Edaravone inhibits the expression of vascular endothelial growth factor in human astrocytes exposed to hypoxia.
Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, reduces brain edema in patients with acute ischemic stroke. We have addressed the effect of edaravone on the expression of vascular endothelial growth factor (VEGF), a potential mediator of brain edema, in astrocytes exposed to hypoxia. Normal human astrocytes in culture were treated with edaravone, and the levels of VEGF mRNA and protein were analyzed by reverse transcription-polymerase chain reaction (RT-PCR), real-time quantitative PCR and enzyme-linked immunosorbent assay (ELISA). The expression of hypoxia-inducible factor-1alpha (HIF-1alpha), a transcriptional activator of VEGF, was examined by RT-PCR, real-time PCR and western blotting; and the binding of HIF-1alpha to the promoter region of VEGF gene by chromatin immunoprecipitation (ChIP) assay. Edaravone moderately suppressed the expression of VEGF mRNA and protein in astrocytes under hypoxia in time- and concentration-dependent manners. It also suppressed the accumulation of HIF-1alpha in the nuclei under hypoxia. ChIP assay confirmed that edaravone reduced HIF-1alpha binding to VEGF promoter. We conclude that edaravone inhibits VEGF expression in astrocytes exposed to hypoxia, at least partly, through the down-regulation of HIF-1alpha. These findings offer a partial explanation for the protective effect of edaravone on the development of brain edema in patients with acute ischemic stroke.
Ishikawa
Akira
A
Department of Vascular Biology, Institute of Brain Science, Hirosaki University School of Medicine, Hirosaki, Japan.
Yoshida
Hidemi
H
Metoki
Norifumi
N
Toki
Tsutomu
T
Imaizumi
Tadaatsu
T
Matsumiya
Tomoh
T
Yamashita
Koji
K
Taima
Kageaki
K
Satoh
Kei
K
D000983:Antipyrine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000378:metabolism; D001929:Brain Edema / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D002467:Cell Nucleus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D002536:Cerebral Arteries / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D000077553:Edaravone; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D002534:Hypoxia, Brain / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
D016166:Free Radical Scavengers; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D000077553:Edaravone; D000983:Antipyrine