53 research outputs found

    Oral Tolerance Induced by Transfer of Food Antigens via Breast Milk of Allergic Mothers Prevents Offspring from Developing Allergic Symptoms in a Mouse Food Allergy Model

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    We examined whether maternal exposure to food antigens during lactation and maternal allergic status would affect the development of food allergy in offspring. OVA-sensitized or OVA-nonsensitized BALB/c female mice were exposed or unexposed to OVA during lactation. After weaning, their offspring were systemically sensitized twice with OVA and repeatedly given OVA by oral intubation. While 97.1% of the mice breastfed by OVA-nonsensitized and OVA-unexposed mothers developed allergic diarrhea, 59.7% of the mice breastfed by OVA-exposed nonallergic mothers during lactation and 24.6% of the mice breastfed by OVA-exposed allergic mothers during lactation developed food allergy. Furthermore, OVA was detected in breast-milk from OVA-exposed nonallergic mothers during lactation (4.6 ± 0.5 μg/mL). In addition, OVA-specific IgG1 titers were markedly increased in breast milk from allergic mothers (OVA-sensitized and OVA-unexposed mother: 11.0 ± 0.5, OVA-sensitized and OVA-exposed mother: 12.3 ± 0.3). Our results suggest that oral tolerance induced by breast milk-mediated transfer of dietary antigens along with their specific immunoglobulins to offspring leads to antigen-specific protection from food allergy

    High glucose-induced apoptosis in human coronary artery endothelial cells involves up-regulation of death receptors

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    <p>Abstract</p> <p>Background</p> <p>High glucose can induce apoptosis in vascular endothelial cells, which may contribute to the development of vascular complications in diabetes. We evaluated the role of the death receptor pathway of apoptotic signaling in high glucose-induced apoptosis in human coronary artery endothelial cells (HCAECs).</p> <p>Methods</p> <p>HCAECs were treated with media containing 5.6, 11.1, and 16.7 mM of glucose for 24 h in the presence or absence of tumor necrosis factor (TNF)-α. For detection of apoptosis, DNA fragmentation assay was used. HCAEC expression of death receptors were analyzed by the PCR and flow cytometry methods. Also, using immunohistochemical techniques, coronary expression of death receptors was assessed in streptozotocin-nicotinamide-induced type 2 diabetic mice.</p> <p>Results</p> <p>Exposure of HCAECs to high glucose resulted in a significant increase in TNF-R1 and Fas expression, compared with normal glucose. High glucose increased TNF-α production by HCAECs and exogenous TNF-α up-regulated TNF-R1 and Fas expression in HCAECs. High glucose-induced up-regulation of TNF-R1 and Fas expression was undetectable in the presence of TNF-α. Treatment with TNF-R1 neutralizing peptides significantly inhibited high glucose-induced endothelial cell apoptosis. Type 2 diabetic mice displayed appreciable expression of TNF-R1 and Fas in coronary vessels.</p> <p>Conclusions</p> <p>In association with increased TNF-α levels, the death receptors, TNF-R1 and Fas, are up-regulated in HCAECs under high glucose conditions, which could in turn play a role in high glucose-induced endothelial cell apoptosis.</p

    Increased Stathmin1 Expression in the Dentate Gyrus of Mice Causes Abnormal Axonal Arborizations

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    Pituitary adenylate cyclase-activating polypeptide (PACAP) is involved in multiple brain functions. To clarify the cause of abnormal behavior in PACAP deficient-mice, we attempted the identification of genes whose expression was altered in the dentate gyrus of PACAP-deficient mice using the differential display method. Expression of stathmin1 was up-regulated in the dentate gyrus at both the mRNA and protein levels. PACAP stimulation inhibited stathmin1 expression in PC12 cells, while increased stathmin1expression in neurons of the subgranular zone and in primary cultured hippocampal neurons induced abnormal arborization of axons. We also investigated the pathways involved in PACAP deficiency. Ascl1 binds to E10 box of the stathmin1 promoter and increases stathmin1 expression. Inhibitory bHLH proteins (Hes1 and Id3) were rapidly up-regulated by PACAP stimulation, and Hes1 could suppress Ascl1 expression and Id3 could inhibit Ascl1 signaling. We also detected an increase of stathmin1 expression in the brains of schizophrenic patients. These results suggest that up-regulation of stathmin1 in the dentate gyrus, secondary to PACAP deficiency, may create abnormal neuronal circuits that cause abnormal behavior

    Structure and growth behavior of centimeter-sized helical oleate assemblies formed with assistance of medium-length carboxylic acids

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    The nonequilibrium organization of self-assemblies from small building-block molecules offers an attractive and essential means to develop advanced functional materials and to understand the intrinsic nature of life systems. Fatty acids are well-known amphiphiles that form self-assemblies of several shapes. Here, we found that the lengths of helical structures of oleic acid formed in a buffered aqueous solution are dramatically different by the presence or absence of certain amphiphilic carboxylic acids. For example, under the coexistence of a small amount of N-decanoyl-L-alanine, we observed the formation of over 1 centimeter-long helical assemblies of oleate with a regular pitch and radius, whereas mainly less than 100 μm-long helices formed without this additive. Such long helical assemblies are unique in terms of their highly dimensional helical structure and growth dynamics. Results from the real-time observation of self-assembly formation, site-selective small-angle X-ray scattering, high-performance liquid chromatography analysis, and pH titration experiments suggested that the coexisting carboxylates assist in elongation by supplying oleate molecules to a scaffold for oleate helical assembly

    Sphingosine Kinase-1-Dependent and -Independent Inhibitory Effects of Zanthoxyli Fructus to Attenuate the Activation of Mucosal Mast Cells and Ameliorate Food Allergies in Mice

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    Food allergy (FA) is relatively a common disease in infants, but effective drug therapies are not yet available. Notably, mucosal mast cells, but not connective-tissue mast cells, play important roles in food allergic reactions via the release of inflammatory mediators. Therefore, we screened medicinal herb extracts for in vitro and in vivo antiallergic activity through inhibiting mucosal mast cell activation. As a result, both antigen-induced and calcium ionophore-induced degranulation was significantly inhibited by Zanthoxyli Fructus water extract (ZF) in mucosal-type murine bone marrow-derived mast cells (mBMMCs). ZF suppressed the antigen-induced [Ca2+] elevation and the antigen-enhanced mRNA expression of TNF-α, IL-4, and IL-13. The transcriptome and real-time PCR analyses revealed that ZF greatly decreased the antigen-enhanced expression level of sphingosine kinase 1 (Sphk1), which plays a key role in the FcεRI-mediated immune responses in mast cells. Furthermore, ZF inhibited allergic symptoms in an ovalbumin-caused murine FA model and decreased the number of infiltrating mucosal mast cells and the enhanced mRNA expression levels of IL-4 and Sphk1 in the FA mice colons. These results indicate that ZF suppresses mucosal mast cell activities mainly through Sphk1-dependent mechanism, and ZF is utilized for the development of a novel, potent anti-FA agent

    Tandem repeats of the 5′ flanking region of human MUC5AC have a role as a novel enhancer in MUC5AC gene expression

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    MUC5AC is a well-known gastric differentiation marker, which has been frequently used for the classification of stomach cancer. However, the molecular mechanism of regulation of MUC5AC expression remains to be elucidated. In previous studies, we have shown that Gli regulated MUC5AC transcription through the Gli-binding motif in the 5′ region of MUC5AC. Gli played important roles, but independently was not sufficient for MUC5AC expression. In this study, we analyzed a 4010 bp fragment of the 5′-flanking promoter region of the human MUC5AC gene by luciferase assay, and found a novel distal enhancer region located between −1434 bp to −3000 bp upstream from the first ATG initiation codon. This region is composed of repetitive DNA sequences 5′-TCACTCAC-3′. The strength of enhancer activities depended on the length of the repetitive region. The tandem repeats are conserved among primates, but not in other mammals. The tandem repeat regions enhanced promoter activities not only of MUC5AC but also of other genes. The enhancer effect of the tandem repeat regions was maintained even when inverted. ChIP analysis revealed that H3K9me3 binds to the tandem repeat regions. Together, our results suggest that the tandem repeat region in the MUC5AC promoter has the potential to act as a strong enhancer, and H3K9me3 may contribute to histone modifications of this region. Keywords: MUC5AC, Tandem repeat, Enhancer, H3K9me
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