| First Author | Lippai D | Year | 2013 |
| Journal | J Leukoc Biol | Volume | 94 |
| Issue | 1 | Pages | 171-82 |
| PubMed ID | 23625200 | Mgi Jnum | J:201853 |
| Mgi Id | MGI:5515867 | Doi | 10.1189/jlb.1212659 |
| Citation | Lippai D, et al. (2013) Alcohol-induced IL-1beta in the brain is mediated by NLRP3/ASC inflammasome activation that amplifies neuroinflammation. J Leukoc Biol 94(1):171-82 |
| abstractText | Alcohol-induced neuroinflammation is mediated by proinflammatory cytokines, including IL-1beta. IL-1beta production requires caspase-1 activation by inflammasomes-multiprotein complexes that are assembled in response to danger signals. We hypothesized that alcohol-induced inflammasome activation contributes to increased IL-1beta in the brain. WT and TLR4-, NLRP3-, and ASC-deficient (KO) mice received an ethanol-containing or isocaloric control diet for 5 weeks, and some received the rIL-1ra, anakinra, or saline treatment. Inflammasome activation, proinflammatory cytokines, endotoxin, and HMGB1 were measured in the cerebellum. Expression of inflammasome components (NLRP1, NLRP3, ASC) and proinflammatory cytokines (TNF-alpha, MCP-1) was increased in brains of alcohol-fed compared with control mice. Increased caspase-1 activity and IL-1beta protein in ethanol-fed mice indicated inflammasome activation. TLR4 deficiency protected from TNF-alpha, MCP-1, and attenuated alcohol-induced IL-1beta increases. The TLR4 ligand, LPS, was not increased in the cerebellum. However, we found up-regulation of acetylated and phosphorylated HMGB1 and increased expression of the HMGB1 receptors (TLR2, TLR4, TLR9, RAGE) in alcohol-fed mice. NLRP3- or ASC-deficient mice were protected from caspase-1 activation and alcohol-induced IL-1beta increase in the brain. Furthermore, in vivo treatment with rIL-1ra prevented alcohol-induced inflammasome activation and IL-1beta, TNF-alpha, and acetylated HMGB1 increases in the cerebellum. Conversely, intracranial IL-1beta administration induced TNF-alpha and MCP-1 in the cerebellum. In conclusion, alcohol up-regulates and activates the NLRP3/ASC inflammasome, leading to caspase-1 activation and IL-1beta increase in the cerebellum. IL-1beta amplifies neuroinflammation, and disruption of IL-1/IL-1R signaling prevents alcohol-induced inflammasome activation and neuroinflammation. Increased levels of acetylated and phosphorylated HMGB1 may contribute to alcoholic neuroinflammation. |
