TY - JOUR A1 - Bernacchioni, Caterina A1 - Ghini, Veronica A1 - Cencetti, Francesca A1 - Japtok, Lukasz A1 - Donati, Chiara A1 - Bruni, Paola A1 - Turano, Paola T1 - NMR metabolomics highlights sphingosine kinase-1 as a new molecular switch in the orchestration of aberrant metabolic phenotype in cancer cells JF - Molecular oncology / Federation of European Biochemical Societies N2 - Strong experimental evidence in animal and cellular models supports a pivotal role of sphingosine kinase-1 (SK1) in oncogenesis. In many human cancers, SK1 levels are upregulated and these increases are linked to poor prognosis in patients. Here, by employing untargeted NMR- based metabolomic profiling combined with functional validations, we report the crucial role of SK1 in the metabolic shift known as the Warburg effect in A2780 ovarian cancer cells. Indeed, expression of SK1 induced a high glycolytic rate, characterized by increased levels of lactate along with increased expression of the proton/monocarboxylate symporter MCT1, and decreased oxidative metabolism, associated with the accumulation of intermediates of the tricarboxylic acid cycle and reduction in CO2 production. Additionally, SK1-expressing cells displayed a significant increase in glucose uptake paralleled by GLUT3 transporter upregulation. The role of SK1 is not limited to the induction of aerobic glycolysis, affecting metabolic pathways that appear to support the biosynthesis of macromolecules. These findings highlight the role of SK1 signaling axis in cancer metabolic reprogramming, pointing out innovative strategies for cancer therapies. KW - NMR-based metabolomics KW - ovarian cancer KW - sphingosine kinase-1 KW - Warburg effect Y1 - 2017 U6 - https://doi.org/10.1002/1878-0261.12048 SN - 1878-0261 VL - 11 SP - 517 EP - 533 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Fayyaz, Susann A1 - Japtok, Lukasz A1 - Schumacher, Fabian A1 - Wigger, Dominik A1 - Schulz, Tim Julius A1 - Haubold, Kathrin A1 - Gulbins, Erich A1 - Völler, Heinz A1 - Kleuser, Burkhard T1 - Lysophosphatidic acid inhibits insulin signaling in primary rat hepatocytes via the LPA(3) receptor subtype and is increased in obesity JF - Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology N2 - Background/Aims: Obesity is a main risk factor for the development of hepatic insulin resistance and it is accompanied by adipocyte hypertrophy and an elevated expression of different adipokines such as autotaxin (ATX). ATX converts lysophosphatidylcholine to lysophosphatidic acid (LPA) and acts as the main producer of extracellular LPA. This bioactive lipid regulates a broad range of physiological and pathological responses by activation of LPA receptors (LPA1-6). Methods: The activation of phosphatidylinositide 3-kinases (PI3K) signaling (Akt and GSK-3ß) was analyzed via western blotting in primary rat hepatocytes. Incorporation of glucose into glycogen was measured by using radio labeled glucose. Real-time PCR analysis and pharmacological modulation of LPA receptors were performed. Human plasma LPA levels of obese (BMI > 30, n = 18) and normal weight individuals (BMI 18.5-25, n = 14) were analyzed by liquid chromatography tandem-mass spectrometry (LC-MS/MS). Results: Pretreatment of primary hepatocytes with LPA resulted in an inhibition of insulin-mediated Gck expression, PI3K activation and glycogen synthesis. Pharmacological approaches revealed that the LPA3-receptor subtype is responsible for the inhibitory effect of LPA on insulin signaling. Moreover, human plasma LPA concentrations (16: 0 LPA) of obese participants (BMI > 30) are significantly elevated in comparison to normal weight individuals (BMI 18.5-25). Conclusion: LPA is able to interrupt insulin signaling in primary rat hepatocytes via the LPA3 receptor subtype. Moreover, the bioactive lipid LPA (16: 0) is increased in obesity. KW - Lysophosphatidic acid KW - Insulin signaling KW - Adipose tissue KW - Autotaxin KW - Hepatic insulin resistance KW - LPA(3) receptor subtype Y1 - 2017 U6 - https://doi.org/10.1159/000480470 SN - 1015-8987 SN - 1421-9778 VL - 43 SP - 445 EP - 456 PB - Karger CY - Basel ER - TY - JOUR A1 - Folkesson, Maggie A1 - Vorkapic, Emina A1 - Gulbins, Erich A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Welander, Martin A1 - Länne, Toste A1 - Wågsäter, Dick T1 - Inflammatory cells, ceramides, and expression of proteases in perivascular adipose tissue adjacent to human abdominal aortic aneurysms JF - Journal of vascular surgery N2 - Background: Abdominal aortic aneurysm (AAA) is a deadly irreversible weakening and distension of the abdominal aortic wall. The pathogenesis of AAA remains poorly understood. Investigation into the physical and molecular characteristics of perivascular adipose tissue (PVAT) adjacent to AAA has not been done before and is the purpose of this study. Methods and Results: Human aortae, periaortic PVAT, and fat surrounding peripheral arteries were collected from patients undergoing elective surgical repair of AAA. Control aortas were obtained from recently deceased healthy organ donors with no known arterial disease. Aorta and PVAT was found in AAA to larger extent compared with control aortas. Immunohistochemistry revealed neutrophils, macrophages, mast cells, and T-cells surrounding necrotic adipocytes. Gene expression analysis showed that neutrophils, mast cells, and T-cells were found to be increased in PVAT compared with AAA as well as cathepsin K and S. The concentration of ceramides in PVAT was determined using mass spectrometry and correlated with content of T-cells in the PVAT. Conclusions: Our results suggest a role for abnormal necrotic, inflamed, proteolytic adipose tissue to the adjacent aneurysmal aortic wall in ongoing vascular damage. Y1 - 2016 U6 - https://doi.org/10.1016/j.jvs.2015.12.056 SN - 0741-5214 VL - 65 IS - 4 SP - 1171 EP - 1179 PB - Elsevier CY - New York ER - TY - JOUR A1 - McVey, Mark J. A1 - Kim, Michael A1 - Tabuchi, Arata A1 - Srbely, Victoria A1 - Japtok, Lukasz A1 - Arenz, Christoph A1 - Rotstein, Ori A1 - Kleuser, Burkhard A1 - Semple, John W. A1 - Kuebler, Wolfgang M. T1 - Acid sphingomyelinase mediates murine acute lung injury following transfusion of aged platelets JF - American journal of physiology : Lung cellular and molecular physiology N2 - Pulmonary complications from stored blood products are the leading cause of mortality related to transfusion. Transfusion-related acute lung injury is mediated by antibodies or bioactive mediators, yet underlying mechanisms are incompletely understood. Sphingolipids such as ceramide regulate lung injury, and their composition changes as a function of time in stored blood. Here, we tested the hypothesis that aged platelets may induce lung injury via a sphingolipid-mediated mechanism. To assess this hypothesis, a two-hit mouse model was devised. Recipient mice were treated with 2 mg/kg intraperitoneal lipopolysaccharide (priming) 2 h before transfusion of 10 ml/kg stored (1-5 days) platelets treated with or without addition of acid sphingomyelinase inhibitor ARC39 or platelets from acid sphingomyelinase-deficient mice, which both reduce ceramide formation. Transfused mice were examined for signs of pulmonary neutrophil accumulation, endothelial barrier dysfunction, and histological evidence of lung injury. Sphingolipid profiles in stored platelets were analyzed by mass spectrophotometry. Transfusion of aged platelets into primed mice induced characteristic features of lung injury, which increased in severity as a function of storage time. Ceramide accumulated in platelets during storage, but this was attenuated by ARC39 or in acid sphingomyelinase-deficient platelets. Compared with wild-type platelets, transfusion of ARC39-treated or acid sphingomyelinase-deficient aged platelets alleviated lung injury. Aged platelets elicit lung injury in primed recipient mice, which can be alleviated by pharmacological inhibition or genetic deletion of acid sphingomyelinase. Interventions targeting sphingolipid formation represent a promising strategy to increase the safety and longevity of stored blood products. KW - transfusion-related acute lung injury KW - ceramide KW - acid sphingomyelinase KW - platelets KW - storage Y1 - 2017 U6 - https://doi.org/10.1152/ajplung.00317.2016 SN - 1040-0605 SN - 1522-1504 VL - 312 IS - 5 SP - 625 EP - 637 PB - American Physiological Society CY - Bethesda ER - TY - JOUR A1 - Hoehn, Richard S. A1 - Jernigan, Peter L. A1 - Japtok, Lukasz A1 - Chang, Alex L. A1 - Midura, Emily F. A1 - Caldwell, Charles C. A1 - Kleuser, Burkhard A1 - Lentsch, Alex B. A1 - Edwards, Michael J. A1 - Gulbins, Erich A1 - Pritts, Timothy A. T1 - Acid sphingomyelinase inhibition in stored erythrocytes reduces transfusion-associated lung inflammation JF - Annals of surgery : a monthly review of surgical science and practice N2 - Objective: We aimed to identify the role of the enzyme acid sphingomyelinase in the aging of stored units of packed red blood cells (pRBCs) and subsequent lung inflammation after transfusion. Summary Background Data: Large volume pRBC transfusions are associated with multiple adverse clinical sequelae, including lung inflammation. Microparticles are formed in stored pRBCs over time and have been shown to contribute to lung inflammation after transfusion. Methods: Human and murine pRBCs were stored with or without amitriptyline, a functional inhibitor of acid sphingomyelinase, or obtained from acid sphingomyelinase-deficient mice, and lung inflammation was studied in mice receiving transfusions of pRBCs and microparticles isolated from these units. Results: Acid sphingomyelinase activity in pRBCs was associated with the formation of ceramide and the release of microparticles. Treatment of pRBCs with amitriptyline inhibited acid sphingomyelinase activity, ceramide accumulation, and microparticle production during pRBC storage. Transfusion of aged pRBCs or microparticles isolated from aged blood into mice caused lung inflammation. This was attenuated after transfusion of pRBCs treated with amitriptyline or from acid sphingomyelinase-deficient mice. Conclusions: Acid sphingomyelinase inhibition in stored pRBCs offers a novel mechanism for improving the quality of stored blood. KW - acid sphingomyelinase KW - blood banking KW - ceramide KW - lung inflammation KW - microparticle Y1 - 2017 U6 - https://doi.org/10.1097/SLA.0000000000001648 SN - 0003-4932 SN - 1528-1140 VL - 265 IS - 1 SP - 218 EP - 226 PB - Lippincott Williams & Wilkins CY - Philadelphia ER -