFT) method. The present test results also indicated that the dissolution of B is controlled by diffusion process and that of Si is controlled by surface reaction process.

Diffusion of Cs and Sr in Compacted Bentonites Under Reducing Conditions and in the Presence of Corrosion Products of Iron

In high-level waste repositories, a carbon steel overpack will be corroded by consuming oxygen trapped in the repository after closure. Iron corrosion products are expected to interfere with migration of radionuclides by filling the pore in bentonite and sorbing radionuclides. In this study the apparent diffusion coefficients of cesium and strontium were measured in compacted Na-bentonites (Kunigel VI® and Kunipia F®, JAPAN) contacted with carbon steel and its corrosion products under reducing conditions or without carbon steel under oxidizing conditions for comparison. The apparent diffusion coefficients of cesium with and without corrosion product were 2.2 to 13 × 10−12 m2/s. The apparent diffusion coefficients of strontium with and without corrosion product were 3.1 to 25 × 10−12 m2/s. There were significant effects of dry density (0.8 to 2.0 g/cm3) and montmorillonite contents (50% for Kunigel V1 or 100% for Kunipia F). The presence of corrosion product decreased the apparent diffusion coefficients of Cs in both bentonites and that of Sr in Kunigel V1, especially at low dry density. This may be due to corrosion product filling the pore in the bentonite, decreasing the free pore size and density for diffusion.

Effects of Water Redox Conditions and Presence of Magnetite on Leaching of Pu and Np From HLW Glass

The objective of this study is to evaluate the effects of water redox conditions and of the presence of iron corrosion products (magnetite) on the release of actinides from HLW glasses. Static corrosion tests were performed on a simulated HLW glass doped with Pu and Np in deionized water in the presence of magnetite under oxidizing and reducing conditions. The tests under oxidizing conditions were performed in air, while the tests under reducing conditions were performed in mixed gas (Ar+5%H2) atmosphere.

The following results were obtained: (1) The presence of magnetite enhances formation of colloids containing Pu and Np in the leachates under both redox conditions. (2) Redox conditions have no remarkable influence on the release of Pu. (3) The reducing conditions combined with the presence of magnetite cause a decrease in the concentrations of Np dissolved species, which is probably the result of the reduction of Np(V) to Np(IV) at the magnetite surface.

Expression of KL-6 mucin, a human MUC1 mucin, in intrahepatic cholangiocarcinoma and its potential involvement in tumor cell adhesion and invasion

AIMS

Aberrant expressions of KL-6 mucin were proved to be associated with worse tumor behaviors of many carcinomas. This study was to evaluate the expression KL-6 mucin, a human MUC1 mucin, in intrahepatic cholangiocarcinoma (CC) and its significance in tumor progression.

MAIN METHODS

KL-6 mucin expressions in 21 patients with CC, 12 with combined hepatocellular and cholangiocarcinoma (cHCC-CC), and 78 with hepatocellular carcinoma (HCC) were detected by immunohistochemical staining. The effects of two glycosylation inhibitors (tunicamycin and benzyl-alpha-N-acetylgalactosamine (BAG)) on CC cell proliferations were assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assays. KL-6 mucin expressions were detected by immunocytochemical staining and western blotting after tunicamycin or BAG treatment. Cell adhesive and invasive properties were evaluated by adhesion tests and transwell chamber assays after tunicamycin or BAG treatment.

KEY FINDINGS

Positive KL-6 mucin staining was observed in all CC tissues and CC areas of cHCC-CC tissues. Immunocytochemical staining and western blotting showed that KL-6 mucin expressions were significantly reduced after both inhibitors treatment. Cell adhesive properties were significantly decreased after both inhibitors treatment, while cell invasive abilities were significantly decreased after BAG but not tunicamycin treatment.

SIGNIFICANCE

This study indicated that KL-6 mucin might be a specific tumor target for CC. Therapeutic strategies that target glycosylation of KL-6 mucin may be useful to control aggressive behaviors of CC.

Shosaikoto increases calprotectin expression in human oral epithelial cells

BACKGROUND AND OBJECTIVE

Oral epithelial cells help to prevent against bacterial infection in the oral cavity by producing antimicrobial peptides (AMPs). A broad-spectrum AMP, calprotectin (a complex of S100A8 and S100A9 proteins), is expressed by oral epithelial cells and is up-regulated by interleukin-1alpha (IL-1alpha). Shosaikoto (SST) is a traditional Japanese herbal medicine that has immunomodulatory effects and is reported to enhance the levels of IL-1alpha in epithelial cells. The purpose of this study was to investigate the effect of SST on the expression of calprotectin and other AMPs through the regulation of IL-1alpha in oral epithelial cells.

MATERIAL AND METHODS

Human oral epithelial cells (TR146) were cultured with SST (at concentrations ranging from 10 to 250 microg/mL) in the presence or absence of anti-IL-1alpha or IL-1 receptor antagonist. The expression of S100A8- and S100A9-specific mRNAs was examined by northern blotting. Calprotectin expression and IL-1alpha secretion were investigated by immunofluorescent staining or ELISA. The expression of other AMPs and IL-1alpha was analyzed by RT-PCR and by quantitative real-time PCR.

RESULTS

Shosaikoto (25 microg/mL) significantly increased the expression of S100A8- and S100A9-specific mRNAs and calprotectin protein. Shosaikoto increased S100A7 expression, but had no effect on the expression of other AMPs. The expression of IL-1alpha-specific mRNA and its protein were slightly increased by SST. A neutralizing antibody against IL-1alpha or IL-1 receptor antagonist inhibited SST up-regulated S100A8/S100A9 mRNA expression.

CONCLUSION

These results suggest that SST increases the expression of calprotectin and S100A7 in oral epithelial cells. In response to SST, up-regulation of calprotectin may be partially induced via IL-1alpha.