Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.297
Filtrar
1.
Int J Mol Sci ; 23(15)2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35955959

RESUMO

Mast cells (MCs) play key roles in IgE-mediated immunoresponses, including in the protection against parasitic infections and the onset and/or symptoms of allergic diseases. IgE-mediated activation induces MCs to release mediators, including histamine and leukotriene, as an early response, and to produce cytokines as a late phase response. Attempts have been made to identify novel antiallergic compounds from natural materials such as Chinese medicines and food ingredients. We herein screened approximately 60 compounds and identified salicylaldehyde, an aromatic aldehyde isolated from plant essential oils, as an inhibitor of the IgE-mediated activation of MCs. A degranulation assay, flow cytometric analyses, and enzyme-linked immunosorbent assays revealed that salicylaldehyde inhibited the IgE-mediated degranulation and cytokine expression of bone-marrow-derived MCs (BMMCs). The salicylaldehyde treatment reduced the surface expression level of FcεRI, the high affinity receptor for IgE, on BMMCs, and suppressed the IgE-induced phosphorylation of tyrosine residues in intercellular proteins, possibly Lyn, Syk, and Fyn, in BMMCs. We also examined the effects of salicylaldehyde in vivo using passive anaphylaxis mouse models and found that salicylaldehyde administration significantly enhanced the recovery of a reduced body temperature due to systemic anaphylaxis and markedly suppressed ear swelling, footpad swelling, and vascular permeability in cutaneous anaphylaxis.


Assuntos
Anafilaxia , Mastócitos , Aldeídos/metabolismo , Anafilaxia/tratamento farmacológico , Anafilaxia/metabolismo , Animais , Degranulação Celular , Citocinas/metabolismo , Imunoglobulina E/metabolismo , Mastócitos/metabolismo , Camundongos , Receptores de IgE/metabolismo , Transdução de Sinais
2.
Molecules ; 27(13)2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35807345

RESUMO

Cuminum cyminum L. (cumin) is an annual plant of the Umbelliferae family native to Egypt. We previously showed that the aqueous extract of cumin seeds suppresses degranulation by downregulating the activation of antigen-induced intracellular signaling molecules in rat basophilic leukemia RBL-2H3 cells. However, the active substances in the extract have not yet been identified. Accordingly, herein, we aimed to ascertain the water-soluble substances present in cumin seeds that inhibit degranulation, which led to the identification of umbelliferose, a characteristic trisaccharide present in plants of the Umbelliferae family. Our study is the first to reveal the degranulation-suppressing activity of umbelliferose, and quantification studies suggest that cumin seed powder contains 1.6% umbelliferose. Raffinose, an isomer of umbelliferose, was also found to significantly suppress antigen-induced degranulation, but less so than umbelliferose. Both umbelliferose and raffinose contain sucrose subunits in their structures, with galactose moieties bound at different sites. These differences in structure suggest that the binding of galactose to the sucrose subunit at the α1-2 bond contributes to its strong degranulation-inhibiting properties.


Assuntos
Cuminum , Leucemia , Animais , Degranulação Celular , Cuminum/química , Galactose/análise , Extratos Vegetais/química , Rafinose/análise , Ratos , Sementes/química , Sacarose/análise
3.
J Med Chem ; 65(15): 10626-10637, 2022 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-35876064

RESUMO

Allergic diseases are a group of allergen-induced unfavorable immune responses initiating various symptoms in different organs. Mas-related G protein-coupled receptor X2 (MRGPRX2) on mast cells has been reported to be responsible for immunoglobulin E (IgE)-independent immune diseases and allergic drug reactions and has therefore been a crucial drug target for the development of anti-pseudo-allergic agents. Considering the active structural features of MRGPRX2, we designed and synthesized a series of diaryl ureas (DPUs). DPUs exert promising potency for inhibiting ß-hexosaminidase release in LAD2 cells with half-maximal inhibitory concentrations (IC50) values of 2.51-0.62 µM, as well as favorable antilocal and systemic anaphylaxis in mice at a dosage of 10 mg/kg. MRGPRX2 is further revealed to participate in the anti-pseudo-allergic activity of DPUs by binding with electrophilic urea and trifluoromethyl substituents. In brief, these results highlight entities with powerful electrophilic substituents as a prospective therapeutic strategy for the treatment of IgE-independent disorders.


Assuntos
Anafilaxia , Antialérgicos , Anafilaxia/induzido quimicamente , Anafilaxia/metabolismo , Animais , Antialérgicos/farmacologia , Antialérgicos/uso terapêutico , Degranulação Celular , Imunoglobulina E/efeitos adversos , Imunoglobulina E/metabolismo , Mastócitos , Camundongos , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Ureia/farmacologia , Ureia/uso terapêutico
4.
Pharmacol Res Perspect ; 10(4): e00990, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35904495

RESUMO

The tachykinin neuropeptide substance P (SP) is the canonical agonist peptide for the neurokinin 1 receptor (NK1 R). More recently, it has also been shown to activate the Mas-related G protein-coupled receptor X2 (MRGPRX2) receptor on mast cells (MCs), triggering degranulation and release of inflammatory mediators. SP undergoes rapid C-terminal truncation in vivo by a number of proteases to generate the metabolites SP(1-9)-COOH and in particular SP(1-7)-COOH. While the C terminus of SP is critical for NK1 R activation, studies have shown that the peptide polycationic N terminus is key for MRGPRX2 and mast cell activation. The study thus aimed to determine if the C-terminally truncated metabolites of SP, SP(1-9)-COOH, and SP(1-7)-COOH retained stimulatory activity at MRGPRX2. SP, SP(1-9)-COOH, and SP(1-7)-COOH were synthesized and tested on HEK293 cells expressing NK1 R or MRGPRX2, and LAD2 human mast cells, to determine the activity of SP and its metabolites in Ca2+ mobilization, degranulation, and cytokine assays. As expected from prior studies, both C-terminally truncated SP metabolites had essentially no activity at NK1 R, even at very high concentrations. In contrast, the in vivo metabolite of SP, SP(1-9)-COOH retained ability to activate MRGPRX2 across all parameters tested, albeit with reduced potency compared to intact SP. SP(1-7)-COOH did not produce any significant MRGRPX2 activation. Our results suggest that the SP metabolite, SP(1-9)-COOH, may play a regulatory role through the activation of MRGPRX2. However, given the relatively low potency of both SP and SP(1-9)-COOH at MRGPRX2, additional work is needed to better understand the biological importance of this expanded SP/MRGPRX2 pathway.


Assuntos
Mastócitos , Receptores de Neuropeptídeos , Degranulação Celular , Células HEK293 , Humanos , Proteínas do Tecido Nervoso/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Substância P/metabolismo , Substância P/farmacologia
5.
Int Immunopharmacol ; 110: 109063, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35853276

RESUMO

Mast cells (MCs) are main effector cells in chronic spontaneous urticaria (CSU). Both Fc epsilon RI (FcεRΙ)- and MAS-related G coupled receptor-X2 (MRGPRX2)-mediated MC activations affect CSU course. Leukocyte mono-immunoglobulin-like receptor 3 (CD300f) has been shown to regulate FcεRΙ activation. However, no study has verified CD300f is a target to cure CSU. Therefore this study aimed to verify whether clarithromycin (CLA) regulates FcεRΙ- and MRGPRX2-mediated MC activations via CD300f and shows therapeutic effect on CSU. The target of CLA was verification. CLA inhibited FcεRΙ- and MRGPRX2-mediated MC activations were shown in vivo and in vitro. A single-center, self-comparison study was performed, and CLA-treated CSU was investigated in 28 patients who were not sensitive to the third-generation antihistamines. Serum inflammatory mediators in patients before and after CLA administration were analyzed. CLA effectively inhibited type Ι anaphylactic reactions and pseudo-allergic reactions in mice. Moreover, CLA inhibited FcεRΙ- and MRGPRX2-mediated MC signaling pathway activation. Regulatory effects of CLA were decreased significantly after CD300f knockdown. CLA effectively alleviated the symptoms of wheal and itch and reduced serum cytokine levels in patients. CLA negatively regulated FcεRΙ- and MRGPRX2-mediated MC activation via CD300f and showed significant therapeutic effect on CSU.


Assuntos
Anafilaxia , Urticária Crônica , Animais , Degranulação Celular , Urticária Crônica/tratamento farmacológico , Claritromicina , Mastócitos , Camundongos , Proteínas do Tecido Nervoso , Receptores Acoplados a Proteínas G , Receptores de Neuropeptídeos
6.
Int J Mol Sci ; 23(12)2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35743021

RESUMO

NK degranulation plays an important role in the cytotoxic activity of innate immunity in the clearance of intracellular infections and is an important factor in the outcome of the disease. This work has studied NK degranulation and innate immunological profiles and functionalities in COVID-19 patients and its association with the severity of the disease. A prospective observational study with 99 COVID-19 patients was conducted. Patients were grouped according to hospital requirements and severity. Innate immune cell subpopulations and functionalities were analyzed. The profile and functionality of innate immune cells differ between healthy controls and severe patients; CD56dim NK cells increased and MAIT cells and NK degranulation rates decreased in the COVID-19 subjects. Higher degranulation rates were observed in the non-severe patients and in the healthy controls compared to the severe patients. Benign forms of the disease had a higher granzymeA/granzymeB ratio than complex forms. In a multivariate analysis, the degranulation capacity resulted in a protective factor against severe forms of the disease (OR: 0.86), whereas the permanent expression of NKG2D in NKT cells was an independent risk factor (OR: 3.81; AUC: 0.84). In conclusion, a prompt and efficient degranulation functionality in the early stages of infection could be used as a tool to identify patients who will have a better evolution.


Assuntos
COVID-19 , Células T Matadoras Naturais , Degranulação Celular , Humanos , Interferon gama/metabolismo , Células Matadoras Naturais , Ativação Linfocitária
7.
Int Immunopharmacol ; 110: 108953, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35724607

RESUMO

Neobavaisoflavone (NBIF), a monomolecular compound extracted from Psoralea corylifolia (Leguminosae), is commonly used in traditional Chinese medicine for multiple purposes. NBIF is known to exert anti-fungal and anti-tumor effects, and promote bone formation. Whether NBIF exhibits anti-allergic effects by regulating mast cell activation remains unclear. Therefore, we designed this study to investigate the anti-allergic effects of NBIF on IgE/Ag-induced mouse bone marrow-derived mast cells and ovalbumin-induced asthma, and the passive systemic anaphylaxis (PSA) reaction in mice. Our results showed that NBIF suppresses the production of leukotriene C4, prostaglandin D2 and inflammatory cytokines, and decreases the degranulation of BMMCs stimulated by IgE/Ag. A thorough investigation ascertained that NBIF suppresses the phosphorylation of mitogen-activated protein kinases, and represses the nuclear factor-κB-related signaling pathway. In addition, the oral administration of NBIF in mice inhibited the IgE-induced PSA reaction in a dose-dependent manner. Overall, we provide new insights into how NBIF regulates the IgE/Ag-mediated signaling pathways. Moreover, our investigation promotes the potential use of NBIF in treating allergy and asthma.


Assuntos
Anafilaxia , Antialérgicos , Asma , Hipersensibilidade , Anafilaxia/tratamento farmacológico , Animais , Antialérgicos/farmacologia , Antialérgicos/uso terapêutico , Asma/tratamento farmacológico , Asma/metabolismo , Degranulação Celular , Hipersensibilidade/tratamento farmacológico , Imunoglobulina E/metabolismo , Isoflavonas , Mastócitos , Camundongos , Camundongos Endogâmicos BALB C
8.
Chin J Nat Med ; 20(6): 421-431, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35750382

RESUMO

Pseudo-allergic reactions (PARs) widely occur upon application of drugs or functional foods. Anti-pseudo-allergic ingredients from natural products have attracted much attention. This study aimed to investigate anti-pseudo-allergic compounds in licorice. The anti-pseudo-allergic effect of licorice extract was evaluated in rat basophilic leukemia 2H3 (RBL-2H3) cells. Anti-pseudo-allergic compounds were screened by using RBL-2H3 cell extraction and the effects of target components were verified further in RBL-2H3 cells, mouse peritoneal mast cells (MPMCs) and mice. Molecular docking and human MRGPRX2-expressing HEK293T cells (MRGPRX2-HEK293T cells) extraction were performed to determine the potential ligands of MAS-related G protein-coupled receptor-X2 (MRGPRX2), a pivotal target for PARs. Glycyrrhizic acid (GA) and licorice chalcone A (LA) were screened and shown to inhibit Compound48/80-induced degranulation and calcium influx in RBL-2H3 cells. GA and LA also inhibited degranulation in MPMCs and increase of histamine and TNF-α in mice. LA could bind to MRGPRX2, as determined by molecular docking and MRGPRX2-HEK293T cell extraction. Our study provides a strong rationale for using GA and LA as novel treatment options for PARs. LA is a potential ligand of MRGPRX2.


Assuntos
Antialérgicos , Glycyrrhiza , Hipersensibilidade , Animais , Antialérgicos/farmacologia , Antialérgicos/uso terapêutico , Cálcio/metabolismo , Degranulação Celular , Células HEK293 , Humanos , Hipersensibilidade/tratamento farmacológico , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Proteínas do Tecido Nervoso/metabolismo , Ratos , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Receptores de Neuropeptídeos/uso terapêutico
9.
Biomed Pharmacother ; 150: 113014, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35658248

RESUMO

Propofol (PPF) has a protective effect on myocardial ischemia-reperfusion (I/R) injury (MIRI). The purpose of this study was to investigate whether the myocardial protective effect of propofol is related to the inhibition of mast cell degranulation and explore the possible mechanisms involved. Our in vivo results showed that compared with the sham group, cardiac function, infarct size, histopathological damage, apoptosis, and markers of myocardial necrosis were significantly increased in the ischemia-reperfusion group, and propofol pretreatment alleviated these effects. In the coculture system, propofol-treated mast cells reduced their tryptase activity, resulting in cardiomyocyte protective effects, such as decreased apoptosis of cardiomyocytes and decreased expression of myocardial necrosis markers. Finally, experimental results in vitro revealed that thapsigargin (TG) can increase mast cell degranulation, tryptase release, calcium ion concentration, and the expression of STIM1 and Orai1 induced by H/R, but propofol pretreatment can partially reverse the above effects. These results suggested that the cardioprotective effect of propofol is achieved in part by inhibiting calcium influx through store-operated Ca2+ channels (SOCs) and thus alleviating mast cell degranulation.


Assuntos
Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Propofol , Animais , Apoptose , Cálcio/metabolismo , Degranulação Celular , Mastócitos , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/patologia , Propofol/farmacologia , Ratos , Ratos Sprague-Dawley , Triptases/metabolismo , Triptases/farmacologia
10.
Molecules ; 27(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35684410

RESUMO

Pseudoallergic reactions are hypersensitivity reactions mediated by an IgE-independent mechanism. Since allantoin (AT)-mediated pseudoallergy has not been studied, in this study, our objective is to investigate the anti-pseudoallergy effect of AT and its underlying mechanism. In vitro, ß-hexosaminidase (ß-Hex) and histamine (HIS) release assays, inflammatory cytokine assays, toluidine blue staining, and F-actin microfilament staining were used to evaluate the inhibitory effect of AT in RBL-2H3 cells stimulated with Compound 48/80 (C48/80). Western blot analysis is further performed to investigate intracellular calcium fluctuation-related signaling pathways. In vivo, Evans Blue extraction, paw swelling, and the diameter of Evans Blue extravasation were evaluated, and skin tissues are examined for histopathological examination in mice with passive cutaneous anaphylaxis (PCA) induced by C48/80. Body temperature is measured, and the levels of cytokines are further determined by ELISA kits in mice with active systemic anaphylaxis (ASA) induced by C48/80. The results show that AT dose-dependently inhibited degranulation in C48/80-stimulated RBL-2H3 cells by inhibiting ß-Hex and HIS release, reducing the levels of TNF-α, IL-8, and MCP-1, inhibiting shape changes due to degranulation and disassembling the F-actin cytoskeleton. Furthermore, AT dose-dependently inhibits the phosphorylation of PLCγ and IP3R. In vivo, AT decreased Evans Blue extravasation, paw swelling, and the diameter of Evans Blue extravasation and significantly ameliorate pathological changes and mast cell degranulation in C48/80-induced PCA. Furthermore, AT help the mice recover from the C48/80-induced decrease in body temperature and decreased the levels of cytokines in C48/80-treated ASA mice. Our results indicate that allantoin inhibits compound 48/80-induced pseudoallergic reactions. AT has the potential to be used in IgE-independent anti-allergic and anti-inflammatory therapies.


Assuntos
Anafilaxia , p-Metoxi-N-metilfenetilamina , Alantoína/metabolismo , Anafilaxia/induzido quimicamente , Anafilaxia/tratamento farmacológico , Anafilaxia/metabolismo , Animais , Degranulação Celular , Citocinas/metabolismo , Edema/patologia , Azul Evans/efeitos adversos , Azul Evans/metabolismo , Imunoglobulina E/metabolismo , Mastócitos , Camundongos , beta-N-Acetil-Hexosaminidases/metabolismo , p-Metoxi-N-metilfenetilamina/efeitos adversos
11.
Theranostics ; 12(7): 3316-3328, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35547746

RESUMO

Nicotinamide adenine dinucleotide (NAD+) acts as a cofactor for multiple biological processes. While previous research has revealed that the NAD+ declines associated with aging contributes to an impairment of immune cells, its role in mast cell function, especially in response to an anaphylactic condition, has remained unexplored. We tested whether the restoration of cellular NAD+ concentration by the supplementation of NAD+ boosting molecules prevented mast cell degranulation and anaphylactic responses. Methods: Bone marrow derived mast cells (BMMCs) and human cord blood derived mast cells were treated with NAD+ precursors nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), and FcεRI downstream signaling was assessed. Animal models of passive systemic anaphylaxis (PSA) and passive cutaneous anaphylaxis (PCA) were used to investigate the effects of NAD+ precursors in the anaphylactic responses of mice. Results: Treatment of murine BMMCs and human cord blood derived mast cells with NAD+ precursors repressed intracellular signaling downstream of FcεRI, as well as the release of inflammatory cytokines and lipid mediators. The intraperitoneal administration of NMN or NR also markedly attenuated IgE-mediated anaphylactic responses in mouse models of PSA and PCA. These beneficial effects of NAD+ precursors, however, were attenuated in mast cell-specific Sirt6 knockout mice, indicating a Sirt6 dependency for their action. Conclusion: NAD+ precursors may serve as an effective therapeutic strategy that limits mast cell-mediated anaphylactic responses.


Assuntos
Anafilaxia , Sirtuínas , Anafilaxia/tratamento farmacológico , Animais , Degranulação Celular , Humanos , Masculino , Mastócitos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NAD , Antígeno Prostático Específico , Sirtuínas/farmacologia
12.
Clin Immunol ; 238: 109008, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35421591

RESUMO

In food allergies, antigen-induced aggregation of FcεRI on mast cells initiates highly ordered and sequential signaling events. Dok-1(downstream of tyrosine kinase 1), undergoes intense tyrosine phosphorylation upon FcεRI stimulation, which negatively regulates Ras/Erk signaling and the subsequent cytokine release, but it remains unclear whether Dok-1 regulates Fc-mediated degranulation. In this study, we investigated the role of Dok-1 in FcεRI-mediated degranulation. Dok-1 overexpressing RBL-2H3 cells were established. Degranulation, immunoprecipitation, co-immunoprecipitation, immunoblotting and flow cytometry assay were performed to explore the effects of Dok-1 and its underlying mechanisms. We found that, following FcεRI activation, Dok-1 was recruited to the plasma membrane, leading to tyrosine phosphorylation. Phosphorylated Dok-1 inhibits FcεRI-operated calcium influx, and negatively regulated degranulation by inhibiting calcium-dependent disassembly of actin filaments. Our data revealed that Dok-1 is a negative regulator of FcεRI-mediated mast cell degranulation. These findings contribute to the identification of therapeutic targets for food allergies.


Assuntos
Cálcio , Degranulação Celular , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Cálcio/metabolismo , Mastócitos , Fosforilação , Receptores de IgE , Tirosina/metabolismo , Tirosina/farmacologia
13.
Biomed Pharmacother ; 150: 112982, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35483187

RESUMO

Anaphylaxis is a severe systemic allergic reaction that exhibits multiple clinical symptoms. The Mas-related G protein-coupled receptor X2 (MRGPRX2) is recognized as a key cell receptor mediating allergic diseases and drug-induced anaphylactoid reactions. Thus, it has been a promising target for preventing and treating these reactions. Based on the potential activity of imperatorin and active structural feature of MRGPRX2, we first demonstrated that the synthetic imperatorin derivatives (IDs) could significantly inhibit MRGPRX2 agonist-induced degranulation and cytokine release in LAD2 cells, as well as alleviate local and systemic anaphylaxis in mice. The IC50 value of the most promising compound is an order of magnitude lower than that of imperatorin. IDs were further identified to display anti-pseudo-allergic activity by binding MRGPRX2 with the tertiary nitrogen substructures, just liking the reported MRGPRX2-ligand. These results would propose evidence for discovery of agents for treating MCs-dependent allergic disorders.


Assuntos
Anafilaxia , Mastócitos , Anafilaxia/induzido quimicamente , Animais , Degranulação Celular , Furocumarinas , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores Acoplados a Proteínas G/metabolismo
14.
Sci Rep ; 12(1): 6650, 2022 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-35459883

RESUMO

MAS-related G protein-coupled receptor X2 (MRGPRX2), expressed in human mast cells, is associated with drug-induced pseudo-allergic reactions. Dogs are highly sensitive to the anaphylactoid reactions induced by certain drugs including fluoroquinolones. Recently, dog MRGPRX2 was identified as a functional ortholog of human MRGPRX2, with dog MRGPRX2 being particularly sensitive to fluoroquinolones. The aim of this study was to determine key residues responsible for the enhanced activity of fluoroquinolone-induced histamine release associated with MRGPRX2. Firstly, a structure model of human and dog MRGPRX2 was built by homology modeling, and docking simulations with fluoroquinolones were conducted. This model indicated that E164 and D184, conserved between human and dog, are essential for the binding to fluoroquinolones. In contrast, F78 (dog: Y) and M109 (dog: W) are unconserved residues, to which the species difference in fluoroquinolone sensitivity is attributable. Intracellular calcium mobilisation assay with human MRGPRX2 mutants, in which residues at positions 78 and 109 were substituted to those of dog MRGPRX2, revealed that M109 and F78 of human MRGPRX2 are crucial residues for enhancing the fluoroquinolone-induced histamine release. In conclusion, these key residues have important clinical implications for revealing the mechanisms and predicting the risks of fluoroquinolone-mediated pseudo-allergic reactions in humans.


Assuntos
Anafilaxia , Hipersensibilidade a Drogas , Anafilaxia/metabolismo , Animais , Degranulação Celular , Cães , Hipersensibilidade a Drogas/genética , Hipersensibilidade a Drogas/metabolismo , Fluoroquinolonas/efeitos adversos , Fluoroquinolonas/metabolismo , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/genética , Receptores de Neuropeptídeos/metabolismo
15.
Cell Immunol ; 375: 104514, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35398603

RESUMO

Morphine derivatives are clinically important anesthetic and sedative drugs, which often show anaphylactic side effects. Mas-related G-protein coupled receptor member X2 (MRGPRX2) triggers mast cell degranulation, which is important process in anaphylactic reactions. MRGPRX2-HEK293 and LAD2 cell membrane chromatographic (CMC) models were used to screen morphine derivatives binding to MRGPRX2. Furthermore, most morphine derivatives significantly enhanced Ca2+ mobilization. More importantly, thebaine was found to effectively promote histamine release. Thebaine induced the increased release of ß-hexosaminidase and high secretion level of cytokines, confirming that thebaine could further trigger anaphylactic reactions and promote subsequent inflammatory reactions. Moreover, the ability of thebaine inducing degranulation and the release of allergenic mediators in mast cells was significantly decreased after MRGPRX2 knockdown, which proved that MRGPRX2 is the key media for thebaine-induced anaphylactic reactions. Significant hind paw swelling and hypothermia in mice after injecting thebaine suggested that thebaine could trigger anaphylactic reactions in vivo.


Assuntos
Anafilaxia , Mastócitos , Proteínas do Tecido Nervoso , Receptores Acoplados a Proteínas G , Receptores de Neuropeptídeos , Tebaína , Anafilaxia/induzido quimicamente , Animais , Degranulação Celular , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Neuropeptídeos/genética , Tebaína/efeitos adversos
16.
Exp Eye Res ; 219: 109065, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35421396

RESUMO

Mast cells (MCs) regulate wound healing and are influenced by the autonomic nervous system (ANS). However, the underlying mechanisms affecting wound healing outcomes remain elusive. Here, we explored the specific role of the ANS by regulating MC degranulation following corneal epithelium abrasion. A mouse model of corneal abrasion was established by mechanically removing a 2-mm central epithelium. Wound closure, neutrophil infiltration, and transcription of injured corneas were investigated using whole-mount immunostaining, flow cytometry, and RNA-sequencing analysis, respectively. Inhibition of MC degranulation by the MC stabilizers cromolyn sodium and lodoxamide tromethamine increased the infiltration of neutrophils and delayed healing of abraded corneas. Moreover, transcriptomic profiling analysis showed that purified MCs from the limbus expressed adrenergic and cholinergic receptors. Pharmacological manipulation and sympathectomy with 6-hydroxydopamine confirmed that sympathetic nervous system signaling inhibited MC degranulation after corneal abrasion, whereas parasympathetic nervous system signaling enhanced MC degranulation. We conclude that normal degranulation of MCs in the corneal limbus and crosstalk between the ANS and MCs are crucial for the appropriate control of inflammation and the repair progress of wounded corneas. This suggests a potential approach for improving defective corneal wound healing by the administration of clinically available autonomic activity-modulating agents.


Assuntos
Lesões da Córnea , Epitélio Corneano , Animais , Sistema Nervoso Autônomo , Degranulação Celular , Epitélio Corneano/fisiologia , Inflamação , Mastócitos , Camundongos , Camundongos Endogâmicos C57BL , Cicatrização/fisiologia
17.
J Allergy Clin Immunol ; 150(3): 676-689, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35469841

RESUMO

BACKGROUND: Mast cells (MCs) are key effectors of the allergic response. Following the cross-linking of IgE receptors (FcεRIs), they release crucial inflammatory mediators through degranulation. Although degranulation depends critically on secretory granule (SG) trafficking toward the plasma membrane, the molecular machinery underlying this transport has not been fully characterized. OBJECTIVES: This study analyzed the function of Rab44, a large, atypical Rab guanosine triphosphatase highly expressed in MC, in the MC degranulation process. METHODS: Murine knockout (KO) mouse models (KORab44 and DKOKif5b/Rab44) were used to perform passive cutaneous anaphylaxis experiments and analyze granule translocation in bone marrow-derived MCs during degranulation. RESULTS: This study demonstrate that mice lacking Rab44 (KORab44) in their bone marrow-derived MCs are impaired in their ability to translocate and degranulate SGs at the plasma membrane on FcεRI stimulation. Accordingly, KORab44 mice were less sensitive to IgE-mediated passive cutaneous anaphylaxis in vivo. A lack of Rab44 did not impair early FcεRI-stimulated signaling pathways, microtubule reorganization, lipid mediator release, or cytokine secretion. Mechanistically, Rab44 appears to interact with and function as part of the previously described kinesin-1-dependent transport pathway. CONCLUSIONS: These results highlight a novel role of Rab44 as a regulator of SG transport during degranulation and anaphylaxis acting through the kinesin-1-dependent microtubule transport machinery. Rab44 can thus be considered a potential target for modulating MC degranulation and inhibiting IgE-mediated allergic reactions.


Assuntos
Anafilaxia , Mastócitos , Proteínas rab de Ligação ao GTP/metabolismo , Anafilaxia/metabolismo , Animais , Degranulação Celular , Imunoglobulina E/metabolismo , Cinesinas , Mastócitos/metabolismo , Camundongos , Camundongos Knockout , Anafilaxia Cutânea Passiva , Receptores de IgE/metabolismo , Vesículas Secretórias/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...