scholarly journals Early Activation of Sphingosine Kinase in Mast Cells and Recruitment to FcεRI Are Mediated by Its Interaction with Lyn Kinase

2004 ◽  
Vol 24 (19) ◽  
pp. 8765-8777 ◽  
Author(s):  
Nicole Urtz ◽  
Ana Olivera ◽  
Elisa Bofill-Cardona ◽  
Robert Csonga ◽  
Andreas Billich ◽  
...  
Keyword(s):  
Mast Cells ◽  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Immunoglobulin E ◽  
Sphingosine Kinase ◽  
Lipid Kinase ◽  
Lyn Kinase ◽  
Sphingosine 1 Phosphate ◽  
High Affinity Receptor

ABSTRACT Sphingosine kinase has been recognized as an essential signaling molecule that mediates the intracellular conversion of sphingosine to sphingosine-1-phosphate. In mast cells, induction of sphingosine kinase and generation of sphingosine-1-phosphate have been linked to the initial rise in Ca2+, released from internal stores, and to degranulation. These events either precede or are concomitant with the activation of phospholipase C-γ and the generation of inositol trisphosphate. Here we show that sphingosine kinase type 1 (SPHK1) interacts directly with the tyrosine kinase Lyn and that this interaction leads to the recruitment of this lipid kinase to the high-affinity receptor for immunoglobulin E (FcεRI). The interaction of SPHK1 with Lyn caused enhanced lipid and tyrosine kinase activity. After FcεRI triggering, enhanced sphingosine kinase activity was associated with FcεRI in sphingolipid-enriched rafts of mast cells. Bone marrow-derived mast cells from Lyn−/ − mice, compared to syngeneic wild-type cells, were defective in the initial induction of SPHK1 activity, and the defect was overcome by retroviral Lyn expression. These findings position the activation of SPHK1 as an FcεRI proximal event.

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 Epithelial cell extrusion requires the sphingosine-1-phosphate receptor 2 pathway

2011 ◽  
Vol 193 (4) ◽  
pp. 667-676 ◽  
Author(s):  
Yapeng Gu ◽  
Tetyana Forostyan ◽  
Roger Sabbadini ◽  
Jody Rosenblatt
Keyword(s):  
Stem Cells ◽  
Epithelial Cell ◽  
Kinase Activity ◽  
Apoptotic Cell ◽  
Sphingosine Kinase ◽  
Live Cells ◽  
Sphingosine 1 Phosphate ◽  
A Cell ◽  
Dying Cells ◽  
Cell Extrusion

To maintain an intact barrier, epithelia eliminate dying cells by extrusion. During extrusion, a cell destined for apoptosis signals its neighboring cells to form and contract a ring of actin and myosin, which squeezes the dying cell out of the epithelium. Here, we demonstrate that the signal produced by dying cells to initiate this process is sphingosine-1-phosphate (S1P). Decreasing S1P synthesis by inhibiting sphingosine kinase activity or by blocking extracellular S1P access to its receptor prevented apoptotic cell extrusion. Extracellular S1P activates extrusion by binding the S1P2 receptor in the cells neighboring a dying cell, as S1P2 knockdown in these cells or its loss in a zebrafish mutant disrupted cell extrusion. Because live cells can also be extruded, we predict that this S1P pathway may also be important for driving delamination of stem cells during differentiation or invasion of cancer cells.

scholarly journals Tyrosine phosphorylation and activation of Bruton tyrosine kinase upon Fc epsilon RI cross-linking.

1994 ◽  
Vol 14 (8) ◽  
pp. 5108-5113 ◽  
Author(s):  
Y Kawakami ◽  
L Yao ◽  
T Miura ◽  
S Tsukada ◽  
O N Witte ◽  
...  
Keyword(s):  
Mast Cells ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Immunoglobulin E ◽  
Cross Linking ◽  
Mouse Bone Marrow ◽  
Ionophore A23187 ◽  
Membrane Compartment ◽  
High Affinity Receptor ◽  
Protein Kinase C Activation

Tyrosine phosphorylation of several cellular proteins is one of the earliest signaling events induced by cross-linking of the high-affinity receptor for immunoglobulin E (Fc epsilon RI) on mast cells or basophils. Tyrosine kinases activated during this process include the Src family kinases, Lyn, c-Yes, and c-Src, and members of another subfamily, Syk and PTK72 (identical or highly related to Syk). Recently, some of us described two novel tyrosine kinases, Emb and Emt, whose expression was limited to subsets of hematopoietic cells, including mast cells. Emb turned out to be identical to Btk, a gene product defective in human X-linked agammaglobulinemia and in X-linked immunodeficient (xid) mice. Here we report that Fc epsilon RI cross-linking induced rapid phosphorylation on tyrosine, serine, and threonine residues and activation of Btk in mouse bone marrow-derived mast cells. A small fraction of Btk translocated from the cytosol to the membrane compartment following receptor cross-linking. Tyrosine phosphorylation of Btk was not induced by either a Ca2+ ionophore (A23187), phorbol 12-myristate 13-acetate, or a combination of the two reagents. Co-immunoprecipitation between Btk and receptor subunit beta or gamma was not detected. The data collectively suggest that Btk is not associated with Fc epsilon but that its activation takes place prior to protein kinase C activation and plays a novel role in the Fc epsilon RI signaling pathway.

scholarly journals Sphingosine Kinase 2 associates with the nsP3 of chikungunya virus and is required for replication

2020 ◽  
Author(s):  
Opeoluwa O. Oyewole ◽  
St Patrick Reid
Keyword(s):  
Viral Replication ◽  
Chikungunya Virus ◽  
Protein Production ◽  
Sphingosine Kinase ◽  
Lipid Kinase ◽  
Replication Complex ◽  
Sphingosine Kinase 2 ◽  
Sphingosine 1 Phosphate ◽  
Viral Replication Complex ◽  
Genetic Targeting

AbstractSphingosine kinase 2 (SK2) is a lipid kinase that catalyzes the production of sphingosine-1-phosphate (S1P) from sphingosine. Previously, we have shown that SK2 is recruited to the viral replication complex (VRC) early during chikungunya virus (CHIKV) infection. In the present study, we demonstrate that SK2 is required for viral replication and protein production. Treatment with a SK2 inhibitor significantly impaired the function of a CHIKV replicon. Similarly, compound treatment or genetic targeting resulted in impaired viral protein production. Mechanistically, we demonstrate that CHIKV nsP3 binds to SK2. Association of nsP3 with SK2 was mediated, in part, through the FGDF motifs within the hypervariable domain (HVD) of nsP3. In a competition assay, SK2 competed with G3BP for binding to nsP3. Collectively, these results extend our previous findings and identify SK2 as a CHIKV host factor recruited by nsP3.

scholarly journals Evolutionary background of allergic reactivity: mast cells, FcεRI, IgE - three components of the effector phase of the allergic response

2018 ◽  
Vol 15 (4) ◽  
pp. 5-16
Author(s):  
I S Gushchin
Keyword(s):  
Mast Cells ◽  
Immunoglobulin E ◽  
The Body ◽  
Allergic Response ◽  
Effector Phase ◽  
Time Regime ◽  
High Affinity Receptor ◽  
Ige Mediated ◽  
Affinity Receptor ◽  
Elimination Function

The literature data on the evolution of the main obligatory participants in the effector phase of the IgE-mediated allergic response are presented: mast cells/basophils, immunoglobulin E, and high affinity receptor for the Fcε fragment (FcεRI). Allergic reactivity is considered as the most recent evolutionary immunologically-mediated acquisition of mammals. It is aimed at recognizing small amounts of allergen entering the body in a certain time regime, and organizing an allergen-specific inflammation that carries features of elimination function. The most biologically justified way to prevent allergies is to restore the function of barrier systems and, accordingly, to prevent the need to develop an allergic response.

Tyrosine phosphorylation and activation of Bruton tyrosine kinase upon Fc epsilon RI cross-linking

1994 ◽  
Vol 14 (8) ◽  
pp. 5108-5113
Author(s):  
Y Kawakami ◽  
L Yao ◽  
T Miura ◽  
S Tsukada ◽  
O N Witte ◽  
...  
Keyword(s):  
Mast Cells ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Immunoglobulin E ◽  
Cross Linking ◽  
Mouse Bone Marrow ◽  
Ionophore A23187 ◽  
Membrane Compartment ◽  
High Affinity Receptor ◽  
Protein Kinase C Activation

Tyrosine phosphorylation of several cellular proteins is one of the earliest signaling events induced by cross-linking of the high-affinity receptor for immunoglobulin E (Fc epsilon RI) on mast cells or basophils. Tyrosine kinases activated during this process include the Src family kinases, Lyn, c-Yes, and c-Src, and members of another subfamily, Syk and PTK72 (identical or highly related to Syk). Recently, some of us described two novel tyrosine kinases, Emb and Emt, whose expression was limited to subsets of hematopoietic cells, including mast cells. Emb turned out to be identical to Btk, a gene product defective in human X-linked agammaglobulinemia and in X-linked immunodeficient (xid) mice. Here we report that Fc epsilon RI cross-linking induced rapid phosphorylation on tyrosine, serine, and threonine residues and activation of Btk in mouse bone marrow-derived mast cells. A small fraction of Btk translocated from the cytosol to the membrane compartment following receptor cross-linking. Tyrosine phosphorylation of Btk was not induced by either a Ca2+ ionophore (A23187), phorbol 12-myristate 13-acetate, or a combination of the two reagents. Co-immunoprecipitation between Btk and receptor subunit beta or gamma was not detected. The data collectively suggest that Btk is not associated with Fc epsilon but that its activation takes place prior to protein kinase C activation and plays a novel role in the Fc epsilon RI signaling pathway.

Lyn Kinase Overexpression Is One of the Mechanisms of Resistance to Nilotinib In Chronic Myeloid Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3181-3181 ◽  
Author(s):  
Francois-Xavi er Mahon ◽  
Sandrine Hayette ◽  
Valerie Lagarde ◽  
Franck E Nicolini ◽  
Francis Belloc ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Cell Line ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Kinase Activity ◽  
Resistant Cell ◽  
Resistant Cell Line ◽  
Over Expression ◽  
Abl Tyrosine Kinase ◽  
Lyn Kinase

Abstract Targeting the tyrosine kinase activity of Bcr-Abl is an attractive therapeutic strategy in Chronic Myeloid Leukemia (CML) and in Bcr-Abl positive Acute Lymphoblastic Leukemia. Whereas imatinib, a selective inhibitor of Bcr-Abl tyrosine kinase, is now used in frontline therapy for CML, second generation inhibitors of Bcr-Abl tyrosine kinase such as nilotinib or dasatinib have been developed. In the current study, we generated nilotinib-resistant cell lines and investigated their mechanism of resistance. Three nilotinib-resistant cell lines were obtained from the Ph-positive cell lines AR230, LAMA84 and K562. Over expression of the BCR-ABL gene was found in two nilotinib-resistant cell lines and the multidrug resistance gene (MDR-1) was found overexpressed in one of them, i.e, LAMA84 nilotinib resistant cell. The K562/DOX cell line, that displays resistance to several drugs by over expressing Pgp, was resistant to nilotinib, and this was reversed by simultaneous incubation with either verapamil or PSC833 confirming that nilotinib is a substrate of the Pgp. In one nilotinib-resistant cell line (K562-rn), we found over expression of p53/56 Lyn kinase, both at the mRNA and protein level (10- fold), and these cells were compared to their sensitive counterpart. Lyn silencing by siRNA restored sensitivity to nilotinib. Two Src kinase inhibitors (PP1 and PP2) partially restored sensitivity to nilotinib, but did not significantly inhibit Bcr-Abl tyrosine kinase activity. In contrast, dasatinib, an inhibitor of Abl and Src-family kinases, inhibited phosphorylation of both BCR-ABL and Lyn, and induced apoptosis of the Bcr-Abl cell line which over expressed p53/56 Lyn. Of 7 nilotinib-resistant CML patients, failure of nilotinib treatment was accompanied by mutations in Bcr-Abl kinase domain in 2 patients and an increase of Lyn mRNA expression (RQ-PCR) in 2 other patients. As an approach to confirm the involvement of the Lyn signalling pathway in nilotinib-resistance, we have used the Stable Isotope Labeling with Amino acids in Cell culture (SILAC) technique. The tyrosine phosphorylated protein fraction was analyzed by tandem mass spectrometry. Peptide sequencing and quantification in the nilotinib-resistant cell line identified >350 proteins, of which several were hyper-phosphorylated; functional analysis of the different candidates is in progress. In conclusion, mechanisms of resistance to nilotinib in imatinib-resistant cell lines resemble those operating in CML patients, and up-regulated Lyn kinase signalling can play an important role in nilotinib resistance.

scholarly journals Interleukin-3 regulates the activity of the LYN protein-tyrosine kinase in myeloid-committed leukemic cell lines

Blood ◽  
1992 ◽  
Vol 80 (3) ◽  
pp. 617-624 ◽  
Author(s):  
T Torigoe ◽  
R O'Connor ◽  
D Santoli ◽  
JC Reed
Keyword(s):  
Tyrosine Kinase ◽  
Cell Lines ◽  
Protein Tyrosine Kinase ◽  
Kinase Activity ◽  
Leukemic Cell ◽  
Beta Subunit ◽  
Gm Csf ◽  
Leukemic Cell Lines ◽  
Lyn Kinase

The lymphokine interleukin-3 (IL-3) promotes the growth and survival of immature hematopoietic cells. Previous studies have shown that IL-3 induces rapid increases in protein-tyrosine kinase (PTK) activity in IL- 3--dependent cells. Unlike some other hematopoietic growth factor receptors (eg, c-fms and c-kit), however, the known subunits of the IL- 3 receptor (IL-3R) lack intrinsic kinase activity. Recently, it was reported that the IL-2R (whose p75 beta-subunit shares sequence homology with a known murine IL-3R subunit and a common beta-subunit of the human IL-3R and granulocyte-macrophage colony-stimulating factor [GM-CSF] receptors) can physically associate with and regulate the activity of the SRC-family PTK, p56-LCK. Because most IL-3--dependent cells contain p53/56-LYN, but not p56-LCK, we explored the effects of IL-3 on the activities of LYN and other SRC-like PTKs in two human leukemic cell lines, AML-193 and TALL-101, which are phenotypically myeloid, and whose in vitro growth is dependent on IL-3. These cells expressed four of the eight known SRC-family proto-oncogenes: lyn, fyn, yes, and hck. When these factor-dependent leukemic cell lines were deprived of lymphokine to achieve cellular quiescence and then restimulated with IL-3, rapid increases (detectable within 1 minute and maximal by 10 minutes) were observed in the activity of the p53/56-LYN kinase, as assessed by in vitro kinase assays. In contrast, no alteration in the activities of other SRC-family PTKs present in these cells was detected after restimulation with IL-3 under the same conditions. This effect of IL-3 reflected an increase in the specific activity of the LYN kinase, because levels of the 53-Kd and 56-Kd LYN proteins were unaltered by IL-3 stimulation, as assessed by immunoblotting. Furthermore, the magnitude of these inducible increases in LYN kinase activity was dependent on the concentration of IL-3, and correlated with IL-3--induced proliferation. The IL-3--induced upregulation of LYN kinase activity may be mediated by the 120-Kd common subunit of the human IL-3 and GM-CSF receptors, because GM-CSF also stimulated marked increases in the activity of the LYN kinase, whereas granulocyte-CSF (G-CSF) did not, despite inducing cellular proliferation. These observations provide the first example of an IL-3-- regulable PTK, and strongly suggest that the p53/56-LYN kinase participates in early IL-3--initiated signalling events, at least in some human leukemic cell lines.

Regulation of the metabolism of apolipoprotein M and sphingosine 1-phosphate by hepatic PPARγ activity

2018 ◽  
Vol 475 (12) ◽  
pp. 2009-2024 ◽  
Author(s):  
Makoto Kurano ◽  
Hitoshi Ikeda ◽  
Naoyuki Iso-O ◽  
Masumi Hara ◽  
Kazuhisa Tsukamoto ◽  
...  
Keyword(s):  
Hepg2 Cells ◽  
Mouse Liver ◽  
Kinase Activity ◽  
Sphingosine Kinase ◽  
Peroxisome Proliferator ◽  
Obese Mice ◽  
Peroxisome Proliferator Activated Receptor ◽  
Apolipoprotein M ◽  
Adenoviral Gene Transfer ◽  
Sphingosine 1 Phosphate

Apolipoprotein M (apoM) is a carrier and a modulator of sphingosine 1-phosphate (S1P), an important multifunctional bioactive lipid. Since peroxisome proliferator-activated receptor γ (PPARγ) is reportedly associated with the function and metabolism of S1P, we investigated the modulation of apoM/S1P homeostasis by PPARγ. First, we investigated the modulation of apoM and S1P homeostasis by the overexpression or knockdown of PPARγ in HepG2 cells and found that both the overexpression and the knockdown of PPARγ decreased apoM expression and S1P synthesis. When we activated or suppressed the PPARγ more mildly with pioglitazone or GW9662, we found that pioglitazone suppressed apoM expression and S1P synthesis, while GW9662 increased them. Next, we overexpressed PPARγ in mouse liver through adenoviral gene transfer and observed that both the plasma and hepatic apoM levels and the plasma S1P levels decreased, while the hepatic S1P levels increased, in the presence of enhanced sphingosine kinase activity. Treatment with pioglitazone decreased both the plasma and hepatic apoM and S1P levels only in diet-induced obese mice. Moreover, the overexpression of apoM increased, while the knockdown of apoM suppressed PPARγ activities in HepG2 cells. These results suggested that PPARγ regulates the S1P levels by modulating apoM in a bell-shaped manner, with the greatest levels of apoM/S1P observed when PPARγ was mildly expressed and that hepatic apoM/PPARγ axis might maintain the homeostasis of S1P metabolism.

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