title: CO Induces Nrf2-Dependent Heme Oxygenase-1 Transcription by Cooperating with Sp1 and c-Jun in Rat Brain Astrocytes.
abstract: Upregulation of heme oxygenase 1 (HO-1) by carbon monoxide (CO) delivered by CO-releasing molecules (CORMs) may be utilized as a therapeutic intervention for neurodegenerative diseases. This study was to delineate the two putative anti-oxidant response elements (AREs) in modulating HO-1 gene by participating with its promoter elements in rat brain astrocytes (RBA-1). CORM-2-induced HO-1 expression was mediated through superoxide, p38 mitogen-activated protein kinase(MAPK), extracellular signal-regulated protein kinases 1 and 2 (Erk1/2), protein tyrosine kinase 2 (Pyk2), platelet-derived growth factor receptor (PDGFR), and phosphatidylinositol 3'-kinase (PI3K/Akt), revealed by the pharmacological inhibitors or knockdown of these signaling molecules. CORM-2-enhanced HO-1 promoter activity was inhibited by co-transfection with small interfering RNA (siRNA) of c-Jun, specificity protein 1 (Sp1), or nuclear factor-erythroid 2-related factor 2 (Nrf2). Immunoprecipitation assay showed that CORM-2 increased the association of nuclear Nrf2 with Sp1 and c-Jun. Furthermore, chromatin immunoprecipitation (ChIP) assay confirmed that Nrf2, Sp1, and c-Jun are associated with the proximal ARE binding site on HO-1 promoter, suggesting that Nrf2/Sp1/c-Jun cooperations are key transcription factors modulating HO-1 expression. Mechanistically, CORM-2-induced ARE promoter activity was reduced by the inhibitors of reactive oxygen species (ROS), p38 MAPK, Pyk2, MAPK/ERK kinases 1 and 2 (MEK1/2), PDGFR, and PI3K/Akt or the siRNAs of c-Jun, SP1, and Nrf2. These findings suggested that CORM-2 increases formation of c-Jun, Sp1, and Nrf2 complex and binding with ARE1 binding site, which is mediated through both ROS/p38 MAPK and Pyk2-dependent PDGFR/PI3K/Akt/Erk1/2 pathways, resulting in HO-1 expression in RBA-1 cells.
authors.affiliation: Department of Physiology and Pharmacology and Health Ageing Research Center, College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan, 33302, Tao-Yuan, Taiwan.
authors.forename: Pei-Ling
authors.initials: PL
authors.lastname: Chi
authors.forename: Chih-Chung
authors.initials: CC
authors.lastname: Lin
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Chen
authors.forename: Li-Der
authors.initials: LD
authors.lastname: Hsiao
authors.forename: Chuen-Mao
authors.initials: CM
authors.lastname: Yang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D001921:Brain / Q000166:cytology*; D002248:Carbon Monoxide / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D051418:Focal Adhesion Kinase 2 / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D009942:Organometallic Compounds / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor; D020218:Response Elements / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D000975:Antioxidants; D051267:NF-E2-Related Factor 2; D009942:Organometallic Compounds; D016755:Proto-Oncogene Proteins c-jun; D017382:Reactive Oxygen Species; D016329:Sp1 Transcription Factor; C447082:tricarbonyldichlororuthenium (II) dimer; D013481:Superoxides; D002248:Carbon Monoxide; D051547:Heme Oxygenase-1; D019255:NADPH Oxidases; D019869:Phosphatidylinositol 3-Kinases; D017479:Receptors, Platelet-Derived Growth Factor; D051418:Focal Adhesion Kinase 2; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases