scholarly journals Enhanced mast cell activation in mice deficient in the A2b adenosine receptor

2007 ◽  
Vol 204 (1) ◽  
pp. 117-128 ◽  
Author(s):  
Xiaoyang Hua ◽  
Martina Kovarova ◽  
Kelly D. Chason ◽  
MyTrang Nguyen ◽  
Beverly H. Koller ◽  
...  

Antigen-mediated cross-linking of IgE bound to mast cells via the high affinity receptor for IgE triggers a signaling cascade that results in the release of intracellular calcium stores, followed by an influx of extracellular calcium. The collective increase in intracellular calcium is critical to the release of the granular contents of the mast cell, which include the mediators of acute anaphylaxis. We show that the sensitivity of the mast cell to antigen-mediated degranulation through this pathway can be dramatically influenced by the A2b adenosine receptor. Loss of this Gs-coupled receptor on mouse bone marrow–derived mast cells results in decreased basal levels of cyclic AMP and an excessive influx of extracellular calcium through store-operated calcium channels following antigen activation. Mice lacking the A2b receptor display increased sensitivity to IgE-mediated anaphylaxis. Collectively, these findings show that the A2b adenosine receptor functions as a critical regulator of signaling pathways within the mast cell, which act in concert to limit the magnitude of mast cell responsiveness when antigen is encountered.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shotaro Nakajima ◽  
Kayoko Ishimaru ◽  
Anna Kobayashi ◽  
Guannan Yu ◽  
Yuki Nakamura ◽  
...  

AbstractInterleukin-33 (IL-33)/ST2–mediated mast cell activation plays important roles in the pathophysiology of allergic diseases. Hence, pharmacologically targeting the IL-33/ST2 pathway in mast cells could help to treat such diseases. We found that resveratrol inhibits IL-33/ST2–mediated mast cell activation. Resveratrol suppressed IL-33–induced IL-6, IL-13, and TNF-α production in mouse bone marrow–derived mast cells (BMMCs), mouse fetal skin–derived mast cells, and human basophils. Resveratrol also attenuated cytokine expression induced by intranasal administration of IL-33 in mouse lung. IL-33–mediated cytokine production in mast cells requires activation of the NF-κB and MAPK p38–MAPK-activated protein kinase-2/3 (MK2/3)–PI3K/Akt pathway, and resveratrol clearly inhibited IL-33–induced activation of the MK2/3–PI3K/Akt pathway, but not the NF-κB pathway, without affecting p38 in BMMCs. Importantly, resveratrol inhibited the kinase activity of MK2, and an MK2/3 inhibitor recapitulated the suppressive effects of resveratrol. Resveratrol and an MK2/3 inhibitor also inhibited IgE-dependent degranulation and cytokine production in BMMCs, concomitant with suppression of the MK2/3–PI3K/Akt pathway. These findings indicate that resveratrol inhibits both IL-33/ST2–mediated and IgE-dependent mast cell activation principally by targeting the MK2/3–PI3K/Akt axis downstream of p38. Thus, resveratrol may have potential for the prevention and treatment of broad ranges of allergic diseases.


2013 ◽  
Author(s):  
Κωνσταντίνος-Διονύσιος Αλυσανδράτος

Atopic dermatitis is a chronic, highly pruritic skin disease, whose prevalence hasincreased considerably in industrialized countries. It is characterized by allergicinflammation in the skin, and has a strong association with other atopic disorders, suchas asthma and allergic rhinitis. The pathogenesis of atopic dermatitis is poorlyunderstood. Stress is thought to worsen skin diseases like atopic dermatitis. Mast cellsare increased in the skin of atopic dermatitis patients, accompanied by an increasednumber of mast cell-nerve interactions. Mast cells also secrete and are activated byneuropeptides and cytokines. The aim of this study was to investigate the interplaybetween neuropeptides and cytokines in the pathogenesis of atopic dermatitis and theirrole on mast cell activation. We speculate that mast cell activation, especially underconditions of stress, accentuates inflammation and angiogenesis, leading to worseningof atopic dermatitis lesions. The primary aim of this doctorate thesis was to investigate the involvement ofneuropeptides and cytokines in atopic dermatitis. For this purpose we used molecularmethods, including ELISA, Luminex and PCR to measure levels of neuropeptides andcytokines that are released by and/or activate mast cells in the serum and lesional skinof atopic dermatitis patients and controls. Our results indicate that the cytokine thymicstromal lymphopoietin (TSLP), is increased in the serum and lesional skin of atopicdermatitis patients, leading to activation of the Th2 response and aggravation of localinflammation. We also found that the neuropeptide neurotensin (NT) is increased in theserum of atopic dermatitis patients, while NT and NT receptor (NTR) gene expression isincreased in the lesional skin compared to controls. The related neuropeptide substanceP (SP) was also found to be increased in the lesional atopic dermatitis skin. NT and SPwere shown to induce corticotropin releasing hormone receptor 1 (CRHR1) expressionand lead to vascular endothelial growth factor (VEGF) release from a human mast cellline, indicating their role in mast cell activation. Gene expression of VEGF, the main proangiogenicfactor, was found to be increased in lesional atopic dermatitis skin, whichhas been previously shown to correlate with progression of local inflammation. Thesefindings may explain why a skin disease like atopic dermatitis is worsened by stress. The molecular mechanism of mast cell activation and degranulation by neuropeptideshas not been studied, but is known to require intracellular calcium and energy. Mitochondria are the primary energy-generating organelles in eukaryotic cells and alsoregulate intracellular calcium. Therefore, we investigated the role of mitochondrialdynamics in mast cell activation and atopic dermatitis. Human umbilical cord bloodderivedmast cells (hCBMCs) and LAD2 mast cells were examined by confocalmicroscopy during activation with IgE/antigen and SP. Degranulation and tumornecrosis factor (TNF) release observed 30 minutes later were accompanied bymitochondrial translocation from a perinuclear location to exocytosis sites. Extracellularcalcium depletion prevented these effects indicating calcium requirement. Mitochondrialdynamics are dependent on the fission dynamin-related protein-1 (DRP1) and itsactivator calcineurin, as inhibition of DRP1 by means of the DRP1 inhibitor MDIVI-1 andsiRNA techniques blocked mitochondrial translocation. Mitochondrial translocation wasalso evident by transmission electron microscopy in skin mast cells from atopicdermatitis biopsies, in which gene expression of calcineurin, DRP1 and SP are highercompared to normal skin. In conclusion, human mast cell activation participates in the pathogenesis of atopicdermatitis and requires mitochondrial dynamics. Atopic dermatitis patients could benefitfrom the development of new therapeutic agents targeting mast cell activation.


2007 ◽  
Vol 204 (4) ◽  
pp. 963-963
Author(s):  
Xiaoyang Hua ◽  
Martina Kovarova ◽  
Kelly D. Chason ◽  
MyTrang Nguyen ◽  
Beverly H. Koller ◽  
...  

2008 ◽  
Vol 105 (46) ◽  
pp. 18053-18057 ◽  
Author(s):  
Katherine M. Nautiyal ◽  
Ana C. Ribeiro ◽  
Donald W. Pfaff ◽  
Rae Silver

Mast cells are resident in the brain and contain numerous mediators, including neurotransmitters, cytokines, and chemokines, that are released in response to a variety of natural and pharmacological triggers. The number of mast cells in the brain fluctuates with stress and various behavioral and endocrine states. These properties suggest that mast cells are poised to influence neural systems underlying behavior. Using genetic and pharmacological loss-of-function models we performed a behavioral screen for arousal responses including emotionality, locomotor, and sensory components. We found that mast cell deficient KitW−sh/W−sh (sash−/−) mice had a greater anxiety-like phenotype than WT and heterozygote littermate control animals in the open field arena and elevated plus maze. Second, we show that blockade of brain, but not peripheral, mast cell activation increased anxiety-like behavior. Taken together, the data implicate brain mast cells in the modulation of anxiety-like behavior and provide evidence for the behavioral importance of neuroimmune links.


2021 ◽  
pp. 000348942199503
Author(s):  
Michael A. Belsky ◽  
Erica Corredera ◽  
Hridesh Banerjee ◽  
John Moore ◽  
Li Wang ◽  
...  

Objectives: Previous work showed that higher polyp mast cell load correlated with worse postoperative endoscopic appearance in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Polyp epithelial mast cells showed increased expression of T-cell/transmembrane immunoglobulin and mucin domain protein 3 (TIM-3), a receptor that promotes mast cell activation and cytokine production. In this study, CRSwNP patients were followed post-operatively to investigate whether mast cell burden or TIM-3 expression among mast cells can predict recalcitrant disease. Methods: Nasal polyp specimens were obtained via functional endoscopic sinus surgery (FESS) and separated into epithelial and stromal layers via enzymatic digestion. Mast cells and TIM-3-expressing mast cells were identified via flow cytometry. Mann-Whitney U tests and Cox proportional hazard models assessed whether mast cell burden and TIM-3 expression were associated with clinical outcomes, including earlier recurrence of polypoid edema and need for treatment with steroids. Results: Twenty-three patients with CRSwNP were studied and followed for 6 months after undergoing FESS. Higher mast cell levels were associated with earlier recurrence of polypoid edema: epithelial HR = 1.283 ( P = .02), stromal HR = 1.103 ( P = .02). Percent of mast cells expressing TIM-3 in epithelial or stromal layers was not significantly associated with earlier recurrence of polypoid edema. Mast cell burden and TIM-3+ expression were not significantly associated with need for future treatment with steroids post-FESS. Conclusions: Mast cell load in polyp epithelium and stroma may predict a more refractory postoperative course for CRSwNP patients. The role of TIM-3 in the chronic inflammatory state seen in CRSwNP remains unclear.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Ilze Bot ◽  
Saskia C de Jager ◽  
Alma Zernecke ◽  
Christian Weber ◽  
Theo J van Berkel ◽  
...  

Activated mast cells have been identified in the perivascular tissue of human coronary artery plaques. As mast cells have been described to release a whole array of chemokines including interleukin 8 (IL-8) and MIP1 α, we propose that activated mast cells play a pivotal role in leukocyte recruitment at advanced stages of atherosclerotic plaque development. Peritoneal mast cells of either C57Bl/6 or mast cell deficient Kit(W −sh /W −sh ) mice were activated by injection of compound 48/80 (1.2 mg/kg). Interestingly, mast cell activation led to a massive neutrophil influx into the peritoneal cavity at 3 hours after activation (controls: 1 ± 0.7*10 4 Gr1 + -neutrophils/ml up to 8 ± 0.2*10 4 Gr1 + neutrophils/ml at 3 hours after activation, *P<0.05), while neutrophil numbers in Kit(W −sh /W −sh ) mice were not affected by compound 48/80 administration. Moreover, increased levels of CXCR2 + Gr1 + neutrophils (t=0: 0.55 ± 0.07% versus t=3 hours: 1.00 ± 0.12%, *P<0.05) were observed after mast cell activation. Next, we investigated whether mast cell activation also translated in induced leukocyte adhesion to advanced atherosclerotic plaques. Adventitial mast cells of advanced collar aided carotid artery plaques were activated by local application of a dinitrophenyl-BSA (DNP) challenge in ApoE −/− mice. Three days later, the carotid artery segments carrying the plaques were isolated and perfused ex vivo with rhodamine labeled leukocytes, showing a dramatically increased number of adherent leukocytes after mast cell activation (49 ± 6 versus 19 ± 4 leukocytes/microscopic field for DNP versus control plaques, respectively, **P<0.001). Strikingly, antibody blockade of either the CXCR2 or VCAM-1 receptor VLA-4 on labeled leukocytes completely inhibited leukocyte adhesion to the atherosclerotic plaque (*P<0.05), while blockade of CCR1, -3 and -5 with Met-RANTES had no effect. In conclusion, our data suggest that chemokines such as IL-8 released from activated perivascular mast cells induce leukocyte recruitment and adhesion to the atherosclerotic plaque, aggravating the ongoing inflammatory response and thus effecting plaque destabilization. We propose that mast cell stabilization could be a new therapeutic approach in the prevention of acute coronary syndromes.


1999 ◽  
Vol 86 (1) ◽  
pp. 202-210 ◽  
Author(s):  
N. Noviski ◽  
J. P. Brewer ◽  
W. A. Skornik ◽  
S. J. Galli ◽  
J. M. Drazen ◽  
...  

Exposure to ambient ozone (O3) is associated with increased exacerbations of asthma. We sought to determine whether mast cell degranulation is induced by in vivo exposure to O3in mice and whether mast cells play an essential role in the development of pulmonary pathophysiological alterations induced by O3. For this we exposed mast cell-deficient WBB6F1- kitW/ kitW-v( kitW/ kitW-v) mice and the congenic normal WBB6F1(+/+) mice to air or to 1 or 3 parts/million O3for 4 h and studied them at different intervals from 4 to 72 h later. We found evidence of O3-induced cutaneous, as well as bronchial, mast cell degranulation. Polymorphonuclear cell influx into the pulmonary parenchyma was observed after exposure to 1 part/milllion O3only in mice that possessed mast cells. Airway hyperresponsiveness to intravenous methacholine measured in vivo under pentobarbital anesthesia was observed in both kitW/ kitW-vand +/+ mice after exposure to O3. Thus, although mast cells are activated in vivo by O3and participate in O3-induced polymorphonuclear cell infiltration into the pulmonary parenchyma, they do not participate detectably in the development of O3-induced airway hyperresponsiveness in mice.


2013 ◽  
Vol 81 (6) ◽  
pp. 2085-2094 ◽  
Author(s):  
Elin Rönnberg ◽  
Gabriela Calounova ◽  
Bengt Guss ◽  
Anders Lundequist ◽  
Gunnar Pejler

ABSTRACTGranzymes are serine proteases known mostly for their role in the induction of apoptosis. Granzymes A and B have been extensively studied, but relatively little is known about granzymes C to G and K to M. T cells, lymphohematopoietic stromal cells, and granulated metrial gland cells express granzyme D, but the function of granzyme D is unknown. Here we show that granzyme D is expressed by murine mast cells and that its level of expression correlates positively with the extent of mast cell maturation. Coculture of mast cells with live, Gram-positive bacteria caused a profound, Toll-like receptor 2 (TLR2)-dependent induction of granzyme D expression. Granzyme D expression was also induced by isolated bacterial cell wall components, including lipopolysaccharide (LPS) and peptidoglycan, and by stem cell factor, IgE receptor cross-linking, and calcium ionophore stimulation. Granzyme D was released into the medium in response to mast cell activation. Granzyme D induction was dependent on protein kinase C and nuclear factor of activated T cells (NFAT). Together, these findings identify granzyme D as a novel murine mast cell protease and implicate granzyme D in settings where mast cells are activated, such as bacterial infection and allergy.


Author(s):  
Goutham Pattabiraman ◽  
Ashlee J Bell-Cohn ◽  
Stephen F. Murphy ◽  
Daniel J Mazur ◽  
Anthony J Schaeffer ◽  
...  

Intraurethral inoculation of mice with uropathogenic E. coli (CP1) results in prostate inflammation, fibrosis, and urinary dysfunction, recapitulating some but not all of the pathognomonic clinical features associated with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). In both patients with LUTS and in CP1-infected mice, we observed increased numbers and activation of mast cells and elevated levels of prostate fibrosis. Therapeutic inhibition of mast cells using a combination of mast cell stabilizer (MCS), cromolyn sodium, and the histamine 1 receptor antagonist (H1RA), cetirizine di-hydrochloride, in the mouse model resulted in reduced mast cell activation in the prostate and significant alleviation of urinary dysfunction. Treated mice showed reduced prostate fibrosis, less infiltration of immune cells, and decreased inflammation. In addition, as opposed to symptomatic CP1-infected mice, treated mice showed reduced myosin light chain (MLC)-2 phosphorylation, a marker of prostate smooth muscle contraction. These results show that mast cells play a critical role in the pathophysiology of urinary dysfunction and may be an important therapeutic target for men with BPH/LUTS.


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