Induction of the expression of heme oxygenase gene in PC12 cells by hypoxia

Abstract

To investigate the expression of the HO-1 gene in PC12 cells in hypoxic environment and gain further insight to the role of HO-1 in cerebral ischemia, PC12 cells were exposed to hypoxia environment (95 % N₂, 5 % CO₂) for 0.5 h, 1 h, 4 h, 8 h, 12 h, 24 h respectively. The level of HO-1 mRNA was examined by reverse transcriptase polymerase chain reaction (RT-PCR); the volume of COHb in the media were measured spectrophotometrically and the cGMP concentration of PC12 cell extracts was determined by radioimmunoassay. We found that after exposure to hypoxia for 1 h, 4 h, 8 h, 12 h, 24 h, HO-1 mRNA increased by 3 %, 4 %, 17 %, 31 %, 36 % as compared with that in control group respectively (P<0.01 orP<0.05); the COHb increased by 12 %, 29 %, 59 %, 88 %, 94 % as compared with that in control group respectively (P<0.01 orP<0.05), and the cGMP concentration were 2.2, 3.4, 5.2, 8.1, 10.9-fold as that of the control group (P<0.01). We are led to conclude that hypoxia induced the expression of HO-1 gene, the production of endogenous CO, and the concentration of cGMP was elevated as well.

Keywords

hypoxia / heme oxygenase / carbon monoxide / PC12 cells

References

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