@article{AhlbergRancanEppleetal.2016, author = {Ahlberg, Sebastian and Rancan, Fiorenza and Epple, Matthias and Loza, Kateryna and H{\"o}ppe, David and Lademann, J{\"u}rgen and Vogt, Annika and Kleuser, Burkhard and Gerecke, Christian and Meinke, Martina C.}, title = {Comparison of different methods to study effects of silver nanoparticles on the pro- and antioxidant status of human keratinocytes and fibroblasts}, series = {Methods : focusing on rapidly developing techniques}, volume = {109}, journal = {Methods : focusing on rapidly developing techniques}, publisher = {Elsevier}, address = {San Diego}, issn = {1046-2023}, doi = {10.1016/j.ymeth.2016.05.015}, pages = {55 -- 63}, year = {2016}, language = {en} } @article{AlFadelFayyazJaptoketal.2016, author = {Al Fadel, Frdoos and Fayyaz, Susann and Japtok, Lukasz and Kleuser, Burkhard}, title = {Involvement of Sphingosine 1-Phosphate in Palmitate-Induced Non-Alcoholic Fatty Liver Disease}, series = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology}, volume = {40}, journal = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology}, publisher = {Karger}, address = {Basel}, issn = {1015-8987}, doi = {10.1159/000453213}, pages = {1637 -- 1645}, year = {2016}, abstract = {Background/Aims: Ectopic lipid accumulation in hepatocytes has been identified as a risk factor for the progression of liver fibrosis and is strongly associated with obesity. In particular, the saturated fatty acid palmitate is involved in initiation of liver fibrosis via formation of secondary metabolites by hepatocytes that in turn activate hepatic stellate cells (HSCs) in a paracrine manner Methods: a-smooth muscle actin-expression (alpha-SMA) as a marker of liver fibrosis was investigated via western blot analysis and immunofluorescence microscopy in HSCs (LX-2). Sphingolipid metabolism and the generation of the bioactive secondary metabolite sphingosine I-phosphate (SIP) in response to palmitate were analyzed by LC-MS/MS in hepatocytes (HepG2). To identify the molecular mechanism involved in the progression of liver fibrosis real-time PCR analysis and pharmacological modulation of SIP receptors were performed. Results: Palmitate oversupply increased intra- and extracellular SIP-concentrations in hepatocytes. Conditioned medium from HepG2 cells initiated fibrosis by enhancing alpha-SMA-expression in LX-2 in a S1P-dependent manner In accordance, fibrotic response in the presence of SIP was also observed in HSCs. Pharmacological inhibition of SIP receptors demonstrated that S1P(3) is the crucial receptor subtype involved in this process. Conclusion: SIP is synthesized in hepatocytes in response to palmitate and released into the extracellular environment leading to an activation of HSCs via the S1P(3) receptor (C) 2016 The Author(s) Published by S. Karger AG, Basel}, language = {en} } @article{BalzusSahleHoenzkeetal.2017, author = {Balzus, Benjamin and Sahle, Fitsum Feleke and H{\"o}nzke, Stefan and Gerecke, Christian and Schumacher, Fabian and Hedtrich, Sarah and Kleuser, Burkhard and Bodmeier, Roland}, title = {Formulation and ex vivo evaluation of polymeric nanoparticles for controlled delivery of corticosteroids to the skin and the corneal epithelium}, series = {European journal of pharmaceutics and biopharmaceutics : EJPB ; official journal of the International Association for Pharmaceutical Technology}, volume = {115}, journal = {European journal of pharmaceutics and biopharmaceutics : EJPB ; official journal of the International Association for Pharmaceutical Technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0939-6411}, doi = {10.1016/j.ejpb.2017.02.001}, pages = {122 -- 130}, year = {2017}, abstract = {Controlled delivery of corticosteroids using nanoparticles to the skin and corneal epithelium may reduce their side effects and maximize treatment effectiveness. Dexamethasone-loaded ethyl cellulose, Eudragit® RS and ethyl cellulose/Eudragit® RS nanoparticles were prepared by the solvent evaporation method. Dexamethasone release from the polymeric nanoparticles was investigated in vitro using Franz diffusion cells. Drug penetration was also assessed ex vivo using excised human skin. Nanoparticle toxicity was determined by MTT and H2DCFDA assays. Eudragit® RS nanoparticles were smaller and positively charged but had a lower dexamethasone loading capacity (0.3-0.7\%) than ethyl cellulose nanoparticles (1.4-2.2\%). By blending the two polymers (1:1), small (105 nm), positively charged (+37 mV) nanoparticles with sufficient dexamethasone loading (1.3\%) were obtained. Dexamethasone release and penetration significantly decreased with decreasing drug to polymer ratio and increased when Eudragit® RS was blended with ethyl cellulose. Ex vivo, drug release and penetration from the nanoparticles was slower than a conventional cream. The nanoparticles bear no toxicity potentials except ethyl cellulose nanoparticles had ROS generation potential at high concentration. In conclusion, the nanoparticles showed great potential to control the release and penetration of corticosteroids on the skin and mucus membrane and maximize treatment effectiveness.}, language = {en} } @inproceedings{BaranyaiGoedtelArmbrustNestleretal.2014, author = {Baranyai, Dorothea and Goedtel-Armbrust, Ute and Nestler, Sebastian and Kleuser, Burkhard and Wojnowski, Leszek}, title = {A role for cutaneous CYP3A in vitamin D homeostasis?}, series = {NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY}, volume = {387}, booktitle = {NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY}, publisher = {Springer}, address = {New York}, issn = {0028-1298}, pages = {S27 -- S27}, year = {2014}, language = {en} } @article{BarceloCoblijnLauraMartindeAlmeidaetal.2011, author = {Barcelo-Coblijn, Gwendolyn and Laura Martin, Maria and de Almeida, Rodrigo F. M. and Antonia Noguera-Salva, Maria and Marcilla-Etxenike, Amaia and Guardiola-Serrano, Francisca and Lueth, Anja and Kleuser, Burkhard and Halver, John E. and Escriba, Pablo V.}, title = {Sphingomyelin and sphingomyelin synthase (SMS) in the malignant transformation of glioma cells and in 2-hydroxyoleic acid therapy}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {49}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1115484108}, pages = {19569 -- 19574}, year = {2011}, abstract = {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.}, language = {en} } @misc{BeckerRiethmuellerSeitzetal.2018, author = {Becker, Katrin Anne and Riethmueller, Joachim and Seitz, Aaron P. and Gardner, Aaron and Boudreau, Ryan and Kamler, Markus and Kleuser, Burkhard and Schuchman, Edward and Caldwell, Charles C. and Edwards, Michael J. and Grassme, Heike and Brodlie, Malcolm and Gulbins, Erich}, title = {Sphingolipids as targets for inhalation treatment of cystic fibrosis}, series = {Advanced drug delivery reviews}, volume = {133}, journal = {Advanced drug delivery reviews}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0169-409X}, doi = {10.1016/j.addr.2018.04.015}, pages = {66 -- 75}, year = {2018}, abstract = {Studies over the past several years have demonstrated the important role of sphingolipids in cystic fibrosis (CF), chronic obstructive pulmonary disease and acute lung injury. Ceramide is increased in airway epithelial cells and alveolar macrophages of CF mice and humans, while sphingosine is dramatically decreased. This increase in ceramide results in chronic inflammation, increased death of epithelial cells, release of DNA into the bronchial lumen and thereby an impairment of mucociliary clearance; while the lack of sphingosine in airway epithelial cells causes high infection susceptibility in CF mice and possibly patients. The increase in ceramide mediates an ectopic expression of beta 1-integrins in the luminal membrane of CF epithelial cells, which results, via an unknown mechanism, in a down-regulation of acid ceramidase. It is predominantly this down-regulation of acid ceramidase that results in the imbalance of ceramide and sphingosine in CF cells. Correction of ceramide and sphingosine levels can be achieved by inhalation of functional acid sphingomyelinase inhibitors, recombinant acid ceramidase or by normalization of beta 1-integrin expression and subsequent re-expression of endogenous acid ceramidase. These treatments correct pulmonary inflammation and prevent or treat, respectively, acute and chronic pulmonary infections in CF mice with Staphylococcus aureus and mucoid or non-mucoid Pseudomonas aeruginosa. Inhalation of sphingosine corrects sphingosine levels only and seems to mainly act against the infection. Many antidepressants are functional inhibitors of the acid sphingomyelinase and were designed for systemic treatment of major depression. These drugs could be repurposed to treat CF by inhalation.}, language = {en} } @misc{BeckmannBeckerKadowetal.2019, author = {Beckmann, Nadine and Becker, Katrin Anne and Kadow, Stephanie and Schumacher, Fabian and Kramer, Melanie and K{\"u}hn, Claudine and Schulz-Schaeffer, Walter J. and Edwards, Michael J. and Kleuser, Burkhard and Gulbins, Erich and Carpinteiro, Alexander}, title = {Acid sphingomyelinase deficiency ameliorates Farber disease}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1087}, issn = {1866-8372}, doi = {10.25932/publishup-44128}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-441282}, pages = {20}, year = {2019}, abstract = {Farber disease is a rare lysosomal storage disorder resulting from acid ceramidase deficiency and subsequent ceramide accumulation. No treatments for Farber disease are clinically available, and affected patients have a severely shortened lifespan. We have recently reported a novel acid ceramidase deficiency model that mirrors the human disease closely. Acid sphingomyelinase is the enzyme that generates ceramide upstream of acid ceramidase in the lysosomes. Using our acid ceramidase deficiency model, we tested if acid sphingomyelinase could be a potential novel therapeutic target for the treatment of Farber disease. A number of functional acid sphingomyelinase inhibitors are clinically available and have been used for decades to treat major depression. Using these as a therapeutic for Farber disease, thus, has the potential to improve central nervous symptoms of the disease as well, something all other treatment options for Farber disease can't achieve so far. As a proof-of-concept study, we first cross-bred acid ceramidase deficient mice with acid sphingomyelinase deficient mice in order to prevent ceramide accumulation. Double-deficient mice had reduced ceramide accumulation, fewer disease manifestations, and prolonged survival. We next targeted acid sphingomyelinase pharmacologically, to test if these findings would translate to a setting with clinical applicability. Surprisingly, the treatment of acid ceramidase deficient mice with the acid sphingomyelinase inhibitor amitriptyline was toxic to acid ceramidase deficient mice and killed them within a few days of treatment. In conclusion, our study provides the first proof-of-concept that acid sphingomyelinase could be a potential new therapeutic target for Farber disease to reduce disease manifestations and prolong survival. However, we also identified previously unknown toxicity of the functional acid sphingomyelinase inhibitor amitriptyline in the context of Farber disease, strongly cautioning against the use of this substance class for Farber disease patients}, language = {en} } @inproceedings{BoehmPolzinLuethetal.2012, author = {Boehm, Andreas and Polzin, A. and Lueth, Anja and Kleuser, Burkhard and Rassaf, T. and Kelm, M. and Kroemer, H. K. and Schroer, K. and Rauch, B. H.}, title = {The release of sphingosine-1-phosphate from human platelets during acute coronary syndrome is attenuated by aspirin}, series = {NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY}, volume = {385}, booktitle = {NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY}, publisher = {Springer}, address = {New York}, issn = {0028-1298}, pages = {12 -- 12}, year = {2012}, language = {en} } @misc{BaeumerRossbachMischkeetal.2011, author = {B{\"a}umer, Wolfgang and Rossbach, Kristine and Mischke, Reinhard and Reines, Ilka and Langbein-Detsch, Ines and L{\"u}th, Anja and Kleuser, Burkhard}, title = {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}, series = {The journal of investigative dermatology}, volume = {131}, journal = {The journal of investigative dermatology}, number = {1}, publisher = {Nature Publ. Group}, address = {New York}, issn = {0022-202X}, doi = {10.1038/jid.2010.252}, pages = {266 -- 268}, year = {2011}, language = {en} } @article{BoehmFloesserErmleretal.2013, author = {B{\"o}hm, Andreas and Fl{\"o}ßer, Anja and Ermler, Swen and Fender, Anke C. and L{\"u}th, Anja and Kleuser, Burkhard and Schr{\"o}r, Karsten and Rauch, Bernhard H.}, title = {Factor-Xa-induced mitogenesis and migration require sphingosine kinase activity and S1P formation in human vascular smooth muscle cells}, series = {Cardiovascular research}, volume = {99}, journal = {Cardiovascular research}, number = {3}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0008-6363}, doi = {10.1093/cvr/cvt112}, pages = {505 -- 513}, year = {2013}, abstract = {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.}, language = {en} }