Regulation of astrocyte nitric oxide synthase type II expression by ATP and glutamate involves loss of transcription factor binding to DNA.
Pretreatment of astrocytes with either glutamate or ATP, acting via specific receptors, suppresses subsequent cytokine-induced expression of type II nitric oxide synthase (NOS). This effect is downstream from the activation and translocation of nuclear factor (NF)-kappaB, as western blotting revealed no difference in accumulation of the p50 subunit in nuclear extracts from agonist-treated vs. nontreated cells. However, evidence from gel-shift assay suggests that the binding of nuclear protein from agonist-treated cells to NF-kappaB and activator protein-1 consensus oligonucleotides is markedly reduced. Selective inhibitors of protein kinases A and C could not restore either binding of transcription factors to DNA or type II NOS mRNA expression in agonist-pretreated cells. The modulation of proinflammatory cytokine-evoked type II NOS expression by ATP and glutamate may play an important role in CNS pathologies associated with stroke and trauma.
Lin
H L
HL
Department of Pharmacology, University of Iowa College of Medicine, Iowa City 52242, USA.
Murphy
S
S
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000201:enzymology*; D015153:Blotting, Western; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D018698:Glutamic Acid / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats
D004791:Enzyme Inhibitors; D016328:NF-kappa B; D018698:Glutamic Acid; D000255:Adenosine Triphosphate; D019001:Nitric Oxide Synthase; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C