title: HIF-1 activation attenuates postischemic myocardial injury: role for heme oxygenase-1 in modulating microvascular chemokine generation.
abstract: The CXC chemokine IL-8, which promotes adhesion, activation, and transmigration of polymorphonuclear neutrophils (PMN), has been associated with production of tissue injury in reperfused myocardium. Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric peptide that is a key regulator of genes such as heme oxygenase (HO)-1 expressed under hypoxic conditions. We hypothesized that HO-1 plays an important role in regulating proinflammatory mediator production under conditions of ischemia-reperfusion. HIF-1 was activated in the human microvascular endothelial cell line (HMEC-1) with the prolyl hydroxylase inhibitor dimethyloxalylglycine (DMOG). DMOG significantly attenuated cytokine-induced IL-8 promoter activity and protein secretion and cytokine-induced PMN migration across human microvascular endothelial cell line HMEC-1 monolayers. In vivo studies in a rabbit model of myocardial ischemia-reperfusion showed that rabbits pretreated with a 20 mg/kg DMOG infusion (n = 6) 24 h before study exhibited a 21.58 +/- 1.76% infarct size compared with 35.25 +/- 2.06% in saline-treated ischemia-reperfusion animals (n = 6, change in reduction = 39%; P < 0.001). In DMOG-pretreated (20 mg/kg) animals, plasma IL-8 levels at 3 h after onset of reperfusion were 405 +/- 40 pg/ml vs. 790 +/- 40 pg/ml in saline-treated ischemia-reperfusion animals (P < 0.001). DMOG pretreatment reduced myocardial myeloperoxidase activity, expressed as number of PMN per gram of myocardium, to 1.43 +/- 0.59 vs. 4.86 +/- 1.1 (P = 0.012) in saline-treated ischemia-reperfused hearts. Both in vitro and in vivo DMOG-attenuated IL-8 production was associated with robust HO-1 expression. Thus our data show that HIF-1 activation induces substantial HO-1 expression that is associated with attenuated proinflammatory chemokine production by microvascular endothelium in vitro and in vivo.
authors.affiliation: Div. of Cardiology, Dept. of Internal Medicine, Virginia Commonwealth Univ., PO Box 980050, Richmond, VA 23298, USA.
authors.forename: Ramzi
authors.initials: R
authors.lastname: Ockaili
authors.forename: Ramesh
authors.initials: R
authors.lastname: Natarajan
authors.forename: Fadi
authors.initials: F
authors.lastname: Salloum
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Fisher
authors.forename: Drew
authors.initials: D
authors.lastname: Jones
authors.forename: Alpha A
authors.initials: AA
authors.lastname: Fowler
authors.forename: Rakesh C
authors.initials: RC
authors.lastname: Kukreja
mesh_terms: D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology; D001808:Blood Vessels / Q000378:metabolism*; D002478:Cells, Cultured; D018925:Chemokines / Q000096:biosynthesis*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D016209:Interleukin-8 / Q000037:antagonists & inhibitors / Q000097:blood / Q000235:genetics; D008565:Membrane Proteins; D008833:Microcirculation; D009203:Myocardial Infarction / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D009206:Myocardium / Q000201:enzymology / Q000473:pathology; D020556:Neutrophil Infiltration / Q000187:drug effects; D009687:Nuclear Proteins / Q000378:metabolism*; D011393:Procollagen-Proline Dioxygenase / Q000037:antagonists & inhibitors; D011401:Promoter Regions, Genetic / Q000187:drug effects; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D000600:Amino Acids, Dicarboxylic; D018925:Chemokines; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D016209:Interleukin-8; D008565:Membrane Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D011393:Procollagen-Proline Dioxygenase; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C040947:oxalylglycine