Induction of the expression of heme oxygenase gene in PC12 cells by hypoxia.
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 or P < 0.05); the COHb increased by 12%, 29%, 59%, 88%, 94% as compared with that in control group respectively (P < 0.01 or P < 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.
Xue
Zheng
Z
Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030.
Pan
Dengji
D
Zhang
Suming
S
D000818:Animals; D002248:Carbon Monoxide / Q000378:metabolism; D015687:Cell Hypoxia; D006152:Cyclic GMP / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000096:biosynthesis / Q000235:genetics*; D051547:Heme Oxygenase-1; D016716:PC12 Cells; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D015854:Up-Regulation
D012333:RNA, Messenger; D002248:Carbon Monoxide; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D006152:Cyclic GMP