| 1. |
- Tang, Xiao, et al.
(författare)
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Activation of succinate receptor 1 boosts human mast cell reactivity and allergic bronchoconstriction
- 2022
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Ingår i: Allergy. European Journal of Allergy and Clinical Immunology. - : John Wiley & Sons. - 0105-4538 .- 1398-9995. ; 77:9, s. 2677-2687
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Tidskriftsartikel (refereegranskat)abstract
- Background SUCNR1 is a sensor of extracellular succinate, a Krebs cycle intermediate generated in excess during oxidative stress and has been linked to metabolic regulation and inflammation. While mast cells express SUCNR1, its role in mast cell reactivity and allergic conditions such as asthma remains to be elucidated. Methods Cord blood-derived mast cells and human mast cell line LAD-2 challenged by SUCNR1 ligands were analyzed for the activation and mediator release. Effects on mast cell-dependent bronchoconstriction were assessed in guinea pig trachea and isolated human small bronchi challenged with antigen and anti-IgE, respectively. Results SUCNR1 is abundantly expressed on human mast cells. Challenge with succinate, or the synthetic non-metabolite agonist cis-epoxysuccinate, renders mast cells hypersensitive to IgE-dependent activation, resulting in augmented degranulation and histamine release, de novo biosynthesis of eicosanoids and cytokine secretion. The succinate-potentiated mast cell reactivity was attenuated by SUCNR1 knockdown and selective SUCNR1 antagonists and could be tuned by pharmacologically targeting protein kinase C and extracellular signal-regulated kinase. Both succinate and cis-epoxysuccinate dose-dependently potentiated antigen-induced contraction in a mast cell-dependent guinea pig airway model, associated with increased generation of cysteinyl-leukotrienes and histamine in trachea. Similarly, cis-epoxysuccinate aggravated IgE-receptor-induced contraction of human bronchi, which was blocked by SUCNR1 antagonism. Conclusion SUCNR1 amplifies IgE-receptor-induced mast cell activation and allergic bronchoconstriction, suggesting a role for this pathway in aggravation of allergic asthma, thus linking metabolic perturbations to mast cell-dependent inflammation.
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| 2. |
- Adner, Mikael, et al.
(författare)
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Budesonide Prevents Cytokine-Induced Decrease of the Relaxant Responses to Formoterol and Terbutaline, but Not to Salmeterol, in Mouse Trachea
- 2010
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0103 .- 0022-3565. ; 333:1, s. 273-280
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Tidskriftsartikel (refereegranskat)abstract
- During asthma exacerbations, increased airway inflammation may impair the effects of beta(2)-adrenoceptor (beta(2)AR) agonists. It is unclear whether this impairment is prevented by inhaled glucocorticoids (GCs). We have investigated the relaxation of carbachol-contracted mouse tracheal segments to the beta(2)AR agonists formoterol, terbutaline, and salmeterol. The segments were pre-exposed for 4 days to the proinflammatory cytokines tumor necrosis factor alpha (100 ng/ml) and interleukin-1 beta (10 ng/ml) with or without the GC, budesonide (1 mu M). Formoterol and terbutaline induced greater maximal relaxation (R-max)than salmeterol. The cytokines decreased R-max of all beta(2)AR agonists, whereas budesonide had no effect. However, after concomitant treatment with cytokines and budesonide, the R-max values of formoterol and terbutaline were not impaired, whereas budesonide did not prevent the decrease in the R-max of salmeterol. A similar pattern was observed for cAMP production by the agonists. In tracheal smooth muscle, beta(2)AR mRNA was not affected by the cytokines but increased with budesonide. However, the cytokines markedly increased cyclooxygenase (COX)-2 mRNA expression, which may lead to heterologous desensitization of beta(2)AR. It is noteworthy that the cytokine-induced increase of COX-2 was blocked by concomitant budesonide suggesting that heterologous desensitization of beta(2)AR by the cytokines may be prevented by budesonide treatment. Budesonide prevented cytokine-induced impairment of the tracheal relaxation and beta(2)AR/cAMP signaling for formoterol but not for salmeterol. This suggests that differences exist between formoterol and salmeterol in beta(2)AR coupling/activation and/or signal transduction upstream of cAMP. These results imply that maximal bronchodilator effects of formoterol, but not of salmeterol, are maintained by budesonide treatment during periods with increased inflammation, such as asthma exacerbations.
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| 3. |
- Ronnberg, Elin, et al.
(författare)
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Analysis of human lung mast cells by single cell RNA sequencing
- 2023
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are tissue-resident cells playing major roles in homeostasis and disease conditions. Lung mast cells are particularly important in airway inflammatory diseases such as asthma. Human mast cells are classically divided into the subsets MCT and MCTC, where MCT express the mast cell protease tryptase and MCTC in addition express chymase, carboxypeptidase A3 (CPA3) and cathepsin G. Apart from the disctintion of the MCT and MCTC subsets, little is known about the heterogeniety of human lung mast cells and a deep analysis of their heterogeniety has previously not been performed. We therefore performed single cell RNA sequencing on sorted human lung mast cells using SmartSeq2. The mast cells showed high expression of classical mast cell markers. The expression of several individual genes varied considerably among the cells, however, no subpopulations were detected by unbiased clustering. Variable genes included the protease-encoding transcripts CMA1 (chymase) and CTSG (cathepsin G). Human lung mast cells are predominantly of the MCT subset and consistent with this, the expression of CMA1 was only detectable in a small proportion of the cells, and correlated moderately to CTSG. However, in contrast to established data for the protein, CPA3 mRNA was high in all cells and the correlation of CPA3 to CMA1 was weak.
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| 4. |
- Ronnberg, Elin, et al.
(författare)
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Immunoprofiling Reveals Novel Mast Cell Receptors and the Continuous Nature of Human Lung Mast Cell Heterogeneity
- 2022
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Immunohistochemical analysis of granule-associated proteases has revealed that human lung mast cells constitute a heterogeneous population of cells, with distinct subpopulations identified. However, a systematic and comprehensive analysis of cell-surface markers to study human lung mast cell heterogeneity has yet to be performed.Methods: Human lung mast cells were obtained from lung lobectomies, and the expression of 332 cell-surface markers was analyzed using flow cytometry and the LEGENDScreen (TM) kit. Markers that exhibited high variance were selected for additional analyses to reveal whether they were correlated and whether discrete mast cell subpopulations were discernable.Results: We identified the expression of 102 surface markers on human lung mast cells, 23 previously not described on mast cells, of which several showed high continuous variation in their expression. Six of these markers were correlated: SUSD2, CD49a, CD326, CD34, CD66 and HLA-DR. The expression of these markers was also correlated with the size and granularity of mast cells. However, no marker produced an expression profile consistent with a bi- or multimodal distribution.Conclusions: LEGENDScreen analysis identified more than 100 cell-surface markers on mast cells, including 23 that, to the best of our knowledge, have not been previously described on human mast cells. The comprehensive expression profiling of the 332 surface markers did not identify distinct mast cell subpopulations. Instead, we demonstrate the continuous nature of human lung mast cell heterogeneity.
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| 5. |
- Tebroke, Julia, et al.
(författare)
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Wnt-3a Induces Cytokine Release in Human Mast Cells
- 2019
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Ingår i: Cells. - : MDPI. - 2073-4409. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are well known for their detrimental effects in allergies and asthma, and Wnt signaling has recently been implicated in asthma and other airway diseases. However, it is not known if or how Wnts affect human mast cells. Since Wnt expression is elevated in individuals with asthma and is linked to a Th2 profile, we hypothesized that mast cells could be affected by Wnts in the context of asthma. We therefore sought to investigate the role of Wnt signaling in human mast cell development and activation. We first examined the expression of the 10 main Wnt receptors, Frizzled 1-10 (FZD(1-10)), and found expression of several FZDs in human mast cells. Treatment with purified recombinant Wnt-3a or Wnt-5a did not affect the proliferation or maturation of CD34(+) progenitors into mast cells, as indicated by cellular expression of CD117 and Fc epsilon RI, activation by Fc epsilon RI crosslinking, and histamine and tryptase release. Furthermore, Wnt treatment did not change the phenotype from MCT to MCTC, since MrgX2 expression, compound 48/80-mediated activation, and carboxypeptidase A3 content were not affected. However, Wnt-3a activated WNT/beta-catenin signaling in mature human mast cells, as revealed by stabilization of beta-catenin, upregulation of IL-8 and CCL8 mRNA expression, and release of IL-8 protein. Thus, our data suggest that Wnt-3a activation of mast cells could contribute to the recruitment of immune cells in conditions associated with increased Wnt-3a expression, such as asthma.
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