CA125/MUC16 interacts with Src family kinases, and over-expression of its C-terminal fragment in human epithelial cancer cells reduces cell-cell adhesion

MUC16/CA125 is over-expressed in human epithelial tumors including ovarian, breast and some other carcinomas. The purpose of this study is to investigate how cell surface MUC16 is functionally involved in tumor progression, with a special focus on the role of its cytoplasmic tail. Forced expression of C-terminal MUC16 fragment (MUC16C) in epithelial cancer cells increased cell migration. We found that MUC16C directly interacted with Src family kinases (SFKs). Notably, localizations of E-cadherin and β-catenin at the cell-cell contacts were more diffuse in MUC16C transfectants compared with mock transfectants. Furthermore, MUC16C transfectants showed reduced Ca(2+)-dependent cell-cell adhesion, but the treatment of cells with PP2, a SFKs inhibitor, restored this. Because cell surface MUC16 is also associated with the E-cadherin/β-catenin complex, the over-expression of MUC16 and its interaction with SFKs may enhance SFKs-induced deregulation of E-cadherin. Thus, our results suggest a role for cell surface MUC16 in cell-cell adhesion of epithelial cancer cells.

Dose-dependent differential effects of thrombin in allergic bronchial asthma

BACKGROUND

Apart from its role in the coagulation system, thrombin plays an important role in the inflammatory response through its protease-activated receptors (PARs). However, the role of thrombin in the immune response is not clear.

OBJECTIVE

To evaluate whether thrombin has a modulatory role in allergic bronchial asthma.

METHODS

Bronchial asthma was induced in mice by intraperitoneal sensitization and inhalation challenge with ovalbumin. Thrombin or its inhibitors were administered by inhalation before each allergen challenge.

RESULTS

Mice with low but sustained coagulation activation had reduced allergic inflammation, and allergic asthma was inhibited by low doses of thrombin but worsened by high doses. Allergic asthma was worsened by antithrombin, argatroban, hirudin, and anti-thrombomodulin antibody. Mice with a higher level of an inhibitor of both thrombin and activated protein C had worse disease. Heterozygous PAR-1 mice had less allergic inflammation, but PAR-1 agonist worsened it. Allergic bronchial inflammation was worsened in mice that received adoptive transfer of PAR-1 agonist-treated Th2 cells as compared with controls. Low levels of thrombin suppressed the maturation and secretion of cytokines in dendritic cells, but high levels enhanced this.

CONCLUSIONS

The effects of thrombin on allergic asthma are dose-dependent, with detrimental effects at high doses and protective effects at low doses. These data demonstrate that thrombin modulates the outcome in allergic bronchial asthma.

Binding of the sialic acid-binding lectin, Siglec-9, to the membrane mucin, MUC1, induces recruitment of β-catenin and subsequent cell growth

Because MUC1 carries a variety of sialoglycans that are possibly recognized by the siglec family, we examined MUC1-binding siglecs and found that Siglec-9 prominently bound to MUC1. An immunochemical study showed that Siglec-9-positive immune cells were associated with MUC1-positive cells in human colon, pancreas, and breast tumor tissues. We investigated whether or not this interaction has any functional implications for MUC1-expressing cells. When mouse 3T3 fibroblast cells and a human colon cancer cell line, HCT116, stably transfected with MUC1cDNA were ligated with recombinant soluble Siglec-9, β-catenin was recruited to the MUC1 C-terminal domain, which was enhanced on stimulation with soluble Siglec-9 in dose- and time-dependent manners. A co-culture model of MUC1-expressing cells and Siglec-9-expressing cells mimicking the interaction between MUC1-expressing malignant cells, and Siglec-9-expressing immune cells in a tumor microenvironment was designed. Brief co-incubation of Siglec-9-expressing HEK293 cells, but not mock HEK293 cells, with MUC1-expressing cells similarly enhanced the recruitment of β-catenin to the MUC1 C-terminal domain. In addition, treatment of MUC1-expressing cells with neuraminidase almost completely abolished the effect of Siglec-9 on MUC1-mediated signaling. The recruited β-catenin was thereafter transported to the nucleus, leading to cell growth. These findings suggest that Siglec-9 expressed on immune cells may play a role as a potential counterreceptor for MUC1 and that this signaling may be another MUC1-mediated pathway and function in parallel with a growth factor-dependent pathway.

Vaccination with recombinant modified vaccinia virus Ankara prevents the onset of intestinal allergy in mice

BACKGROUND

Modified vaccinia virus Ankara (MVA)-encoding antigens are considered as safe vaccine candidates for various infectious diseases in humans. Here, we investigated the immune-modulating properties of MVA-encoding ovalbumin (MVA-OVA) on the allergen-specific immune response.

METHODS

The immune-modulating properties of MVA-OVA were investigated using GM-CSF-differentiated BMDCs from C57BL/6 mice. OVA expression upon MVA-OVA infection of BMDCs was monitored. Activation and maturation markers on viable MVA-OVA-infected mDCs were analyzed by flow cytometry. Secretion of INF-γ, IL-2, and IL-10 was determined in a co-culture of BMDCs infected with wtMVA or MVA-OVA and OVA-specific OT-I CD8(+) and OT-II CD4(+ ) T cells. BALB/c mice were vaccinated with wtMVA, MVA-OVA, or PBS, sensitized to OVA/alum and challenged with a diet containing chicken egg white. OVA-specific IgE, IgG1, and IgG2a and cytokine secretion from mesenteric lymph node (MLN) cells were analyzed. Body weight, body temperature, food uptake, intestinal inflammation, and health condition of mice were monitored.

RESULTS

Infection with wtMVA and MVA-OVA induced comparable activation of mDCs. MVA-OVA-infected BMDCs expressed OVA and induced enhanced IFN-γ and IL-2 secretion from OVA-specific CD8(+ ) T cells in comparison with OVA, wtMVA, or OVA plus wtMVA. Prophylactic vaccination with MVA-OVA significantly repressed OVA-specific IgE, whereas OVA-specific IgG2a was induced. MVA-OVA vaccination suppressed TH 2 cytokine production in MLN cells and prevented the onset of allergic symptoms and inflammation in a mouse model of OVA-induced intestinal allergy.

CONCLUSION

Modified vaccinia virus Ankara-ovalbumin (MVA-OVA) vaccination induces a strong OVA-specific TH 1- immune response, likely mediated by the induction of IFN-γ and IgG2a. Finally, MVA-based vaccines need to be evaluated for their therapeutic potential in established allergy models.

Activin A is stimulated by tumor necrosis factor-alpha and modulates collagen gene expression in human amniotic cells

BACKGROUND

Accumulating evidence supports the idea of activin A as a modulator of inflammation. In human pregnancy, elevated activin A concentrations in amniotic fluid are reported in women with intra-amniotic infection and inflammation- induced pre-term birth.

AIM

To test the hypothesis that activin A was involved in the pathophysiology of amnionitis, we evaluated the effects of tumor necrosis factor-α and lipopolysaccharide on activin A production in human amniotic epithelial cells, and the effects of activin A on the expression of collagen mRNA in amniotic mesenchymal cells.

MATERIALS AND METHODS

Amniotic membranes were obtained from patients without systemic disease, signs of premature delivery or fetal complications, during elective cesarean sections at term. Amniotic epithelial cells and mesenchymal cells were separately obtained by enzymatic digestion and cultured. Activin A was measured by enzyme-linked immunosorbent assay and collagen mRNA levels were assessed by quantitative PCR.

RESULTS

Amniotic epithelial cells produced activin A in a cell density- and time-dependent manner. Tumor necrosis factor- α enhanced activin A production in a time-dependent (48-120 h) and dose-dependent (10-300 ng/ml) manner in amniotic epithelial cells. Lipopolysaccharide also stimulated activin A production, but the effect was less prominent. In amniotic mesenchymal cells, the effect of activin A on the expression of type I and type III collagen mRNA was suppressive.

CONCLUSIONS

Tumor necrosis factor-α and lipopolysaccharide stimulated activin A production in amniotic epithelial cells, and activin A modulated expression of collagen mRNA in amniotic mesenchymal cells. These results support the idea that activin A is involved in the pathophysiology of amnionitis.

Review: Exploration of placentation from human beings to ocean-living species

This review covers four topics. 1) Placental pathology in Himalayan mountain people. To determine morphological changes of the placenta at high altitude, pathological examination was made of 1000 Himalayan placentas obtained in Nepal and Tibet and the results compared with Japanese placentas delivered at sea level. Characteristic findings in the placental villi of the Himalayan group included high incidences of villous chorangiosis and chorangioma. These processes were clarified by ultrastructural observation. 2) Placentation in Sirenians. The giant Takikawa sea cow, which lived 5 million years ago, was discovered on Hokkaido, Japan. It was an ancestor of the dugong as well as the manatees. Sirenia, the sea cow group, shares a common ancestor with Proboscidea, the elephants, even though they now inhabit quite different environments. A comparison was made of their zonary endothelial type of placentation. 3) Placentation in sharks and rays. The remarkable placentation of hammerhead sharks and manta rays is described. 4) Placentation in the Antarctic minke whale. Placental tissue samples of this whale were obtained from the Japan Institute of Cetacean Research. In an ultrastructural study of the utero-placental junction, microfilamental processes of the allantochorionic zone and crypt formation were visualized.

Isolation of fucosyltransferase-producing bacteria from marine environments

Fucose-containing oligosaccharides on the cell surface of some pathogenic bacteria are thought to be important for host-microbe interactions and to play a major role in the pathogenicity of bacterial pathogens. Here, we screened marine bacteria for glycosyltransferases using two methods: a one-pot glycosyltransferase assay method and a lectin-staining method. Using this approach, we isolated marine bacteria with fucosyltransferase activity. There have been no previous reports of marine bacteria producing fucosyltransferase. This paper thus represents the first report of fucosyltransferase-producing marine bacteria.

The unique correlation between anti-mutagenicity of human saliva and change in body weight

The purpose of this study was to investigate the effect of weight reduction on the anti-mutagenicity of human saliva. Subjects were 16 male college judo players. The anti-mutagenicity of the saliva was measured using the umu test. There was an inhibiting effect of the saliva on the mutagenicity of AF-2. However, a modifying effect of the saliva on Trp-P-1 was not observed. On the day before a competition and 7 days after the competition, the inhibiting capacity of the saliva for the mutagenicity of AF-2 decreased and increased in two non-weight reduction and two weight reduction groups, respectively.However, on the day before the competition, the changed body weights (r=-0.77, p<0.01) and BMI (r=-0.77, p<0.01) were significantly correlated with that of the inhibiting capacity of the saliva for the mutagenicity of AF-2. In addition, the BMI at 20 days before the competition was not significantly but markedly correlated with it (r=0.50, p=0.057). At 7 days after the competition, however, these correlations were not found.These findings suggest a unique correlation between the anti-mutagenicity of human saliva and body weight or BMI.

Genetic Divergence among Southeast and East Asian Populations of Rana limnocharis (Amphibia: Anura), with Special Reference to Sympatric Cryptic Species in Java

An electrophoretic survey was conducted for the Southeast and East Asian populations of Rana limnocharis. Results indicated that specimens from a single locality in Java derived from two genodemes showing complete allelic displacement at eight out of 25 presumptive loci examined. Within each of these genodemes, genotype frequencies at all polymorphic loci were well concordant with the Hardy-Weinberg expectation. These results strongly suggest that those specimens actually represent two biological species. Comprehensive distance analyses suggested that one of the two species from Java is genetically most divergent among all samples examined, whereas the other is most similar to the Laos sample and then to a group consisting of samples from Hongkong, western China, and the southern Ryukyus. Large values of genetic distances obtained for each combination of allopatric samples imply the presence of additional cryptic species in this nominal species.

Exogenous activated protein C inhibits the progression of diabetic nephropathy

BACKGROUND

Activated protein C (APC) can regulate immune and inflammatory responses and apoptosis. Protein C transgenic mice develop less diabetic nephropathy but whether exogenous administration of APC suppresses established diabetic nephropathy is unknown.

OBJECTIVES

We investigated the therapeutic potential of APC in mice with streptozotocin-induced diabetic nephropathy.

METHODS

Diabetes was induced in unilaterally nephrectomized C57/Bl6 mice using intraperitoneal (i.p.) injection of streptozotocin. Four weeks later, the mice were treated with i.p. exogenous APC every other day for 1 month.

RESULTS

APC-treated mice had a significantly improved blood nitrogen urea-to-creatinine ratio, urine total protein to creatinine ratio and proteinuria, and had significantly less renal fibrosis as measured by the levels of collagen and hydroxyproline. The renal tissue concentration of monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF) and the RNA expression of platelet-derived growth factor (PDGF), transforming growth factor-β1 and connective tissue growth factor (CTGF) were significantly lower in APC-treated mice than in untreated animals. The percentage of apoptotic cells was reduced and the expression of podocin, nephrin and WT-1 in the glomeruli was significantly improved in mice treated with APC compared with untreated mice. The levels of coagulation markers were not affected by APC treatment.

CONCLUSION

Exogenous APC improves renal function and mitigates pathological changes in mice with diabetic nephropathy by suppressing the expression of fibrogenic cytokines, growth factors and apoptosis, suggesting its potential usefulness for the therapy of this disease.

Long-range spin Seebeck effect and acoustic spin pumping

Imagine that a metallic wire is attached to a part of a large insulator, which itself exhibits no magnetization. It seems impossible for electrons in the wire to register where the wire is positioned on the insulator. Here we found that, using a Ni₈₁Fe₁₉/Pt bilayer wire on an insulating sapphire plate, electrons in the wire recognize their position on the sapphire. Under a temperature gradient in the sapphire, surprisingly, the voltage generated in the Pt layer is shown to reflect the wire position, although the wire is isolated both electrically and magnetically. This non-local voltage is due to the coupling of spins and phonons: the only possible carrier of information in this system. We demonstrate this coupling by directly injecting sound waves, which realizes the acoustic spin pumping. Our finding provides a persuasive answer to the long-range nature of the spin Seebeck effect, and it opens the door to 'acoustic spintronics' in which sound waves are exploited for constructing spin-based devices.

Visualization of sialic acid produced on bacterial cell surfaces by lectin staining

Oligosaccharides containing N-acetylneuraminic acid on the cell surface of some pathogenic bacteria are important for host-microbe interactions. N-acetylneuraminic acid (Neu5Ac) plays a major role in the pathogenicity of bacterial pathogens. For example, cell surface sialyloligosaccharide moieties of the human pathogen Haemophilus influenzae are involved in virulence and adhesion to host cells. In this study, we have established a method of visualizing Neu5Ac linked to a glycoconjugate on the bacterial cell surface based on lectin staining. Photobacterium damselae strain JT0160, known to produce a-2,6-sialyltransferase, was revealed to possess Neu5Ac by HPLC. Using the strain, a strong Sambucus sieboldiana lectin-binding signal was detected. The bacteria producing α-2,6-sialyltransferases could be divided into two groups: those with a lot of α-2,6-linked Neu5Ac on the cell surface and those with a little. In the present study, we developed a useful method for evaluating the relationship between Neu5Ac expression on the cell surface and the degree of virulence of marine bacteria.

High incidence of tumors in diabetic thrombin activatable fibrinolysis inhibitor and apolipoprotein E double-deficient mice

BACKGROUND

Activation of the complement system has been implicated in tumor growth. The antifibrinolytic protein, activated thrombin-activatable fibrinolysis inhibitor (TAFIa), can modulate the activation of the complement system by inactivating the anaphylatoxins C3a and C5a. The apolipoprotein-E (ApoE) genotype has been associated with carcinogenesis.

OBJECTIVE

The aim of this study was to evaluate whether TAFIa can affect the development of cancer in the ApoE-deficient mouse model.

METHODS

TAFI and ApoE double-knockout mice were generated. A group of mice was treated with the diabetogenic and carcinogenic compound streptozotocin (stz). Mice treated with saline, single knockout mice and wild-type (wt) mice served as controls.

RESULTS

Six months after treatment with stz, mice were sacrificed. Hepatic tumors were found in male double-knockout mice treated with stz but none was found in control animals that were not treated with stz or in single knockout of ApoE or wt animals. There was no significant difference in coagulation system activation between the groups of mice. The plasma concentrations of C5a, factor D and transforming growth factor-β1 were increased in TAFI/ApoE double-deficient mice treated with stz compared with the mice of the same genotype treated with saline.

CONCLUSION

Apo-E deficiency alone was not associated with tumors but the lack of TAFI appears to make the mice permissive for tumor formation in ApoE mice.

Immunomodulation of monocyte-derived dendritic cells through ligation of tumor-produced mucins to Siglec-9

Dendritic cells (DCs) play an essential role in the induction and maintenance of an effective immune response and express multiple siglecs. In the present study, we investigated whether or not the ligation of tumor-produced mucins with Siglec-9 expressed on immature DCs is related to escape from immunosurveillance in the tumor-bearing state. Expression of Siglec-9 was up-regulated on the development of monocytes into immature DCs and was decreased in mature DCs. Binding of various mucins and artificial glycopolymers carrying poly (NeuAc α2,6 LacNAc) or poly (NeuAc α2,3 LacNAc) to Siglec-9 was demonstrated by means of a plate assay. These mucins also bound to the surface of immature DCs. When immature DCs were treated with LPS in the presence of these mucins or artificial glycopolymers, the production of IL-12 was significantly reduced, but that of IL-10 was not. Furthermore, IL-12 production was decreased to a similar level on treatment with anti-Siglec-9 mAb. Mucins prepared from serum of cancer patients actually could bind to Siglec-9. These results suggest that Siglec-9 expressed on DCs is involved in immunoregulation through ligation with mucins in an epithelial cancer patient.

Induction of Th1 immune responses to Japanese cedar pollen allergen (Cry j 1) in mice immunized with Cry j 1 conjugated with CpG oligodeoxynucleotide

We determined whether a major Japanese cedar pollen allergen (Cry j 1) conjugated with CpG oligodeoxynucleotide would enhance allergen-specific Th1 responses in mice. Cry j 1 conjugated with CpG (Cry j 1-CpG) induced IL-12 in the spleen cells of naïve mice. Cry j 1-CpG immunization of BALB/c mice suppressed anti-Cry j 1 IgE response and enhanced anti-Cry j 1 IgG(2a) to subsequent Cry j 1 and alum adjuvant injection. CD4(+)T cells isolated from the spleens in mice immunized with Cry j 1-CpG produced higher IFN-γ levels than did CD4(+)T cells obtained from mice as negative controls. Our results suggested that Cry j 1-CpG immunization can induce Cry j 1-specific Th1 immune responses, thereby inhibiting IgE response to the pollen allergen.

Pulmonary hypertension is ameliorated in mice deficient in thrombin-activatable fibrinolysis inhibitor

BACKGROUND

The fibrinolytic system has been implicated in the pathogenesis of pulmonary hypertension (PH). Thrombin-activatable fibrinolysis inhibitor (TAFI) inhibits fibrinolysis and therefore its absence would be expected to increase fibrinolysis and ameliorate PH.

OBJECTIVE

The objective of the present study was to evaluate the effect of TAFI deficiency on pulmonary hypertension in the mouse.

METHODS AND RESULTS

PH was induced in C57/Bl6 wild-type (WT) or TAFI-deficient (KO) mice by weekly subcutaneous treatment with 600 mg kg(-1) monocrotaline (MCT) for 8 weeks. PH was inferred from right heart hypertrophy measured using the ratio of right ventricle-to-left ventricle-plus-septum weight [RV/(LV+S)]. Pulmonary vascular remodeling was analyzed by morphometry. TAFI-deficient MCT-treated and wild-type MCT-treated mice suffered similar weight loss. TAFI-deficient MCT-treated mice had reduced levels of total protein and tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), transforming growth factor-beta (TGF-beta) and monocyte chemoattractant protein-1 (MCP-1) in bronchial alveolar lavage compared with wild-type MCT-treated mice. The ratio of RV to (LV+S) weight was significantly higher in WT/MCT than in KO/MCT mice. The pulmonary artery wall area and vascular stenosis were both greater in MCT-treated WT mice compared with MCT-treated TAFI-deficient mice.

CONCLUSIONS

TAFI-deficient MCT-treated mice had less pulmonary hypertension, vascular remodeling and reduced levels of cytokines compared with MCT-treated WT animals, possibly as a result of reduced coagulation activation.