A novel therapeutic strategy for atherosclerosis: autophagy-dependent cholesterol efflux

Atherosclerosis (AS) is a chronic inflammatory disease characterized by abnormal lipid metabolism. Foam cell formation is also known as an early event of AS. Cholesterol efflux is a process whereby cholesterol is excreted from foam cells through transporters, which serves as one of the effective regulatory mechanisms to prevent AS. Autophagy is a biodegradable mechanism, and lipophagy is a special form of autophagy that selectively degrades lipids. Cholesterol efflux is regulated by several mechanisms. Moreover, numerous studies have shown that autophagy is also process whereby cholesterol efflux is regulated. In early studies, scholars found that cholesterol efflux is related to autophagy. Subsequent studies have shown that various targeted molecules can induce autophagy and promote the expression of cholesterol transporters (such as LXRα, ABCA1, and ABCG1) through specific signaling pathways. Several novel treatments for AS use these small molecules as entry points for research and development based on autophagy. However, this autophagy-dependent cholesterol efflux involves many different molecular mechanisms. This not only indicates that cholesterol efflux is the result of multiple factors, but also that autophagy, which mediates cholesterol efflux, is a complex physiological mechanism. Through a literature review, we found that the role of autophagy in cholesterol efflux is related to cell type and is regulated by both the level of autophagy and the mechanism that triggers autophagy. In this review, we aim to discuss the role of autophagy in cholesterol efflux from many aspects based on recent relevant studies to aid in the treatment of AS.