Regulation of expression of nuclear factor kappa B RelA in oligodendrocytes: effect of hypoxia

Little is known about the expression of nuclear factor kappa B (NF-kappa B) in oligodendrocytes. We demonstrate that under normal culture conditions o nly 21% of oligodendrocytes express NF-kappa B p65; exposure to hypoxia inc reased this to 69%. A similar increase in total p65 was seen with Western b lots. Northern blot analysis demonstrated that NF-kappa B p65 mRNA increase d during the first few h following hypoxia, suggesting that exposure to hyp oxia affects NF-kappa B p65 transcription or p65 mRNA stability. Under norm oxic conditions only 2% of the oligodendrocytes exhibited activated NF-kapp a B; this was increased to 8% by hypoxia followed by reoxygenation. Despite activation of NF-kappa B, no detectable expression of the proinflammatory genes INOS and ICAM-1 was seen. This is the first demonstration that hypoxi a can up-regulate p65. NeuroReport 11:1877-1881 (C) 2000 Lippincott William s & Wilkins.