Hereditary deficiency of gp91(phox) is associated with enhanced arterial dilatation: results of a multicenter study.
BACKGROUND
NADPH oxidase is believed to modulate arterial tone, but its role in humans is still unclear. The objective of this study was to evaluate whether NADPH oxidase is involved in flow-mediated arterial dilation (FMD).


RESULTS
Twenty-five patients with hereditary deficiency of gp91(phox), the catalytic core of NADPH oxidase, (X-CGD), 25 healthy subjects, and 25 obese patients matched for sex and age were recruited. FMD, platelet gp91(phox), serum levels of nitrite and nitrate as markers of nitric oxide generation, oxidized low-density lipoprotein, and urinary excretion of isoprostanes as markers of oxidative stress were determined. Platelet gp91(phox) expression was downregulated in X-CGD patients (1.0+/-0.8 mean fluorescence; P<0.001) and upregulated in obese patients (4.1+/-2.2 mean fluorescence; P=0.01) compared with healthy subjects (2.9+/-1.7 mean fluorescence). Urinary excretion of isoprostanes was reduced in X-CGD patients (41.7+/-33.3 pg/mg creatinine; P=0.04) and increased in obese patients (154.4+/-91 pg/mg creatinine; P<0.001) compared with healthy subjects (69.5+/-52.4 pg/mg creatinine). Obese patients had higher serum oxidized low-density lipoprotein than healthy subjects (35.3+/-6.7 versus 24.8+/-9.8 U/L; P<0.001) and X-CGD patients (28.5+/-7.2 U/L; P<0.001). X-CGD patients had significantly higher FMD (14.7+/-5.9%) compared with healthy subjects (7.9+/-2.5%; P<0.001); obese patients had lower FMD (5.3+/-3.0%; P=0.028) compared with healthy subjects. Serum nitrite and nitrate levels were significantly higher in patients with X-CGD (36.0+/-10.8 micromol/L; P=0.016) and lower in obese patients (9.3+/-11.0 micromol/L; P=0.001) compared with healthy subjects (27.1+/-19.1 micromol/L). Serum nitrite and nitrate levels significantly correlated with FMD (R(s)=0.403, P<0.001) and platelet gp91(phox) (R(s)=-0.515, P<0.001). FMD inversely correlated with platelet gp91(phox) (R(s)=-0.502, P<0.001) and isoprostanes (R(s)=-0.513, P<0.001).


CONCLUSIONS
This study provides the first evidence that, in humans, gp91(phox) is implicated in the modulation of arterial tone.
Violi
Francesco
F
Department of Experimental Medicine, Divisione I Clinica Medica, University of Rome La Sapienza, Rome, Italy. francesco.violi@uniroma1.it
Sanguigni
Valerio
V
Carnevale
Roberto
R
Plebani
Alessandro
A
Rossi
Paolo
P
Finocchi
Andrea
A
Pignata
Claudio
C
De Mattia
Domenico
D
Martire
Baldassarre
B
Pietrogrande
Maria Cristina
MC
Martino
Silvana
S
Gambineri
Eleonora
E
Soresina
Anna Rosa
AR
Pignatelli
Pasquale
P
Martino
Francesco
F
Basili
Stefania
S
Loffredo
Lorenzo
L
D000293:Adolescent; D000328:Adult; D001158:Arteries / Q000503:physiopathology*; D001792:Blood Platelets / Q000378:metabolism; D002648:Child; D015536:Down-Regulation; D006801:Humans; D028421:Isoprostanes / Q000652:urine; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood / Q000172:deficiency* / Q000652:urine; D008661:Metabolism, Inborn Errors / Q000503:physiopathology*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000097:blood / Q000172:deficiency* / Q000652:urine; D009566:Nitrates / Q000097:blood; D009573:Nitrites / Q000097:blood; D009765:Obesity / Q000097:blood / Q000503:physiopathology / Q000652:urine; D012039:Regional Blood Flow; D015854:Up-Regulation; D014664:Vasodilation; D055815:Young Adult
D028421:Isoprostanes; D008562:Membrane Glycoproteins; D009566:Nitrates; D009573:Nitrites; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases