Dynamic changes in expression of heme oxygenases in mouse heart and liver during hypoxia.
Heme oxygenase cleaves heme to form biliverdin, carbon monoxide (CO), and iron, and consists of two structurally related isozymes, HO-1 and HO-2. HO-2 is also known as a potential oxygen sensor. Here we show that the relative CO content in arterial blood, which reflects the total amount of endogenous heme degradation, dynamically changes in mice during acclimatization to normobaric hypoxia (10% O2), with the two peaks at 1 day and 21 days of hypoxia. The expression levels of HO-1 and HO-2 proteins were decreased by 20% and 40%, respectively, in the mouse liver at 7 days of hypoxia, which returned to the basal levels at 14 days. On the other hand, HO-1 and HO-2 proteins were increased 2-fold and 1.3-fold, respectively, in the heart at 28 days of hypoxia. Thus, hypoxia induces or represses the expression of HO-1 and HO-2 in vivo, depending on cellular microenvironments.
Han
Feng
F
Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan.
Takeda
Kazuhisa
K
Yokoyama
Satoru
S
Ueda
Hideo
H
Shinozawa
Yotaro
Y
Furuyama
Kazumichi
K
Shibahara
Shigeki
S
D000818:Animals; D002248:Carbon Monoxide / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D006419:Heme Oxygenase (Decyclizing) / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D051547:Heme Oxygenase-1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D000860:Hypoxia / Q000201:enzymology*; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D008099:Liver / Q000201:enzymology*; D008297:Male; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000201:enzymology*; D011086:Polycythemia / Q000378:metabolism
D007527:Isoenzymes; D008565:Membrane Proteins; D002248:Carbon Monoxide; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; C105245:heme oxygenase-2