1. E3 ubiquitin ligase Cblb regulates the acute inflammatory response underlying lung injury
- Author
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Xiaopei Gao, Randall S. Frey, Stephen M. Vogel, Gye Young Park, Sophie Toya, Chinnaswamy Tiruppathi, Sean Garrean, Asrar B. Malik, John W. Christman, Kurt Bachmaier, Thomas Triantafillou, and Richard D. Minshall
- Subjects
Lipopolysaccharides ,Chemokine ,Inflammation ,Lung injury ,General Biochemistry, Genetics and Molecular Biology ,Gene Expression Regulation, Enzymologic ,Proinflammatory cytokine ,Mice ,Downregulation and upregulation ,medicine ,Animals ,Proto-Oncogene Proteins c-cbl ,Lung ,Adaptor Proteins, Signal Transducing ,Mice, Knockout ,Mice, Inbred BALB C ,biology ,NF-kappa B ,General Medicine ,Lung Injury ,Pneumonia ,Ubiquitin ligase ,Survival Rate ,Toll-Like Receptor 4 ,Protein Transport ,Phenotype ,Immunology ,Acute Disease ,Myeloid Differentiation Factor 88 ,biology.protein ,TLR4 ,Cytokines ,CBLB ,medicine.symptom ,Gene Deletion ,Protein Binding ,Signal Transduction - Abstract
The E3 ubiquitin ligase Cblb has a crucial role in the prevention of chronic inflammation and autoimmunity. Here we show that Cblb also has an unexpected function in acute lung inflammation. Cblb attenuates the sequestration of inflammatory cells in the lungs after administration of lipopolysaccharide (LPS). In a model of polymicrobial sepsis in which acute lung inflammation depends on the LPS receptor (Toll-like receptor 4, TLR-4), the loss of Cblb expression accentuates acute lung inflammation and reduces survival. Loss of Cblb significantly increases sepsis-induced release of inflammatory cytokines and chemokines. Cblb controls the association between TLR4 and the intracellular adaptor MyD88. Expression of wild-type Cblb, but not expression of a Cblb mutant that lacks E3 ubiquitin ligase function, prevents the activity of a reporter gene for the transcription factor nuclear factor-kappaB (NF-kappaB) in monocytes that have been challenged with LPS. The downregulation of TLR4 expression on the cell surface of neutrophils is impaired in the absence of Cblb. Our data reveal that Cblb regulates the TLR4-mediated acute inflammatory response that is induced by sepsis.
- Published
- 2007