Methamphetamine-induced TNF-alpha gene expression and activation of AP-1 in discrete regions of mouse brain: potential role of reactive oxygen intermediates and lipid peroxidation.
Cellular and molecular mechanisms of methamphetamine (METH)-induced neurotoxicity may involve alterations of cellular redox status and induction of inflammatory genes. To study this hypothesis, molecular signaling pathways of METH-induced inflammatory responses via activation of redox-sensitive transcription factors were investigated in discrete regions (corpus striatum, frontal cortex, and hippocampus) of mouse brain. Intraperitoneal injection of METH at a dose of 10 mg/kg body weight resulted in a significant increase in oxidative stress, as measured by 2,7-dichlorofluorescein (DCF) fluorescence assay, thiobarbituric acid-reactive substances (TBARS), and total glutathione levels. Glutathione peroxidase activity was also significantly increased after METH exposure. In addition, DNA binding activity of activator protein-1 (AP-1), a redox-responsive transcription factor, was increased in all studied brain regions in response to METH treatment. Because AP-1 is known to regulate expression of inflammatory genes, levels of TNF-alpha mRNA were also studied. Expression of the tumor necrosis factor-alpha (TNF-alpha) gene was induced 3 h after METH injection and remained elevated for up to 6 h of METH exposure. In addition, stimulation of the TNF-alpha gene was associated with increased TNF-a protein production in the frontal cortex. These results suggest that METH-induced disturbances in cellular redox status and that activation of AP-1 can play a critical role in signaling pathways leading to upregulation of inflammatory genes in vivo. Furthermore, these data provide evidence for the role of oxidative stress in the neurotoxic effects of METH.
Flora
Govinder
G
Departments of Surgery, University of Kentucky, Lexington 40536, USA.
Lee
Yong Woo
YW
Nath
Avindra
A
Maragos
William
W
Hennig
Bernhard
B
Toborek
Michal
M
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism; D015259:Dopamine Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D005978:Glutathione / Q000032:analysis; D005979:Glutathione Peroxidase / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007249:Inflammation / Q000235:genetics; D007274:Injections, Intraperitoneal; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D015398:Signal Transduction / Q000187:drug effects; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
D000697:Central Nervous System Stimulants; D015259:Dopamine Agents; D009419:Nerve Tissue Proteins; D017392:Thiobarbituric Acid Reactive Substances; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D008694:Methamphetamine; D004247:DNA; D005979:Glutathione Peroxidase; D005978:Glutathione