scholarly journals Role of cytosolic phospholipase A2 in the production of lipid mediators and histamine release in mouse bone-marrow-derived mast cells

2000 ◽  
Vol 352 (2) ◽  
pp. 311-317 ◽  
Author(s):  
Noriaki NAKATANI ◽  
Naonori UOZUMI ◽  
Kazuhiko KUME ◽  
Makoto MURAKAMI ◽  
Ichiro KUDO ◽  
...  

Cytosolic phospholipase A2 (cPLA2) plays a critical role in mast-cell-related allergic responses [Uozumi, Kume, Nagase, Nakatani, Ishii, Tashiro, Komagata, Maki, Ikuta, Ouchi et al. (1997) Nature (London) 390, 618–622]. Bone-marrow-derived mast cells from mice lacking cPLA2 (cPLA-/- mice) were used in order to better define the role of cPLA2 in the maturation and degranulation of such cells. Cross-linking of high-affinity receptors for IgE (FcεRI) on cells from cPLA-/-mice led to the release of negligible amounts of arachidonic acid or its metabolites, the cysteinyl leukotrienes and prostaglandin D2, indicating an essential role for cPLA2 in the production of these allergic and pro-inflammatory lipid mediators. In addition, the histamine content of the mast cells and its release from the cells were reduced to 60%. While these results are in agreement with a reduced anaphylactic phenotype of cPLA-/- mice, the ratios of release of histamine and β-hexosaminidase were, paradoxically, significantly higher for cells from cPLA-/- mice than for those from wild-type mice. Consistently, IgE-induced calcium influx in mast cells was greater and more prolonged in cells from cPLA-/- mice than in those from wild-type mice. Thus the loss of cPLA2 not only diminishes the release of lipid mediators, but also alters degranulation. While the overall effect is still a decrease in the release of mast cell mediators, explaining the in vivo findings, the present study proposes a novel link between cPLA2 and the degranulation machinery.

2000 ◽  
Vol 352 (2) ◽  
pp. 311 ◽  
Author(s):  
Noriaki NAKATANI ◽  
Naonori UOZUMI ◽  
Kazuhiko KUME ◽  
Makoto MURAKAMI ◽  
Ichiro KUDO ◽  
...  

1999 ◽  
Vol 59 (1-6) ◽  
pp. 39
Author(s):  
Bruno L. Diaz ◽  
Hiroshi Fujishima ◽  
RenéO. Sanchez Mejia ◽  
Adam Sapirstein ◽  
Joseph V. Bonventre ◽  
...  

1995 ◽  
Vol 182 (1) ◽  
pp. 197-206 ◽  
Author(s):  
M Murakami ◽  
K F Austen ◽  
J P Arm

c-kit ligand (KL) activated mouse bone marrow-derived mast cells (BMMC) for the dose- and time-dependent release of arachidonic acid from cell membrane phospholipids, with generation of leukotriene (LT) C4 in preference to prostaglandin (PG)D2. KL at concentrations of 10 ng/ml elicited half-maximal eicosanoid generation and at concentrations of > 50 ng/ml elicited a maximal generation of approximately 15 ng LTC4 and 1 ng PGD2 per 10(6) cells, with 20% net beta-hexosaminidase release 10 min after stimulation. Of the other cytokines tested, none, either alone or in combination with KL, elicited or modulated the immediate phase of mediator release by BMMC, indicating strict specificity for KL. Activation of BMMC in response to KL was accompanied by transient phosphorylation of cytosolic phospholipase A2 and reversible translocation of 5-lipoxygenase to a cell membrane fraction 2-5 min after stimulation, when the rate of arachidonic acid release and LTC4 production were maximal. BMMC continuously exposed to KL in the presence of IL-10 and IL-1 beta generated LTC4 in marked preference to PGD2 over the first 10 min followed by delayed generation of PGD2 with no LTC4 over several hours. Pharmacologic studies revealed that PGD2 generation in the immediate phase depended on prostaglandin endoperoxide synthase (PGHS)-1 and in the delayed phase on PGHS-2. Thus, KL provided a nonallergic stimulus for biphasic eicosanoid generation by mast cells. The immediate phase is dominated by LTC4 generation with kinetics and postreceptor biosynthetic events similar to those observed after cell activation through the high affinity IgE receptor, whereas the delayed phase of slow and selective PGD2 production is mediated by induction of PGHS-2.


Blood ◽  
2000 ◽  
Vol 96 (6) ◽  
pp. 2172-2180 ◽  
Author(s):  
Kotaro Suzuki ◽  
Hiroshi Nakajima ◽  
Norihiko Watanabe ◽  
Shin-ichiro Kagami ◽  
Akira Suto ◽  
...  

Abstract The regulatory roles of the common cytokine receptor γ chain (γc)– and Jak3-dependent signaling in the proliferation and survival of mast cells were determined using γc-deficient (γc−) and Jak3-deficient (Jak3−) mice. Although the mast cells in γc− and Jak3− mice were morphologically indistinguishable from those in wild-type mice, the number of peritoneal mast cells was decreased in γc− and Jak3− mice as compared with that in wild-type mice. Among γc-related cytokines, interleukin (IL)-4 and IL-9, but not IL-2, IL-7, or IL-15, enhanced the proliferation and survival of bone marrow–derived mast cells (BMMCs) from wild-type mice. However, the effects of IL-4 and IL-9 were absent in BMMCs from γc− and Jak3−mice. In addition, IL-4Rα, γc, and Jak3, but not IL-2Rβ or IL-7Rα, were expressed in BMMCs. In contrast, IL-13 did not significantly induce the proliferation and survival of BMMCs even from wild-type mice, and IL-13Rα1 was not expressed in BMMCs. Furthermore, IL-4 phosphorylated the 65-kd isoform of Stat6 in BMMCs from wild-type mice but not from γc− and Jak3− mice. These results indicate that γc- and Jak3-dependent signaling is essential for IL-4– and IL-9–induced proliferation and survival of murine mast cells, that the effects of IL-4 are mediated by type I IL-4R and that type II IL-4R is absent on mast cells, and that IL-4 phosphorylates the 65-kd isoform of Stat6 in mast cells in a γc- and Jak3-dependent manner.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1707-1707
Author(s):  
Giovanni Migliaccio ◽  
Barbara Ghinassi ◽  
Lucia Centurione ◽  
Maria Zingariello ◽  
Lucia Bianchi ◽  
...  

Abstract Megakaryocytopoiesis is regulated by extrinsic (interaction of the growth factor thrombopoietin, TPO with its receptor Mpl) and intrinsic (interaction between the trascription factors GATA-1 and Fog-1) factors. The observation that mice impaired for GATA-1 expression (i.e. harbouring the GATA-1low mutation) are defective not only in megakaryocyte maturation but also in mast cell differentiation (Migliaccio et al. J Exp Med197:281, 2003), led us to investigate whether TPO might control mast cell differentiation as well. We first observed that mice genetically unable to responde to TPO (Mplnull mice) express in the connective tissues 5 times more mast cells than their normal littermates. Then, we analysed the effects on mast cell differentiation of in vivo treatment with TPO. Normal mice, and their GATA-1low littermates, were injected i.p. with TPO (100 μg/kg/day per 5 days, kindly provided by Kirin Brewery, Japan) and the number of immature (Toluidinepos) and mature (AlcianBlue/Saphraninepos) mast cells present in the connective tissues of the animals, as well as the frequency of GATA-1pos and TUNELpos mast cells, was evaluated 14 days after treatment. In wild-type animals, TPO reduced the presence of GATA-1 in mast cells (by immuno-histochemistry) and increased the number of immature cells (from 320±28 to 852±60) and of those undergoing apoptosis (from 16±1 to 600±43). In contrast, in GATA-1low animals, TPO-treatment induced the expression of GATA-1 in mast cells while decreased the number of immature cells (from 1100±72 to 427±29) as well as that of apoptotic cells (from 600±45 to 60±2). The role of TPO on mast cell differentiation were further confirmed by the analysis of the effects exerted by the growth factor on in vitro differentiation of bone marrow derived mast cells (BMMC). In these experiments, wild type bone marrow and spleen cells were cultured for 21 days with SCF and IL-3 with or without TPO and BMMC differentiation measured on the basis of the number of cells expressing the phenotype c-kithigh/CD34high and FcεRIpos. In cultures stimulated with SCF and IL-3, all the cells expressed the phenotype c-kithigh/CD34high and FcεRIpos. In contrast, in cultures supplemented also with SCF, IL-3 and TPO, only 25% of the cells were c-kithigh/CD34high and none of them was FcεRIpos. These results establish a role for TPO in the control of mast cell differentiation (possibly by modulating the GATA-1 content of the cells) and unveil further similarities between the mechanism(s) controlling megakaryocyte and mast cell differentiation.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1335-1335
Author(s):  
Fabrizio Martelli ◽  
Giovanni Amabile ◽  
Barbara Ghinassi ◽  
Rodolfo Lorenzini ◽  
Alessandro M. Vannucchi ◽  
...  

Abstract Mast cells are hematopoietic cells localized in extramedullary sites where they engage themselves in the process of allergic response and in the immune reaction against parasites. Mast cells derive from multilineage c-KitlowCD34lowSca-1pos progenitor cells present in the marrow. These cells give rise to Linnegc-KitposSca-1neg T1/ST2pos mast cell restricted progenitor cells (MCP) whose futher maturation in the marrow remains limited under steady state conditions. MCP migrate through the blood in extramedullary sites were they mature into tissue-retricted c-KitposFceRIpos mast cells characterized by a specific mast cell protease (MMCP) profiling (dermal, mucosal and serosal mast cells in skin, gut and peritoneal cavity, respectively). The molecular mechanism that, in normal mice, restricts the mastocytopoietic potential of progenitor cells to the extramedullary sites, as well as the factors that guide the tissue-restricted differentiation of these cells, are unknown. Thrombopoietin (TPO)-Mpl interactions play an important role in the regulation of hematopoietic stem/progenitor cell proliferation and differentiation in the marrow. Here we report that mast cells, and their precursors, express Mpl (both as mRNA and cell surface protein) (see Table). Furthermore, targeted deletion of this gene (Mplnull mutation) decrease the number of MCP (by 1-log) and increases that of mast cells in dermis (by 3-fold), peritoneal cavity (by 3-fold), bone marrow (2-log) and spleen (2-log). Furthermore, because of their higher (by 2-log) MMCP-7 expression, serosal Mplnull mast cells resemble more wild-type dermal rather than serosal mast cells. On the other hand, either treatment of mice with TPO or addition of TPO to bone marrow-derived mast cell cultures induces mast cell apoptosis (by Tunel and Annexin staining) and severely hampers mast cell differentiation (by expression profiling). These data are consistent with a regulatory mechanism for murine mastocytopoiesis according to which TPO favours the transition from multilineage progenitors to CMP but blocks differentiation of MCP to mature mast cells. We propose TPO as the growth factor that restrict mast cell differentiation to extramedullaty sites and that control the switch between serosal vs dermal mast cell differentiation. Mpl expression mRNA 2-ΔCt Protein (AFU) Cy7-A Protein (AFU) Cy7-AMM2 AFU= arbitrary fluorescence intensity. p< 0.01 with respect to Cy7-A (irrilevant antibody) Wild type Marrow B cells (B220pos) b.d. 120±4 205±4 Wild type Marrow Megakaryocytes (CD61pos/CD41pos) 5.0±0.1 × 10-2 178±3 978±74* Wild type Marrow MCP (cKitpos/T1ST2pos) 1.3±0.01 × 10-2 139±16 1658±73* Wild-type Marrow Mast Cells (cKitpos/Fcε RIpos) 1.9±0.1 × 10-2 110±1 868±71* Serosal Mast Cells (cKitpos/FcεRIpos) 7.2±2.1 × 10-4 393±1 1374±25* Mplnull Marrow Megakaryocytes (CD61pos/CD41pos) b.d. 365±28 469±50 Mplnull Marrow Mast Cells (cKitpos/FcεRIpos) b.d 107±1 109±3


2000 ◽  
Vol 118 (4) ◽  
pp. A732-A733
Author(s):  
Gerardo Nardone ◽  
Eileen Holicky ◽  
Jim R. Uhl ◽  
Vittorio Colantuoni ◽  
Lina Sabatino ◽  
...  

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