RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels

Gene editing therapy for cardiovascular diseases

The development of gene editing tools has been a significant area of research in the life sciences for nearly 30 years. These tools have been widely utilized in disease detection and mechanism research. In the new century, they have shown potential in addressing various scientific challenges and saving lives through gene editing therapies, particularly in combating cardiovascular disease (CVD). The rapid advancement of gene editing therapies has provided optimism for CVD patients. The progress of gene editing therapy for CVDs is a comprehensive reflection of the practical implementation of gene editing technology in both clinical and basic research settings, as well as the steady advancement of research and treatment of CVDs. This article provides an overview of the commonly utilized DNA-targeted gene editing tools developed thus far, with a specific focus on the application of these tools, particularly the clustered regularly interspaced short palindromic repeat/CRISPR-associated genes (Cas) (CRISPR/Cas) system, in CVD gene editing therapy. It also delves into the challenges and limitations of current gene editing therapies, while summarizing ongoing research and clinical trials related to CVD. The aim is to facilitate further exploration by relevant researchers by summarizing the successful applications of gene editing tools in the field of CVD.

Post-translational regulation of the low-density lipoprotein receptor provides new targets for cholesterol regulation

The amount of the low-density lipoprotein receptor (LDLR) on the surface of hepatocytes is the primary determinant of plasma low-density lipoprotein (LDL)-cholesterol level. Although the synthesis and cellular trafficking of the LDLR have been well-documented, there is growing evidence of additional post-translational mechanisms that regulate or fine tune the surface availability of the LDLR, thus modulating its ability to bind and internalise LDL-cholesterol. Proprotein convertase subtilisin/kexin type 9 and the asialoglycoprotein receptor 1 both independently interact with the LDLR and direct it towards the lysosome for degradation. While ubiquitination by the E3 ligase inducible degrader of the LDLR also targets the receptor for lysosomal degradation, ubiquitination of the LDLR by a different E3 ligase, RNF130, redistributes the receptor away from the plasma membrane. The activity of the LDLR is also regulated by proteolysis. Proteolytic cleavage of the transmembrane region of the LDLR by γ-secretase destabilises the receptor, directing it to the lysosome for degradation. Shedding of the extracellular domain of the receptor by membrane-type 1 matrix metalloprotease and cleavage of the receptor in its LDL-binding domain by bone morphogenetic protein-1 reduces the ability of the LDLR to bind and internalise LDL-cholesterol at the cell surface. A better understanding of how the activity of the LDLR is regulated will not only unravel the complex biological mechanisms controlling LDL-cholesterol metabolism but also could help inform the development of alternative pharmacological intervention strategies for the treatment of hypercholesterolaemia.