1. Src-family kinase-Cbl axis negatively regulates NLRP3 inflammasome activation.
- Author
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Chung IC, Yuan SN, OuYang CN, Lin HC, Huang KY, Chen YJ, Chung AK, Chu CL, Ojcius DM, Chang YS, and Chen LC
- Subjects
- Animals, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Bone Marrow Cells drug effects, Bone Marrow Cells immunology, Bone Marrow Cells pathology, Colitis chemically induced, Colitis genetics, Colitis prevention & control, Colon drug effects, Colon immunology, Colon pathology, Dextran Sulfate administration & dosage, Focal Adhesion Kinase 2 genetics, Focal Adhesion Kinase 2 immunology, Gene Expression Regulation, Inflammasomes drug effects, Inflammasomes genetics, Interleukin-18 genetics, Interleukin-18 immunology, Macrophages drug effects, Macrophages immunology, Macrophages pathology, Mice, Mice, Inbred C57BL, Mice, Knockout, Mitochondria, NLR Family, Pyrin Domain-Containing 3 Protein genetics, Phosphorylation drug effects, Primary Cell Culture, Proto-Oncogene Proteins c-cbl genetics, Reactive Oxygen Species antagonists & inhibitors, Reactive Oxygen Species immunology, Reactive Oxygen Species metabolism, Signal Transduction, Tetrahydroisoquinolines pharmacology, src-Family Kinases genetics, Colitis immunology, Inflammasomes immunology, NLR Family, Pyrin Domain-Containing 3 Protein immunology, Proto-Oncogene Proteins c-cbl immunology, src-Family Kinases immunology
- Abstract
Activation of the NLRP3 inflammasome is crucial for immune defense, but improper and excessive activation causes inflammatory diseases. We previously reported that Pyk2 is essential for NLRP3 inflammasome activation. Here we show that the Src-family kinases (SFKs)-Cbl axis plays a pivotal role in suppressing NLRP3 inflammasome activation in response to stimulation by nigericin or ATP, as assessed using gene knockout and gene knockdown cells, dominant active/negative mutants, and pharmacological inhibition. We reveal that the phosphorylation of Cbl is regulated by SFKs, and that phosphorylation of Cbl at Tyr371 suppresses NLRP3 inflammasome activation. Mechanistically, Cbl decreases the level of phosphorylated Pyk2 (p-Pyk2) through ubiquitination-mediated proteasomal degradation and reduces mitochondrial ROS (mtROS) production by contributing to the maintenance of mitochondrial size. The lower levels of p-Pyk2 and mtROS dampen NLRP3 inflammasome activation. In vivo, inhibition of Cbl with an analgesic drug, hydrocotarnine, increases inflammasome-mediated IL-18 secretion in the colon, and protects mice from dextran sulphate sodium-induced colitis. Together, our novel findings provide new insights into the role of the SFK-Cbl axis in suppressing NLRP3 inflammasome activation and identify a novel clinical utility of hydrocortanine for disease treatment.
- Published
- 2018
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