TY - GEN A1 - Hollmann, C. A1 - Reuter, D. A1 - Werner, S. A1 - Avota, Elita A1 - Mueller, N. A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Becker, Katrin Anne A1 - Gulbins, Erich A1 - Schneider-Schaulies, Jürgen A1 - Beyersdorf, Niklas T1 - Pharmacological inhibition of acid sphingomyelinase or genetic ablation enhances CD4(+) Foxp3(+) regulatory T cell activity T2 - European journal of immunology Y1 - 2016 SN - 0014-2980 SN - 1521-4141 VL - 46 SP - 14 EP - 14 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Nojima, Hiroyuki A1 - Konishi, Takanori A1 - Freeman, Christopher M. A1 - Schuster, Rebecca M. A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Gulbins, Erich A1 - Lentsch, Alex B. T1 - Chemokine Receptors, CXCR1 and CXCR2, Differentially Regulate Exosome Release in Hepatocytes JF - PLoS one N2 - Exosomes are small membrane vesicles released by different cell types, including hepatocytes, that play important roles in intercellular communication. We have previously demonstrated that hepatocyte-derived exosomes contain the synthetic machinery to form sphingosine-1-phosphate (S1P) in target hepatocytes resulting in proliferation and liver regeneration after ischemia/reperfusion (I/R) injury. We also demonstrated that the chemokine receptors, CXCR1 and CXCR2, regulate liver recovery and regeneration after I/R injury. In the current study, we sought to determine if the regulatory effects of CXCR1 and CXCR2 on liver recovery and regeneration might occur via altered release of hepatocyte exosomes. We found that hepatocyte release of exosomes was dependent upon CXCR1 and CXCR2. CXCR1-deficient hepatocytes produced fewer exosomes, whereas CXCR2-deficient hepatocytes produced more exosomes compared to their wild-type controls. In CXCR2-deficient hepatocytes, there was increased activity of neutral sphingomyelinase (Nsm) and intracellular ceramide. CXCR1-deficient hepatocytes had no alterations in Nsm activity or ceramide production. Interestingly, exosomes from CXCR1-deficient hepatocytes had no effect on hepatocyte proliferation, due to a lack of neutral ceramidase and sphingosine kinase. The data demonstrate that CXCR1 and CXCR2 regulate hepatocyte exosome release. The mechanism utilized by CXCR1 remains elusive, but CXCR2 appears to modulate Nsm activity and resultant production of ceramide to control exosome release. CXCR1 is required for packaging of enzymes into exosomes that mediate their hepatocyte proliferative effect. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0161443 SN - 1932-6203 VL - 11 SP - 6900 EP - + PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Sahle, Fitsum Feleke A1 - Balzus, Benjamin A1 - Gerecke, Christian A1 - Kleuser, Burkhard A1 - Bodmeier, Roland T1 - Formulation and in vitro evaluation of polymeric enteric nanoparticles as dermal carriers with pH-dependent targeting potential JF - European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, EUFEPS N2 - pH-sensitive nanoparticles which release in a controlled fashion on the skin or dissolve in the hair follicle could significantly improve treatment effectiveness and make transfollicular drug delivery a success. Dexamethasone-loaded Eudragit L 100 nanoparticles were prepared by nanoprecipitation from an organic drug-polymer solution. Their toxicity potential was assessed using isolated human fibroblasts. pH-dependent swelling and erosion kinetics of the nanoparticles were investigated by dynamic light scattering and viscosity measurements and its effect on drug release was assessed in vitro with Franz diffusion cells. Stable, 100-550 nm-sized dexamethasone-loaded Eudragit L 100 nanoparticles with drug loading capacity and entrapment efficiency as high as 83% and 85%, respectively, were obtained by using polyvinyl alcohol as a stabilizer and ethanol as organic solvent The nanoparticles showed little or no toxicity on isolated normal human fibroblasts. Dexamethasone existed in the nanoparticles as solid solution or in amorphous form. The nanoparticles underwent extensive swelling and slow drug release in media with a low buffer capacity (as low as 10 mM) and a higher pH or at a pH close to the dissolution pH of the polymer (pH 6) and a higher buffer capacity. In 40 mM buffer and above pH 6.8, the nanoparticles eroded fast or dissolved completely and thus released the drug rapidly. pH-sensitive nanoparticles which potentially release in a controlled manner on the stratum corneum but dissolve in the hair follicle could be prepared. (C) 2016 Elsevier B.V. All rights reserved. KW - Dexamethasone KW - Enteric polymer KW - Eudragit L 100 KW - pH-sensitive nanoparticles KW - Skin nanocarrier KW - Erosion kinetics Y1 - 2016 U6 - https://doi.org/10.1016/j.ejps.2016.07.004 SN - 0928-0987 SN - 1879-0720 VL - 92 SP - 98 EP - 109 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Nojima, Hiroyuki A1 - Konishi, Takanori A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Gulbins, Erich A1 - Lentsch, Alex B. T1 - Chemokine receptors, CXCR1 and CXCR2, differentially regulate exosome release in hepatocytes T2 - Hepatology : official journal of the American Association for the Study of Liver Diseases Y1 - 2016 SN - 0270-9139 SN - 1527-3350 VL - 64 SP - 165A EP - 165A PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Ahlberg, Sebastian A1 - Rancan, Fiorenza A1 - Epple, Matthias A1 - Loza, Kateryna A1 - Höppe, David A1 - Lademann, Jürgen A1 - Vogt, Annika A1 - Kleuser, Burkhard A1 - Gerecke, Christian A1 - Meinke, Martina C. T1 - Comparison of different methods to study effects of silver nanoparticles on the pro- and antioxidant status of human keratinocytes and fibroblasts JF - Methods : focusing on rapidly developing techniques KW - Oxidative stress KW - Dichlorofluorescein assay KW - Electron paramagnetic resonance spectroscopy KW - HaCaT cells KW - Glutathione KW - Free radicals Y1 - 2016 U6 - https://doi.org/10.1016/j.ymeth.2016.05.015 SN - 1046-2023 SN - 1095-9130 VL - 109 SP - 55 EP - 63 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Hollmann, Claudia A1 - Werner, Sandra A1 - Avota, Elita A1 - Reuter, Dajana A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Gulbins, Erich A1 - Becker, Katrin Anne A1 - Schneider-Schaulies, Jürgen A1 - Beyersdorf, Niklas T1 - Inhibition of Acid Sphingomyelinase Allows for Selective Targeting of CD4(+) Conventional versus Foxp3(+) Regulatory T Cells JF - The journal of immunology N2 - CD4(+) Foxp3(+) regulatory T cells (Tregs) depend on CD28 signaling for their survival and function, a receptor that has been previously shown to activate the acid sphingomyelinase (Asm)/ceramide system. In this article, we show that the basal and CD28-induced Asm activity is higher in Tregs than in conventional CD4(+) T cells (Tconvs) of wild-type (wt) mice. In Asm-deficient (Smpd1(-/-); Asm(-/-)) mice, as compared with wt mice, the frequency of Tregs among CD4(+) T cells, turnover of the effector molecule CTLA-4, and their suppressive activity in vitro were increased. The biological significance of these findings was confirmed in our Treg-sensitive mouse model of measles virus (MV) CNS infection, in which we observed more infected neurons and less MV-specific CD8(+) T cells in brains of Asm(-/-) mice compared with wt mice. In addition to genetic deficiency, treatment of wt mice with the Asm inhibitor amitriptyline recapitulated the phenotype of Asm-deficient mice because it also increased the frequency of Tregs among CD4(+) T cells. Reduced absolute cell numbers of Tconvs after inhibitor treatment in vivo and extensive in vitro experiments revealed that Tregs are more resistant toward Asm inhibitor-induced cell death than Tconvs. Mechanistically, IL-2 was capable of providing crucial survival signals to the Tregs upon inhibitor treatment in vitro, shifting the Treg/Tconv ratio to the Treg side. Thus, our data indicate that Asm-inhibiting drugs should be further evaluated for the therapy of inflammatory and autoimmune disorders. Y1 - 2016 U6 - https://doi.org/10.4049/jimmunol.1600691 SN - 0022-1767 SN - 1550-6606 VL - 197 SP - 3130 EP - 3141 PB - American Assoc. of Immunologists CY - Bethesda ER - TY - JOUR A1 - Henze, Andrea A1 - Homann, Thomas A1 - Rohn, Isabelle A1 - Aschner, Michael A. A1 - Link, Christopher D. A1 - Kleuser, Burkhard A1 - Schweigert, Florian J. A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Caenorhabditis elegans as a model system to study post-translational modifications of human transthyretin JF - Scientific reports N2 - The visceral protein transthyretin (TTR) is frequently affected by oxidative post-translational protein modifications (PTPMs) in various diseases. Thus, better insight into structure-function relationships due to oxidative PTPMs of TTR should contribute to the understanding of pathophysiologic mechanisms. While the in vivo analysis of TTR in mammalian models is complex, time-and resource-consuming, transgenic Caenorhabditis elegans expressing hTTR provide an optimal model for the in vivo identification and characterization of drug-mediated oxidative PTPMs of hTTR by means of matrix assisted laser desorption/ionization - time of flight - mass spectrometry (MALDI-TOF-MS). Herein, we demonstrated that hTTR is expressed in all developmental stages of Caenorhabditis elegans, enabling the analysis of hTTR metabolism during the whole life-cycle. The suitability of the applied model was verified by exposing worms to D-penicillamine and menadione. Both drugs induced substantial changes in the oxidative PTPM pattern of hTTR. Additionally, for the first time a covalent binding of both drugs with hTTR was identified and verified by molecular modelling. Y1 - 2016 U6 - https://doi.org/10.1038/srep37346 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Hönzke, Stefan A1 - Gerecke, Christian A1 - Elpelt, Anja A1 - Zhang, Nan A1 - Unbehauen, Michael A1 - Kral, Vivian A1 - Fleige, Emanuel A1 - Paulus, Florian A1 - Haag, Rainer A1 - Schäfer-Korting, Monika A1 - Kleuser, Burkhard A1 - Hedtrich, Sarah T1 - Tailored dendritic core-multishell nanocarriers for efficient dermal drug delivery: A systematic top-down approach from synthesis to preclinical testing JF - Journal of controlled release N2 - Drug loaded dendritic core-multishell (CMS) nanocarriers are of especial interest for the treatment of skin diseases, owing to their striking dermal delivery efficiencies following topical applications. CMS nanocarriers are composed of a polyglycerol core, connected by amide-bonds to an inner alkyl shell and an outer methoxy poly(ethylene glycol) shell. Since topically applied nanocarriers are subjected to biodegradation, the application of conventional amide-based CMS nanocarriers (10-A-18-350) has been limited by the potential production of toxic polyglycerol amines. To circumvent this issue, three tailored ester-based CMS nanocarriers (10-E-12-350, 10-E-15-350, 10-E-18-350) of varying inner alkyl chain length were synthesized and comprehensively characterized in terms of particle size, drug loading, biodegradation and dermal drug delivery efficiency. Dexamethasone (DXM), a potent drug widely used for the treatment of inflammatory skin diseases, was chosen as a therapeutically relevant test compound for the present study. Ester-and amide-based CMS nanocarriers delivered DXM more efficiently into human skin than a commercially available DXM cream. Subsequent in vitro and in vivo toxicity studies identified CMS (10-E-15-350) as the most biocompatible carrier system. The anti-inflammatory potency of DXM-loaded CMS (10-E-15-350) nanocarriers was assessed in TNF alpha supplemented skin models, where a significant reduction of the pro-inflammatory cytokine IL-8 was seen, with markedly greater efficacy than commercial DXM cream. In summary, we report the rational design and characterization of tailored, biodegradable, ester-based CMS nanocarriers, and their subsequent stepwise screening for biocompatibility, dermal delivery efficiency and therapeutic efficacy in a top-down approach yielding the best carrier system for topical applications. (C) 2016 Elsevier B.V. All rights reserved. KW - Dendritic core-multishell nanocarriers KW - Biocompatibility KW - Dexamethasone KW - Inflammatory skin disease KW - Dermal drug delivery KW - Skin model Y1 - 2016 U6 - https://doi.org/10.1016/j.jconrel.2016.06.030 SN - 0168-3659 SN - 1873-4995 VL - 242 SP - 50 EP - 63 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Döge, Nadine A1 - Hönzke, Stefan A1 - Schumacher, Fabian A1 - Balzus, Benjamin A1 - Colombo, Miriam A1 - Hadam, Sabrina A1 - Rancan, Fiorenza A1 - Blume-Peytavi, Ulrike A1 - Schäfer-Korting, Monika A1 - Schindler, Anke A1 - Rühl, Eckart A1 - Skov, Per Stahl A1 - Church, Martin K. A1 - Hedtrich, Sarah A1 - Kleuser, Burkhard A1 - Bodmeier, Roland A1 - Vogt, Annika T1 - Ethyl cellulose nanocarriers and nanocrystals differentially deliver dexamethasone into intact, tape-stripped or sodium lauryl sulfate-exposed ex vivo human skin - assessment by intradermal microdialysis and extraction from the different skin layers JF - Journal of controlled release N2 - Understanding penetration not only in intact, but also in lesional skin with impaired skin barrier function is important, in order to explore the surplus value of nanoparticle-based drug delivery for anti-inflammatory dermatotherapy. Herein, short-termex vivo cultures of (i) intact human skin, (ii) skin pretreated with tape-strippings and (iii) skin pre-exposed to sodium lauryl sulfate (SLS) were used to assess the penetration of dexamethasone (Dex). Intradermal microdialysis was utilized for up to 24 h after drug application as commercial cream, nanocrystals or ethyl cellulose nanocarriers applied at the therapeutic concentration of 0.05%, respectively. In addition, Dex was assessed in culture media and extracts from stratum corneum, epidermis and dermis after 24 h, and the results were compared to those in heat-separated split skin from studies in Franz diffusion cells. Providing fast drug release, nanocrystals significantly accelerated the penetration of Dex. In contrast to the application of cream and ethyl cellulose nanocarriers, Dex was already detectable in eluates after 6 h when applying nanocrystals on intact skin. Disruption of the skin barrier further accelerated and enhanced the penetration. Encapsulation in ethyl cellulose nanocarriers delayed Dex penetration. Interestingly, for all formulations highly increased concentrations in the dialysate were observed in tape-stripped skin, whereas the extent of enhancement was less in SLS-exposed skin. The results were confirmed in tissue extracts and were in line with the predictions made by in vitro release studies and ex vivo Franz diffusion cell experiments. The use of 45 kDa probes further enabled the collection of inflammatory cytokines. However, the estimation of glucocorticoid efficacy by Interleukin (IL)-6 and IL-8 analysis was limited due to the trauma induced by the probe insertion. Ex vivo intradermal microdialysis combined with culture media analysis provides an effective, skin-sparing method for preclinical assessment of novel drug delivery systems at therapeutic doses in models of diseased skin. (C) 2016 Elsevier B.V. All rights reserved. KW - Drug delivery systems KW - Polymeric nanoparticles KW - Dexamethasone KW - Microdialysis KW - Skin penetration KW - Skin barrier disruption Y1 - 2016 U6 - https://doi.org/10.1016/j.jconrel.2016.07.009 SN - 0168-3659 SN - 1873-4995 VL - 242 SP - 25 EP - 34 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Nojima, Hiroyuki A1 - Konishi, Takanori A1 - Freeman, Christopher M. A1 - Schuster, Rebecca M. A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Gulbins, Erich A1 - Lentsch, Alex B. T1 - Chemokine receptors, CXCR1 and CXCR2, differentially regulate exosome release in hepatocytes T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Exosomes are small membrane vesicles released by different cell types, including hepatocytes, that play important roles in intercellular communication. We have previously demonstrated that hepatocyte-derived exosomes contain the synthetic machinery to form sphingosine-1-phosphate (S1P) in target hepatocytes resulting in proliferation and liver regeneration after ischemia/reperfusion (I/R) injury. We also demonstrated that the chemokine receptors, CXCR1 and CXCR2, regulate liver recovery and regeneration after I/R injury. In the current study, we sought to determine if the regulatory effects of CXCR1 and CXCR2 on liver recovery and regeneration might occur via altered release of hepatocyte exosomes. We found that hepatocyte release of exosomes was dependent upon CXCR1 and CXCR2. CXCR1-deficient hepatocytes produced fewer exosomes, whereas CXCR2-deficient hepatocytes produced more exosomes compared to their wild-type controls. In CXCR2-deficient hepatocytes, there was increased activity of neutral sphingomyelinase (Nsm) and intracellular ceramide. CXCR1-deficient hepatocytes had no alterations in Nsm activity or ceramide production. Interestingly, exosomes from CXCR1-deficient hepatocytes had no effect on hepatocyte proliferation, due to a lack of neutral ceramidase and sphingosine kinase. The data demonstrate that CXCR1 and CXCR2 regulate hepatocyte exosome release. The mechanism utilized by CXCR1 remains elusive, but CXCR2 appears to modulate Nsm activity and resultant production of ceramide to control exosome release. CXCR1 is required for packaging of enzymes into exosomes that mediate their hepatocyte proliferative effect. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 538 KW - hepatic ischemia-reperfusion KW - liver-regeneration KW - injury KW - ischemia/reperfusion KW - neutrophil KW - ceramide KW - homolog KW - mice KW - mechanisms KW - recovery Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-410885 SN - 1866-8372 IS - 538 ER - TY - GEN A1 - Walter, Tim A1 - Collenburg, Lena A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Schneider-Schaulies, Sibylle A1 - Müller, Nora A1 - Becam, Jerome A1 - Schubert-Unkmeir, Alexandra A1 - Kong, Ji Na A1 - Bieberich, Erhard A1 - Seibel, Jürgen T1 - Incorporation and visualization of azido-functionalized N-oleoyl serinol in Jurkat cells, mouse brain astrocytes, 3T3 fibroblasts and human brain microvascular endothelial cells N2 - The synthesis and biological evaluation of azido-N-oleoyl serinol is reported. It mimicks biofunctional lipid ceramides and has shown to be capable of click reactions for cell membrane imaging in Jurkat and human brain microvascular endothelial cells. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 324 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394960 ER - TY - GEN A1 - Henze, Andrea A1 - Homann, Thomas A1 - Rohn, Isabelle A1 - Aschner, Michael A. A1 - Link, Christopher D. A1 - Kleuser, Burkhard A1 - Schweigert, Florian J. A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Caenorhabditis elegans as a model system to study post-translational modifications of human transthyretin N2 - The visceral protein transthyretin (TTR) is frequently affected by oxidative post-translational protein modifications (PTPMs) in various diseases. Thus, better insight into structure-function relationships due to oxidative PTPMs of TTR should contribute to the understanding of pathophysiologic mechanisms. While the in vivo analysis of TTR in mammalian models is complex, time- and resource-consuming, transgenic Caenorhabditis elegans expressing hTTR provide an optimal model for the in vivo identification and characterization of drug-mediated oxidative PTPMs of hTTR by means of matrix assisted laser desorption/ionization – time of flight – mass spectrometry (MALDI-TOF-MS). Herein, we demonstrated that hTTR is expressed in all developmental stages of Caenorhabditis elegans, enabling the analysis of hTTR metabolism during the whole life-cycle. The suitability of the applied model was verified by exposing worms to D-penicillamine and menadione. Both drugs induced substantial changes in the oxidative PTPM pattern of hTTR. Additionally, for the first time a covalent binding of both drugs with hTTR was identified and verified by molecular modelling. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 312 KW - binding KW - c. elegans KW - cells KW - disease KW - force-field KW - life-span KW - menadione KW - n-acetyl-cysteine KW - protein KW - s-glutathionylation Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-103674 ER - TY - JOUR A1 - Henze, Andrea A1 - Homann, Thomas A1 - Rohn, Isabelle A1 - Aschner, Michael A. A1 - Link, Christopher D. A1 - Kleuser, Burkhard A1 - Schweigert, Florian J. A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Caenorhabditis elegans as a model system to study post-translational modifications of human transthyretin JF - Scientific reports N2 - The visceral protein transthyretin (TTR) is frequently affected by oxidative post-translational protein modifications (PTPMs) in various diseases. Thus, better insight into structure-function relationships due to oxidative PTPMs of TTR should contribute to the understanding of pathophysiologic mechanisms. While the in vivo analysis of TTR in mammalian models is complex, time- and resource-consuming, transgenic Caenorhabditis elegans expressing hTTR provide an optimal model for the in vivo identification and characterization of drug-mediated oxidative PTPMs of hTTR by means of matrix assisted laser desorption/ionization – time of flight – mass spectrometry (MALDI-TOF-MS). Herein, we demonstrated that hTTR is expressed in all developmental stages of Caenorhabditis elegans, enabling the analysis of hTTR metabolism during the whole life-cycle. The suitability of the applied model was verified by exposing worms to D-penicillamine and menadione. Both drugs induced substantial changes in the oxidative PTPM pattern of hTTR. Additionally, for the first time a covalent binding of both drugs with hTTR was identified and verified by molecular modelling. KW - n-acetyl-cysteine KW - s-glutathionylation KW - force-field KW - c. elegans KW - life-span KW - protein KW - cells KW - menadione KW - disease KW - binding Y1 - 2016 U6 - https://doi.org/10.1038/srep37346 SN - 2045-2322 VL - 6 PB - Nature Publishing Group CY - London ER -