Preconditioning induces prolonged expression of transcription factors pCREB and NF-kappa B in the neocortex of rats before and following severe hypobaric hypoxia.
Preconditioning using mild repetitive hypobaric hypoxia is known to increase a tolerance of brain neurons to severe hypoxia and other injurious exposures. In the present study, the effects of mild hypoxic preconditioning on the expression of transcription factors NF-kappaB and phosphorylated CREB (pCREB) has been studied in the neocortex of rats exposed to severe hypobaric hypoxia. As revealed by quantitative immunocytochemistry, the injurious severe hypobaric hypoxia (180 Torr, 3 h) remarkably reduced the neocortical levels of pCREB and NF-kappaB. The three-trial hypoxic preconditioning (360 Torr, 2 h, 3 days) induced persistent up-regulation of pCREB and NF-kappaB expression in the neocortex of rats 3-24 h following the severe hypoxia. In addition, the preconditioning alone which was not followed by the severe hypoxia, considerably increased neocortical pCREB and NF-kappaB levels. The findings suggest a role for transcription factors cAMP response element-binding protein and NF-kappaB in the neuroprotective mechanisms activated by the hypoxic preconditioning.
Laboratory of Neuroendocrinology, Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russian Federation. rybnikova1@rambler.ru
Elena
E
Rybnikova
Tatjana
T
Gluschenko
Ekaterina
E
Tulkova
Anna
A
Churilova
Oksana
O
Jaroshevich
Ksenia
K
Baranova
Michail
M
Samoilov
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D002534:Hypoxia, Brain / Q000378:metabolism* / Q000503:physiopathology; D019194:Ischemic Preconditioning / Q000379:methods; D008297:Male; D016328:NF-kappa B / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D019579:Neocortex / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology
D017362:Cyclic AMP Response Element-Binding Protein; D016328:NF-kappa B