Effects of acute hypoxia and intermittent hypoxic acclimatization on vascular endothelial growth factor gene expression in HepG2 cells.
- Author:
Wei CHEN
1
;
Jia-Pei CHEN
;
Shi-Li GE
;
Xiao-Bing FU
;
Yu-Wen CONG
Author Information
- Publication Type:Journal Article
- MeSH: Acclimatization; genetics; Cell Hypoxia; genetics; Gene Expression; Hep G2 Cells; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; genetics; metabolism; Nuclear Proteins; genetics; Oxygen; metabolism; Vascular Endothelial Growth Factor A; genetics; metabolism
- From: Chinese Journal of Applied Physiology 2005;21(3):274-277
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo explore the influence of acute hypoxia and intermittent hypoxic acclimatization on vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1alpha (HIF-1alpha) gene expression in HepG2 cells underlying their possible biological significance.
METHODSHepG2 was cultured in 1% O2 for 24 hours, then in 21% O2 for another 24 hours, which composed a hypoxic exposure cycle. After 6 cycles, HepG2 cells reached the status of hypoxic acclimatization. Gene transcription and translation of VEGF and HIF-1alpha were detected with Northern blot and Western blot methods.
RESULTSAcute hypoxia could induce gene transcription and translation of VEGF and HIF-1alpha. After intermittent hypoxia acclimatization, the contents of VEGF and HIF-1alpha mRNA were 108.6% +/- 17.7% and 116.7% +/- 19.8% of those in normoxic control cells, while the protein contents were significantly increased to 1.4 and 2.7 times of those in control cells, respectively (P < 0.05). The protein expression levels of VEGF and HIF-1alpha were decreased in cells subjected to hypoxia acclimatization compared to cells treated with acute hypoxia.
CONCLUSIONWhen HepG2 cells reached the status of hypoxic acclimatization, the acute hypoxia-induced increment of VEGF gene transcription and translation in cells were inhibited, in which HIF-1alpha might play an important role.