scholarly journals Impaired degranulation but enhanced cytokine production after FcεRI stimulation of diacylglycerol kinase ζ–deficient mast cells

2006 ◽  
Vol 203 (6) ◽  
pp. 1471-1480 ◽  
Author(s):  
Benjamin A. Olenchock ◽  
Rishu Guo ◽  
Michael A. Silverman ◽  
Jennifer N. Wu ◽  
Jeffery H. Carpenter ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cytokine Production ◽  
Cell Function ◽  
Second Messengers ◽  
Diacylglycerol Kinase ◽  
Negative Regulator ◽  
Calcium Flux ◽  
Cross Linking

Calcium and diacylglycerol are critical second messengers that together effect mast cell degranulation after allergen cross-linking of immunoglobulin (Ig)E-bound FcεRI. Diacylglycerol kinase (DGK)ζ is a negative regulator of diacylglycerol-dependent signaling that acts by converting diacylglycerol to phosphatidic acid. We reported previously that DGKζ−/− mice have enhanced in vivo T cell function. Here, we demonstrate that these mice have diminished in vivo mast cell function, as revealed by impaired local anaphylactic responses. Concordantly, DGKζ−/− bone marrow–derived mast cells (BMMCs) demonstrate impaired degranulation after FcεRI cross-linking, associated with diminished phospholipase Cγ activity, calcium flux, and protein kinase C–βII membrane recruitment. In contrast, Ras-Erk signals and interleukin-6 production are enhanced, both during IgE sensitization and after antigen cross-linking of FcεRI. Our data demonstrate dissociation between cytokine production and degranulation in mast cells and reveal the importance of DGK activity during IgE sensitization for proper attenuation of FcεRI signals.

scholarly journals Glutamate triggers the expression of functional ionotropic and metabotropic glutamate receptors in mast cells

2020 ◽  
Author(s):  
Md Abdul Alim ◽  
Mirjana Grujic ◽  
Paul W. Ackerman ◽  
Per Kristiansson ◽  
Pernilla Eliasson ◽  
...  
Keyword(s):  
Mast Cell ◽  
Immune System ◽  
Mast Cells ◽  
Glutamate Receptors ◽  
Glutamate Receptor ◽  
Metabotropic Glutamate Receptors ◽  
Cell Function ◽  
Metabotropic Glutamate ◽  
Protein Levels

Abstract Mast cells are emerging as players in the communication between peripheral nerve endings and cells of the immune system. However, it is not clear the mechanism by which mast cells communicate with peripheral nerves. We previously found that mast cells located within healing tendons can express glutamate receptors, raising the possibility that mast cells may be sensitive to glutamate signaling. To evaluate this hypothesis, we stimulated primary mast cells with glutamate and showed that glutamate induced the profound upregulation of a panel of glutamate receptors of both the ionotropic type (NMDAR1, NMDAR2A, and NMDAR2B) and the metabotropic type (mGluR2 and mGluR7) at both the mRNA and protein levels. The binding of glutamate to glutamate receptors on the mast cell surface was confirmed. Further, glutamate had extensive effects on gene expression in the mast cells, including the upregulation of pro-inflammatory components such as IL-6 and CCL2. Glutamate also induced the upregulation of transcription factors, including Egr2, Egr3 and, in particular, FosB. The extensive induction of FosB was confirmed by immunofluorescence assessment. Glutamate receptor antagonists abrogated the responses of the mast cells to glutamate, supporting the supposition of a functional glutamate–glutamate receptor axis in mast cells. Finally, we provide in vivo evidence supporting a functional glutamate–glutamate receptor axis in the mast cells of injured tendons. Together, these findings establish glutamate as an effector of mast cell function, thereby introducing a novel principle for how cells in the immune system can communicate with nerve cells.

scholarly journals p85β regulatory subunit of class IA PI3 kinase negatively regulates mast cell growth, maturation, and leukemogenesis

Blood ◽  
2012 ◽  
Vol 119 (17) ◽  
pp. 3951-3961 ◽  
Author(s):  
Subha Krishnan ◽  
Raghuveer Singh Mali ◽  
Baskar Ramdas ◽  
Emily Sims ◽  
Peilin Ma ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cell Function ◽  
Receptor Internalization ◽  
Regulatory Subunit ◽  
Growth Defects ◽  
Microphthalmia Transcription Factor ◽  
Carboxy Terminal

Abstract We show that loss of p85α inhibits the growth and maturation of mast cells, whereas loss of p85β enhances this process. Whereas restoring the expression of p85α in P85α−/− cells restores these functions, overexpression of p85β has the opposite effect. Consistently, overexpression of p85β in WT mast cells represses KIT-induced proliferation and IL-3–mediated maturation by inhibiting the expression of Microphthalmia transcription factor. Because p85α and p85β differ in their N-terminal sequences, chimeric proteins consisting of amino or carboxy-terminal of p85α and/or p85β do not rescue the growth defects of p85α−/− cells, suggesting cooperation between these domains for normal mast cell function. Loss of p85β impaired ligand induced KIT receptor internalization and its overexpression enhanced this process, partly because of increased binding of c-Cbl to p85β relative to p85α. In vivo, loss of p85β resulted in increased mast cells, and bone marrow transplantation of cells overexpressing p85β resulted in significant reduction in some tissue mast cells. Overexpression of p85β suppressed the growth of oncogenic KIT-expressing cells in vitro and prolonged the survival of leukemic mice in vivo. Thus, p85α and p85β differentially regulate SCF and oncogenic KIT-induced signals in myeloid lineage-derived mast cells.

scholarly journals Pak1 regulates multiple c-Kit mediated Ras-MAPK gain-in-function phenotypes in Nf1+/− mast cells

Blood ◽  
2008 ◽  
Vol 112 (12) ◽  
pp. 4646-4654 ◽  
Author(s):  
Andrew S. McDaniel ◽  
Jayme D. Allen ◽  
Su-Jung Park ◽  
Zahara M Jaffer ◽  
Elizabeth G. Michels ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Mapk Pathway ◽  
Genetic Disorder ◽  
Neurofibromatosis Type ◽  
Mapk Signaling ◽  
Tumor Formation ◽  
Negative Regulator ◽  
P21 Activated Kinase

Abstract Neurofibromatosis type 1 (NF1) is a common genetic disorder caused by mutations in the NF1 locus, which encodes neurofibromin, a negative regulator of Ras. Patients with NF1 develop numerous neurofibromas, which contain many inflammatory mast cells that contribute to tumor formation. Subsequent to c-Kit stimulation, signaling from Ras to Rac1/2 to the MAPK pathway appears to be responsible for multiple hyperactive mast cell phenotypes; however, the specific effectors that mediate these functions remain uncertain. p21-activated kinase 1 (Pak1) is a downstream mediator of Rac1/2 that has been implicated as a positive regulator of MAPK pathway members and is a modulator of cell growth and cytoskeletal dynamics. Using an intercross of Pak 1−/− mice with Nf1+/− mice, we determined that Pak1 regulates hyperactive Ras-dependent proliferation via a Pak1/Erk pathway, whereas a Pak1/p38 pathway is required for the increased migration in Nf1+/− mast cells. Furthermore, we confirmed that loss of Pak1 corrects the dermal accumulation of Nf1+/− mast cells in vivo to levels found in wild-type mice. Thus, Pak1 is a novel mast cell mediator that functions as a key node in the MAPK signaling network and potential therapeutic target in NF1 patients.

scholarly journals SWAP-70 Regulates c-kit-Induced Mast Cell Activation, Cell-Cell Adhesion, and Migration

2004 ◽  
Vol 24 (23) ◽  
pp. 10277-10288 ◽  
Author(s):  
Raja Rajeswari Sivalenka ◽  
Rolf Jessberger
Keyword(s):  
Mast Cell ◽  
Cell Adhesion ◽  
Mast Cells ◽  
Cell Activation ◽  
Mast Cell Activation ◽  
Calcium Flux ◽  
Mutant Cells

ABSTRACT SWAP-70, an unusual phosphatidylinositol-3-kinase-dependent protein that interacts with the RhoGTPase Rac, is highly expressed in mast cells. Cultured bone marrow mast cells (BMMC) from SWAP-70−/− mice are reduced in FcεRI-triggered degranulation. This report describes the hitherto-unknown role of SWAP-70 in c-kit receptor signaling, a key proliferation and differentiation pathway in mast cells. Consistent with the role of Rac in cell motility and regulation of the actin cytoskeleton, mutant cells show abnormal actin rearrangements and are deficient in migration in vitro and in vivo. SWAP-70−/− BMMC are impaired in calcium flux, in proper translocation and activity of Akt kinase (required for mast cell activation and survival), and in translocation of Rac1 and Rac2 upon c-kit stimulation. Adhesion to fibronectin is reduced, but homotypic cell association induced through c-kit is strongly increased in SWAP-70−/− BMMC. Homotypic association requires extracellular Ca2+ and depends on the integrin αLβ2 (LFA-1). ERK is hyperactivated upon c-kit signaling in adherent and dispersed mutant cells. Together, we suggest that SWAP-70 is an important regulator of specific effector pathways in c-kit signaling, including mast cell activation, migration, and cell adhesion.

scholarly journals Positive and Negative Regulation of FcεRI-Mediated Signaling by the Adaptor Protein LAB/NTAL

2004 ◽  
Vol 200 (8) ◽  
pp. 991-1000 ◽  
Author(s):  
Minghua Zhu ◽  
Yan Liu ◽  
Surapong Koonpaew ◽  
Olivia Granillo ◽  
Weiguo Zhang
Keyword(s):  
B Cells ◽  
Mast Cells ◽  
Cytokine Production ◽  
Cell Function ◽  
Adaptor Protein ◽  
Thymocyte Development ◽  
Positive Role ◽  
Erk Activation ◽  
Deficient Mice

Linker for activation of B cells (LAB, also called NTAL; a product of wbscr5 gene) is a newly identified transmembrane adaptor protein that is expressed in B cells, NK cells, and mast cells. Upon BCR activation, LAB is phosphorylated and interacts with Grb2. LAB is capable of rescuing thymocyte development in LAT-deficient mice. To study the in vivo function of LAB, LAB-deficient mice were generated. Although disruption of the Lab gene did not affect lymphocyte development, it caused mast cells to be hyperresponsive to stimulation via the FcεRI, evidenced by enhanced Erk activation, calcium mobilization, degranulation, and cytokine production. These data suggested that LAB negatively regulates mast cell function. However, mast cells that lacked both linker for activation of T cells (LAT) and LAB proteins had a more severe block in FcεRI-mediated signaling than LAT−/− mast cells, demonstrating that LAB also shares a redundant function with LAT to play a positive role in FcεRI-mediated signaling.

scholarly journals Rcan1 negatively regulates FcɛRI-mediated signaling and mast cell function

2009 ◽  
Vol 206 (1) ◽  
pp. 195-207 ◽  
Author(s):  
Yong Jun Yang ◽  
Wei Chen ◽  
Alexander Edgar ◽  
Bo Li ◽  
Jeffery D. Molkentin ◽  
...  
Keyword(s):  
Mast Cell ◽  
Cell Activation ◽  
Cytokine Production ◽  
Cell Function ◽  
Immunoglobulin E ◽  
Quantitative Polymerase Chain Reaction ◽  
Late Phase ◽  
Negative Regulator ◽  
Mast Cell Activation ◽  
Nuclear Factor

Aggregation of the high affinity IgE receptor (FcɛRI) activates a cascade of signaling events leading to mast cell activation. Subsequently, inhibitory signals are engaged for turning off activating signals. We identified that regulator of calcineurin (Rcan) 1 serves as a negative regulator for turning off FcɛRI-mediated mast cell activation. FcɛRI-induced Rcan1 expression was identified by suppression subtractive hybridization and verified by real-time quantitative polymerase chain reaction and Western blotting. Deficiency of Rcan1 led to increased calcineurin activity, increased nuclear factor of activated T cells and nuclear factor κB activation, increased cytokine production, and enhanced immunoglobulin E–mediated late-phase cutaneous reactions. Forced expression of Rcan1 in wild-type or Rcan1-deficient mast cells reduced FcɛRI-mediated cytokine production. Rcan1 deficiency also led to increased FcɛRI-mediated mast cell degranulation and enhanced passive cutaneous anaphylaxis. Analysis of the Rcan1 promoter identified a functional Egr1 binding site. Biochemical and genetic evidence suggested that Egr1 controls Rcan1 expression. Our results identified Rcan1 as a novel inhibitory signal in FcɛRI-induced mast cell activation and established a new link of Egr1 and Rcan1 in FcɛRI signaling.

scholarly journals Blunted IgE-mediated activation of mast cells in mice lacking the serum- and glucocorticoid-inducible kinase SGK3

2010 ◽  
Vol 299 (5) ◽  
pp. C1007-C1014 ◽  
Author(s):  
Irina M. Zemtsova ◽  
Nicole Heise ◽  
Henning Fröhlich ◽  
Syed M. Qadri ◽  
Yuliya Kucherenko ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cell Function ◽  
Sharp Decrease ◽  
Pi3 Kinase ◽  
Antigen Stimulation ◽  
Intracellular Ca ◽  
Cognate Antigen

Previous studies have shown that pharmacological inhibition of the phosphoinositol-3 (PI3) kinase disrupts the activation of mast cells. Through phosphoinositide-dependent kinase PDK1, PI3 kinase activates the serum- and glucocorticoid-inducible kinase 3 (SGK3). The present study explored the role of SGK3 in mast cell function. Mast cells were isolated and cultured from bone marrow (BMMCs) of gene-targeted mice lacking SGK3 ( sgk3 −/−) and their wild-type littermates ( sgk3 +/+). BMMC numbers in the ear conch were similar in both genotypes. Stimulation with IgE and cognate antigen triggered the release of intracellular Ca2+ and entry of extracellular Ca2+. Influx of extracellular Ca2+ but not Ca2+ release from intracellular stores was significantly blunted in sgk3 −/− BMMCs compared with sgk3 +/+ BMMCs. Antigen stimulation further led to a rapid increase of a K+-selective conductance in sgk3 +/+ BMMCs, an effect again blunted in sgk3 −/− BMMCs. In contrast, the Ca2+ ionophore ionomycin activated K+ currents to a similar extent in sgk3 −/− and in sgk3 +/+ BMMCs. β-Hexosaminidase release, triggered by antigen stimulation, was also significantly decreased in sgk3 −/− BMMCs. IgE-dependent anaphylaxis measured as a sharp decrease in body temperature upon injection of DNP-HSA antigen was again significantly blunted in sgk3 −/− compared with sgk3 +/+ mice. Serum histamine levels measured 30 min after induction of an anaphylactic reaction were significantly lower in sgk3 −/− than in sgk3 +/+ mice. In conclusion, both in vitro and in vivo function of BMMCs are impaired in gene targeted mice lacking SGK3. Thus SGK3 is critical for proper mast cell function.

scholarly journals Exon skipping of FcεRIβ eliminates expression of the high-affinity IgE receptor in mast cells with therapeutic potential for allergy

2016 ◽  
Vol 113 (49) ◽  
pp. 14115-14120 ◽  
Author(s):  
Glenn Cruse ◽  
Yuzhi Yin ◽  
Tomoki Fukuyama ◽  
Avanti Desai ◽  
Greer K. Arthur ◽  
...  
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Cell Function ◽  
Specific Treatment ◽  
Exon Skipping ◽  
Allergic Diseases ◽  
Ige Receptor ◽  
High Affinity ◽  
High Affinity Ige Receptor

Allergic diseases are driven by activation of mast cells and release of mediators in response to IgE-directed antigens. However, there are no drugs currently available that can specifically down-regulate mast cell function in vivo when chronically administered. Here, we describe an innovative approach for targeting mast cells in vitro and in vivo using antisense oligonucleotide-mediated exon skipping of the β-subunit of the high-affinity IgE receptor (FcεRIβ) to eliminate surface high-affinity IgE receptor (FcεRI) expression and function, rendering mast cells unresponsive to IgE-mediated activation. As FcεRIβ expression is restricted to mast cells and basophils, this approach would selectively target these cell types. Given the success of exon skipping in clinical trials to treat genetic diseases such as Duchenne muscular dystrophy, we propose that exon skipping of FcεRIβ is a potential approach for mast cell-specific treatment of allergic diseases.

Analysis of mouse LMIR5/CLM-7 as an activating receptor: differential regulation of LMIR5/CLM-7 in mouse versus human cells

Blood ◽  
2008 ◽  
Vol 111 (2) ◽  
pp. 688-698 ◽  
Author(s):  
Yoshinori Yamanishi ◽  
Jiro Kitaura ◽  
Kumi Izawa ◽  
Takayuki Matsuoka ◽  
Toshihiko Oki ◽  
...  
Keyword(s):  
Mast Cells ◽  
Cytokine Production ◽  
Fetal Liver ◽  
Human Cells ◽  
Cross Linking ◽  
Wild Type ◽  
Predominant Role ◽  
Innate Immunity Cells ◽  
Production Cell ◽  
Activating Receptor

We have analyzed leukocyte mono-Ig–like receptor 5 (LMIR5) as an activating receptor among paired LMIRs. Mouse LMIR5 (mLMIR5) is expressed in myeloid cells such as mast cells, granulocytes, macrophages, and dendritic cells. Cross-linking of transduced mLMIR5 in bone marrow–derived mast cells (BMMCs) caused activation events, including cytokine production, cell survival, degranulation, and adhesion to the extracellular matrix. mLMIR5 associated with DAP12 and to a lesser extent with DAP10, and mLMIR5-mediated functions of BMMCs were strongly inhibited by DAP12 deficiency. Importantly, cross-linking of endogenous mLMIR5 induced Syk-dependent activation of fetal liver–derived mast cells. Unlike mLMIR5, cross-linking of human LMIR5 (hLMIR5) induced cytokine production of BMMCs even in the absence of both DAP12 and DAP10, suggesting the existence of unidentified adaptors. Interestingly, hLMIR5 possessed a tyrosine residue (Y188) in the cytoplasmic region. Signaling via Y188 phosphorylation played a predominant role in hLMIR5-mediated cytokine production in DAP12-deficient, but not wild-type BMMCs. In addition, experiments using DAP10/DAP12 double-deficient BMMCs suggested the existence of Y188 phoshorylation-dependent and -independent signals from unidentified adaptors. Collectively, although both mouse and human LMIR5 play activatory roles in innate immunity cells, the functions of LMIR5 were differentially regulated in mouse versus human cells.

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