title: Cytokines induce HIF-1 DNA binding and the expression of HIF-1-dependent genes in cultured rat enterocytes.
abstract: Cellular adaptation to hypoxia depends, in part, on the transcription factor hypoxia-inducible factor-1 (HIF-1). Normoxic cells exposed to an inflammatory milieu often manifest phenotypic changes, such as increased glycolysis, that are reminiscent of those observed in hypoxic cells. Accordingly, we investigated the effects of cytomix, a mixture containing IFN-gamma, TNF, and IL-1beta on the expression of HIF-1-dependent proteins under normoxic and hypoxic conditions. Incubation of intestine-derived epithelial cells (IEC-6) under 1% O(2) increased HIF-1 DNA binding and expression of aldolase A, enolase-1, and VEGF mRNA. Incubation of normoxic cells with cytomix for 48 h also markedly increased HIF-1 DNA binding and expression of mRNAs for these proteins. Incubation of hypoxic cells with cytomix did not inhibit HIF-1 DNA binding or upregulation of HIF-1-dependent genes in response to hypoxia. Neither cytomix nor hypoxia increased steady-state levels of HIF-1alpha mRNA. Incubation of IEC-6 cells with cytomix induced nitric oxide (NO.) biosynthesis, which was blocked if the cultures contained l-N(G)-(1-iminoethyl)lysine hydrochloride (l-NIL). Treatment with l-NIL, however, failed to significantly alter aldolase A, enolase-1, and VEGF mRNA levels in normoxic cytomix-treated cells. Proinflammatory cytokines activate the HIF-1 pathway and increase expression of glycolytic genes in nontransformed rat intestinal epithelial cells, largely through an NO.-independent mechanism.
authors.affiliation: Klinik und Poliklinik für Anästhesiologie und Operative Intensivmedizin, Universitätsklinikum Münster, Münster, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Scharte
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Han
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Bertges
authors.forename: Mitchell P
authors.initials: MP
authors.lastname: Fink
authors.forename: Russell L
authors.initials: RL
authors.lastname: Delude
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D016228:Endothelial Growth Factors / Q000096:biosynthesis; D020895:Enterocytes / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005634:Fructose-Bisphosphate Aldolase / Q000096:biosynthesis; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007202:Indicators and Reagents; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis; D019344:Lactic Acid / Q000096:biosynthesis; D008222:Lymphokines / Q000096:biosynthesis; D009566:Nitrates / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D052250:Nitric Oxide Synthase Type III; D009573:Nitrites / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D010751:Phosphopyruvate Hydratase / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D017077:Culture Media, Conditioned; D016207:Cytokines; D004268:DNA-Binding Proteins; D016228:Endothelial Growth Factors; D004791:Enzyme Inhibitors; C497444:Hif1a protein, rat; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007202:Indicators and Reagents; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D009566:Nitrates; D009573:Nitrites; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D019344:Lactic Acid; D004247:DNA; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D005634:Fructose-Bisphosphate Aldolase; D010751:Phosphopyruvate Hydratase; D005947:Glucose