Retrovirus-mediated HO gene transfer into endothelial cells protects against oxidant-induced injury.
Heme oxygenase (HO)-1 is a stress protein that has been implicated in defense mechanisms against agents that may induce oxidative injury, such as endotoxins, heme, and cytokines. Overexpression of HO-1 in cells might, therefore, protect against oxidative stress produced by certain agents, specifically heme, by catalyzing its degradation to bilirubin, which by itself has antioxidant properties. We report for the first time the successful transduction of human HO-1 gene into rat lung microvessel endothelium using replication-defective retroviral vector. Cells transduced with human HO-1 gene exhibited a 2.1-fold increase in HO-1 protein level, which was associated with a 2.3-fold elevation in enzyme activity compared with that in nontransduced cells. The cGMP content in transduced endothelial cells was increased by 2.9-fold relative to that in nontransduced cells. Moreover, human HO-1 gene-transduced endothelial cells acquired substantial resistance to toxicity produced by exposure to heme and H(2)O(2) compared with that in nontransduced cells. The protective effect of enhancement of HO-1 activity against heme and H(2)O(2) was reversed by pretreatment with stannic mesoporphyrin, a competitive inhibitor of HO. These data demonstrate that the induction of HO-1 in response to injurious stimuli represents an important mechanism for moderating the severity of cell damage. Regulation of HO activity in this manner may have clinical applications.
Department of Pharmacology, New York Medical College, Valhalla, New York 10595, USA.
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Yang
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Quan
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Abraham
D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology; D018014:Gene Transfer Techniques; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics*; D006801:Humans; D008168:Lung / Q000187:drug effects; D008171:Lung Diseases / Q000517:prevention & control*; D051379:Mice; D008833:Microcirculation / Q000502:physiology; D016877:Oxidants / Q000494:pharmacology*; D011652:Pulmonary Circulation / Q000502:physiology*; D051381:Rats; D012190:Retroviridae / Q000235:genetics*; D014161:Transduction, Genetic / Q000502:physiology
D016877:Oxidants; D006419:Heme Oxygenase (Decyclizing); D006152:Cyclic GMP