Rethinking reverse cholesterol transport and dysfunctional high-density lipoproteins

Area of Science:

• Cardiovascular Science
• Lipid Metabolism
• Atherosclerosis Research

Background:

• Plasma high-density lipoprotein cholesterol (HDL-C) is a negative risk factor for cardiovascular disease.
• Previous attempts to increase HDL-C for therapeutic benefit have yielded disappointing results.
• Current research emphasizes HDL quality (functional vs. dysfunctional) over quantity.

Purpose of the Study:

• To investigate the dual mechanisms of reverse cholesterol transport (RCT) and the role of HDL quality.
• To understand the impact of dysfunctional HDL on cholesterol bioavailability and related pathologies.
• To inform future therapeutic strategies for improving RCT and reducing cardiovascular risk.

Main Methods:

• Review of existing evidence on HDL function and RCT pathways.
• Analysis of the trans-hepatic and trans-intestinal cholesterol efflux mechanisms.
• Examination of studies involving Scavenger Receptor B1 (SR-B1) deficient models.

Main Results:

• RCT involves both trans-hepatic and trans-intestinal pathways, with direct hepatic transfer being a major route for HDL-cholesterol.
• Dysfunctional, free cholesterol-rich HDL is associated with impaired RCT and increased cardiovascular pathology.
• SR-B1 deficiency leads to dysfunctional HDL, hypercholesterolemia, and multiple pathologies.

Conclusions:

• Future therapies should consider both RCT pathways and the impact of HDL quality on cholesterol bioavailability.
• Improving HDL function is a promising strategy for managing atherosclerosis.
• Understanding the nuances of HDL metabolism is key to developing effective cardiovascular treatments.