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Immunol Cell Biol. 2015 Oct;93(9):825-36. doi: 10.1038/icb.2015.47. Epub 2015 Apr 2.

Exacerbation of experimental autoimmune encephalomyelitis in ceramide synthase 6 knockout mice is associated with enhanced activation/migration of neutrophils.

Author information

1
Pharmazentrum Frankfurt/ZAFES, Institut für Klinische Pharmakologie, Klinikum der Goethe-Universität Frankfurt, Frankfurt/Main, Germany.
2
Molecular Genetics, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany.
3
Department of Neurology, Goethe-University Frankfurt, Frankfurt/Main, Germany.
4
Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Project Group Translational Medicine and Pharmacology (TMP), Frankfurt am Main, Germany.

Abstract

Ceramides are mediators of inflammatory processes. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we observed that CerS6 mRNA expression was upregulated 15-fold in peripheral blood leukocytes before the onset of EAE symptoms. In peripheral blood leukocytes from MS patients, a 3.9-fold upregulation was found. Total genetic deletion of CerS6 and the selective deletion of CerS6 in peripheral blood leucocytes exacerbated the progression of clinical symptoms in EAE mice. This was associated with enhanced leukocyte, predominantly neutrophil infiltration and enhanced demyelination in the lumbar spinal cord of EAE mice. Interferon-gamma/tumor necrosis factor alpha (IFN-γ/TNF-α) and granulocyte colony-stimulating factor (G-CSF) both drive EAE development and induce expression of the integrin CD11b and the chemokine receptor C-X-C motif chemokine receptor 2 (CXCR2), and we found they also induce CerS6 expression. In vivo, the genetic deletion of CerS6 enhanced the activation/migration of neutrophils, as reflected by an enhanced upregulation of CD11b and CXCR2. In vitro, the genetic deletion of CerS6 enhanced the activation status of IFN-γ/TNF-α-stimulated neutrophils, as shown by increased expression of nitric oxide and CD11b and an increased adhesion capacity. In G-CSF-stimulated neutrophils, the migration status was enhanced, as reflected by an elevated level of CXCR2 and an increased migration capacity. These data suggest that CerS6/C16-Cer mediates feedback regulation by inhibiting the formation of CD11b and CXCR2, which are induced either by IFN-γ/TNF-α or by G-CSF, respectively. We conclude that CerS6/C16-Cer mediates anti-inflammatory effects during the development of EAE and MS possibly by suppressing the migration and deactivation of neutrophils.

Comment in

PMID:
25833068
DOI:
10.1038/icb.2015.47
[Indexed for MEDLINE]

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