Induction of NAD(P)H oxidase by oxidized low-density lipoprotein in human endothelial cells: antioxidative potential of hydroxymethylglutaryl coenzyme A reductase inhibitor therapy.
BACKGROUND
Elevated oxidative stress and superoxide anion formation in vascular cells could promote conversion of LDL to atherogenic oxidized LDL (oxLDL), contributing to endothelial dysfunction and atherosclerosis. As a major source of vascular superoxide anion formation, an endothelial NAD(P)H oxidase, similar to the leukocyte enzyme, has been identified.


RESULTS
To elucidate functional differences between NAD(P)H oxidases of endothelial cells and leukocytes, DNA sequences of endothelial NAD(P)H oxidase subunits were determined. Gp91phox cDNA sequence showed no difference between the 2 cell types. Endothelial p67phox cDNA sequence revealed 2 known polymorphisms, which do not affect NAD(P)H oxidase function. Next, we analyzed relative mRNA expression of NAD(P)H subunits in human umbilical vein endothelial cells (HUVECs) and leukocytes using a common cRNA standard in competitive reverse transcription-polymerase chain reaction. NAD(P)H oxidase subunits p22phox and p47phox are expressed at a similar level in both cell types, whereas p67phox (2.5%) and gp91phox (1.1%) are expressed at a much lower level in endothelial cells than in leukocytes. Differences of gp91phox expression in leukocytes and HUVECs correlate with differences in superoxide release. Gp91phox mRNA and endothelial superoxide anion formation are induced in response to oxLDL in HUVECs. Furthermore, a lower gp91phox mRNA expression was found in internal mammary artery biopsy samples of patients with coronary artery disease treated with HMG-CoA reductase inhibitors before coronary bypass surgery.


CONCLUSIONS
We conclude that oxLDL induces proatherosclerotic NAD(P)H oxidase expression and superoxide anion formation in human endothelial cells and an antioxidative potential of HMG-CoA reductase inhibition via reduction of vascular NAD(P)H oxidase expression.
Rueckschloss
U
U
Institute of Pathophysiology, the Julius-Bernstein-Institute of Physiology, Clinic for Cardiothoracic Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany.
Galle
J
J
Holtz
J
J
Zerkowski
H R
HR
Morawietz
H
H
D000975:Antioxidants / Q000494:pharmacology; D002478:Cells, Cultured; D003324:Coronary Artery Disease / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D004790:Enzyme Induction / Q000187:drug effects; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D007962:Leukocytes / Q000187:drug effects / Q000201:enzymology; D008077:Lipoproteins, LDL / Q000378:metabolism* / Q000494:pharmacology; D008323:Mammary Arteries / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D026901:Membrane Transport Proteins; D009252:NADPH Dehydrogenase / Q000096:biosynthesis / Q000235:genetics; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000096:biosynthesis* / Q000235:genetics; D018384:Oxidative Stress / Q000187:drug effects; D010750:Phosphoproteins / Q000096:biosynthesis / Q000235:genetics; D021122:Protein Subunits; D012333:RNA, Messenger / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
D000975:Antioxidants; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008077:Lipoproteins, LDL; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D010750:Phosphoproteins; D021122:Protein Subunits; D012333:RNA, Messenger; C079789:neutrophil cytosol factor 67K; C099252:oxidized low density lipoprotein; D013481:Superoxides; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C086986:CYBA protein, human; C060505:neutrophil cytosolic factor 1; D009252:NADPH Dehydrogenase