[Effect of hypoxia on hypoxia inducible factor 1alpha (HIF-1alpha) activation in intestinal epithelial cells].
OBJECTIVE
To investigate the effect of hypoxia on HIF-1alpha activation in intestinal epithelial cells.


METHODS
Intestinal epithelial cells were randomly divided into normal control group, hypoxia group and hypoxia plus oligomycin group (oligomycin group). In hypoxia group, the cells were exposed to hypoxia for 1, 2, 6, 12 and 24 h. In oligomycin group, the cells were treated with oligomycin in concentration of 5, 10, 20 and 40 microg/mL for 1 h prior to 6-hour hypoxic exposure. HIF-1alpha protein expression was assayed by western blot method. Nuclear translocation of HIF-1alpha was detected by immunofluorescence analysis.


RESULTS
Compared with that in control group (0.08 +/- 0.07), HIF-1alpha protein expression in hypoxia group increased significantly at 1 h (0.52 +/- 0.30, P < 0.05), and reached the peak value (2.37 +/- 1.08, P < 0.05) at 6 h. Nuclear translocation of HIF-1alpha was also induced by hypoxia. HIF-1alpha protein expression in oligomycin group in the concentration of 5, 10, 20 and 40 microg/mL of oligomycin was 1.62 +/- 0.96, 1.48 +/- 0.56, 1.08 +/- 0.36 and 0.58 +/- 0.11 respectively, which was significantly lower than that only after exposure to hypoxia for 6 h (2.67 +/- 1.38, P < 0.05). The nuclear translocation of HIF-1alpha induced by hypoxia was also obviously inhibited by oligomycin pretreatment.


CONCLUSIONS
Oligomycin, a specific inhibitor of respiratory chain, inhibits HIF-1alpha activation, which suggests that mitochondria respiratory chain may play an important role in aforementioned process.
Li
Mu
M
Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, the Third Military Medical University, Chongqing 400038, PR China.
Wang
Pei
P
Liu
Chen
C
Chen
Chuan-li
CL
Wang
Feng-jun
FJ
D015153:Blotting, Western; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D007422:Intestines / Q000166:cytology; D009840:Oligomycins / Q000494:pharmacology*
C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009840:Oligomycins