Exogenous administration of heme oxygenase-1 by gene transfer provides protection against hyperoxia-induced lung injury.
Heme oxygenase-1 (HO-1) confers protection against a variety of oxidant-induced cell and tissue injury. In this study, we examined whether exogenous administration of HO-1 by gene transfer could also confer protection. We first demonstrated the feasibility of overexpressing HO-1 in the lung by gene transfer. A fragment of the rat HO-1 cDNA clone containing the entire coding region was cloned into plasmid pAC-CMVpLpA, and recombinant adenoviruses containing the rat HO-1 cDNA fragment Ad5-HO-1 were generated by homologous recombination. Intratracheal administration of Ad5-HO-1 resulted in a time-dependent increase in expression of HO-1 mRNA and protein in the rat lungs. Increased HO-1 protein expression was detected diffusely in the bronchiolar epithelium of rats receiving Ad5-HO-1, as assessed by immunohistochemical studies. We then examined whether ectopic expression of HO-1 could confer protection against hyperoxia-induced lung injury. Rats receiving Ad5-HO-1, but not AdV-betaGal, a recombinant adenovirus expressing Escherichia coli beta-galactosidase, before exposure to hyperoxia (>99% O2) exhibited marked reduction in lung injury, as assessed by volume of pleural effusion and histological analyses (significant reduction of edema, hemorrhage, and inflammation). In addition, rats receiving Ad5-HO-1 also exhibited increased survivability against hyperoxic stress when compared with rats receiving AdV-betaGal. Expression of the antioxidant enzymes manganese superoxide dismutase (Mn-SOD) and copper-zinc superoxide dismutase (CuZn-SOD) and of L-ferritin and H-ferritin was not affected by Ad5-HO-1 administration. Furthermore, rats treated with Ad5-HO-1 exhibited attenuation of hyperoxia-induced neutrophil inflammation and apoptosis. Taken together, these data suggest the feasibility of high-level HO-1 expression in the rat lung by gene delivery. To our knowledge, we have demonstrated for the first time that HO-1 can provide protection against hyperoxia-induced lung injury in vivo by modulation of neutrophil inflammation and lung apoptosis.
Otterbein
L E
LE
Section of Pulmonary and Critical Care Medicine, Yale University School of Medicine, New Haven, Connecticut 06250, USA.
Kolls
J K
JK
Mantell
L L
LL
Cook
J L
JL
Alam
J
J
Choi
A M
AM
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D018014:Gene Transfer Techniques; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics* / Q000494:pharmacology; D051547:Heme Oxygenase-1; D018496:Hyperoxia / Q000503:physiopathology*; D007150:Immunohistochemistry; D008168:Lung / Q000378:metabolism / Q000503:physiopathology*; D018384:Oxidative Stress; D010100:Oxygen / Q000633:toxicity; D010996:Pleural Effusion / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000235:genetics
D012333:RNA, Messenger; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D013482:Superoxide Dismutase; D010100:Oxygen