RBL-2H3 Mast Cells Research Articles

Identification of anti-allergic effect of Clonorchis sinensis-derived protein venom allergen-like proteins (CsVAL)

Previous studies demonstrated that Clonochis sinensis-derived crude antigens suppress development of allergic responses. We investigated the effects of C. sinensis venom allergen-like (CsVAL) proteins on immune-modulating activities in allergic inflammatory response. Using RBL-2H3 rat mast cells, we demonstrated that CsVAL inhibits antigen-induced β-hexosaminidase release from immunoglobulin E-sensitized RBL-2H3 cells, and this inhibitory activity occurs by suppressing Lyn phosphorylation and intracellular reactive oxygen species production. In addition, CsVAL peptide treatment inhibits activation of protein kinase C-α and extracellular signal-regulated kinase 1/2, which are involved in degranulation of immunoglobulin E-sensitized mast cells. Furthermore, immunization with CsVAL suppressed development of skin inflammation by assessing ear thickness and cutaneous infiltration by eosinophils and mast cells in oxazolone-induced contact hypersensitivity in vivo mouse model. These results suggest that CsVAL is a promising candidate as an effective mast cell inhibitor for allergic and inflammatory diseases.

Super-Resolution Localization Microscopy Identifies Distinct Stages of Antigen-Induced IgE Receptor Cross-Linking and Immobilization in Rbl-2H3 Mast Cells

Cross-linking of immunoglobulin E (IgE) bound to its receptor, FceRI, by multivalent antigen initiates a transmembrane signaling cascade essential for mast cell activation and important for inflammatory immune responses and allergic disease. In this study, we apply super-resolution fluorescence localization microscopy to record receptor organization and dynamics on live RBL-2H3 mast cells undergoing antigen-mediated signaling, allowing us to measure nanoscale clustering and diffusion of FceRI simultaneously. Through comparison of cross-linking-induced changes in these properties as a function of time, we are able to resolve two distinct temporal phases of receptor clustering and immobilization. Additionally, we correlate the time-dependence of the distinct phases with a functional signaling response, Ca2+ mobilization. In the first phase of receptor clustering and immobilization, receptors slow dramatically with a relatively small average increase in clustering, and individual receptors appear to transiently associate with small clusters. This first phase occurs before Ca2+ mobilization and concurrently with initial signaling steps. At later times, receptor-rich clusters become increasingly dense while receptors remain predominately immobilized. These latter behaviors are observed at times following the initiation of the Ca2+ response, and we conclude that although cross-linking is necessary for commencement of downstream signaling, receptor assembly into large, densely packed clusters at later times is likely associated with termination of the stimulated response. These findings motivate future study of the physical interactions that give rise to the observed changes in receptor organization and mobility, and how these translate into cellular functions. In ongoing experiments, we are exploring the requirements of signaling for receptor cross-linking through the use of antigens with controlled structure and valency, and we will correlate our observations with functional responses such as Ca2+ mobilization and receptor association with downstream signaling partners.

Effects of C18 Fatty Acids on Intracellular Ca(2+) Mobilization and Histamine Release in RBL-2H3 Cells.

To investigate the underlying mechanisms of C18 fatty acids (stearic acid, oleic acid, linoleic acid and α-linolenic acid) on mast cells, we measured the effect of C18 fatty acids on intracellular Ca2+ mobilization and histamine release in RBL-2H3 mast cells. Stearic acid rapidly increased initial peak of intracellular Ca2+ mobilization, whereas linoleic acid and α-linolenic acid gradually increased this mobilization. In the absence of extracellular Ca2+, stearic acid (100 µM) did not cause any increase of intracellular Ca2+ mobilization. Both linoleic acid and α-linolenic acid increased intracellular Ca2+ mobilization, but the increase was smaller than that in the presence of extracellular Ca2+. These results suggest that C18 fatty acid-induced intracellular Ca2+ mobilization is mainly dependent on extracellular Ca2+ influx. Verapamil dose-dependently inhibited stearic acid-induced intracellular Ca2+ mobilization, but did not affect both linoleic acid and α-linolenic acid-induced intracellular Ca2+ mobilization. These data suggest that the underlying mechanism of stearic acid, linoleic acid and α-linolenic acid on intracellular Ca2+ mobilization may differ. Linoleic acid and α-linolenic acid significantly increased histamine release. Linoleic acid (C18:2: ω-6)-induced intracellular Ca2+ mobilization and histamine release were more prominent than α-linolenic acid (C18:3: ω-3). These data support the view that the intake of more α-linolenic acid than linoleic acid is useful in preventing inflammation.

Nobiletin, a polymethoxy flavonoid, exerts anti-allergic effect by suppressing activation of phosphoinositide 3-kinase

Nobiletin is a polymethoxy flavonoid present in fruit tissues of citrus species and has been reported to suppress degranulation of RBL-2H3 cells. However, the detailed mechanism is still unknown. In this study the mechanism of suppressive effect of nobiletin on degranulation of RBL-2H3 cells was examined. Nobiletin suppressed degranulation of both RBL-2H3 cells and bone marrow-derived mast cells induced by antigen stimulation. Nobiletin also suppressed degranulation stimulated by the calcium ionophore A23187 and thapsigargin, a specific inhibitor of the Ca2+-dependent ATPase. Elevation of intracellular free Ca2+ concentration was also suppressed by nobiletin when RBL-2H3 cells were stimulated by either antigen or A23187. Immunoblot analysis revealed that the inhibitory effect results from down-regulated phosphorylation of both phosphatidylinositol 3-kinase (PI3K) and phospholipase Cγ1 in the signaling pathways related to degranulation stimulated by antigen. Furthermore, oral administration of nobiletin suppressed vascular permeability in passive cutaneous anaphylaxis model mice. The tendency in all experiments obtained by treating with nobiletin was highly similar to that obtained by wortmannin, a specific inhibitor of PI3K. These findings suggest that nobiletin suppresses Ca2+ influx and consequently exerts the anti-allergy activity in a similar way to wortmannin.

Distinct Stages of Stimulated FcεRI Receptor Clustering and Immobilization Are Identified through Superresolution Imaging

Recent advances in fluorescence localization microscopy have made it possible to image chemically fixed and living cells at 20 nm lateral resolution. We apply this methodology to simultaneously record receptor organization and dynamics on the ventral surface of live RBL-2H3 mast cells undergoing antigen-mediated signaling. Cross-linking of IgE bound to FcεRI by multivalent antigen initiates mast cell activation, which leads to inflammatory responses physiologically. We quantify receptor organization and dynamics as cells are stimulated at room temperature (22°C). Within 2 min of antigen addition, receptor diffusion coefficients decrease by an order of magnitude, and single-particle trajectories are confined. Within 5 min of antigen addition, receptors organize into clusters containing ∼100 receptors with average radii of ∼70 nm. By comparing simultaneous measurements of clustering and mobility, we determine that there are two distinct stages of receptor clustering. In the first stage, which precedes stimulated Ca2+ mobilization, receptors slow dramatically but are not tightly clustered. In the second stage, receptors are tightly packed and confined. We find that stimulation-dependent changes in both receptor clustering and mobility can be reversed by displacing multivalent antigen with monovalent ligands, and that these changes can be modulated through enrichment or reduction in cellular cholesterol levels.

Influences of "Antiphlogistic No.1" on the degranultion of Activated RBL-2H3 cells

Objective To investigate the direct effect ofAntiphlogistic No.1 on the degranultion of RBL-2H3 mast cells stimulated by anti-DNP IgE and DNP-BSA complex.Methods The effect of Antiphlogistic No.1 on stabilization of RBL-2H3 cell membrane was assessed by degranultion inhibition rate.β-hexosaminidase and IL-4 released from RBL-2H3 cells were detected by PNAG colorimetric assay and ELISA.Results β-hexosaminidase and cytokine IL-4 production releases from RBL-2H3 cells was reduced after they had been treated with Antiphlogistic No.1.The inhibition rate of β-hexosaminidase release was 42.47％ at the concentration of 8 μg/ml (P＜0.01) and dose dependently increased to 52.40％,68.26％ and 72.15％ respectively when drug concentration up to 80 μg/ml,800 μg/ml,8000 μg/ml,while inhibition rate of IL-4 generation were 13.87％,23.27％,31.95％,39.99％ (P＜0.01).Antiphlogistic No.1 maximum inhibition rate of β-hexosaminidase release is 84.48％ of dexamethason maximum inhibition rate while Antiphlogistic No.l maximum inhibition rate of IL-4 is close to dexamethason maximum inhibition rate.Conclusion Antiphlogistic No.1 could stabilize the cellular membrane of RBL-2H3 and provide protection against Ⅰ type allergic response. Key words: Antiphlogistic No.1; RBL-2H3; Degranultion; β-hexosaminidase; IL-4; Dexamethasone

Effects of magnolialide isolated from the leaves of Laurus nobilis L. (Lauraceae) on immunoglobulin E-mediated type I hypersensitivity in vitro

Ethnopharmacological relevanceLaurus nobilis L. (Lauraceae) has been used for folk medicines in the Mediterranean area and Europe to treat various disorders including skin inflammation (dermatitis) and asthma. Aim of the studyOur aim was to investigate the scientific evaluation of the compounds from Laurus nobilis L. on immuniglobulin E (IgE)-mediated type I hypersensitivity responses in vitro such as atopic dermatitis and asthma. Methods and materialsSeven compounds were isolated and examined for the mast cell stabilizing effect on IgE-sensitized RBL-2H3 mast cells by measuring the β-hexosaminidase activity. In addition, the effects on interleukin (IL)-4 production and IL-5-dependent Y16 early B cell proliferation were investigated as well as their cytotoxic effects on RBL-2H3 cells. ResultsAmong the seven isolated compounds, magnolialide attenuated the release of β-hexosaminidase from RBL-2H3 cells with an IC50 value of 20.2μM, while the other compounds revealed no significant effects at concentrations tested. Furthermore, magnolialide significantly inhibited the IL-4 release with an IC50 value of 18.1μM and IL-4 mRNA expression with an IC50 value of 15.7μM in IgE-sensitized RBL-2H3 cells. In addition, the inhibition of IL-5-dependent proliferation of early B cells (Y16 cells) by magnolialide was demonstrated with an IC50 value of 18.4μM. ConclusionThese results suggest that the magnolialide might be a candidate for the treatment of IgE-mediated hypersensitivity responses such as atopic dermatitis and asthma by inhibiting mast cell degranulation, the IL-4 production, and IL-5-dependent early B cell proliferation, key factors in the development and amplification of type I hypersensitivity reactions.

Purification of novel anti-inflammatory peptides from enzymatic hydrolysate of the edible microalgal Spirulina maxima

Natural bioactive peptides have been known as ingredients in nutraceuticals and pharmaceuticals. In this study, the potential anti-inflammatory peptides were purified from enzymatic hydrolysate of the edible microalgae Spirulina maxima using gastrointestinal endopeptidases (trypsin, α-chymotrypsin, and pepsin). Purification of the hydrolysate resulted in two peptides with amino acid sequences of LDAVNR (P1, 686Da) and MMLDF (P2, 655Da). It was found that peptides P1 and P2 exhibited significant inhibition on the release and production of histamine from antigen-stimulated RBL-2H3 mast cells. Moreover, the suppressive effect of P1 and P2 on production as well as expression of interleukin-8 in histamine-stimulated EA.hy926 endothelial cells was determined. Notably, the production of intracellular reactive oxygen species from mast cells and endothelial cells was decreased in the presence of P1 or P2. Collectively, the peptides P1 and P2 from S. maxima could be used as functional ingredients with potent anti-inflammatory benefits.

Anti-allergic and anti-inflammatory effects of bakkenolide B isolated from Petasites japonicus leaves

Aims of the studyTo elucidate the anti-allergic and anti-inflammatory effects of Petasites genus, we studied the effects of several compounds isolated from Petasites japonicas leaves. Materials and methodsBakkenolide B was isolated from Petasites japonicus leaves. Antigen-induced degranulation was measured in RBL-2H3 mast cells by measuring β-hexosamidase activity. Induction of inducible nitric oxide synthase and cyclooxygenase 2 was measured by Western blotting in peritoneal macrophages. Ovalbumin-induced asthma model was used for in vivo efficacy test of bakkanolide B. ResultsWe found that bakkenolide B, a major component of the leaves, concentration-dependently inhibited RBL-2H3 mast cell degranulation. Bakkenolide B also inhibited the gene inductions of inducible nitric oxide synthase and cyclooxygenase 2 in mouse peritoneal macrophages. Furthermore, in an ovalbumin-induced asthma model, bakkenolide B strongly inhibited the accumulation of eosinophils, macrophages, and lymphocytes to bronchoalveolar lavage fluid. ConclusionBakkenolide B has suppressive properties for allergic and inflammatory responses and may be utilized as a potent agent for the treatment of asthma.

Resveratrol Inhibits IgE-Mediated Basophilic Mast Cell Degranulation and Passive Cutaneous Anaphylaxis in Mice

AbstractResveratrol is a phytoalexin abundantly found in red grape skin and is effective in antitumor and antiinflammation associated with immune responses. This study investigated whether resveratrol suppressed immunoglobulin (Ig)E-mediated allergic responses and passive cutaneous anaphylaxis (PCA) in rat RBL-2H3 mast cells and in BALB/c mice. The release of β-hexosaminidase and histamine was enhanced in mast cells sensitized with anti-dinitrophenyl (DNP)-IgE and subsequently stimulated by DNP-human serum albumin (HSA), indicative of mast cell degranulation. When mast cells were pretreated with nontoxic resveratrol at 1–25 μmol/L, such induction was dose dependently diminished. Spleen tyrosine kinase (Syk) and phospholipase Cγ (PLCγ) of sensitized mast cells were activated by stimulation with DNP-HSA antigen, which was dampened by ≥5 μmol/L resveratrol. The phosphorylation of protein kinase C (PKC)μ and PKCθ was attenuated by administering resveratrol to DNP-HSA–exposed mast cells, whereas quiescent PKCζ/λ in sensitized cells was dose-dependently activated by resveratrol. Male BALB/c mice were sensitized for 24 h with DNP-IgE and orally administered with resveratrol 1 h before the DNP-HSA challenge. The histamine concentration was enhanced in sensitized mice challenged to DNP-HSA, which was reversed by administration of 10 mg/kg resveratrol. Additionally, it encumbered the tissue activation of Syk, PLCγ, and PKCμ in antigen-exposed mice. Resveratrol decreased IgE-mediated PCA and alleviated allergic edema of mouse ear and dorsal skin. Mast cell degranulation and allergic inflammation, accompanying the induction of monocyte chemotactic protein-1 and macrophage inflammatory protein-2, were inhibited by supplementing resveratrol to antigen-challenged mice. Resveratrol inhibited mast cell-derived, immediate-type allergic reactions, and these responses of resveratrol suggest possible therapeutic strategies in preventing allergic inflammatory diseases.

Anti-allergic actions of rottlerin from Mallotus philippinensis in experimental mast cell-mediated anaphylactic models

Allergy is an acquired hypersensitivity reaction of the immune system mediated by cross-linking of the allergen-specific IgE-bound high-affinity IgE receptors, leading to immediate mast cell degranulation. Rottlerin is an active molecule isolated from Mallotus philippinensis, a medicinal plant used in Ayurvedic Medicine System for anti-allergic and anti-helminthic treatments. The present study investigated potential anti-allergic effects of rottlerin in animal models of IgE-dependent anaphylaxis and the anti-allergic mechanisms of action of rottlerin in mast cells. Anti-allergic actions of rottlerin were evaluated in passive cutaneous anaphylaxis and passive systemic anaphylaxis mouse models, and in anaphylactic contraction of bronchial rings isolated from sensitized guinea pigs. Direct mast cell-stabilizing effect of rottlerin was examined in RBL-2H3 mast cell line. Anti-allergic signaling mechanisms of action of rottlerin in mast cells were also examined. Rottlerin prevented IgE-mediated cutaneous vascular extravasation, hypothermia, elevation in plasma histamine level and tracheal tissue mast cell degranulation in mice in a dose-dependent manner. In addition, rottlerin suppressed ovalbumin-induced guinea pig bronchial smooth muscle contraction. Furthermore, rottlerin concentration-dependently blocked IgE-mediated immediate release of β-hexosaminidase from RBL-2H3 mast cells. Rottlerin was found to inhibit IgE-induced PLCγ1 and Akt phosphorylation, production of IP3 and rise in cytosolic Ca2+ level in mast cells. We report here for the first time that rottlerin possesses anti-allergic activity by blocking IgE-induced mast cell degranulation, providing a foundation for developing rottlerin for the treatment of allergic asthma and other mast cell-mediated allergic disorders.

Crucial role of the hydrophobic pocket region of Munc18 protein in mast cell degranulation

The function of the Munc18-1 protein hydrophobic pocket, which interacts with the syntaxin-1 N-terminal peptide, has been highly controversial in neurosecretion. Recent analysis of patients with familial hemophagocytic lymphohistiocytosis type 5 has identified the E132A mutation in the hydrophobic pocket of Munc18-2, prompting us to examine the role of this region in the context of immune cell secretion. Double knockdown of Munc18-1 and Munc18-2 in RBL-2H3 mast cells eliminates both IgE-dependent and ionomycin-induced degranulation and causes a significant reduction in syntaxin-11 without altering expressions of the other syntaxin isoforms examined. These phenotypes were effectively rescued on reexpression of wild-type Munc18-1 or Munc18-2 but not the mutants (F115E, E132A, and F115E/E132A) in the hydrophobic pocket of Munc18. In addition, these mutants show that they are unable to directly interact with syntaxin-11, as tested through protein interaction experiments. Our results demonstrate the crucial roles of the hydrophobic pocket of Munc18 in mast cell degranulation, which include the regulation of syntaxin-11. We also suggest that the functional importance of this region is significantly different between neuronal and immune cell exocytosis.

Anti‐allergic action of anti‐malarial drug artesunate in experimental mast cell‐mediated anaphylactic models

Allergy is an acquired hypersensitivity reaction of the immune system mediated by cross-linking of allergen-specific IgE-bound high-affinity IgE receptors, leading to immediate mast cell degranulation. Artesunate is a semi-synthetic derivative of artemisinin, an active component of the medicinal plant Artemisia annua. Artesunate is a clinically effective anti-malarial drug and has recently been shown to attenuate allergic asthma in mouse models. This study investigated potential anti-allergic effects of artesunate in animal models of IgE-dependent anaphylaxis. Anti-allergic actions of artesunate were evaluated in passive cutaneous anaphylaxis and passive systemic anaphylaxis mouse models, and in ovalbumin-induced contraction of bronchial rings isolated from sensitized guinea pigs. Direct mast cell-stabilizing effect of artesunate was examined in RBL-2H3 mast cell line and in mature human cultured mast cells. Anti-allergic signaling mechanisms of action of artesunate in mast cells were also investigated. Artesunate prevented IgE-mediated cutaneous vascular hyperpermeability, hypothermia, elevation in plasma histamine level, and tracheal tissue mast cell degranulation in mice in a dose-dependent manner. In addition, artesunate suppressed ovalbumin-mediated guinea pig bronchial smooth muscle contraction. Furthermore, artesunate concentration-dependently blocked IgE-mediated degranulation of RBL-2H3 mast cells and human culture mast cells. Artesunate was found to inhibit IgE-induced Syk and PLCγ1 phosphorylation, production of IP(3) , and rise in cytosolic Ca(+2) level in mast cells. We report here for the first time that artesunate possesses anti-allergic activity by blocking IgE-induced mast cell degranulation, providing a foundation for developing artesunate for the treatment of allergic asthma and other mast cell-mediated allergic disorders.

가감양격산(加減凉膈散)이 RBL-2H3 비만세포와 OVA/alum에 감작된 생쥐에 미치는 항알레르기 효과

Objectives: Gagamyanggyeoksan (G-YGS) has been used to suppress allergic reaction, however, the cellular target of G-YGS and its mode of action remain unclear. The present study was designed to investigate the effect of extracted G-YGS on the PMA and lonomycin (PI)-induced activation of RBL-2H3. Methods: For this investigation, We examined IL-4, IL-13 mRNA expression by Real-Time PCR, IL-4, IL-13 production by ELISA analysis and manifestations of GATA-1, GATA-2, NF-AT1, NF-AT2, AP-1 and NF-<TEX>${\kappa}B$</TEX> p65 transcription factors by western blotting, OVA-specific IgE, IL-4, IL-13 by mouse be sensitive to OVA. Results: Here we showed that treatment of RBL-2H3 mast cells with G-YGS, suppressed PI-induced production of Th2 cytokines including IL-4 and IL-13 in a dose dependent manner. The mRNA expression of IL-4 were completely abolished by G-YGS at the concentration of <TEX>$100{\mu}g/ml$</TEX>. Data from a stable cell lines consistently expressing IL-4. And the mRNA expression of IL-13 were abolished by G-YGS at the <TEX>$200{\mu}g/ml$</TEX>. But there is no difference between the <TEX>$50{\mu}g/ml$</TEX>, the <TEX>$100{\mu}g/ml$</TEX> and the comparison. Results from the western blot analysis of transcription factors involving IL-4 and IL-13 expression indicated that it prominently decreased the expression of mast cell specific transcricption factors including GATA-1, GATA-2, NF-AT2, c-Jun, NF-<TEX>${\kappa}B$</TEX> p65 but not c-Fos. And G-YGS suppressed IgE, IL-4, IL-13 in mouse be sensitive to OVA. Conclusions We suggested the anti-allergic activities of G-YGS might be mediated by down-regulation of Th2 cytokines such as IL-4 and IL-13 through the regulation of transcription factors as GATA-1, GATA-2, NF-AT2, c-Jun, NF-<TEX>${\kappa}B$</TEX> p65.

Novel pyrazole compounds for pharmacological discrimination between receptor-operated and store-operated Ca(2+) entry pathways.

Background and purposePyrazole derivatives have recently been suggested as selective blockers of transient receptor potential cation (TRPC) channels but their ability to distinguish between the TRPC and Orai pore complexes is ill-defined. This study was designed to characterize a series of pyrazole derivatives in terms of TRPC/Orai selectivity and to delineate consequences of selective suppression of these pathways for mast cell activation.Experimental approachPyrazoles were generated by microwave-assisted synthesis and tested for effects on Ca2+ entry by Fura-2 imaging and membrane currents by patch-clamp recording. Experiments were performed in HEK293 cells overexpressing TRPC3 and in RBL-2H3 mast cells, which express classical store-operated Ca2+ entry mediated by Orai channels. The consequences of inhibitory effects on Ca2+ signalling in RBL-2H3 cells were investigated at the level of both degranulation and nuclear factor of activated T-cells activation.Key ResultsPyr3, a previously suggested selective inhibitor of TRPC3, inhibited Orai1- and TRPC3-mediated Ca2+ entry and currents as well as mast cell activation with similar potency. By contrast, Pyr6 exhibited a 37-fold higher potency to inhibit Orai1-mediated Ca2+ entry as compared with TRPC3-mediated Ca2+ entry and potently suppressed mast cell activation. The novel pyrazole Pyr10 displayed substantial selectivity for TRPC3-mediated responses (18-fold) and the selective block of TRPC3 channels by Pyr10 barely affected mast cell activation.Conclusions and ImplicationsThe pyrazole derivatives Pyr6 and Pyr10 are able to distinguish between TRPC and Orai-mediated Ca2+ entry and may serve as useful tools for the analysis of cellular functions of the underlying Ca2+ channels.

Anthocyanins, but not Anthocyanidins, from Bilberry (Vaccinium myrtillus L.) Alleviate Pruritus via Inhibition of Mast Cell Degranulation

We have previously reported that bilberry anthocyanins exhibit an anti-pruritic effect in a mouse model of allergic contact dermatitis. It has been reported that anthocyanins are particularly sensitive to thermal treatment and are easily hydrolyzed to anthocyanidins when exposed to high temperatures. The objective of this study was to compare the anti-pruritic effect of anthocyanin-rich quality-controlled bilberry extract and anthocyanidin-rich degraded extract using a mouse model of allergic contact dermatitis. BALB/c mice with allergic contact dermatitis induced by 4 weeks of repeated application of 2,4,6-trinitro-1-chlorobenzene (TNCB) were administered Bilberon-25 orally for 4 weeks after sensitization with TNCB. The effect of Bilberon-25 on pruritus was evaluated by measurement of scratching behavior. RBL-2H3 mast cells were used to investigate the effect of Bilberon-25 on degranulation in 48/80-stimulated mast cells. Compared with nonheated Bilberon-25, the proportion of anthocyanins in heated Bilberon-25 decreased, and the proportion of anthocyanidins was increased in heated-time dependent manner. Treatment with non-heated Bilberon-25 significantly attenuated the TNCB-induced increase in scratching behavior, whereas treatment with 2 h-heated Bilberon-25 did not. Moreover, 300 μg/mL nonheated Bilberon-25 showed significant inhibition of degranulation in RBL-2H3 mast cells, whereas 2 h-heated Bilberon-25 had no effect at any concentration studied. It is assumed that the inhibitory effect of bilberry anthocyanins on pruritus might be mediated, at least in part, by its inhibitory effect on mast cell degranulation. In conclusion, the anthocyanin-rich but not anthocyanidin-rich bilberry extract may be a useful dietary supplement for skin diseases involving pruritic symptoms, such as chronic allergic contact dermatitis, atopic dermatitis, and rhinitis.

Experimental study of suspicious sensitization component screening on Huachansu injection

To explore a new experimental method for screening of allergens in post-market traditional Chinese medicine injections by confirming allergens in Huachansu injection. First of all, the serum of patients allergic to Huachansu injection were collected, at the same time, the dubious allergen was conjugated to bovine serum albumin (BSA) by EDC coupling procedure to form complete antigen (BNP-BSA), which makes it possible to reproduce the allergic reaction of Huachansu injection in vitro. The histamine liberation ratio, the level of TNF-alpha and Histamine released from RBL-2H3 mast cell were detected; the above data were compared with those obtained in vivo. The difference of the histamine liberation ratio, the levels of TNF-alpha and histamine of the resibufogenin-BSA group, group of patients allergic to Huachansu injection were not significant compared with those of normal control group. However, there were significant difference in those data among the cinobufagin-BSA group, the blank control and normal control group (P<0.05). The allergen in the serum collected from patients allergic to Huachansu injection is resibufogenin.

RBL-2H3 비만세포와 OVA/alum 감작 생쥐에서 청심보혈탕(淸心補血湯)의 항알레르기 효과

Objectives The suppressive effect of CSBHT has been mysterious. Thus, the present study is designed to investigate the suppressive effect and its mechanism. Methods To investigate the anti-allergy effect from ChungShimBoHyeolTang(CSBHT), RBL-2H3 cell was used and examined by Real-Time PCR, and IL-4 and IL-13 from RBL-2H3 was examined by ELIS. In addition, GATA-1, GATA-2, NFAT-1, NFAT-2, c-Fos, c-Jun, NF- p65 transcription factors of RBL-2H3 mast cell were examined by Western Blotting. Also, OVA/alum-sensitized mice were orally administrated CSBHT and serum OVA-specific IgE production, IL-4, and IL-13 production in splenocytes supernatant were examined. Results As a result of treating with CSBHT extract, RBL-2H3 mast cells significantly suppressed the IL-4 and IL-13 mRNA expression and IL-4 and IL-13 production. Western blot analysis of transcription factors involving IL-4 and IL-13 expression also revealed a prominent decreases of mast cell`s specific transcription factors including GATA-1, GATA-2, NFAT-1, NFAT-2, c-Fos, and NF- p65. Also, examining the mice, administration of CSBHT suppressed the amount of OVA-specific IgE in OVA/alum-sensitized mice and IL-4 and IL-13 production in splenocytes supernatant. Conclusions The study suggested that the anti-allergic activities of CSBHT suppresses IL-4 and IL-13 production from the Th2 cytokines by suppressing transcription factors as GATA-1, GATA-2, NFAT-1, NFAT-2, c-Fos and NF- p65 in mast cells.

Polyphosphate Is a Novel Pro-inflammatory Regulator of Mast Cells and Is Located in Acidocalcisomes

Polyphosphate (polyP) is a pro-inflammatory agent and a potent modulator of the human blood-clotting system. The presence of polyP of 60 phosphate units was identified in rat basophilic leukemia (RBL-2H3) mast cells using specific enzymatic assays, urea-polyacrylamide gel electrophoresis of cell extracts, and staining of cells with 4,6-diamidino-2-phenylindole (DAPI), and the polyP-binding domain of Escherichia coli exopolyphosphatase. PolyP co-localizes with serotonin- but not with histamine-containing granules. PolyP levels greatly decreased in mast cells stimulated to degranulate by IgE. Mast cell granules were isolated and found to be acidic and decrease their polyP content upon alkalinization. In agreement with these results, when RBL-2H3 mast cells were loaded with the fluorescent calcium indicator fura-2 acetoxymethyl ester to measure their intracellular Ca(2+) concentration ([Ca(2+)](i)), they were shown to possess a significant amount of Ca(2+) stored in an acidic compartment different from lysosomes. PolyP derived from RBL-2H3 mast cells stimulated bradykinin formation, and it was also detected in human basophils. All of these characteristics of mast cell granules, together with their known elemental composition, and high density, are similar to those of acidocalcisomes. The results suggest that mast cells polyP could be an important mediator of their pro-inflammatory and pro-coagulant activities.

An involvement of neurokinin-1 receptor in FcεRΙ-mediated RBL-2H3 mast cell activation

Objective and designTo determine whether the neurokinin-1 receptor (NK1R) plays a role in the activation of RBL-2H3 mast cells after FcεRΙ aggregation.Materials and methodsNK1R expression in RBL-2H3 cells was inhibited by small hairpin RNA (shRNA) against NK1R, and determined by western blotting. For activation, both NK1R knockdown and control RBL-2H3 cells were sensitized by dinitrophenol (DNP)-specific IgE and stimulated with the antigen DNP-bovine serum albumin (BSA). Following the activation of RBL-2H3 cells, monocyte chemoattractant protein (MCP-1) production and intracellular calcium flux were monitored by ELISA and confocal microscopy assay, respectively. For investigation of the signaling mechanism, phosphorylation of mitogen-activated protein kinases (MAPKs) after RBL-2H3 cell activation was assessed by western blotting.ResultsshRNA-NK1R mediated an effective inhibition of NK1R expression in RBL-2H3 cells. Protein production of MCP-1 was reduced by more than 55 % in NK1R knockdown RBL-2H3 cells compared with control RBL-2H3 cells. In addition, both calcium mobilization and phosphorylation levels of MAPKs (Erk1/2, JNK, and p38) after DNP-BSA stimulation (via FcεRΙ) were decreased due to the inhibition of NK1R expression.ConclusionNK1R is required for the activation of RBL-2H3 cells following FcεRΙ engagement and involved in the regulation of MAPK signaling pathways.Electronic supplementary materialThe online version of this article (doi:10.1007/s00011-012-0523-x) contains supplementary material, which is available to authorized users.