1. IL-18; a cytokine translates a stress into medical science.
- Author
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Sekiyama A, Ueda H, Kashiwamura S, Nishida K, Kawai K, Teshima-kondo S, Rokutan K, and Okamura H
- Subjects
- Adrenal Cortex drug effects, Adrenal Cortex metabolism, Adrenocorticotropic Hormone metabolism, Animals, Caspase Inhibitors, Enzyme Activation, Enzyme Inhibitors pharmacology, Humans, Hypothalamo-Hypophyseal System, Immunoblotting, Immunohistochemistry, Interleukin-6 blood, Mice, Pituitary-Adrenal System, Reactive Oxygen Species antagonists & inhibitors, Restraint, Physical physiology, Superoxides metabolism, Time Factors, Up-Regulation, p38 Mitogen-Activated Protein Kinases antagonists & inhibitors, Interleukin-18 blood, Medicine, Science, Stress, Psychological physiopathology
- Abstract
Psychological/physical stresses have been reported to exacerbate auto-immune and inflammatory diseases. To clarify a mechanism by which non-inflammatory stresses disrupt host defenses, responses to immobilization stress in mice were investigated, focusing on the role of a multifunctional cytokine, interleukin-18 (IL-18). In the adrenal cortex, the stress induced IL-18 precursor proteins (pro-IL-18) via ACTH and a superoxide-mediated caspase-1 activation pathway, resulting in conversion of pro-IL-18 to the mature form which was released into plasma. Inhibitors of caspase-1, reactive oxygen species and P38 MAPK prevented stress-induced accumulation of plasma IL-18. These inhibitors also blocked stress-induced IL-6 expression. This, together with the observation that IL-6 was not induced in stressed-IL-18 deficient mice, showed that IL-6 induction by stress is dependent on IL-18. In stressed organisms, IL-18 may influence pathological and physiological processes. Controlling the caspase-1 activating pathway to suppress IL-18 levels may provide preventative means against stress-related disruption of host defenses.
- Published
- 2005
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