S100 proteins in atherosclerosis

Atherosclerosis is an arterial disease associated with dyslipidemia, abnormal arterial calcification and oxidative stress. It has been shown that a continued chronic inflammatory state of the arterial wall contributes to the development of atherosclerosis. The inflammatory stimulation, recruitment of inflammatory cells and production of pro-inflammatory cytokines enhances vascular inflammation. Some members of the S100 proteins family bind with their receptors, such as advanced glycation end products (RAGE), scavenger receptors (CD36) and toll-like receptor 4 (TLR-4), contributing to the cellular response in atherosclerotic progression. This review summarizes the roles of S100 proteins (S100A8, S100A9 and S100A12) in the vascular inflammation, vascular calcification and vascular oxidative stress. S100 proteins are released from monocytes, smooth muscle cells and endothelial cells in response to cellular stress stimuli, and then the binding of S100 proteins to RAGE activate downstream signaling such as transcription factor kappa B (NF-κB) translocation and reactive oxygen species (ROS) production, which act as a positive feedback loop for inducing pro-inflammatory phenotype in a wide variety of cell types including endothelial cells, vascular smooth muscle cells and leukocytes. Thus, it suggests that the inhibition of S100 proteins-mediated RAGE and TLR4 activation appears to be a promising approach to treat atherosclerosis. In addition, recent study showed that serum S100A12 can predict future cardiovascular events, highlighting that S100A12 is likely to be a potential biomarker of therapeutic efficacy and disease progression in coronary heart disease. Future studies of patients with coronary heart disease may provide more evidences supporting that S100 proteins is promising drug target in the prevention and therapy of atherosclerosis.