Hyperoxia increases AP-1 DNA binding in rat brain.
Oxidative stress appears to contribute to neurodegenerative outcomes after ischemia, hypoxia, and hyperoxia. The AP-1 transcription factor is made up of a family of regulatory proteins that can be activated by oxidative stress. In the present study, we examined AP-1 DNA binding activity in terms of specific participating AP-1 proteins in rat brain after hyperoxia. Male Sprague-Dawley rats were exposed to 100% oxygen under isobaric conditions over time. The AP-1 DNA binding activity present in the rat hippocampus and basal forebrain was characterized by electrophoretic mobility shift analysis (EMSA) and the participating AP-1 proteins identified by immunodepletion/supershift and Western blotting analyses. The Fos and Jun proteins were localized by immunohistochemistry to hippocampus. There were significant increases in AP-1 DNA binding in both hippocampus and basal forebrain after hyperoxia. There was also a significant increase in c-Jun protein levels and the proportion of c-Jun present in AP-1 DNA binding complexes in hippocampal nuclei after hyperoxia. These results suggest that AP-1 activation via c-Jun binding to DNA is an important component of brain responses to oxidative stress.
Tong
LiQi
L
Department of Human Biological Chemistry and Genetics, The University of Texas Medical Branch, Galveston, Texas, 77555-0652, USA.
Toliver-Kinsky
Tracy
T
Rassin
David
D
Werrbach-Perez
Karin
K
Perez-Polo
J Regino
JR
D000818:Animals; D004247:DNA / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D006624:Hippocampus / Q000378:metabolism*; D018496:Hyperoxia / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D016548:Prosencephalon / Q000378:metabolism*; D011485:Protein Binding; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D018808:Transcription Factor AP-1 / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D004247:DNA