scholarly journals Roles for Ca2+ mobilization and its regulation in mast cell functions: recent progress

2016 ◽  
Vol 44 (2) ◽  
pp. 505-509 ◽  
Author(s):  
David Holowka ◽  
Marcus Wilkes ◽  
Christopher Stefan ◽  
Barbara Baird
Keyword(s):  
Membrane Protein ◽  
Cross Linking ◽  
Recycling Endosomes ◽  
Cell Functions ◽  
High Affinity ◽  
Rho Family Gtpases ◽  
High Affinity Receptor ◽  
Selective Channel ◽  
Affinity Receptor ◽  
Rho Family

Ca2+ mobilization in response to cross-linking of IgE bound to its high affinity receptor, FcεRI, on mast cells is central to immune allergic responses. Stimulated tyrosine phosphorylation caused by this cross-linking activates store-operated Ca2+ entry that results in sustained Ca2+ oscillations dependent on Rho family GTPases and phosphoinositide synthesis. Coupling of the endoplasmic reticulum (ER) Ca2+ sensor, stromal interaction molecule 1 (STIM1), to the Ca2+-selective channel, Orai1, is regulated by these elements and depends on membrane organization, both at the plasma membrane and at the ER. Mitochondria also contribute to the regulation of Ca2+ mobilization, and we describe recent evidence that the ER membrane protein vesicle-associated membrane protein-associated protein (VAP) plays a significant role in the coupling between ER and mitochondria in this process. In addition to granule exocytosis, Ca2+ mobilization in these cells also contributes to stimulated outward trafficking of recycling endosomes and to antigen-stimulated chemotaxis, and it is pathologically regulated by protozoan parasitic invasion.

scholarly journals Transactivation of Sphingosine-1–Phosphate Receptors by FcεRI Triggering Is Required for Normal Mast Cell Degranulation and Chemotaxis

2004 ◽  
Vol 199 (7) ◽  
pp. 959-970 ◽  
Author(s):  
Puneet S. Jolly ◽  
Meryem Bektas ◽  
Ana Olivera ◽  
Claudia Gonzalez-Espinosa ◽  
Richard L. Proia ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Sphingosine Kinase ◽  
Cross Linking ◽  
Cell Functions ◽  
Sphingosine 1 Phosphate ◽  
High Affinity Receptor ◽  
Affinity Receptor ◽  
And Migration ◽  
Cytoskeletal Rearrangements

Mast cells secrete various substances that initiate and perpetuate allergic responses. Cross-linking of the high-affinity receptor for IgE (FcεRI) in RBL-2H3 and bone marrow–derived mast cells activates sphingosine kinase (SphK), which leads to generation and secretion of the potent sphingolipid mediator, sphingosine-1–phosphate (S1P). In turn, S1P activates its receptors S1P1 and S1P2 that are present in mast cells. Moreover, inhibition of SphK blocks FcεRI-mediated internalization of these receptors and markedly reduces degranulation and chemotaxis. Although transactivation of S1P1 and Gi signaling are important for cytoskeletal rearrangements and migration of mast cells toward antigen, they are dispensable for FcεRI-triggered degranulation. However, S1P2, whose expression is up-regulated by FcεRI cross-linking, was required for degranulation and inhibited migration toward antigen. Together, our results suggest that activation of SphKs and consequently S1PRs by FcεRI triggering plays a crucial role in mast cell functions and might be involved in the movement of mast cells to sites of inflammation.

scholarly journals IL-33 and Superantigenic Activation of Human Lung Mast Cells Induce the Release of Angiogenic and Lymphangiogenic Factors

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 145
Author(s):  
Leonardo Cristinziano ◽  
Remo Poto ◽  
Gjada Criscuolo ◽  
Anne Lise Ferrara ◽  
Maria Rosaria Galdiero ◽  
...  
Keyword(s):  
Mast Cells ◽  
Human Lung ◽  
Protein A ◽  
Protein L ◽  
Variable Regions ◽  
Prolonged Incubation ◽  
High Affinity ◽  
High Affinity Receptor ◽  
Affinity Receptor ◽  
Pleiotropic Functions

Human lung mast cells (HLMCs) express the high-affinity receptor FcεRI for IgE and are strategically located in different compartments of human lung, where they play a role in several inflammatory disorders and cancer. Immunoglobulin superantigens (e.g., protein A of Staphylococcus aureus and protein L of Peptostreptococcus magnus) bind to the variable regions of either the heavy (VH3) or light chain (κ) of IgE. IL-33 is a cytokine expressed by epithelial cells that exerts pleiotropic functions in the lung. The present study investigated whether immunoglobulin superantigens protein A and protein L and IL-33 caused the release of inflammatory (histamine), angiogenic (VEGF-A) and lymphangiogenic (VEGF-C) factors from HLMCs. The results show that protein A and protein L induced the rapid (30 min) release of preformed histamine from HLMCs. By contrast, IL-33 did not induce the release of histamine from lung mast cells. Prolonged incubation (12 h) of HLMCs with superantigens and IL-33 induced the release of VEGF-A and VEGF-C. Preincubation with IL-33 potentiated the superantigenic release of histamine, angiogenic and lymphangiogenic factors from HLMCs. Our results suggest that IL-33 might enhance the inflammatory, angiogenic and lymphangiogenic activities of lung mast cells in pulmonary disorders.

The Temporal Distribution of the 1α,25-Dihydroxycholecalciferol Receptor in the Rat Jejunal Villus

1984 ◽  
Vol 67 (3) ◽  
pp. 285-290 ◽  
Author(s):  
S. D. H. Chan ◽  
D. Atkins
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Calcium Absorption ◽  
Sedimentation Coefficient ◽  
Temporal Distribution ◽  
High Affinity ◽  
High Affinity Receptor ◽  
Affinity Receptor ◽  
Cell Fractions ◽  
Crypt Cells

1. The distribution of the 1α,25-dihydroxycholecalciferol receptor was studied in enterocytes isolated from the upper, mid and lower villus and crypt cells of the jejunum of normal and rachitic rats. 2. In all cell fractions a high-affinity receptor (KD ⋍ 0.07 nmol/l) with a sedimentation coefficient of 3.5S was demonstrated. 3. In normal rats there was a 60% reduction in receptor numbers in crypt cells compared with the mid and upper villous cells. 4. Vitamin D deficiency led to a reduction in receptor numbers in all cell fractions (45% upper villus, 78% crypt cells). 5. The data are compatible with the concept of calcium absorption occurring in the differentiated villous cells and also account for the reduction in absorption in rachitic animals.

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