[The role of adventitia in atherosclerosis]

In the past decade, studies of vascular injury and repair have mainly focused on endothelial cells and medial smooth muscle cells. However, increasing evidence supports a new paradigm of an "outside-in" hypothesis, in which vascular adventitia may take part as a precursor in response to injury or vascular inflammation. During early stage of injury, the major cellular component of adventitia-fibroblasts, not only proliferate/migrate to media and intima, but also affect inflammatory response by increased production of reactive oxygen species and release of various proinflammatory cytokines, growth factors, matrix metalloproteinase etc. All of these eventually synergistically initiate neointima formation, followed by subsequent vascular remodeling and cardiovascular diseases. Thus the current review will focus on most advanced studies related to the role of adventitial fibroblasts in some cardiovascular diseases such as atherosclerosis.