Chronic ethanol treatment enhances inflammatory mediators and cell death in the brain and in astrocytes.
Inflammatory processes and cytokine expression have been implicated in the pathogenesis of several neurodegenerative disorders. Chronic ethanol intake induces brain damage, although the mechanisms involved in this effect are not well understood. We tested the hypothesis that activation of glial cells by ethanol would induce stimulation of signaling pathways and inflammatory mediators in brain, and would cause neurotoxicity. We used cerebral cortex from control and chronic ethanol-fed rats, which received ethanol-liquid diet for 5 months and cultured of astrocytes exposed to 75 mM ethanol for 7 days. Our results demonstrate that chronic ethanol treatment up-regulates iNOS, COX-2 and IL-1beta in rat cerebral cortex and in cultured astrocytes. Under both experimental conditions, up-regulation of these inflammatory mediators and IL-1RI concomitantly occurs with the stimulation of IRAK and MAP kinases, including ERK1/2, p-38 and JNK, which trigger the downstream activation of oxidant-sensitive transcription factors NF-KB and AP-1. These effects were associated with an increased in both caspase-3 and apoptosis in ethanol-fed rats and in astrocytes exposed to ethanol. In conclusion, chronic ethanol treatment stimulates glial cells, up-regulating the production and the expression of inflammatory mediators in the brain, and activating signalling pathways and transcription factors involved in inflammatory damage and cell death.
Vallés
Soraya L
SL
Instituto de Investigaciones Citológicas (FVIB), Valencia, Spain.
Blanco
Ana M
AM
Pascual
María
M
Guerri
Consuelo
C
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects*; D015153:Blotting, Western / Q000379:methods; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D051546:Cyclooxygenase 2; D053938:DNA Fragmentation / Q000187:drug effects; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D020672:I-kappa B Proteins / Q000378:metabolism; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D048670:MAP Kinase Kinase 4; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D018808:Transcription Factor AP-1 / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D002492:Central Nervous System Depressants; D020672:I-kappa B Proteins; D007375:Interleukin-1; D007527:Isoenzymes; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D000431:Ethanol; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; D048031:JNK Mitogen-Activated Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases