scholarly journals Sphingosine kinase type 1 inhibition reveals rapid turnover of circulating sphingosine 1-phosphate

2011 ◽  
Vol 440 (3) ◽  
pp. 345-353 ◽  
Author(s):  
Yugesh Kharel ◽  
Thomas P. Mathews ◽  
Amanda M. Gellett ◽  
Jose L. Tomsig ◽  
Perry C. Kennedy ◽  
...  
Keyword(s):  
Cell Survival ◽  
Sphingosine Kinase ◽  
Rapid Onset ◽  
Physiological Functions ◽  
Extracellular Signal ◽  
Signalling Molecule ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
And Migration

S1P (sphingosine 1-phosphate) is a signalling molecule involved in a host of cellular and physiological functions, most notably cell survival and migration. S1P, which signals via a set of five G-protein-coupled receptors (S1P1–S1P5), is formed by the action of two SphKs (sphingosine kinases) from Sph (sphingosine). Interfering RNA strategies and SphK1 (sphingosine kinase type 1)-null (Sphk1−/−) mouse studies implicate SphK1 in multiple signalling cascades, yet there is a paucity of potent and selective SphK1 inhibitors necessary to evaluate the effects of rapid onset inhibition of this enzyme. We have identified a set of submicromolar amidine-based SphK1 inhibitors and report using a pair of these compounds to probe the cellular and physiological functions of SphK1. In so doing, we demonstrate that our inhibitors effectively lower S1P levels in cell-based assays, but we have been unable to correlate SphK1 inhibition with changes in cell survival. However, SphK1 inhibition did diminish EGF (epidermal growth factor)-driven increases in S1P levels and Akt (also known as protein kinase B)/ERK (extracellular-signal-regulated kinase) phosphorylation. Finally, administration of the SphK1 inhibitor to wild-type, but not Sphk1−/−, mice resulted in a rapid decrease in blood S1P levels indicating that circulating S1P is rapidly turned over.

scholarly journals Mice Deficient in Sphingosine Kinase 1 Are Rendered Lymphopenic by FTY720

2004 ◽  
Vol 279 (50) ◽  
pp. 52487-52492 ◽  
Author(s):  
Maria L. Allende ◽  
Teiji Sasaki ◽  
Hiromichi Kawai ◽  
Ana Olivera ◽  
Yide Mi ◽  
...  
Keyword(s):  
Vascular Development ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Cellular Functions ◽  
Lymphocyte Trafficking ◽  
Signaling Molecule ◽  
Physiological Functions ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
S1p Receptor

Sphingosine-1-phosphate (S1P), a lipid signaling molecule that regulates many cellular functions, is synthesized from sphingosine and ATP by the action of sphingosine kinase. Two such kinases have been identified, SPHK1 and SPHK2. To begin to investigate the physiological functions of sphingosine kinase and S1P signaling, we generated mice deficient in SPHK1.Sphk1null mice were viable, fertile, and without any obvious abnormalities. Total SPHK activity in mostSphk1-/-tissues was substantially, but not completely, reduced indicating the presence of multiple sphingosine kinases. S1P levels in most tissues from theSphk1-/- mice were not markedly decreased. In serum, however, there was a significant decrease in the S1P level. Although S1P signaling regulates lymphocyte trafficking, lymphocyte distribution was unaffected in lymphoid organs ofSphk1-/- mice. The immunosuppressant FTY720 was phosphorylated and elicited lymphopenia in theSphk1null mice showing that SPHK1 is not required for the functional activation of this sphingosine analogue prodrug. The results with theseSphk1null mice reveal that some key physiologic processes that require S1P receptor signaling, such as vascular development and proper lymphocyte distribution, can occur in the absence of SPHK1.

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.

Modulation of cellular S1P levels with a novel, potent and specific inhibitor of sphingosine kinase-1

2012 ◽  
Vol 444 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Mark E. Schnute ◽  
Matthew D. McReynolds ◽  
Tom Kasten ◽  
Matthew Yates ◽  
Gina Jerome ◽  
...  
Keyword(s):  
Potent Inhibitor ◽  
Inflammatory Diseases ◽  
Specific Inhibitor ◽  
Sphingosine Kinase ◽  
Head And Neck Carcinoma ◽  
High Rate ◽  
Neck Carcinoma ◽  
Sphingosine 1 Phosphate ◽  
Proportional Increase ◽  
And Migration

SphK (sphingosine kinase) is the major source of the bioactive lipid and GPCR (G-protein-coupled receptor) agonist S1P (sphingosine 1-phosphate). S1P promotes cell growth, survival and migration, and is a key regulator of lymphocyte trafficking. Inhibition of S1P signalling has been proposed as a strategy for treatment of inflammatory diseases and cancer. In the present paper we describe the discovery and characterization of PF-543, a novel cell-permeant inhibitor of SphK1. PF-543 inhibits SphK1 with a Ki of 3.6 nM, is sphingosine-competitive and is more than 100-fold selective for SphK1 over the SphK2 isoform. In 1483 head and neck carcinoma cells, which are characterized by high levels of SphK1 expression and an unusually high rate of S1P production, PF-543 decreased the level of endogenous S1P 10-fold with a proportional increase in the level of sphingosine. In contrast with past reports that show that the growth of many cancer cell lines is SphK1-dependent, specific inhibition of SphK1 had no effect on the proliferation and survival of 1483 cells, despite a dramatic change in the cellular S1P/sphingosine ratio. PF-543 was effective as a potent inhibitor of S1P formation in whole blood, indicating that the SphK1 isoform of sphingosine kinase is the major source of S1P in human blood. PF-543 is the most potent inhibitor of SphK1 described to date and it will be useful for dissecting specific roles of SphK1-driven S1P signalling.

scholarly journals Sphingosine Kinase Regulates the Sensitivity of Dictyostelium discoideum Cells to the Anticancer Drug Cisplatin

2005 ◽  
Vol 4 (1) ◽  
pp. 178-189 ◽  
Author(s):  
Junxia Min ◽  
David Traynor ◽  
Andrew L. Stegner ◽  
Lei Zhang ◽  
Marie H. Hanigan ◽  
...  
Keyword(s):  
Dictyostelium Discoideum ◽  
Drug Targets ◽  
Sphingosine Kinase ◽  
Biochemical Properties ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
Cisplatin Sensitivity ◽  
Increased Sensitivity ◽  
Tumor Types ◽  
Null Mutants

ABSTRACT The drug cisplatin is widely used to treat a number of tumor types. However, resistance to the drug, which remains poorly understood, limits its usefulness. Previous work using Dictyostelium discoideum as a model for studying drug resistance showed that mutants lacking sphingosine-1-phosphate (S-1-P) lyase, the enzyme that degrades S-1-P, had increased resistance to cisplatin, whereas mutants overexpressing the enzyme were more sensitive to the drug. S-1-P is synthesized from sphingosine and ATP by the enzyme sphingosine kinase. We have identified two sphingosine kinase genes in D. discoideum—sgkA and sgkB—that are homologous to those of other species. The biochemical properties of the SgkA and SgkB enzymes suggest that they are the equivalent of the human Sphk1 and Sphk2 enzymes, respectively. Disruption of the kinases by homologous recombination (both single and double mutants) or overexpression of the sgkA gene resulted in altered growth rates and altered response to cisplatin. The null mutants showed increased sensitivity to cisplatin, whereas mutants overexpressing the sphingosine kinase resulted in increased resistance compared to the parental cells. The results indicate that both the SgkA and the SgkB enzymes function in regulating cisplatin sensitivity. The increase in sensitivity of the sphingosine kinase-null mutants was reversed by the addition of S-1-P, and the increased resistance of the sphingosine kinase overexpressor mutant was reversed by the inhibitor N,N-dimethylsphingosine. Parallel changes in sensitivity of the null mutants are seen with the platinum-based drug carboplatin but not with doxorubicin, 5-fluorouracil, and etoposide. This pattern of specificity is similar to that observed with the S-1-P lyase mutants and should be useful in designing therapeutic schemes involving more than one drug. This study identifies the sphingosine kinases as new drug targets for modulating the sensitivity to platinum-based drugs.

scholarly journals A novel role for mitochondrial sphingosine-1-phosphate produced by sphingosine kinase-2 in PTP-mediated cell survival during cardioprotection

2011 ◽  
Vol 106 (6) ◽  
pp. 1341-1353 ◽  
Author(s):  
Ludovic Gomez ◽  
Melanie Paillard ◽  
Megan Price ◽  
Qun Chen ◽  
Geoffrey Teixeira ◽  
...  
Keyword(s):  
Cell Survival ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 2 ◽  
Sphingosine 1 Phosphate

scholarly journals Sphingosine Kinase 1 Signaling in Breast Cancer: A Potential Target to Tackle Breast Cancer Stem Cells

2021 ◽  
Vol 8 ◽  
Author(s):  
Ling-Wei Hii ◽  
Felicia Fei-Lei Chung ◽  
Chun-Wai Mai ◽  
Pei Yuen Ng ◽  
Chee-Onn Leong
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Cancer Cells ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Signaling Axis ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
Research Findings

Sphingosine kinases (SPHKs) are conserved lipid enzymes that catalyze the formation of sphingosine-1-phosphate (S1P) through ATP-dependent phosphorylation of sphingosine. Two distinct SPHK isoforms, namely SPHK1 and SPHK2, have been identified to date, and the former has been implicated for its oncogenic roles in cancer development and progression. While SPHK1 signaling axis has been extensively studied in non-stem breast cancer cells, recent evidence has emerged to suggest a role of SPHK1 in regulating cancer stem cells (CSCs). With the clinical implications of CSCs in disease relapse and metastasis, it is believed that therapeutic approaches that can eradicate both non-stem cancer cells and CSCs could be a key to cancer cure. In this review, we first explore the oncogenic functions of sphingosine kinase 1 in human cancers and summarize current research findings of SPHK1 signaling with a focus on breast cancer. We also discuss the therapeutic potentials and perspectives of targeting SPHK1 signaling in breast cancer and cancer stem cells. We aim to offer new insights and inspire future studies looking further into the regulatory functions of SPHK1 in CSC-driven tumorigenesis, uncovering novel therapeutic avenues of using SPHK1-targeted therapy in the treatment of CSC-enriched refractory cancers.

scholarly journals Roles of sphingosine-1-phosphate signaling in cancer

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Peng Wang ◽  
Yonghui Yuan ◽  
Wenda Lin ◽  
Hongshan Zhong ◽  
Ke Xu ◽  
...  
Keyword(s):  
Cell Fate ◽  
Cancer Progression ◽  
Therapeutic Potential ◽  
Receptor Activation ◽  
Signaling Cascades ◽  
Lipid Mediator ◽  
Downstream Signaling ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
And Migration

AbstractThe potent pleiotropic lipid mediator sphingosine-1-phosphate (S1P) participates in numerous cellular processes, including angiogenesis and cell survival, proliferation, and migration. It is formed by one of two sphingosine kinases (SphKs), SphK1 and SphK2. These enzymes largely exert their various biological and pathophysiological actions through one of five G protein-coupled receptors (S1PR1–5), with receptor activation setting in motion various signaling cascades. Considerable evidence has been accumulated on S1P signaling and its pathogenic roles in diseases, as well as on novel modulators of S1P signaling, such as SphK inhibitors and S1P agonists and antagonists. S1P and ceramide, composed of sphingosine and a fatty acid, are reciprocal cell fate regulators, and S1P signaling plays essential roles in several diseases, including inflammation, cancer, and autoimmune disorders. Thus, targeting of S1P signaling may be one way to block the pathogenesis and may be a therapeutic target in these conditions. Increasingly strong evidence indicates a role for the S1P signaling pathway in the progression of cancer and its effects. In the present review, we discuss recent progress in our understanding of S1P and its related proteins in cancer progression. Also described is the therapeutic potential of S1P receptors and their downstream signaling cascades as targets for cancer treatment.

scholarly journals Sphingosine kinase type 2 inhibition elevates circulating sphingosine 1-phosphate

2012 ◽  
Vol 447 (1) ◽  
pp. 149-157 ◽  
Author(s):  
Yugesh Kharel ◽  
Mithun Raje ◽  
Ming Gao ◽  
Amanda M. Gellett ◽  
Jose L. Tomsig ◽  
...  
Keyword(s):  
G Protein Coupled Receptors ◽  
Lipid Mediator ◽  
Wild Type ◽  
Downstream Effects ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases ◽  
And Migration ◽  
G Protein Coupled ◽  
Hybrid Mice

S1P (sphingosine 1-phosphate) is a pleiotropic lipid mediator involved in numerous cellular and physiological functions. Of note among these are cell survival and migration, as well as lymphocyte trafficking. S1P, which exerts its effects via five GPCRs (G-protein-coupled receptors) (S1P1–S1P5), is formed by the action of two SphKs (sphingosine kinases). Although SphK1 is the more intensively studied isotype, SphK2 is unique in it nuclear localization and has been reported to oppose some of the actions ascribed to SphK1. Although several scaffolds of SphK1 inhibitors have been described, there is a scarcity of selective SphK2 inhibitors that are necessary to evaluate the downstream effects of inhibition of this isotype. In the present paper we report a cationic amphiphilic small molecule that is a selective SphK2 inhibitor. In the course of characterizing this compound in wild-type and SphK-null mice, we discovered that administration of the inhibitor to wild-type mice resulted in a rapid increase in blood S1P, which is in contrast with our SphK1 inhibitor that drives circulating S1P levels down. Using a cohort of F2 hybrid mice, we confirmed, compared with wild-type mice, that circulating S1P levels were higher in SphK2-null mice and lower in SphK1-null mice. Thus both SphK1 and SphK2 inhibitors recapitulate the blood S1P levels observed in the corresponding null mice. Moreover, circulating S1P levels mirror SphK2 inhibitor levels, providing a convenient biomarker of target engagement.

scholarly journals A novel function of sphingosine kinase 2 in the metabolism of sphinga-4,14-diene lipids

2020 ◽  
Author(s):  
Timothy A Couttas ◽  
Yepy H Rustam ◽  
Huitong Song ◽  
Yanfei Qi ◽  
Jonathan D Teo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cultured Cells ◽  
Sphingosine Kinase ◽  
Metabolic Enzyme ◽  
Sphingoid Base ◽  
Double Bonds ◽  
Sphingosine Kinase 2 ◽  
Long Chain Base ◽  
Sphingosine 1 Phosphate ◽  
Sphingosine Kinases

AbstractThe number, position, and configuration of double bonds in lipid acyl chains affects membrane packing, fluidity, and recruitment of signalling proteins. Studies on mammalian sphingolipids have focused on those with a saturated sphinganine or mono-unsaturated sphingosine long chain base. Sphingolipids with a diunsaturated sphingadiene base have been reported but are poorly characterised. Employing high-resolution untargeted mass spectrometry, we observed marked accumulation of lipids containing a sphingadiene base, but not those with a more common sphingosine backbone, in the hippocampus of mice lacking the metabolic enzyme sphingosine kinase 2 (SphK2). Applying ultraviolet photodissociation tandem mass spectrometry (UVPD-MS/MS) the double bonds were confidently assigned to the C4-C5 and C14-C15 positions of the sphingoid base. Sphingosine kinases are involved in lysosomal catabolism of all sphingolipids, producing sphingoid base phosphates that are irreversibly degraded by sphingosine 1-phosphate lyase. Both SphK1 and SphK2 phosphorylated sphinga-4,14-diene as efficiently as sphingosine, however deuterated tracer experiments demonstrated that ceramides with a sphingosine base are more rapidly metabolised in cultured cells than those with a sphingadiene base. SphK2 silencing significantly impeded the catabolism of both sphingosine- and sphingadiene-based sphingolipids. Since SphK2 is the dominant sphingosine kinase in brain, we propose that accumulation of sphingadiene lipids in SphK2-deficient brains results from the intrinsically slower catabolism of sphingadiene lipids, combined with a bottleneck in the catabolic pathway created by the absence of SphK2. We speculate that accumulation of these lipids in the absence of SphK2 function may affect the fluidity and signalling properties of cell membranes.

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