Vascular oxidative stress and nitric oxide depletion in HIV-1 transgenic rats are reversed by glutathione restoration.
Human immunodeficiency virus (HIV)-infected patients have a higher incidence of oxidative stress, endothelial dysfunction, and cardiovascular disease than uninfected individuals. Recent reports have demonstrated that viral proteins upregulate reactive oxygen species, which may contribute to elevated cardiovascular risk in HIV-1 patients. In this study we employed an HIV-1 transgenic rat model to investigate the physiological effects of viral protein expression on the vasculature. Markers of oxidative stress in wild-type and HIV-1 transgenic rats were measured using electron spin resonance, fluorescence microscopy, and various molecular techniques. Relaxation studies were completed on isolated aortic rings, and mRNA and protein were collected to measure changes in expression of nitric oxide (NO) and superoxide sources. HIV-1 transgenic rats displayed significantly less NO-hemoglobin, serum nitrite, serum S-nitrosothiols, aortic tissue NO, and impaired endothelium-dependent vasorelaxation than wild-type rats. NO reduction was not attributed to differences in endothelial NO synthase (eNOS) protein expression, eNOS-Ser1177 phosphorylation, or tetrahydrobiopterin availability. Aortas from HIV-1 transgenic rats had higher levels of superoxide and 3-nitrotyrosine but did not differ in expression of superoxide-generating sources NADPH oxidase or xanthine oxidase. However, transgenic aortas displayed decreased superoxide dismutase and glutathione. Administering the glutathione precursor procysteine decreased superoxide, restored aortic NO levels and NO-hemoglobin, and improved endothelium-dependent relaxation in HIV-1 transgenic rats. These results show that HIV-1 protein expression decreases NO and causes endothelial dysfunction. Diminished antioxidant capacity increases vascular superoxide levels, which reduce NO bioavailability and promote peroxynitrite generation. Restoring glutathione levels reverses HIV-1 protein-mediated effects on superoxide, NO, and vasorelaxation.
Kline
Erik R
ER
Division of Pulmonary, Allergy and Critical Care Medicine, Free Radicals in Medicine Core, Emory University School of Medicine/Atlanta Veterans Affairs Medical Center, Atlanta, Georgia, USA.
Kleinhenz
Dean J
DJ
Liang
Bill
B
Dikalov
Sergey
S
Guidot
David M
DM
Hart
C Michael
CM
Jones
Dean P
DP
Sutliff
Roy L
RL
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D030801:Animals, Genetically Modified; D000975:Antioxidants / Q000494:pharmacology; D001011:Aorta / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000503:physiopathology / Q000821:virology; D001708:Biopterins / Q000031:analogs & derivatives / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000821:virology; D005978:Glutathione / Q000378:metabolism*; D015658:HIV Infections / Q000378:metabolism* / Q000503:physiopathology / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D054298:Human Immunodeficiency Virus Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D019255:NADPH Oxidases / Q000378:metabolism; D009569:Nitric Oxide / Q000097:blood / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D011533:Proviruses / Q000235:genetics / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D013481:Superoxides / Q000378:metabolism; D053778:Thiazolidines / Q000494:pharmacology; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D014664:Vasodilation; D014665:Vasodilator Agents / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000378:metabolism
D000975:Antioxidants; D054298:Human Immunodeficiency Virus Proteins; D053778:Thiazolidines; D014665:Vasodilator Agents; D013481:Superoxides; D009599:Nitroprusside; D001708:Biopterins; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D014969:Xanthine Oxidase; D019255:NADPH Oxidases; C003402:sapropterin; D005978:Glutathione; D000109:Acetylcholine; D011761:Pyrrolidonecarboxylic Acid; C029536:2-oxothiazolidine-4-carboxylic acid