Role of Sphingosine Kinase 2 in Cell Migration toward Epidermal Growth Factor

Hait, Nitai C.; Sarkar, Sukumar; Stunff, Hervé Le; Mikami, Aki; Maceyka, Michael; Milstien, Sheldon; Spiegel, Sarah

doi:10.1074/jbc.m502922200

Cited by 151 publications

(186 citation statements)

References 54 publications

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“…Single point mutation of the second conserved glycine residue of the ATP-binding sequence of both SphKs resulted in a complete loss of sphingosine phosphorylating activity (11,35,36). The catalytically inactive G82D-SphK1 and G231E-SphK2 mutants have been shown to block various functions of these enzymes (11,26,36). Expression of G82D-SphK1 or G231E-SphK2 did not significantly affect the increased ceramide levels induced by sphingosine in SPP-1-expressing cells (Fig.…”

Section: Effect Of Spp-1 On Ceramide Metabolism-there Was An Increasementioning

confidence: 99%

“…siRNA Transfection-Cells were transfected with 50 nmol of sequence-specific, ON-TARGETplus SMARTpool siRNA against SPP-1 SphK2, and control siRNA from Dharmacon (Lafayette, CO) using Oligofectamine (Invitrogen) as described previously (26). Total RNA was isolated with TRIzol reagent (Invitrogen) and reverse-transcribed with Superscript II (Invitrogen).…”

Section: Methodsmentioning

confidence: 99%

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Recycling of Sphingosine Is Regulated by the Concerted Actions of Sphingosine-1-phosphate Phosphohydrolase 1 and Sphingosine Kinase 2

Stunff

Giussani

Maceyka

et al. 2007

Journal of Biological Chemistry

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106

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In yeast, the long-chain sphingoid base phosphate phosphohydrolase Lcb3p is required for efficient ceramide synthesis from exogenous sphingoid bases. Similarly, in this study, we found that incorporation of exogenous sphingosine into ceramide in mammalian cells was regulated by the homologue of Lcb3p, sphingosine-1-phosphate phosphohydrolase 1 (SPP-1), an endoplasmic reticulum resident protein. Sphingosine incorporation into endogenous long-chain ceramides was increased by SPP-1 overexpression, whereas recycling of C 6 -ceramide into long-chain ceramides was not altered. The increase in ceramide was inhibited by fumonisin B 1 , an inhibitor of ceramide synthase, but not by ISP-1, an inhibitor of serine palmitoyltransferase, the rate-limiting step in the de novo biosynthesis of ceramide. Mass spectrometry analysis revealed that SPP-1 expression increased the incorporation of sphingosine into all ceramide acyl chain species, particularly enhancing C16:0, C18:0, and C20:0 long-chain ceramides. The increased recycling of sphingosine into ceramide was accompanied by increased hexosylceramides and, to a lesser extent, sphingomyelins. Sphingosine kinase 2, but not sphingosine kinase 1, acted in concert with SPP-1 to regulate recycling of sphingosine into ceramide. Collectively, our results suggest that an evolutionarily conserved cycle of phosphorylation-dephosphorylation regulates recycling and salvage of sphingosine to ceramide and more complex sphingolipids.Sphingolipids are a structurally diverse family of membrane lipids. Several lines of evidence have implicated metabolites of sphingolipids such as ceramide, sphingosine, and sphingosine 1-phosphate (S1P) 5 in diverse cellular processes (1, 2). Ceramide and sphingosine have been implicated in pathways involving stress responses, cell differentiation, apoptosis, and cell cycle arrest (1). Unlike ceramide and sphingosine, S1P promotes cell growth and survival and inhibits apoptosis (2, 3). Because of their inter-convertibility and opposing effects, the dynamic balance between S1P and ceramide/sphingosine has been proposed to be an important factor that determines cell fate (2). Accumulating evidence suggests that the S1P/ceramide balance is ultimately regulated by the relative activities of enzymes controlling the turnover of these sphingolipid metabolites. However, the molecular mechanisms involved in the regulation of intracellular levels of these sphingolipids are not yet fully understood. Cellular levels of S1P are kept low by tight spatio-temporal regulation of its synthesis and degradation. Sphingosine kinases (SphKs) catalyze the synthesis of S1P by phosphorylation of sphingosine. Two distinct SphK isoforms, SphK1 and SphK2, have been cloned and characterized in mammals (2). Diverse external stimuli, particularly growth and survival factors, stimulate SphK1, generating S1P that has been implicated in their mitogenic and anti-apoptotic effects (4, 5). In contrast to SphK1, rather than promoting growth and survival, overexpression of SphK2 suppressed growth and...

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Section: Effect Of Spp-1 On Ceramide Metabolism-there Was An Increasementioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Recycling of Sphingosine Is Regulated by the Concerted Actions of Sphingosine-1-phosphate Phosphohydrolase 1 and Sphingosine Kinase 2

Stunff

Giussani

Maceyka

et al. 2007

Journal of Biological Chemistry

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106

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“…15 In addition, ON-TARGETplus SMARTpool siRNA against SphK1, SphK2, and control siRNA from Dharmacon (Lafayette, CO) was used to confirm lack of off-target effects. LAD2 cells were transfected with 100 nM sequencespecific ON-TARGETplus SMARTpool siRNAs against SphK1, SphK2, and control siRNA in Stem-Pro-34 medium using Lipofectamine 2000 (Invitrogen).…”

Section: Sirna Transfectionmentioning

confidence: 99%

Distinct roles of sphingosine kinases 1 and 2 in human mast-cell functions

Oskeritzian

Alvarez

Hait

et al. 2008

Blood

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114

127

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Sphingosine-1-phosphate (S1P) is now emerging as a potent lipid mediator produced by mast cells that contributes to inflammatory and allergic responses. In contrast to its weak effect on degranulation of murine mast cells, S1P potently induced degranulation of the human LAD2 mast-cell line and cord blood-derived human mast cells (hMCs). S1P also stimulated production and secretion of cytokines, TNF-␣ and IL-6, and markedly enhanced secretion of a chemokine, CCL2/MCP-1, important modulators of inflammation. S1P is produced in mast cells by the 2 sphingosine kinases, SphK1 and SphK2. SphK1 but not SphK2 plays a critical role in IgE/Ag-induced degranulation, migration toward antigen, and CCL2 secretion from hMCs, as determined by specifically down-regulating their expression. However, both isoenzymes were required for efficient TNF-␣ secretion. Taken together, our data suggest that differential formation of S1P by SphK1 and SphK2 has distinct and important actions in hMCs. IntroductionMast cells (MCs) play pivotal roles in immediate-type and inflammatory allergic reactions initiated by cross-linking with antigen (Ag) of the antigen-specific immunoglobulin E (IgE) on their cell-surface high-affinity receptors for IgE (Fc⑀RI). MC activation leads to release of preformed mediators, such as histamine, localized in specialized granules, and the de novo synthesis and secretion of a plethora of cytokines, chemokines, eicosanoids, and the bioactive sphingolipid metabolite, sphingosine-1-phosphate (S1P). The combined actions of these mediators trigger symptoms associated with allergy and propagate inflammatory responses. S1P levels are elevated in the bronchoalveolar lavage (BAL) fluid of asthmatics after Ag challenge, suggesting that secretion of S1P by MCs is of relevance in inflammatory responses and asthma. 1 S1P is a ligand for 5 G protein-coupled receptors (GPCRs), designated S1P 1-5 , through which it exerts many of its actions. 2,3 Indeed, S1P is secreted by activated MCs, 4,5 and studies with rodent MCs have shown that this S1P is able to rapidly bind and activate its receptors, S1P 1 and S1P 2 , in an autocrine manner. S1P 1 induces cytoskeletal rearrangements, leading to the movement of MCs toward an Ag gradient, whereas activation of S1P 2 is critical for degranulation. 4 In rodent MCs and human bone marrow-derived mast cells (BMMCs), aggregation of Fc⑀RI leads to activation of both isoforms of sphingosine kinase, SphK1 and SphK2, the enzymes that produce S1P from sphingosine. 4,6-8 Down-regulation of SphK1 but not SphK2 in these MCs inhibits calcium mobilization, degranulation, and migration induced by Ag. 4,6,7 In human BMMCs and murine MCs, SphK1 translocates to the plasma membrane within minutes of Fc⑀RI clustering. 4,6 SphK1 interacts with the protein tyrosine kinases, Src kinase members Lyn and Fyn (Fc⑀RI proximal kinases that initiate the signaling events following cross-linking of this receptor), but not Src or other tyrosine kinases, such as Syk. Following interaction with Lyn, SphK1 is recruited to me...

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“…Increased S1P formation, in turn, activates S1P receptors on the same and͞or neighboring cells in an autocrine or paracrine manner. It has been demonstrated that this type of ''inside-out'' signaling by S1P is critical for migratory responses of fibroblasts and smooth muscle cells toward PDGF (9,12) and human breast cancer cells toward EGF (8). Similarly, S1P secreted by mast cells is important for migration of mast cells toward antigen (Ag) and might be involved in the movement of mast cells to sites of inf lammation (13).…”

mentioning

confidence: 99%

“…1 and 6). To date, only EGF (8) and cross-linking of Ig receptors (4) have been shown to stimulate SphK2.…”

mentioning

confidence: 99%

Role of ABCC1 in export of sphingosine-1-phosphate from mast cells

Mitra

Oskeritzian

Payne

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

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382

329

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Mast cells play a pivotal role in inflammatory and immediate-type allergic reactions by secreting a variety of potent inflammatory mediators, including sphingosine-1-phosphate (S1P). However, it is not known how S1P is released from cells. Here, we report that S1P is exported from mast cells independently of their degranulation and demonstrate that it is mediated by ATP binding cassette (ABC) transporters. Constitutive and antigen-stimulated S1P release was inhibited by MK571, an inhibitor of ABCC1 (MRP1), but not by inhibitors of ABCB1 (MDR-1, P-glycoprotein). Moreover, downregulation of ABCC1 with small interfering RNA, which decreased its cell surface expression, markedly reduced S1P export from both rat RBL-2H3 and human LAD2 mast cells. Transport of S1P by ABCC1 influenced migration of mast cells toward antigen but not degranulation. These findings have important implications for S1P functions in mast cell-mediated immune responses.secretion ͉ sphingolipids ͉ multidrug resistance ͉ allergic responses ͉ sphingosine kinase S phingosine-1-phosphate (S1P) is a pleiotropic lipid mediator that has been implicated in cancer, immunity, and allergy (1-4). S1P is a ligand for a family of five specific G protein-coupled receptors, designated S1P 1-5 (collectively referred to as S1PRs) (5), through which it regulates many different biological responses, including growth, survival, differentiation, cytoskeleton rearrangements, motility, angiogenesis, vascular maturation, lymphocyte trafficking, and mast cell functions (reviewed in refs. 1-3, 5, and 6). Moreover, like its precursors, sphingosine (Sph) and ceramide, S1P may also have intracellular functions (1, 2, 7). S1P is produced in cells by phosphorylation of Sph, the backbone of all sphingolipids, catalyzed by two closely related Sph kinase (SphK) isoenzymes. SphK1 activity is enhanced by numerous external stimuli, including growth factors, ligands for G protein-coupled receptors, and proinflammatory cytokines, and by cross-linking of Ig receptors (reviewed in refs. 1 and 6). To date, only EGF (8) and cross-linking of Ig receptors (4) have been shown to stimulate SphK2.Although S1P secretion has been demonstrated in only a few types of cells (platelets, astroglial cells, and mast cells) activation of SphK1 involves its translocation to the plasma membrane where its substrate Sph resides (9 -11). Increased S1P formation, in turn, activates S1P receptors on the same and͞or neighboring cells in an autocrine or paracrine manner. It has been demonstrated that this type of ''inside-out'' signaling by S1P is critical for migratory responses of fibroblasts and smooth muscle cells toward PDGF (9, 12) and human breast cancer cells toward EGF (8). Similarly, S1P secreted by mast cells is important for migration of mast cells toward antigen (Ag) and might be involved in the movement of mast cells to sites of inf lammation (13). In addition, S1P provokes human airway smooth muscle contraction and may promote inf lammation and airway remodeling in asthma (14). Because S1P's level...

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Role of Sphingosine Kinase 2 in Cell Migration toward Epidermal Growth Factor

Cited by 151 publications

References 54 publications

Recycling of Sphingosine Is Regulated by the Concerted Actions of Sphingosine-1-phosphate Phosphohydrolase 1 and Sphingosine Kinase 2

Recycling of Sphingosine Is Regulated by the Concerted Actions of Sphingosine-1-phosphate Phosphohydrolase 1 and Sphingosine Kinase 2

Distinct roles of sphingosine kinases 1 and 2 in human mast-cell functions

Role of ABCC1 in export of sphingosine-1-phosphate from mast cells

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