Recent Progress of Sterol Regulatory Element-binding Proteins Role in Atherosclerosis

Atherosclerotic cardiovascular disease (ASCVD), influenced by elevated plasma low-density lipoprotein (LDL) and cholesterol levels, is important to various acute cardiovascular and cerebrovascular diseases, causing life-threatening deaths worldwide. Early intervention for atherosclerosis is both essential and beneficial. As members of a class of transcription factors, sterol regulatory element-binding proteins (SREBPs) regulate the expression of most genes involved in lipid metabolism. This review aimed to present three aspects of SREBP regulation in the Endoplasmic Reticulum (ER), Golgi apparatus, and nucleus after maturation. Different subcellular localizations play integral roles in regulating the maturation and activity of SREBPs. Moreover, several drugs that target SREBPs for the treatment of atherosclerosis are described, with the aim of exploring SREBPs as new targets for treating atherosclerosis.

There are three members of the SREBP family, namely, SREBP-1a, SREBP-1c, and SREBP-2, all of which have differing functions. SREBP-1a and SREBP-1c regulate the synthesis of fatty acids, while SREBP-2 regulates cholesterol metabolism. SREBPs combine with the SREBP Cleavage-Activating Protein (SCAPs) to form the SCAP/SREBP complex. This complex can bind to and is regulated by insulin-induced genes (INSIG), affecting endoplasmic reticulum (ER)-to-Golgi translocation. SREBPs are sheared by 1-site protease (S1P) and 2-site protease (S2P) in a regular sequence on arrival at the Golgi apparatus, and are processed, matured, and transported to the nucleus for action. The review focuses on how SREBPs, crucial regulators of cholesterol and fatty acid metabolism, are controlled at different cellular locations (ER, Golgi, Nucleus), and explores their potential as drug targets for treating atherosclerosis, a major global health threat driven by high LDL cholesterol.