Reactive oxygen species limit neutrophil life span by activating death receptor signaling
| Autor: | Mike Salmon, Helen M. McGettrick, Keqing Wang, Dagmar Scheel-Toellner, Paul Webb, Erich Gulbins, Louise E. Clough, Neal Parkes, Rachel Craddock, Janet M. Lord, Lakhvir K Assi |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Ceramide
Neutrophils Immunology Apoptosis Biology Ceramides Caspase 8 Biochemistry Mice chemistry.chemical_compound Membrane Microdomains medicine Animals Humans fas Receptor Receptor Lipid raft Cells Cultured Mice Knockout chemistry.chemical_classification Reactive oxygen species Cell Biology Hematology Fas receptor Mitochondria Cell biology Enzyme Activation Sphingomyelin Phosphodiesterase chemistry Caspases Acid sphingomyelinase Carrier Proteins Reactive Oxygen Species BH3 Interacting Domain Death Agonist Protein Signal Transduction medicine.drug |
| Zdroj: | Blood. 104:2557-2564 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood-2004-01-0191 |
| Popis: | Neutrophils are abundant, short-lived leukocytes, and their death by apoptosis is central to hemostasis and the resolution of inflammation, yet the trigger for their entry into apoptosis is unknown. We show here that death receptor signaling, including CD95 death-inducing signaling complex (DISC) formation and caspase 8 activation, occurred early in neutrophil apoptosis. However, death receptor ligation was not required for apoptosis, suggesting a novel mechanism for caspase 8 activation. We detected ceramide generation and clustering of CD95 in lipid rafts early in neutrophil apoptosis, and neutrophil apoptosis and ceramide generation were both significantly inhibited in acid sphingomyelinase knockout (ASM–/–) mice compared to wild-type littermates. Further studies revealed that ceramide generation, CD95 clustering, and neutrophil apoptosis were dependent on reactive oxygen species (ROSs) and were preceded by a fall in reduced glutathione levels. We propose that accumulation of ROSs, as a consequence of altered redox status, initiates ligand-independent death receptor signaling via activation of ASM and clustering of preformed DISC components in lipid rafts and is therefore a primary factor limiting neutrophil life span. |
| Databáze: | OpenAIRE |
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