title: Variation in gene expression profiles of human monocytic U937 cells exposed to various fluxes of nitric oxide.
abstract: We examined early and late alterations in gene expression patterns and phosphorylation levels of key regulators of selected signaling pathways in U937 cells exposed to various (*)NO fluxes. cDNA microarray analysis and real-time quantitative PCR identified 45 NO-sensitive genes (>or=2-fold change), among which KLF2, KLF6, TSC22D3, DDIT4, MKP-5 (up-regulated), KIF23, histone H4, ARL6IP2, CLNS1A, SLC7A6, CDKN3, SRP19, and BCL11A (down-regulated) have not been reported before. For two selected genes, KLF2 and DDIT4, the sensitivity to (.)NO was also proven at the protein level. Among the examined genes, only KLF2 had a higher sensitivity to slow release of NO (DETA-NO) than to high-dose, short-duration exposure (DPTA-NO), reaching an about 50-fold increase in mRNA level. Our study revealed that fast and slow NO donors activate similar signaling pathways and induce phosphorylation of MAP kinases and downstream transcription factors ATF2 and c-Jun. Inhibitory analysis of major signaling pathways showed that activity of p38 MAPK and tyrosine kinases is indispensable for gene induction in cells exposed to DPTA-NO, whereas G-protein Rho suppression caused superinduction of KLF2 in (*)NO-stimulated cells. Finally, we showed that both (*)NO donors caused a marked decrease in phosphorylation of p70S6K, an mTOR substrate and regulator of mRNA translation, and protein kinase Akt, an upstream positive regulator of mTOR.
authors.affiliation: Institut de Chimie des Substances Naturelles, Centre de Recherche de Gif, Centre National de la Recherche Scientifique, 91190 Gif-sur-Yvette, France.
authors.forename: Kyril
authors.initials: K
authors.lastname: Turpaev
authors.forename: Annie
authors.initials: A
authors.lastname: Glatigny
authors.forename: Jérome
authors.initials: J
authors.lastname: Bignon
authors.forename: Hervé
authors.initials: H
authors.lastname: Delacroix
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Drapier
mesh_terms: D051698:Activating Transcription Factor 2 / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D020555:GTP-Binding Protein Regulators / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D046228:Microarray Analysis; D009000:Monocytes / Q000378:metabolism* / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism; D010766:Phosphorylation; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D020298:U937 Cells
chemical_list: C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; C469991:DDIT4 protein, human; D020555:GTP-Binding Protein Regulators; C096161:KLF2 protein, human; C105465:KLF6 protein, human; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D009569:Nitric Oxide; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D048049:Extracellular Signal-Regulated MAP Kinases