Heme oxygenase-1 gene transfer inhibits inducible nitric oxide synthase expression and protects genetically fat Zucker rat livers from ischemia-reperfusion injury.
BACKGROUND
Ischemia/reperfusion (I/R) injury is a critical factor in the dysfunction of steatotic orthotopic liver transplants. Heme oxygenase-1 (HO-1), a cytoprotective protein, may be important in ameliorating hepatic I/R injury.


METHODS
We used adenovirus (Ad)-based HO-1 gene transfer to analyze the effects of HO-1 overexpression in a well-established fatty Zucker rat model of I/R followed by orthotopic liver transplantation.


RESULTS
Ad-HO-1 gene therapy increased recipient survival (80% vs. 40-50% in controls) and significantly diminished hepatocyte injury, as compared with untreated and Ad-beta-galactosidase (Ad-beta-Gal)-treated livers. Orthotopic liver transplants in the Ad-HO-1 group exhibited less macrophage infiltration in the portal areas, as compared with controls. Unlike untreated and Ad-beta-Gal-treated orthotopic liver transplant controls, which showed elevated levels of inducible nitric oxide synthase by infiltrating macrophages, inducible nitric oxide synthase expression in the Ad-HO-1 group was almost absent. In contrast, endothelial nitric oxide synthase was comparable in Ad-HO-1- and Ad-beta-Gal-transduced fatty orthotopic liver transplants. Intragraft expression of antiapoptotic Bcl-2 and Bag-1 was increased in Ad-HO-1-treated orthotopic liver transplants, as compared with Ad-beta-Gal controls. Moreover, increased HO enzymatic activity was accompanied by inhibition of caspase-3 protein expression.


CONCLUSIONS
HO-1 gene transfer significantly prolongs survival of steatotic orthotopic liver transplants, depresses macrophage infiltration, suppresses local expression of inducible nitric oxide synthase, and modulates pro- and antiapoptotic pathways.
Dumont-UCLA Transplant Center, Department of Surgery, UCLA School of Medicine, 90095, USA.
Ana J
AJ
Coito
Roland
R
Buelow
Xiu-Da
XD
Shen
Farin
F
Amersi
Carolina
C
Moore
Hans-Dieter
HD
Volk
Ronald W
RW
Busuttil
Jerzy W
JW
Kupiec-Weglinski
D000818:Animals; D017209:Apoptosis; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D015316:Genetic Therapy; D006085:Graft Survival; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics*; D051547:Heme Oxygenase-1; D008099:Liver / Q000166:cytology / Q000201:enzymology / Q000473:pathology; D016031:Liver Transplantation; D008264:Macrophages / Q000166:cytology; D008297:Male; D009504:Neutrophils / Q000166:cytology; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D009765:Obesity / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011924:Rats, Zucker; D015427:Reperfusion Injury / Q000628:therapy*; D013601:T-Lymphocytes / Q000166:cytology; D014162:Transfection
D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1