Protective effect of heme oxygenase-1 gene transfer against oxyhemoglobin-induced endothelial dysfunction.
The current study was designed to determine the effect of recombinant heme oxygenase-1 (HO-1) gene expression on endothelial function in cerebral arteries. Isolated canine basilar arteries were exposed ex vivo (30 minutes at 37 degrees C) to an adenoviral vector (10(10) PFU/mL, total volume 300 microL) encoding either the HO-1 gene (AdCMVHO-1) or the beta-galactosidase (beta-Gal) reporter gene (AdCMVbeta-Gal). Twenty-four hours after transduction, arterial rings were suspended in organ chamber for isometric force recording. Endothelium-dependent relaxations were obtained in response to bradykinin (10(-10) to 10(-6) mol/L) during contraction to uridine-5'-triphosphate (UTP; 3 x 10(-6) to 3 x 10(-5) mol/L). Certain rings were incubated with oxyhemoglobin (OxyHb; 10(-5) mol/L) overnight (16 to 18 hours of 24 hours). Expression and localization of recombinant protein were shown by Western blot analysis and immunohistochemistry. Endothelium-dependent relaxation to bradykinin and endothelium-independent relaxation to forskolin (10(-9) to 10(-5) mol/L) and DEA-NONOate (10(-10) to 10(-5) mol/L) were identical in beta-Gal- and HO-1-transduced arteries. Exposure to OxyHb caused impairment of endothelium-dependent relaxation to bradykinin (P < 0.01). In contrast, OxyHb did not affect endothelium-dependent relaxation in arteries expressing recombinant HO-1 ( P > 0.05). This protective effect of HO-1 was reversed by coincubation with tin protoporphyrin (SnPP9; 10(-5) mol/L), a selective inhibitor of HO-1 (P < 0.01). Basal levels of 3',5'-cyclic monophosphate (cGMP) in HO-1-transduced vessels were not significantly different from those in beta-Gal-transduced vessels. Pretreatment with OxyHb significantly reduced cGMP level in beta-Gal-transduced rings (P < 0.01), whereas it had no effect in HO-1-transduced rings. These results demonstrate that HO-1 gene transfer does not affect endothelial and smooth muscle function of normal arteries, and that expression of recombinant HO-1 in cerebral arteries protects vasomotor function against OxyHb-induced injury.
Eguchi
D
D
Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
Weiler
D
D
Alam
J
J
Nath
K
K
Katusic
Z S
ZS
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects / Q000201:enzymology; D002122:Calcium Chloride / Q000494:pharmacology; D002417:Cattle; D002460:Cell Line; D004285:Dogs; D004492:Edetic Acid; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics*; D051547:Heme Oxygenase-1; D007700:Kinetics; D008278:Magnesium Sulfate / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D010108:Oxyhemoglobins / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis; D014162:Transfection; D014664:Vasodilation / Q000187:drug effects
D010108:Oxyhemoglobins; D011994:Recombinant Proteins; D011189:Potassium Chloride; D008278:Magnesium Sulfate; D004492:Edetic Acid; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; D002122:Calcium Chloride; D019331:NG-Nitroarginine Methyl Ester