Cytochrome b558-dependent NAD(P)H oxidase-phox units in smooth muscle and macrophages of atherosclerotic lesions.
OBJECTIVE
Despite studies implicating superoxide anion-producing oxidases in atherosclerosis, their characteristics, expression, and regulation in cells of lesions are poorly understood. We examined the following: (1) whether cytochrome b558-dependent NAD(P)H oxidase-phox peptides are expressed by intimal smooth muscle cells (iSMCs) and macrophages of human aortic atherosclerotic lesions and their regulation and (2) whether cytochrome b558-dependent NAD(P)H oxidase represents a major NAD(P)H oxidase in iSMCs.


RESULTS
Using a combination of immunochemical and reverse transcription-polymerase chain reaction procedures, we demonstrate that p22(phox) and gp91(phox) (cytochrome b558) expression in normal intima was restricted to a quarter of the iSMCs. In fatty streaks, a similar fraction of iSMCs expressed cytochrome b558, whereas macrophages also expressed low levels of p47(phox) and p67(phox). In fibrofatty lesions, the majority of iSMCs expressed the cytochrome b558 subunits; p67(phox) was also detected. Macrophages and macrophage-derived foam cells expressed the 4 phox subunits that constitute superoxide-producing cytochrome b558-dependent NAD(P)H oxidase. These were upregulated by transforming growth factor-beta1 and interferon-gamma. Aortic lesions also expressed Thox1 and Nox4, and although their expression also increases with lesion severity, their expression is less frequent than that of gp91(phox).


CONCLUSIONS
In human aortic fibrofatty lesions, a cytochrome b558-dependent NAD(P)H oxidase appears to be a major iSMC and macrophage oxidase whose expression is upregulated by cytokines.
Kalinina
Natalia
N
Baker Medical Research Institute, Alfred Hospital, Melbourne, Australia. cardiocell@cardio.ru
Agrotis
Alex
A
Tararak
Eduard
E
Antropova
Yulia
Y
Kanellakis
Peter
P
Ilyinskaya
Olga
O
Quinn
Mark T
MT
Smirnov
Vladimir
V
Bobik
Alex
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001018:Aortic Diseases / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D001161:Arteriosclerosis / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D003573:Cytochrome b Group / Q000032:analysis* / Q000096:biosynthesis; D016207:Cytokines / Q000502:physiology; D000074623:Dual Oxidases; D005260:Female; D005420:Flavoproteins / Q000096:biosynthesis; D006801:Humans; D008264:Macrophages / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000096:biosynthesis; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009000:Monocytes / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D009131:Muscle, Smooth, Vascular / Q000201:enzymology* / Q000378:metabolism* / Q000473:pathology; D009247:NADH, NADPH Oxidoreductases / Q000032:analysis* / Q000096:biosynthesis; D009252:NADPH Dehydrogenase / Q000032:analysis* / Q000096:biosynthesis; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000096:biosynthesis; D010750:Phosphoproteins / Q000032:analysis* / Q000096:biosynthesis; D017539:Tunica Intima / Q000201:enzymology* / Q000473:pathology; D015854:Up-Regulation
D003573:Cytochrome b Group; D016207:Cytokines; D005420:Flavoproteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D010750:Phosphoproteins; C036888:cytochrome b558; D000074623:Dual Oxidases; D009247:NADH, NADPH Oxidoreductases; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; C086986:CYBA protein, human; C431513:DUOX1 protein, human; D009252:NADPH Dehydrogenase