• The Journal of Korean Physical Therapy
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• v.20 no.3
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• pp.53-59
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• 2008

Purpose: The non-receptor-type protein tyrosine kinase Syk (636 amino acids, 72 kDa) is ubiquitously expressed in hematopoietic stem cells and has been widely studied as a regulator and effector of B cell receptor signaling that occurs in processes such as differentiation, proliferation and apoptosis. However, the mechanism relating Syk and p38 mitogen-activated protein kinases (p38MAPK) by endothelin-1 (ET-1, 21 amino acids) stimulation in muscle cells, especially in the volume-dependent hypertensive state, remains unclear. Methods: In this study, we investigated the relationship between Syk and p38MAPK for isometric contraction and enzymatic activity by ET-1 from rat aortic smooth muscle cells and aldosterone-analogue deoxycorticosterone acetate (DOCA) hypertensive state rats (ADHR). Results: The systolic blood pressure was significantly increased in ADHR than in a control group of animals. ET-1 induced isometric contraction and phosphorylation of p38MAPK, which was increased in muscle strips from ADHR. Increased vasoconstriction and phosphorylation of p38MAPK induced by treatment with 30 nM ET-1 were inhibited by the use of 10${\mu}M$ SB203580, an inhibitor of p38MAPK from ADHR. Furthermore, ET-1 induced isometric contraction and phosphorylation of Syk and p38MAPK, which were increased in the aortic smooth muscle cells. Increased tension and phosphorylation of Syk and p38MAPK induced by ET-1 were inhibited by SB203580 from rat aortic smooth muscle cells. Conclusion: These results, suggest that the Syk activity affects ET-1-induced contraction through p38MAPK in smooth muscle cells and that the same pathway directly or indirectly is associated with volume dependent hypertension. The findings suggest the need to develop cardiovascular disease-specialized physical therapy.

• YAKHAK HOEJI
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• v.56 no.1
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• pp.26-34
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• 2012

Mast cells play an important role in early and late phase allergic reactions through allergen and IgE-dependent release of histamine, proteases, prostaglandins, and several multifunctional cytokines. In this study, we investigated whether Cudrania tricuspidata extract (CTE) suppresses IgE-mediated allergic responses in mast cells, an allergic animal model, and its mechanism of action in mast cells. We found that CTE inhibited IgE-mediated degranulation and cytokine production in rat basophilic leukemia (RBL)-2H3 mast cells and bone marrow-derived mast cells (BMMC), as well as passive cutaneous anaphylaxis (PCA) in mice. With regard to its mechanism of action, CTE suppressed the activating phosphorylation of spleen tyrosine kinase (Syk), a key enzyme in mast cell signaling processes and that of LAT, a downstream adaptor molecule of Syk in $Fc{\varepsilon}RI$-mediated signal pathways. CTE also suppressed the activating phosphorylation of mitogen-activated protein (MAP) kinases and Akt. The present results strongly suggest that the anti-allergic activity of CTE is mediated through inhibiting degranulation and allergic cytokine secretion by inhibition of Syk kinase in mast cells. Therefore, CTE may be useful for the treatment of allergic diseases.

• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.118-124
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• 2013

Mast cells is the key effector cells for IgE-mediated allergic responses. In this study, we investigated whether Rhus trichocarpa extract (RT) inhibited IgE-mediated allergic responses in mast cells and an allergic animal model. We further tried to find its mechanism of action in mast cells. We found that RT suppressed antigen-stimulated degranulation and production of TNF-${\alpha}$ and IL-4 in rat basophilic leukemia (RBL)-2H3 mast cells and bone marrow-derived mast cells (BMMC), as well as IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. As the mechanism of action of RT, it inhibited the activation of spleen tyrosine kinase (Syk), a pivotal signaling molecule for activation of mast cells and that of LAT, a downstream adaptor molecule of Syk in $Fc{\varepsilon}RI$-mediated signal pathways. RT also suppressed the activation of mitogen-activated protein (MAP) kinases and Akt. The current results demonstrated for the first time that RT has the anti-allergic effect through inhibiting degranulation and secretion of cytokines by suppression of Syk in antigen-stimulated mast cells. Therefore, RT might be useful for allergic diseases.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.356-362
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• 2014

Allergic diseases have increased rapidly over the past decades, affecting an estimated 20~30% of the population in developed countries. In this study, we investigated whether or not a typical costal sand dune plant Carex pumila (CPE) suppresses the activation of mast cells and IgE-mediated allergic response in vitro and in vivo. As the results, the extract of Carex pumila inhibited antigen-stimulated degranulation in RBL-2H3 cells and Bone marrow-derived mast cells (BMMCs), and IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. CPE also suppressed the production of pro-inflammatory cytokines, TNF-${\alpha}$ and IL-4, in antigen-stimulated mast cells. As its mechanism of action, CPE inhibited the activation of Syk in $Fc{\varepsilon}RI$-mediated signalling pathway, and that of LAT, a downstream adaptor molecule of Syk, in a dose-dependent manner. CPE also suppressed the activation of mitogen-activated protein (MAP) kinases, p38, ERK1/2, JNK, and Akt. Altogether, CPE inhibited mast cell activation and IgE-mediated allergic response by antigen through suppressing the activation of Syk. These results suggest that CPE may be useful for the treatment of allergic diseases.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.317-324
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• 2020

Mast cells play a key role in IgE-mediated allergic response. We investigated whether Swertia pseudochinensis Hara extract (SPE) inhibits IgE-mediated allergic response in mast cells and an allergic animal model. Additionally, we explored SPE's mechanism of action in mast cells. Our results showed that SPE inhibited both antigen-stimulated degranulation and the production of TNF-α and IL-4 in bone marrow-derived mast cells (BMMCs) and rat basophilic leukemia (RBL)-2H3 cells. SPE also suppressed allergic response in IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. As for the mechanism of action of SPE in mast cells, it inhibited the activation of Syk kinase, a critical signaling protein in the FcεRI-mediated signaling pathway, and also the activation of LAT, a downstream adaptor protein of Syk. We further observed the reduced activation of mitogen-activated protein (MAP) kinases (P38, ERK1/2, and JNK) and Akt in mast cells. Our results described for the first time that SPE has an anti-allergic effect by suppressing mast cells through the inhibition of Syk kinase. Therefore, SPE may be useful for the treatment of type I allergic diseases.

• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.520-528
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• 2022

Mast cells are an effector cell that plays a pivotal role in type I hypersensitive immune responses. Mast cells exist in connective tissues, such as skin and mucosal tissue, and contain granules which contain bioactive substances such as histamine and heparin in cells. The granules of mast cells are secreted by antigen stimulation to cause the type I allergic hypersensitivity. In addition, stimulated by antigen, mast cells synthesize and secrete various eicosanoids and cytokines. While AT9283 is known to have anticancer effects, the therapeutic effect of AT9283 on allergic disorders is completely unknown. In this study, it was found that AT9283 reversibly inhibited antigen-IgE binding-induced degranulation in mast cells (IC₅₀, approx. 0.58 μM) and suppressed the secretion of the inflammatory cytokines IL-4 (IC₅₀, approx. 0.09 μM) and TNF-α (IC₅₀, approx. 0.19 μM). For a mechanism of mast cell inhibition, while not inhibiting Syk phosphorylation, AT9283 suppressed the activation of LAT, a downstream substrate protein of Syk, in a dose-dependent manner. As expected, AT9283 also inhibited the activation of PLCγ1 and Akt, downstream signaling molecules of Syk/LAT, and MAP kinases such as JNK, Erk1/2, and P38. In an in vitro protein tyrosine kinase assay, AT9283 directly inhibited Syk activity. Next, AT9283 dose-dependently inhibited passive cutaneous anaphylaxis (PCA), an IgE-mediated allergic acute response, in mice (ED50, approx. 34 mg/kg, p.o.). These findings suggest that AT9283 has potential to use as a new drug for alleviating the symptoms of IgE-mediated allergic disorders.

• Biomolecules & Therapeutics
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• v.28 no.5
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• pp.456-464
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• 2020

Mast cells (MCs) are systemically distributed and secrete several allergic mediators such as histamine and leukotrienes to cause type I hypersensitivity. Dasatinib is a type of anti-cancer agent and it has also been reported to inhibit human basophils. However, dasatinib has not been reported for its inhibitory effects on MCs or type I hypersensitivity in mice. In this study, we examined the inhibitory effect of dasatinib on MCs and MC-mediated allergic response in vitro and in vivo. In vitro, dasatinib inhibited the degranulation of MCs by antigen stimulation in a dose-dependent manner (IC₅₀, ~34 nM for RBL-2H3 cells; ~52 nM for BMMCs) without any cytotoxicity. It also suppressed the secretion of inflammatory cytokines IL-4 and TNF-α by antigen stimulation. Furthermore, dasatinib inhibited MC-mediated passive cutaneous anaphylaxis (PCA) in mice (ED₅₀, ~29 mg/kg). Notably, dasatinib significantly suppressed the degranulation of MCs in the ear tissue. As the mechanism of its effect, dasatinib inhibited the activation of Syk and Syk-mediated downstream signaling proteins, LAT, PLCγ1, and three typical MAP kinases (Erk1/2, JNK, and p38), which are essential for the activation of MCs. Interestingly, in vitro tyrosine kinase assay, dasatinib directly inhibited the activities of Lyn and Fyn, the upstream tyrosine kinases of Syk in MCs. Taken together, dasatinib suppresses MCs and PCA in vitro and in vivo through the inhibition of Lyn and Fyn Src-family kinases. Therefore, we suggest the possibility of repositioning the anti-cancer drug dasatinib as a treatment for various MC-mediated type I hypersensitive diseases.

• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.376-382
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• 2015

Allergic diseases have rapidly increased in recent years. Mast cells play a critical role in IgE-mediated allergy responses and, therefore, closely associated with rhinitis, asthma, and atopic dermatitis. We studied anti-allergic effect of Penthorum chinense extract (PCE) in vitro and in vivo. PCE inhibited the degranulation of mast cells by antigen stimulation and its effect was dose-dependent and reversible in mast cells. PCE also suppressed the production of inflammatory cytokines such as TNF-${\alpha}$ and IL-4 by antigen in mast cells. Mechanistically, PCE inhibited the activation of Syk/LAT pathway which is a key signaling pathway for the activation of mast cells by antigen. Notably, PCE suppressed IgE-mediated allergic responses by antigen in mice. These results strongly suggest that PCE is a potential candidate for anti-allergic treatment.

• Biomolecules & Therapeutics
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• v.22 no.3
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• pp.193-199
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• 2014

The aim of this study was to determine whether britanin, isolated from the flowers of Inula japonica (Inulae Flos), modulates the generation of allergic inflammatory mediators in activated mast cells. To understand the biological activity of britanin, the authors investigated its effects on the generation of prostaglandin $D_2$ ($PGD_2$), leukotriene $C_4$ ($LTC_4$), and degranulation in IgE/Ag-induced bone marrow-derived mast cells (BMMCs). Britanin dose dependently inhibited degranulation and the generations of $PGD_2$ and $LTC_4$ in BMMCs. Biochemical analyses of IgE/Ag-mediated signaling pathways demonstrated that britanin suppressed the phosphorylation of Syk kinase and multiple downstream signaling processes, including phospholipase $C{\gamma}1$ ($PLC{\gamma}1$)-mediated calcium influx, the activation of mitogen-activated protein kinases (MAPKs; extracellular signal-regulated kinase 1/2, c-Jun $NH_2$-terminal kinase and p38), and the nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) pathway. Taken together, the findings of this study suggest britanin suppresses degranulation and eicosanoid generation by inhibiting the Syk-dependent pathway and britanin might be useful for the treatment of allergic inflammatory diseases.

• Journal of Ginseng Research
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• v.39 no.3
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• pp.189-198
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• 2015

Background: Antiallergic effect of 20(S)-protopanaxatriol (PPT), an intestinal metabolite of ginseng saponins, was investigated in guinea pig lung mast cells and mouse bone marrow-derived mast cells activated by a specific antigen/antibody reaction. Methods: Increasing concentrations of PPT were pretreated 5 min prior to antigen stimulation, and various inflammatory mediator releases and their relevant cellular signaling events were measured in those cells. Results: PPT dose-dependently reduced the release of histamine and leukotrienes in both types of mast cells. Especially, in activated bone marrow-derived mast cells, PPT inhibited the expression of Syk protein, cytokine mRNA, cyclooxygenase-1/2, and phospholipase $A_2$ ($PLA_2$), as well as the activities of various protein kinase C isoforms, mitogen-activated protein kinases, $PLA_2$, and transcription factors (nuclear factor-${\kappa}B$ and activator protein-1). Conclusion: PPT reduces the release of inflammatory mediators via inhibiting multiple cellular signaling pathways comprising the $Ca^{2+}$ influx, protein kinase C, and $PLA_2$, which are propagated by Syk activation upon allergic stimulation of mast cells.