TY - JOUR A1 - Barcelo-Coblijn, Gwendolyn A1 - Laura Martin, Maria A1 - de Almeida, Rodrigo F. M. A1 - Antonia Noguera-Salva, Maria A1 - Marcilla-Etxenike, Amaia A1 - Guardiola-Serrano, Francisca A1 - Lueth, Anja A1 - Kleuser, Burkhard A1 - Halver, John E. A1 - Escriba, Pablo V. T1 - Sphingomyelin and sphingomyelin synthase (SMS) in the malignant transformation of glioma cells and in 2-hydroxyoleic acid therapy JF - Proceedings of the National Academy of Sciences of the United States of America N2 - The mechanism of action of 2-hydroxyoleic acid (2OHOA), a potent antitumor compound, has not yet been fully elucidated. Here, we show that human cancer cells have markedly lower levels of sphingomyelin (SM) than nontumor (MRC-5) cells. In this context, 2OHOA treatment strongly augments SM mass (4.6-fold), restoring the levels found in MRC-5 cells, while a loss of phosphatidylethanolamine and phosphatidylcholine is observed (57 and 30%, respectively). The increased SM mass was due to a rapid and highly specific activation of SM synthases (SMS). This effect appeared to be specific against cancer cells as it did not affect nontumor MRC-5 cells. Therefore, low SM levels are associated with the tumorigenic transformation that produces cancer cells. SM accumulation occurred at the plasma membrane and caused an increase in membrane global order and lipid raft packing in model membranes. These modifications would account for the observed alteration by 2OHOA in the localization of proteins involved in cell apoptosis (Fas receptor) or differentiation (Ras). Importantly, SMS inhibition by D609 diminished 2OHOA effect on cell cycle. Therefore, we propose that the regulation of SMS activity in tumor cells is a critical upstream event in 2OHOA antitumor mechanism, which also explains its specificity for cancer cells, its potency, and the lack of undesired side effects. Finally, the specific activation of SMS explains the ability of this compound to trigger cell cycle arrest, cell differentiation, and autophagy or apoptosis in cancer cells. KW - anticancer KW - membrane-lipid therapy KW - lung cancer KW - membrane lipids Y1 - 2011 U6 - https://doi.org/10.1073/pnas.1115484108 SN - 0027-8424 VL - 108 IS - 49 SP - 19569 EP - 19574 PB - National Acad. of Sciences CY - Washington ER - TY - GEN A1 - Bäumer, Wolfgang A1 - Rossbach, Kristine A1 - Mischke, Reinhard A1 - Reines, Ilka A1 - Langbein-Detsch, Ines A1 - Lüth, Anja A1 - Kleuser, Burkhard T1 - Decreased concentration and enhanced metabolism of sphingosine-1-Phosphate in lesional skin of dogs with atopic dermatitis disturbed Sphingosine-1-Phosphate homeostasis in atopic Dermatitis T2 - The journal of investigative dermatology Y1 - 2011 U6 - https://doi.org/10.1038/jid.2010.252 SN - 0022-202X VL - 131 IS - 1 SP - 266 EP - 268 PB - Nature Publ. Group CY - New York ER - TY - JOUR A1 - Lüth, Anja A1 - Neuber, Corinna A1 - Kleuser, Burkhard T1 - Novel methods for the quantification of (2E)-hexadecenal by liquid chromatography with detection by either ESI QTOF tandem mass spectrometry or fluorescence measurement JF - Analytica chimica acta : an international journal devoted to all branches of analytical chemistry N2 - Sphingosine-1-phosphate lyase (SPL) is the only known enzyme that irreversibly cleaves sphingosine-1-phosphate (S1P) into phosphoethanolamine and (2E)-hexadecenal during the final step of sphingolipid catabolism. Because S1P is involved in a wide range of physiological and diseased processes, determining the activity of the degrading enzyme is of great interest. Therefore, we developed two procedures based on liquid chromatography (LC) for analysing (2E)-hexadecenal, which is one of the two S1P degradation products. After separation, two different quantification methods were performed, tandem mass spectrometry (MS) and fluorescence detection. However, (2E)-hexadecenal as a long-chain aldehyde is not ionisable by electrospray ionisation (ESI) for MS quantification and has an insufficient number of corresponding double bonds for fluorescence detection. Therefore, we investigated 2-diphenylacetyl-1,3-indandione-1-hydrazone (DAIH) as a derivatisation reagent. DAIH transforms the aldehyde into an ionisable and fluorescent analogue for quantitative analysis. Our conditions were optimised to obtain the outstanding limit of detection (LOD) of 1 fmol per sample (30 mu L) for LC-MS/MS and 0.75 pmol per sample (200 mu l) for LC determination with fluorescence detection. We developed an extraction procedure to separate and concentrate (2E)-hexadecenal from biological samples for these measurements. To confirm our new methods, we analysed the (2E)-hexadecenal level of different cell lines and human plasma for the first time ever. Furthermore, we treated HT-29 cells with different concentrations of 4-deoxypyridoxine (DOP), which competitively inhibits pyridoxal-5-phosphate (P5P), an essential cofactor for SPL activity, and observed a significant decrease in (2E)-hexadecenal relative to the untreated cells. KW - (2E)-Hexadecenal KW - Sphingosine-1-phosphate lyase KW - Derivatisation KW - Tandem mass spectrometry KW - Fluorescence Y1 - 2012 U6 - https://doi.org/10.1016/j.aca.2012.01.063 SN - 0003-2670 VL - 722 SP - 70 EP - 79 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Boehm, Andreas A1 - Polzin, A. A1 - Lueth, Anja A1 - Kleuser, Burkhard A1 - Rassaf, T. A1 - Kelm, M. A1 - Kroemer, H. K. A1 - Schroer, K. A1 - Rauch, B. H. T1 - The release of sphingosine-1-phosphate from human platelets during acute coronary syndrome is attenuated by aspirin T2 - NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY Y1 - 2012 SN - 0028-1298 VL - 385 SP - 12 EP - 12 PB - Springer CY - New York ER - TY - CHAP A1 - Schaper, K. A1 - Kietzmann, M. A1 - Kleuser, Burkhard A1 - Baeumer, W. T1 - Effects of sphingosine-1-phosphate and FTY720 on epidermal hyperproliferation and inflammation in an imiquimod induced mouse model of psoriasis T2 - NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY Y1 - 2012 SN - 0028-1298 VL - 385 IS - 3 SP - 80 EP - 80 PB - Springer CY - New York ER - TY - JOUR A1 - Gerecke, Christian A1 - Mascher, Conny A1 - Gottschalk, Uwe A1 - Kleuser, Burkhard A1 - Scholtka, Bettina T1 - Ultrasensitive detection of unknown colon cancer-initiating mutations using the example of the adenomatous polyposis coli gene JF - Cancer prevention research N2 - Detection of cancer precursors contributes to cancer prevention, for example, in the case of colorectal cancer. To record more patients early, ultrasensitive methods are required for the purpose of noninvasive precursor detection in body fluids. Our aim was to develop a method for enrichment and detection of known as well as unknown driver mutations in the Adenomatous polyposis coli (APC) gene. By coupled wild-type blocking (WTB) PCR and high-resolution melting (HRM), referred to as WTB-HRM, a minimum detection limit of 0.01% mutant in excess wild-type was achieved according to as little as 1 pg mutated DNA in the assay. The technique was applied to 80 tissue samples from patients with colorectal cancer (n = 17), adenomas (n = 50), serrated lesions (n = 8), and normal mucosa (n = 5). Any kind of known and unknown APC mutations (deletions, insertions, and base exchanges) being situated inside the mutation cluster region was distinguishable from wild-type DNA. Furthermore, by WTB-HRM, nearly twice as many carcinomas and 1.5 times more precursor lesions were identified to be mutated in APC, as compared with direct sequencing. By analyzing 31 associated stool DNA specimens all but one of the APC mutations could be recovered. Transferability of the WTB-HRM method to other genes was proven using the example of KRAS mutation analysis. In summary, WTB-HRM is a new approach for ultrasensitive detection of cancer-initiating mutations. In this sense, it appears especially applicable for noninvasive detection of colon cancer precursors in body fluids with excess wild-type DNA like stool. Cancer Prev Res; 6(9); 898-907. (C) 2013 AACR. Y1 - 2013 U6 - https://doi.org/10.1158/1940-6207.CAPR-13-0145 SN - 1940-6207 VL - 6 IS - 9 SP - 898 EP - 907 PB - American Association for Cancer Research CY - Philadelphia ER - TY - JOUR A1 - Lotinun, Sutada A1 - Kiviranta, Riku A1 - Matsubara, Takuma A1 - Alzate, Jorge A. A1 - Neff, Lynn A1 - Lüth, Anja A1 - Koskivirta, Ilpo A1 - Kleuser, Burkhard A1 - Vacher, Jean A1 - Vuorio, Eero A1 - Horne, William C. A1 - Baron, Roland T1 - Osteoclast-specific cathepsin K deletion stimulates S1P-dependent bone formation JF - The journal of clinical investigation N2 - Cathepsin K (CTSK) is secreted by osteoclasts to degrade collagen and other matrix proteins during bone resorption. Global deletion of Ctsk in mice decreases bone resorption, leading to osteopetrosis, but also increases the bone formation rate (BFR). To understand how Ctsk deletion increases the BFR, we generated osteoclast- and osteoblast-targeted Ctsk knockout mice using floxed Ctsk alleles. Targeted ablation of Ctsk in hematopoietic cells, or specifically in osteoclasts and cells of the monocyte-osteoclast lineage, resulted in increased bone volume and BFR as well as osteoclast and osteoblast numbers. In contrast, targeted deletion of Ctsk in osteoblasts had no effect on bone resorption or BFR, demonstrating that the increased BFR is osteoclast dependent. Deletion of Ctsk in osteoclasts increased their sphingosine kinase 1 (Sphk1) expression. Conditioned media from Ctsk-deficient osteoclasts, which contained elevated levels of sphingosine-l-phosphate (S1P), increased alkaline phosphatase and mineralized nodules in osteoblast cultures. An S1P(1,3) receptor antagonist inhibited these responses. Osteoblasts derived from mice with Ctsk-deficient osteoclasts had an increased RANKL/OPG ratio, providing a positive feedback loop that increased the number of osteoclasts. Our data provide genetic evidence that deletion of CTSK in osteoclasts enhances bone formation in vivo by increasing the generation of osteoclast-derived S1P. Y1 - 2013 U6 - https://doi.org/10.1172/JCI64840 SN - 0021-9738 VL - 123 IS - 2 SP - 666 EP - 681 PB - American Society for Clinical Investigation CY - Ann Arbor ER - TY - GEN A1 - Polzin, Amin A1 - Rassaf, Tienush A1 - Boehm, Andreas A1 - Lueth, Anja A1 - Kleuser, Burkhard A1 - Zeus, Tobias A1 - Kelm, Malte A1 - Kroemer, Heyo K. A1 - Schroer, Karsten A1 - Rauch, Bernhard H. T1 - Aspirin inhibits release of platelet-derived sphingosine-1-phosphate in acute myocardial infarction T2 - INTERNATIONAL JOURNAL OF CARDIOLOGY KW - Sphingosine-1-phosphate KW - Acute coronary syndrome KW - Platelets KW - Aspirin Y1 - 2013 U6 - https://doi.org/10.1016/j.ijcard.2013.10.050 SN - 0167-5273 SN - 1874-1754 VL - 170 IS - 2 SP - E23 EP - E24 PB - ELSEVIER IRELAND LTD CY - CLARE ER - TY - JOUR A1 - Böhm, Andreas A1 - Flößer, Anja A1 - Ermler, Swen A1 - Fender, Anke C. A1 - Lüth, Anja A1 - Kleuser, Burkhard A1 - Schrör, Karsten A1 - Rauch, Bernhard H. T1 - Factor-Xa-induced mitogenesis and migration require sphingosine kinase activity and S1P formation in human vascular smooth muscle cells JF - Cardiovascular research N2 - Sphingosine-1-phosphate (S1P) is a cellular signalling lipid generated by sphingosine kinase-1 (SPHK1). The aim of the study was to investigate whether the activated coagulation factor-X (FXa) regulates SPHK1 transcription and the formation of S1P and subsequent mitogenesis and migration of human vascular smooth muscle cells (SMC). FXa induced a time- (36 h) and concentration-dependent (330 nmol/L) increase of SPHK1 mRNA and protein expression in human aortic SMC, resulting in an increased synthesis of S1P. FXa-stimulated transcription of SPHK1 was mediated by the protease-activated receptor-1 (PAR-1) and PAR-2. In human carotid artery plaques, expression of SPHK1 was observed at SMC-rich sites and was co-localized with intraplaque FX/FXa content. FXa-induced SPHK1 transcription was attenuated by inhibitors of Rho kinase (Y27632) and by protein kinase C (PKC) isoforms (GF109203X). In addition, FXa rapidly induced the activation of the small GTPase Rho A. Inhibition of signalling pathways which regulate SPHK1 expression, inhibition of its activity or siRNA-mediated SPHK1 knockdown attenuated the mitogenic and chemotactic response of human SMC to FXa. These data suggest that FXa induces SPHK1 expression and increases S1P formation independent of thrombin and that this involves the activation of Rho A and PKC signalling. In addition to its key function in coagulation, this direct effect of FXa on human SMC may increase cell proliferation and migration at sites of vessel injury and thereby contribute to the progression of vascular lesions. KW - Factor-Xa KW - Atherosclerosis KW - Proliferation KW - Smooth muscle cells KW - Sphingosine kinase-1 Y1 - 2013 U6 - https://doi.org/10.1093/cvr/cvt112 SN - 0008-6363 VL - 99 IS - 3 SP - 505 EP - 513 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Schaper, Katrin A1 - Dickhaut, Jeannette A1 - Japtok, Lukasz A1 - Kietzmann, Manfred A1 - Mischke, Reinhard A1 - Kleuser, Burkhard A1 - Bäumer, Wolfgang T1 - Sphingosine-1-phosphate exhibits anti-proliferative and anti-inflammatory effects in mouse models of psoriasis JF - Journal of dermatological scienc N2 - Background: It has been indicated that the sphingolipid sphingosine-1-phosphate (SIP) restrains the ability of dendritic cells to migrate to lymph nodes. Furthermore SIP has been demonstrated to inhibit cell growth in human keratinocytes. However, only little is known about the effect of S1P in hyperproliferative and inflammatory in vivo models. Objective: In this study, locally acting SIP was explored in different experimental mouse models of psoriasis vulgaris. Methods: S1P and FTY720 were tested in the imiquimod-induced psoriasis mouse model, the mouse tail assay and a pilot study of the severe combined immunodeficiency mice (SCID). Results: In the imiquimod model the positive control diflorasone diacetate and S1P, but not FTY720 reduced the imiquimod-induced epidermal hyperproliferation of the ear skin. This effect was confirmed in the SCID model, where S1P treated skin from patients suffering from psoriasis showed a decrease in epidermal thickness compared to vehicle. In the imiquimod model, there was also significant inhibition of ear swelling and a moderate reduction of inflammatory cell influx and oedema formation in ear skin by SIP treatment. The inflammatory response on the back skin was, however, only reduced by diflorasone diacetate. In the mouse tail assay, the influence of S1P and FTY720 in stratum granulosum formation was tested compared to the positive control calcipotriol. Whereas topical administration of calcipotriol led to a low but significant increase of stratum granulosum, S1P and FTY720 lacked such an effect. Conclusion: Taken together, these results imply that topical administration of SIP might be a new option for the treatment of mild to moderate psoriasis lesions. KW - Imiquimod KW - Psoriasis KW - SCID mice KW - Sphingosine-1-phosphate Y1 - 2013 U6 - https://doi.org/10.1016/j.jdermsci.2013.03.006 SN - 0923-1811 VL - 71 IS - 1 SP - 29 EP - 36 PB - Elsevier CY - Clare ER -