Involvement of the Renin‐Angiotensin System in Atherosclerosis

The renin-angiotensin system (RAS) is a well known for its role in the regulation of the blood pressure (BP). Angiotensin II (Ang II), the main mediator of the RAS, may act either, as a systemic molecule or a locally produced factor. Within the vessel wall it has significant proinflammatory role by inducing the oxidative stress, secretion of inflammatory cytokines and adhesion molecules. Ang II could trigger proliferation of vascular smooth muscle cells (VSMC) and its migration to the outer layer of the vessel wall. It could induce the release of matrix metalloproteinase (MMPs), from human VSMC and thus increase susceptibility to rupture of atherosclerotic lesions. Binding of Ang II to AT1R/AT2R could have opposing actions in vascular injury. The ACE2/Ang (1-7)/Mas axis of the RAS also opposes the unfavourable actions of ACE/Ang II/ATR1 axis. Inhibition of RAS could reduce inflammation-associated processes in vasculature, independently of lowering BP. RAS is significantly modulated by the genes coding for this system. Certain genetic variants (SNPs) in the RAS genes have been denoted as the functional ones and have been associated with hypertension, cardiovascular phenotypes and atherosclerosis. Also, the genetic components of the RAS interfere with the regulators of gene expression by microRNAs (miRs)