ABCG1 orchestrates adipose tissue macrophage plasticity and insulin resistance in obesity by rewiring saturated fatty acid pools.

The mechanisms governing adipose tissue macrophage (ATM) metabolic adaptation during diet-induced obesity (DIO) are poorly understood. In obese adipose tissue, ATMs are exposed to lipid fluxes, which can influence the activation of specific inflammatory and metabolic programs and contribute to the development of obesity-associated insulin resistance and other metabolic disorders. In the present study, we demonstrate that the membrane ATP-binding cassette g1 (Abcg1) transporter controls the ATM functional response to fatty acids (FAs) carried by triglyceride-rich lipoproteins, which are abundant in high-energy diets.

Reduced Capacity of High-Density Lipoprotein to Acquire Free Cholesterol From Triglyceride-Rich Lipoproteins Is Associated With Elevated Postprandial Hypertriglyceridemia in Healthy Men.

Background: The capacity of high-density lipoprotein cholesterol (HDL) to acquire free cholesterol (FC) from triglyceride-rich lipoproteins during lipoprotein lipase-dependent lipolysis in a process of reverse remnant cholesterol transport, has been proposed as a key biological function of HDL particles that underlies the U-shaped relationship between HDLcholesterol and cardiovascular diseases. Although reverse remnant cholesterol transport has been evaluated in a fasting state, it has never been explored under nonfasting conditions.

Methods And Results: FC transfer was evaluated in healthy men (n=78) before and throughout the postprandial phase up to 8 hours after consumption of a test meal.

CD63 sorts cholesterol into endosomes for storage and distribution via exosomes.

Extracellular vesicles such as exosomes are now recognized as key players in intercellular communication. Their role is influenced by the specific repertoires of proteins and lipids, which are enriched when they are generated as intraluminal vesicles (ILVs) in multivesicular endosomes. Here we report that a key component of small extracellular vesicles, the tetraspanin CD63, sorts cholesterol to ILVs, generating a pool that can be mobilized by the NPC1/2 complex, and exported via exosomes to recipient cells.

Acute myocardial infarction preferentially alters low-abundant, long-chain unsaturated phospholipid and sphingolipid species in plasma high-density lipoprotein subpopulations.

Aim: High-density lipoprotein (HDL) particles in ST-segment elevation myocardial infarction (STEMI) are deficient in their anti-atherogenic function. Molecular determinants of such deficiency remain obscure.

Methods: Five major HDL subpopulations were isolated using density-gradient ultracentrifugation from STEMI patients (n = 12) and healthy age- and sex-matched controls (n = 12), and 160 species of phosphatidylcholine, lysophosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylglycerol, phosphatidylserine, phosphatidic acid, sphingomyelin and ceramide were quantified by LC-MS/MS.

Sweet swell of burning fat: emerging role of high-density lipoprotein in energy homeostasis.

Purpose Of Review: Metabolism of lipids and lipoproteins, including high-density lipoprotein (HDL), plays a central role in energy homeostasis. Mechanisms underlying the relationship between energy homeostasis and HDL however remain poorly studied.

Recent Findings: Available evidence reveals that HDL is implicated in energy homeostasis.