TY - JOUR A1 - Pewzner-Jung, Yael A1 - Tabazavareh, Shaghayegh Tavakoli A1 - Grassme, Heike A1 - Becker, Katrin Anne A1 - Japtok, Lukasz A1 - Steinmann, Joerg A1 - Joseph, Tammar A1 - Lang, Stephan A1 - Tuemmler, Burkhard A1 - Schuchman, Edward H. A1 - Lentsch, Alex B. A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Futerman, Anthony H. A1 - Gulbins, Erich T1 - Sphingoid long chain bases prevent lung infection by Pseudomonas aeruginosa JF - EMBO molecular medicine N2 - Cystic fibrosis patients and patients with chronic obstructive pulmonary disease, trauma, burn wound, or patients requiring ventilation are susceptible to severe pulmonary infection by Pseudomonas aeruginosa. Physiological innate defense mechanisms against this pathogen, and their alterations in lung diseases, are for the most part unknown. We now demonstrate a role for the sphingoid long chain base, sphingosine, in determining susceptibility to lung infection by P.aeruginosa. Tracheal and bronchial sphingosine levels were significantly reduced in tissues from cystic fibrosis patients and from cystic fibrosis mouse models due to reduced activity of acid ceramidase, which generates sphingosine from ceramide. Inhalation of mice with sphingosine, with a sphingosine analog, FTY720, or with acid ceramidase rescued susceptible mice from infection. Our data suggest that luminal sphingosine in tracheal and bronchial epithelial cells prevents pulmonary P.aeruginosa infection in normal individuals, paving the way for novel therapeutic paradigms based on inhalation of acid ceramidase or of sphingoid long chain bases in lung infection. KW - cystic fibrosis KW - long chain base KW - lung infection KW - Pseudomonas aeruginosa KW - sphingosine Y1 - 2014 U6 - https://doi.org/10.15252/emmm.201404075 SN - 1757-4676 SN - 1757-4684 VL - 6 IS - 9 SP - 1205 EP - 1214 PB - Wiley-Blackwell CY - Hoboken 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 -