Perivascular Adipose Tissue Angiotensin II Type 1 Receptor Promotes Vascular Inflammation and Aneurysm FormationNovelty and Significance [Aortic Aneurysm]

Perivascular adipose tissue exhibits characteristics of active local inflammation, which contributes to the development of atherosclerotic disease as a complication of obesity/metabolic syndrome. However, the precise role of perivascular adipose tissue in the progression of abdominal aortic aneurysm remains unclear. To test the hypothesis that genetic deletion of angiotensin II type 1a (AT1a) receptor in perivascular visceral adipose tissue (VAT) can attenuate aortic aneurysm formation in apolipoprotein E–deficient (ApoE−/−) mice, we performed adipose tissue transplantation experiments by using an angiotensin II–induced aneurysm murine model, in which we transplanted VAT from ApoE−/− or ApoE−/− AT1a−/− donor mice onto the abdominal aorta of ApoE−/− recipient mice. Compared with ApoE−/− VAT transplantation, ApoE−/− AT1a−/− VAT transplantation markedly attenuated aortic aneurysm formation, macrophage infiltration, and gelatinolytic activity in the abdominal aorta. AT1a receptor activation led to the polarization of macrophages in perivascular VAT toward the proinflammatory phenotype. Moreover, osteopontin expression and gelatinolytic activity were considerably lower in ApoE−/− AT1a−/− perivascular VAT than in ApoE−/− perivascular VAT, and angiotensin II–induced osteopontin secretion from adipocytes was eliminated after deletion of AT1a receptor in adipocytes. Notably, induction of macrophage migration by conditioned medium from ...
Source: Hypertension - Category: Cardiology Authors: Tags: ACE/Angiotensin Receptors/Renin Angiotensin System, Animal Models of Human Disease, Inflammation, Lipids and Cholesterol, Aneurysm Original Articles Source Type: research