miRNAs in Inflammatory Macrophages

Several processes including endothelial angiogenesis, vascular neointimal lesion formation, vascular inflammation process, lipoprotein metabolism, and hypertension are critically involved in atherosclerosis. This chapter aims to introduce the role of miRNAs in vascular inflammation process. Atherosclerosis is now widely accepted to be an inflammatory disease, characterized by degenerative as well as proliferative changes and extracellular accumulation of lipid and cholesterol, in which an ongoing inflammatory reaction plays an important role in both initiation and progression/destabilization, converting a chronic process into an acute disorder. In early atheromotous plaques, inflammatory macrophages strive to alleviate the subendothelial accumulation of modified lipoproteins carrying cholesterol esters. Consequently, the further recruitment and migration of cells induce chronic inflammation. To date, only a few miRNAs have been shown to be involved in the vascular inflammation process. These include miR-126 in regulating adhesion molecules, and miR-155 and miR-125a in regulating inflammatory cytokine.