Novel aspects of PCSK9 and lipoprotein receptors in renal disease-related dyslipidemia

Abstract

Chronic kidney disease (CKD) is a global health problem with a profound impact on quality of life. Cardiovascular disease is established as a major cause of morbidity and mortality in patients with CKD. Dyslipidemia is frequently observed in CKD patients, suggesting a causal relation between dyslipidemia and cardiovascular disease in CKD patients. Currently, lipid-lowering drugs such as statins, are the primary choice for lipid lowering therapy in high-risk populations. Despite many studies showing CVD risk reduction with statins, CVD still remains the leading cause of the death in CKD. This underscores the need for new therapeutic approaches to reduce cardiovascular risk in CKD patients. Reduced lipoprotein lipase activity, increased very low-density lipoprotein production, increased proprotein convertase subtilisin kexin type 9 (PCSK9) expression and loss of hepatic heparan sulfate proteoglycans (HSPG) syndecan-1 have been associated with CKD-related dyslipidemia. Low-density lipoprotein receptor (LDLR), low-density lipoprotein receptor-related protein 1 (LRP-1) and syndecan-1, are the most important hepatic receptors for lipoprotein clearance. However, their contributions to the pathogenesis of dyslipidemia and cardiovascular disease in CKD remain unclear. Interestingly, in CKD, increased plasma lipid levels are associated with elevated levels of PCSK9. This promotes the proteolysis of LDLR, suggesting a role for PCSK9 in CKD-associated dyslipidemia. Fully humanized monoclonal antibodies targeting PCSK9 have been approved by the US Food and Drug Administration and the European Medicines Agency as lipid lowering treatment for patients with hypercholesterolemia. In CKD sub-group analysis, ODYSSEY COMBO I and ODYSSEY COMBO II studies demonstrated strong reduction in LDL-C by alirocumab compared to placebo and ezetimibe and when added to statins. However, their efficacy in reducing plasma TG is controversial. Therefore, further research work is need for a detailed analysis on efficacy and safety of PCSK9 antibodies in CKD groups. Interestingly, novel findings on PCSK9 interaction with HSPG might shed new insight on altered lipid metabolism in CKD. In this review, we discuss various aspects of lipoprotein metabolism and hepatic lipoprotein receptor signaling pathways along with the concept of renal disease-related dyslipidemia. Furthermore, this review highlights the drawbacks of current lipid-lowering therapies and proposes novel approaches for lipid management in CKD.