Previous studies demonstrated that deficiency of angiotensin-converting enzyme 2 (ACE2) augmented angiotensin II (AngII)-induced atherosclerosis and abdominal aortic aneurysm (AAA) formation in hypercholesterolemic mice.
Application of NaHS, an H<sub>2</sub>S donor considerably attenuated the severity of atherosclerosis with upregulating carotid expression of ACE2, thus converting pro-atherosclerotic angiotensin II (Ang II) to anti-atherosclerotic angiotensin 1-7 (Ang-(1-7)).
Accelerated atherosclerosis was studied in vivo, and atherosclerosis was induced in apoE-deficient mice which were divided randomly into four groups that received respectively a ACE2 gene transfer, Ad-ACE2, Ad-EGFP, Ad-ACE2 + A779, an Ang-(1-7) receptor antagonist, control group.
To determine whether leukocytic ACE2 influenced atherosclerosis, irradiated low-density lipoprotein receptor-deficient male mice were repopulated with bone marrow-derived cells from Ace2(+/y) or Ace2(-/y) mice and fed a high-fat diet for 3 months.
To this aim, we performed in vitro gain and loss of function experiments in endothelial cells and evaluated in vivo angiogenesis and atherosclerosis in apolipoprotein E-knockout mice treated with AdACE2.
These results suggest a differential regulation of ACE2 activity during the progression of atherosclerosis and suggest that this novel molecule of the renin-angiotensin system may play a role in the pathogenesis of atherosclerosis.
L-NG monomethyl arginine induced greater constriction in patients with the ACE DD compared with ACE II genotype (coronary blood flow -10 +/- 4% vs. 11 +/- 5%, p = 0.003, ACE DD vs. II and diameter constriction -6.3 +/- 1.2% vs. -1.9 +/- 1.2%, p = 0.01, respectively, in patients with atherosclerosis).