Methodist Journal

IN THIS ISSUE

Lipids and Lipoproteins

Vol 15, Issue 1 (2019)


FEATURED GUEST EDITOR

ISSUE INTRO

Lipids and Cardiovascular Disease: Putting it All Together

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RECOGNITIONS

Guest Editors Henry Pownall and Antonio Gotto Offer Insight and Expertise on the topic of Lipids and Cardiovascular Disease

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REVIEW ARTICLES See More

Cholesterol: Can’t Live With It, Can’t Live Without It

How Much Do Lipid Guidelines Help the Clinician? Reading Between the (Guide)lines

Statins: Then and Now

Poststatin Lipid Therapeutics: A Review

HDL and Reverse Cholesterol Transport Biomarkers

Revisiting Reverse Cholesterol Transport in the Context of High-Density Lipoprotein Free Cholesterol Bioavailability

High-Density Lipoprotein Subspecies in Health and Human Disease: Focus on Type 2 Diabetes

Gene Delivery in Lipid Research and Therapies

CASE REPORTS See More

Device-Related Thrombus: A Reason for Concern?

Retained Coronary Balloon Requiring Emergent Open Surgical Retrieval: An Uncommon Complication Requiring Individualized Management Strategies

Loperamide Mimicking Brugada Pattern

Reversed Pulsus Paradoxus in Right Ventricular Failure

MUSEUM OF HMH MULTIMODALITY IMAGING CENTER See More

Transcatheter Embolization of a Persistent Vertical Vein: A Rare Cause of Left-to-Right Shunt and Right-Sided Heart Failure

CLINICAL PERSPECTIVES See More

POINTS TO REMEMBER

Lipids and Renal Disease

EXCERPTA

Addressing the Feedback Loop Between Depression, Diabetes, and Cardiovascular Disease

POINTS TO REMEMBER

The Kidney as an Endocrine Organ

EXCERPTA

The Other Side of the Prescription

EDITORIALS

Letter to the Editor in response to “Role of Subcutaneous Leadless Implantable Cardioverter Defibrillator in Young Patients

Vol 15, Issue 1 (2019)

Article Abstract

Revisiting Reverse Cholesterol Transport in the Context of High-Density Lipoprotein Free Cholesterol Bioavailability


Article Citation:

Rosales C, Gillard BK, Xu B, Gotto AM Jr, Pownall HJ. Revisiting Reverse Cholesterol Transport in the Context of High-Density Lipoprotein Free Cholesterol Bioavailability. Methodist DeBakey Cardiovasc J. 2019:15(1):47-54.

doi:

Abstract

Dysregulated free cholesterol (FC) metabolism has been implicated in nearly all stages of atherosclerosis, the underlying cause of most cardiovascular disease. According to a widely cited model, the burden of macrophage FC in the arterial wall is relieved by transhepatic reverse cholesterol transport (RCT), which comprises three successive steps: (1) macrophage FC efflux to high-density lipoprotein (HDL) and/or its major protein, apolipoprotein AI; (2) FC esterification by lecithin:cholesterol acyltransferase (LCAT); and (3) HDL-cholesteryl ester (CE) uptake via the hepatic HDL-receptor, scavenger receptor class B type 1 (SR-B1). Recent studies have challenged the validity of this model, most notably the role of LCAT, which appears to be of minor importance. In mice, most macrophage-derived FC is rapidly cleared from plasma (t1/2 < 5 min) without esterification by hepatic uptake; the remainder is taken up by multiple tissue and cell types, especially erythrocytes. Further, some FC is cleared by the nonhepatic transintestinal pathway. Lastly, FC movement among lipid surfaces is reversible, so that a higher-than-normal level of HDL-FC bioavailability—defined by high plasma HDL levels concurrent with a high mol% HDL-FC—leads to the transfer of excess FC to cells in vivo. SR-B1-/- mice provide an animal model to study the mechanistic consequences of high HDL-FC bioavailability that provokes atherosclerosis and other metabolic abnormalities. Future efforts should aim to reduce HDL-FC bioavailability, thereby reducing FC accretion by tissues and the attendant atherosclerosis.

Keywords
free cholesterol bioavailability , reverse cholesterol transport , cholesterol , high density lipoproteins , atherogenesis , lipid metabolism