抄録
Increased catalytic activity of CBS (cystathionine β-synthase) was recently shown to mediate vasodilation of the cerebral microcirculation, which is initiated within minutes of the onset of acute hypoxia. To test whether chronic hypoxia was a stimulus for increased CBS expression, U87-MG human glioblastoma and PC12 rat phaeochromocytoma cells were exposed to 1% or 20%O2 for 24-72 h. CBS mRNA and protein expression were increased in hypoxic cells. Hypoxic induction of CBS expression was abrogated in cells transfected with vector encoding shRNA targeting HIF (hypoxia-inducible factor) 1α or 2α. Exposure of rats to hypobaric hypoxia (0.35 atm; 1 atm = 101.325 kPa) for 3 days induced increased CBS mRNA, protein and catalytic activity in the cerebral cortex and cerebellum, which was blocked by administration of the HIF inhibitor digoxin. HIF-binding sites, located 0.8 and 1.2 kb 5 to the transcription start site of the human CBS and rat Cbs genes respectively, were identified by ChIP assays. A 49-bp human sequence, which encompassed an inverted repeat of the core HIF-binding site, functioned as a hypoxiaresponse element in luciferase reporter transcription assays. Thus HIFsmediate tissue-specificCBSexpression, whichmay augment cerebral vasodilation as an adaptive response to chronic hypoxia.
本文言語 | English |
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ページ(範囲) | 203-211 |
ページ数 | 9 |
ジャーナル | Biochemical Journal |
巻 | 458 |
号 | 2 |
DOI | |
出版ステータス | Published - 2014 3月 1 |
ASJC Scopus subject areas
- 生化学
- 分子生物学
- 細胞生物学