Aldosterone administration to mice stimulates macrophage NADPH oxidase and increases atherosclerosis development: a possible role for angiotensin-converting enzyme and the receptors for angiotensin II and aldosterone.
BACKGROUND
The renin-angiotensin-aldosterone system is involved in the pathogenesis of atherosclerosis, partially because of its pro-oxidative properties. We questioned the effect and mechanisms of action of administration of aldosterone to apolipoprotein E-deficient (E(0)) mice on their macrophages and aorta oxidative status and the ability of pharmacological agents to block this effect.


RESULTS
Aldosterone (0.2 to 6 microg. mouse(-1) x d(-1)) was administered to E(0) mice alone or in combination with eplerenone (200 mg x kg(-1) x d(-1)), ramipril (5 mg x kg(-1) x d(-1)), or losartan (25 mg x kg(-1) x d(-1)). Mouse aortic atherosclerotic lesion area and macrophage and aortic oxidative status were evaluated. Aldosterone administration enhanced the mouse atherosclerotic lesion area by 32%. Mouse peritoneal macrophages and aortic segments from aldosterone-treated mice exhibited increased superoxide anion formation by up to 155% and 69%, respectively, and this effect was probably mediated by NADPH oxidase activation, because increased translocation of its cytosolic component p47phox to the macrophage plasma membrane was observed. THP-1 macrophages incubated in vitro with aldosterone (10 micromol/L) exhibited a higher capacity to release superoxide ions by 110% and increased ability to oxidize LDL by 74% compared with control cells. Aldosterone administration enhanced mouse peritoneal macrophage ACE activity and mRNA expression by 2.3-fold and 2.4-fold, respectively. Only cotreatment of eplerenone with ramipril or losartan completely blocked the oxidative effects of aldosterone.


CONCLUSIONS
Aldosterone administration to E(0) mice increased macrophage oxidative stress and atherosclerotic lesion development. Blocking of the mineralocorticoid receptor and inhibition of tissue ACE and/or the angiotensin receptor-1 reduced aldosterone deleterious pro-oxidative and proatherogenic effects.
Keidar
Shlomo
S
Lipid Research Laboratory, Technion Faculty of Medicine, the Rappaport Family Institute for Research in Medical Sciences and Rambam Medical Center, Haifa, Israel. skeidar@rambam.health.gov.il
Kaplan
Marielle
M
Pavlotzky
Elsa
E
Coleman
Raymond
R
Hayek
Tony
T
Hamoud
Shadi
S
Aviram
Michael
M
D000450:Aldosterone / Q000494:pharmacology* / Q000502:physiology / Q000633:toxicity; D000804:Angiotensin II / Q000502:physiology*; D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D001018:Aortic Diseases / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics; D001161:Arteriosclerosis / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D002460:Cell Line / Q000187:drug effects / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D000077545:Eplerenone; D006727:Hormone Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000378:metabolism; D019808:Losartan / Q000494:pharmacology / Q000627:therapeutic use; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000201:enzymology; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D000451:Mineralocorticoid Receptor Antagonists; D019255:NADPH Oxidases / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D007703:Peptidyl-Dipeptidase A / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D010750:Phosphoproteins / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis; D017257:Ramipril / Q000494:pharmacology / Q000627:therapeutic use; D044140:Receptor, Angiotensin, Type 1 / Q000502:physiology*; D018161:Receptors, Mineralocorticoid / Q000502:physiology*; D013148:Spironolactone / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D013481:Superoxides / Q000378:metabolism
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D001057:Apolipoproteins E; D006727:Hormone Antagonists; D008077:Lipoproteins, LDL; D008565:Membrane Proteins; D000451:Mineralocorticoid Receptor Antagonists; D010750:Phosphoproteins; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D018161:Receptors, Mineralocorticoid; C099252:oxidized low density lipoprotein; D013481:Superoxides; D000804:Angiotensin II; D013148:Spironolactone; D000450:Aldosterone; D000077545:Eplerenone; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D007703:Peptidyl-Dipeptidase A; D019808:Losartan; D017257:Ramipril