Cardiovascular Research Advance Access [Accepted Manuscript] published online on January 28, 2009
Cardiovascular Research, doi:10.1093/cvr/cvp035
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Cardioprotection by hypoxia-inducible factor 1 alpha transfection in skeletal muscle is dependent on heme oxygenase activity in mice
1 Department of Physiology
2 Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
3 Institute for Cellular and Molecular Biology, Department of Developmental Biology, Karolinska Institute, Stockholm, Sweden
Corresponding author: Gabor Czibik Dept. of Physiology, IMB, University of Oslo P.O. box 1103, Blindern NO-0317, Oslo, Norway Tel: +47-22851224 Fax: +47-22851249 e-mail: gaborc{at}medisin.uio.no
Aims: The present study investigates whether the cardioprotection achieved by gene delivery of hypoxia-inducible factor-1
(HIF-1) depends on the downstream factor heme oxygenase (HMOX)-1.
Methods: Immortalized cardiomyocytes (HL-1 cells) were transfected with HIF-1 or HMOX-1 and injured with hydrogen peroxide (H2O2), and death was evaluated by trypan blue staining. Quadriceps muscles of mice were treated with DNA for HIF-1, HMOX-1 or sham-treated and electroporated, and 3 days later hearts were isolated and subjected to global ischemia and reperfusion. Some HIF-1- and sham-treated mice received the HMOX blocker zinc deuteroporphyrin 2,4-bis glycol (ZnBG) (n = 6-8 in each group). HL-1 cells were stimulated with bilirubin or the carbon monoxide donor CORM-2 before injury with H2O2.
Results: HL-1 cells which were transfected with HIF-1 or HMOX-1 had an increased survival to H2O2-induced injury compared to empty vector (n = 10-12 per group; p < 0.01 for both). When HMOX-1-luciferase reporter mice were treated with HIF-1 in the quadriceps muscle, increased luciferase activity was found locally, but nowhere else. Mice pretreated with HIF-1 or HMOX-1 had a reduced infarct size, improved post-ischemic function, and increased serum bilirubin (p < 0.05). ZnBG inhibited all these effects afforded by HIF-1. Stimulation of HL-1 cells with bilirubin and CORM-2 reduced cell death evoked by H2O2 (p < 0.05 for both, n = 11-15 in each group).
Conclusions: HIF-1 and HMOX-1 provided protection against H2O2-induced damage in HL-1 cells. Remote gene delivery of HIF-1 afforded cardioprotective effects. These were dependent on HMOX activity, as a HMOX blocker abolished the effects, and they were mimicked by pretreatment with HMOX-1. Downstream to HMOX-1, bilirubin as well as carbon monoxide may be organ effectors.
Time for primary review: 35 Days