High-density Lipoprotein and Inflammation and Its Significance to Atherosclerosis

Great advances are being made in the understanding of the structural and functional diversity of high-density lipoprotein at the mechanistic level. High-density lipoprotein possesses numerous physiological activities, the most studied of which is the ability to promote excess cholesterol efflux from peripheral tissues to the liver for excretion via a mechanism believed to confer protection against atherosclerosis. Accumulating evidence has demonstrated that atherosclerosis is a chronic inflammatory response. Recent studies have suggested that high-density lipoprotein possesses anti-inflammatory properties and regulates both innate and adaptive immune responses. However, further complicating this very complex system is the finding that inflammation, via alteration of the proteomic and lipidomic composition of high-density lipoprotein species, can modulate at least some of their functional activities. Modified high-density lipoprotein exhibits a reduced ability to mediate cholesterol efflux from peripheral tissues and to inhibit cytokine-induced adhesion molecule expression and even promotes the occurrence of inflammation. This review focuses on the underlying mechanism of the interaction between high-density lipoprotein and inflammation to clarify the pathologic process of atherosclerosis.