Article: article from journal or magazin.
Endogenous angiotensin II induces atherosclerotic plaque vulnerability and elicits a Th1 response in ApoE-/- mice.
Publication types: Journal Article ; Research Support, Non-U.S. Gov't - Publication Status: ppublish
Rupture of vulnerable plaques is the main cause of acute cardiovascular events. However, mechanisms responsible for transforming a stable into a vulnerable plaque remain elusive. Angiotensin II, a key regulator of blood pressure homeostasis, has a potential role in atherosclerosis. To study the contribution of angiotensin II in plaque vulnerability, we generated hypertensive hypercholesterolemic ApoE-/- mice with either normal or endogenously increased angiotensin II production (renovascular hypertension models). Hypertensive high angiotensin II ApoE-/- mice developed unstable plaques, whereas in hypertensive normal angiotensin II ApoE-/- mice plaques showed a stable phenotype. Vulnerable plaques from high angiotensin II ApoE-/- mice had thinner fibrous cap (P<0.01), larger lipid core (P<0.01), and increased macrophage content (P<0.01) than even more hypertensive but normal angiotensin II ApoE-/- mice. Moreover, in mice with high angiotensin II, a skewed T helper type 1-like phenotype was observed. Splenocytes from high angiotensin II ApoE-/- mice produced significantly higher amounts of interferon (IFN)-gamma than those from ApoE-/- mice with normal angiotensin II; secretion of IL4 and IL10 was not different. In addition, we provide evidence for a direct stimulating effect of angiotensin II on lymphocyte IFN-gamma production. These findings suggest a new mechanism in plaque vulnerability demonstrating that angiotensin II, within the context of hypertension and hypercholesterolemia, independently from its hemodynamic effect behaves as a local modulator promoting the induction of vulnerable plaques probably via a T helper switch.
Angiotensin II, Animals, Aorta, Apolipoproteins E, Arteriosclerosis, Coronary Artery Disease, Fibrosis, Hypercholesterolemia, Hypertension, Renovascular, Ligation, Mice, Mice, Knockout, Nephrectomy, Renal Artery, Renin, Renin-Angiotensin System, Rupture, Spontaneous, Th1 Cells, Th2 Cells, Vasculitis
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