@article{KakkasserySkosyrskiLuethetal.2017,
  author    = {Kakkassery, Vinodh and Skosyrski, S. and L{\"u}th, A. and Kleuser, Burkhard and van der Giet, Maria and Tate, R. and Reinhard, J. and Faissner, Andreas and Joachim, Stephanie Christine and Kociok, N.},
  title     = {Etoposide Upregulates Survival Favoring Sphingosine-1-Phosphate in Etoposide-Resistant Retinoblastoma Cells},
  series = {Pathology \& Oncology Research},
  volume    = {25},
  journal   = {Pathology \& Oncology Research},
  number    = {1},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1219-4956},
  doi       = {10.1007/s12253-017-0360-x},
  pages     = {391 -- 399},
  year      = {2017},
  abstract  = {Improved knowledge of retinoblastoma chemotherapy resistance is needed to raise treatment efficiency. The objective of this study was to test whether etoposide alters glucosyl-ceramide, ceramide, sphingosine, and sphingosine-1-phosphate (sphingosine-1-P) levels in parental retinoblastoma cells (WERI Rb1) or their etoposide-resistant subclones (WERI EtoR). WERI Rb1 and WERI EtoR were incubated with 400 ng/ml etoposide for 24 h. Levels of glucosyl-ceramides, ceramides, sphingosine, sphingosine-1-P were detected by Q-TOF mass spectrometry. Statistical analysis was done by ANOVA followed by Tukey post-hoc test (p < 0.05). The mRNA expression of sphingolipid pathways enzymes in WERI Rb1, WERI EtoR and four human retinoblastoma tissue samples was analyzed by quantitative real-time PCR. Pathways enzymes mRNA expression confirmed similarities of human sphingolipid metabolism in both cell lines and tissue samples, but different relative expression. Significant up-regulation of sphingosine was seen in both cell lines (p < 0.001). Only sphingosine-1-P up-regulation was significantly increased in WERI EtoR (p < 0.01), but not in WERI Rb1 (p > 0.2). Both cell lines upregulate pro-apoptotic sphingosine after etoposide incubation, but only WERI EtoR produces additional survival favorable sphingosine-1-P. These data may suggest a role of sphingosine-1-P in retinoblastoma chemotherapy resistance, although this seems not to be the only resistance mechanism.},
  language  = {en}
}
@misc{ArltSchwiebsJaptoketal.2014,
  author    = {Arlt, Olga and Schwiebs, Anja and Japtok, Lukasz and Rueger, Katja and Katzy, Elisabeth and Kleuser, Burkhard and Radeke, Heinfried H.},
  title     = {Sphingosine-1-Phosphate modulates dendritic cell function: focus on non-migratory effects in vitro and in vivo},
  series = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology},
  volume    = {34},
  journal   = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology},
  number    = {1},
  publisher = {Karger},
  address   = {Basel},
  issn      = {1015-8987},
  doi       = {10.1159/000362982},
  pages     = {27 -- 44},
  year      = {2014},
  abstract  = {Dendritic cells (DCs) are the cutting edge in innate and adaptive immunity. The major functions of these antigen presenting cells are the capture, endosomal processing and presentation of antigens, providing them an exclusive ability to provoke adaptive immune responses and to induce and control tolerance. Immature DCs capture and process antigens, migrate towards secondary lymphoid organs where they present antigens to naive T cells in a well synchronized sequence of procedures referred to as maturation. Indeed, recent research indicated that sphingolipids are modulators of essential steps in DC homeostasis. It has been recognized that sphingolipids not only modulate the development of DC subtypes from precursor cells but also influence functional activities of DCs such as antigen capture, and cytokine profiling. Thus, it is not astonishing that sphingolipids and sphingolipid metabolism play a substantial role in inflammatory diseases that are modulated by DCs. Here we highlight the function of sphingosine 1-phosphate (S1P) on DC homeostasis and the role of SIP and SW metabolism in inflammatory diseases.},
  language  = {en}
}
@article{SicKrausMadletal.2014,
  author    = {Sic, Heiko and Kraus, Helene and Madl, Josef and Flittner, Karl-Andreas and von Muenchow, Audrey Lilly and Pieper, Kathrin and Rizzi, Marta and Kienzler, Anne-Kathrin and Ayata, Korcan and Rauer, Sebastian and Kleuser, Burkhard and Salzer, Ulrich and Burger, Meike and Zirlik, Katja and Lougaris, Vassilios and Plebani, Alessandro and Roemer, Winfried and Loeffler, Christoph and Scaramuzza, Samantha and Villa, Anna and Noguchi, Emiko and Grimbacher, Bodo and Eibel, Hermann},
  title     = {Sphingosine-1-phosphate receptors control B-cell migration through signaling components associated with primary immunodeficiencies, chronic lymphocytic leukemia, and multiple sclerosis},
  series = {The journal of allergy and clinical immunology},
  volume    = {134},
  journal   = {The journal of allergy and clinical immunology},
  number    = {2},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0091-6749},
  doi       = {10.1016/j.jaci.2014.01.037},
  pages     = {420 -- +},
  year      = {2014},
  abstract  = {Background: Five different G protein-coupled sphingosine-1-phosphate (S1P) receptors (S1P1-S1P5) regulate a variety of physiologic and pathophysiologic processes, including lymphocyte circulation, multiple sclerosis (MS), and cancer. Although B-lymphocyte circulation plays an important role in these processes and is essential for normal immune responses, little is known about S1P receptors in human B cells. Objective: To explore their function and signaling, we studied B-cell lines and primary B cells from control subjects, patients with leukemia, patients with S1P receptor inhibitor-treated MS, and patients with primary immunodeficiencies. Methods: S1P receptor expression was analyzed by using multicolor immunofluorescence microscopy and quantitative PCR. Transwell assays were used to study cell migration. S1P receptor internalization was visualized by means of time-lapse imaging with fluorescent S1P receptor fusion proteins expressed by using lentiviral gene transfer. B-lymphocyte subsets were characterized by means of flow cytometry and immunofluorescence microscopy. Results: Showing that different B-cell populations express different combinations of S1P receptors, we found that S1P1 promotes migration, whereas S1P4 modulates and S1P2 inhibits S1P1 signals. Expression of CD69 in activated B lymphocytes and B cells from patients with chronic lymphocytic leukemia inhibited S1P-induced migration. Studying B-cell lines, normal B lymphocytes, and B cells from patients with primary immunodeficiencies, we identified Bruton tyrosine kinase, beta-arrestin 2, LPS-responsive beige-like anchor protein, dedicator of cytokinesis 8, and Wiskott-Aldrich syndrome protein as critical signaling components downstream of S1P1. Conclusion: Thus S1P receptor signaling regulates human B-cell circulation and might be a factor contributing to the pathology of MS, chronic lymphocytic leukemia, and primary immunodeficiencies.},
  language  = {en}
}
@article{SchaperDickhautJaptoketal.2013,
  author    = {Schaper, Katrin and Dickhaut, Jeannette and Japtok, Lukasz and Kietzmann, Manfred and Mischke, Reinhard and Kleuser, Burkhard and B{\"a}umer, Wolfgang},
  title     = {Sphingosine-1-phosphate exhibits anti-proliferative and anti-inflammatory effects in mouse models of psoriasis},
  series = {Journal of dermatological scienc},
  volume    = {71},
  journal   = {Journal of dermatological scienc},
  number    = {1},
  publisher = {Elsevier},
  address   = {Clare},
  issn      = {0923-1811},
  doi       = {10.1016/j.jdermsci.2013.03.006},
  pages     = {29 -- 36},
  year      = {2013},
  abstract  = {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.},
  language  = {en}
}
@misc{PolzinRassafBoehmetal.2013,
  author    = {Polzin, Amin and Rassaf, Tienush and Boehm, Andreas and Lueth, Anja and Kleuser, Burkhard and Zeus, Tobias and Kelm, Malte and Kroemer, Heyo K. and Schroer, Karsten and Rauch, Bernhard H.},
  title     = {Aspirin inhibits release of platelet-derived sphingosine-1-phosphate in acute myocardial infarction},
  series = {INTERNATIONAL JOURNAL OF CARDIOLOGY},
  volume    = {170},
  journal   = {INTERNATIONAL JOURNAL OF CARDIOLOGY},
  number    = {2},
  publisher = {ELSEVIER IRELAND LTD},
  address   = {CLARE},
  issn      = {0167-5273},
  doi       = {10.1016/j.ijcard.2013.10.050},
  pages     = {E23 -- E24},
  year      = {2013},
  language  = {en}
}