OBJECTIVE: Several proatherogenic agents including oxidized LDL and its major component, 13-hydroperoxyoctadecadienoic acid (13-HPODE), upregulate heme oxygenase-1 (HO-1). Our previous studies have demonstrated that 13-HPODE-mediated HO-1 induction occurs via transcriptional mechanisms. The purpose of this study was to evaluate the molecular regulation and identify the signaling pathways involved in 13-HPODE-mediated HO-1 induction in human aortic endothelial cells. METHODS AND RESULTS: The half-life of HO-1 mRNA after stimulation with 13-HPODE was approximately 1.8 hours. Antioxidants such as N-acetylcysteine, iron chelation with deferoxamine mesylate, and protein kinase C inhibition with Gö6976 blocked HO-1 induction. Using promoter constructs up to 9.1 kb, no significant reporter activity was observed in response to 13-HPODE. A 13-HPODE-inducible DNase I hypersensitive site was identified that maps to a region approximately 10 to 11 kb from the transcription start site of the human HO-1 gene. Based on the DNase I analysis, a -11.6-kb human HO-1 promoter construct was generated and elicited a 2.5-fold increase in reporter activity, indicating that 13-HPODE-mediated human HO-1 induction requires, at least in part, sequences that reside between 9.1 and 11.6 kb of the human HO-1 promoter. CONCLUSIONS: Elucidation of the molecular mechanisms which control HO-1 gene expression will allow us to develop therapeutic strategies to enhance the cytoprotective potential of HO-1 in atherosclerosis.
OBJECTIVE: Several proatherogenic agents including oxidized LDL and its major component, 13-hydroperoxyoctadecadienoic acid (13-HPODE), upregulate heme oxygenase-1 (HO-1). Our previous studies have demonstrated that 13-HPODE-mediated HO-1 induction occurs via transcriptional mechanisms. The purpose of this study was to evaluate the molecular regulation and identify the signaling pathways involved in 13-HPODE-mediated HO-1 induction in human aortic endothelial cells. METHODS AND RESULTS: The half-life of HO-1 mRNA after stimulation with 13-HPODE was approximately 1.8 hours. Antioxidants such as N-acetylcysteine, iron chelation with deferoxamine mesylate, and protein kinase C inhibition with Gö6976 blocked HO-1 induction. Using promoter constructs up to 9.1 kb, no significant reporter activity was observed in response to 13-HPODE. A 13-HPODE-inducible DNase I hypersensitive site was identified that maps to a region approximately 10 to 11 kb from the transcription start site of the humanHO-1 gene. Based on the DNase I analysis, a -11.6-kb humanHO-1 promoter construct was generated and elicited a 2.5-fold increase in reporter activity, indicating that 13-HPODE-mediated humanHO-1 induction requires, at least in part, sequences that reside between 9.1 and 11.6 kb of the humanHO-1 promoter. CONCLUSIONS: Elucidation of the molecular mechanisms which control HO-1 gene expression will allow us to develop therapeutic strategies to enhance the cytoprotective potential of HO-1 in atherosclerosis.
Authors: Emoke Nagy; John W Eaton; Viktória Jeney; Miguel P Soares; Zsuzsa Varga; Zoltán Galajda; József Szentmiklósi; Gábor Méhes; Tamás Csonka; Ann Smith; Gregory M Vercellotti; György Balla; József Balla Journal: Arterioscler Thromb Vasc Biol Date: 2010-04-08 Impact factor: 8.311
Authors: Marcienne M Wright; Francisco J Schopfer; Paul R S Baker; Vijay Vidyasagar; Pam Powell; Phil Chumley; Karen E Iles; Bruce A Freeman; Anupam Agarwal Journal: Proc Natl Acad Sci U S A Date: 2006-03-06 Impact factor: 11.205
Authors: Marcienne M Wright; Junghyun Kim; Thomas D Hock; Norbert Leitinger; Bruce A Freeman; Anupam Agarwal Journal: Biochem J Date: 2009-08-13 Impact factor: 3.857
Authors: Weihong Hou; Ying Shan; Jianyu Zheng; Richard W Lambrecht; Susan E Donohue; Herbert L Bonkovsky Journal: Biochim Biophys Acta Date: 2008-02-14