FINE PARTICULATE MATTER EXACERBATES FOAM CELLS FORMATION BY MACROPHAGES, BY ENHANCING THE LDL OXIDATION IN AN OXIDATIVE MEDIUM

The exposure to fine particulate material (PM2.5), an atmospheric pollutant, is a risk factor for cardiovascular diseases, especially atherosclerosis. The reduced diameter of PM2.5 (0.1 to 2.5 µm) allows the pollutant to go deeper in the respiratory tract and trigger systemic effects. In this context, macrophages are the first immune cells to phagocyte these particles and to activate the immune defense, by releasing inflammatory cytokines. In an inflammatory milieu, circulating monocytes can switch their phenotype to an oxidative one, and enhance the risk of vascular damage. Within the vessels, the oxidated LDL can be phagocyted by macrophages, and lead to the formation of foam cells. Moreover, macrophages apoptosis can aggravate thrombus formation. However, if the cardiovascular effects of PM2.5 are related to changes in macrophages phenotype, and the consequent foam cells formation remains unclear until now.