New roles of HDL in inflammation and hematopoiesis

Annu Rev Nutr. 2012 Aug 21;32:161-82. doi: 10.1146/annurev-nutr-071811-150709. Epub 2012 Apr 23.

Abstract

High-density lipoprotein (HDL) levels are inversely associated with coronary heart disease due to HDL's ability to transport excess cholesterol in arterial macrophages to the liver for excretion [i.e., reverse cholesterol transport (RCT)]. However, recent advances highlight additional atheroprotective roles for HDL beyond bulk cholesterol removal from cells through RCT. By promoting cellular free cholesterol (FC) efflux, HDL and its apolipoproteins (apoA-I and apoE) decrease plasma membrane FC and lipid raft content in immune and hematopoietic stem cells, decreasing inflammatory and cell proliferation signaling pathways. HDL and apoA-I also dampen inflammatory signaling pathways independent of cellular FC efflux. In addition, HDL lipid and protein cargo provide protection against parasitic and bacterial infection, endothelial damage, and oxidant toxicity. Here, current knowledge is reviewed regarding the role of HDL and its apolipoproteins in regulating cellular cholesterol homeostasis, highlighting recent advances on novel functions and mechanisms by which HDLs regulate inflammation and hematopoiesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Apolipoprotein A-I / metabolism
  • Cardiovascular Diseases / blood
  • Cardiovascular Diseases / immunology*
  • Cardiovascular Diseases / metabolism
  • Cell Proliferation
  • Cholesterol / metabolism*
  • Endothelium, Vascular / immunology
  • Endothelium, Vascular / metabolism
  • Hematopoiesis*
  • Hematopoietic Stem Cells / immunology
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Lipoproteins, HDL / blood
  • Lipoproteins, HDL / metabolism*
  • Lymphocytes / immunology
  • Lymphocytes / metabolism
  • Membrane Microdomains / immunology
  • Membrane Microdomains / metabolism

Substances

  • Apolipoprotein A-I
  • Lipoproteins, HDL
  • Cholesterol