First Author | Fernandez-Lizarbe S | Year | 2009 |
Journal | J Immunol | Volume | 183 |
Issue | 7 | Pages | 4733-44 |
PubMed ID | 19752239 | Mgi Jnum | J:152765 |
Mgi Id | MGI:4359955 | Doi | 10.4049/jimmunol.0803590 |
Citation | Fernandez-Lizarbe S, et al. (2009) Critical role of TLR4 response in the activation of microglia induced by ethanol. J Immunol 183(7):4733-44 |
abstractText | Microglial cells are the primary immune effector cells in the brain and play a pivotal role in the neuroinflammatory processes associated with a variety of neurological and pathological disorders. Alcohol consumption induces brain damage, although the neuropathological processes are poorly understood. We previously suggested that ethanol promotes inflammatory processes in the brain, up-regulating inflammatory mediators and signaling pathways associated with IL-1RI/TLR4 receptors. In the present study we investigate whether ethanol induces microglia activation by stimulating TLR4 response and whether this response causes neuronal death and contributes to ethanol-induced neuroinflammatory damage. We demonstrate that ethanol activates microglia and stimulates NF-kappaB, MAPKs, and MyD88-independent (IFN regulatory factor-3, IFN-beta) pathways to trigger the production of inflammatory mediators, causing neuronal death. The inflammatory response induced by ethanol is completely abrogated in microglia of TLR4-deficient mice (TLR4(-/-)), thus supporting the role of these receptors in microglia activation and neuronal death. In accord with the in vitro findings, acute ethanol administration induces microglia activation (CD11b(+) cells) in cerebral cortex of TLR4(+/+) mice, but not in TLR4(-/-) mice. Taken together, our results not only provide the first evidence of the critical role of the TLR4 response in the ethanol-induced microglia activation, but also new insight into the basic mechanisms participating in ethanol-induced neuroinflammatory damage. |