[Pathophysiological mechanisms of angiogenesis in atherogenesis]

Atherosclerosis is a progressive, multifactorial, diffuse, multisystemic, chronic, inflammatory disease, which is manifested by disorders of vascular, immune and metabolic system. Pathogenesis of this disease is not fully understood. Accordingly, angiogenesis represents a special field of research due to its role in atherogenesis. STEPS OF ANGIOGENESIS: Angiogenesis is a complex biological process, which requires the precise coordination of its four steps (vasodilatation and permeability, vessel destabilization and matrix degradation, endothelial cell proliferation and migration, and lumen formation and vessel stabilization). MEDIATORS OF ANGIOGENIC PROCESS: The process of forming new blood vessels is regulated by a delicate balance between proangiogenic and antiangiogenic molecules. Numerous soluble growth factors and inhibitors, cytokines, proteases, extracellular matrix proteins and adhesion molecules, as well as hypoxia, inflammatory process, shear stress, hypertension and interaction between cells and extracellular matrix strictly control the angiogenic process. Neovascularization is halted due to the downregulation of angiogenic factors or the increase of inhibitors of this process. TUMOR VASCULARIZATION: In the asymptomatic phase of cancerogenesis, cancer rarely exceeds the diameter of 1-2 millimeters. However, when the metabolic demand increases, it leads to tumor vascularization. In this way, tumor switches to an angiogenic phenotype. The molecular basis of angiogenic switch refers to increased production of angiogenic factors and/or loss of angiogenic inhibitors.

The contribution of angiogenic process has become increasingly meaningful in understanding the pathogenesis ofatherosclerosis.