Sustained elevations in NEFA induce cyclooxygenase-2 activity and potentiate THP-1 macrophage foam cell formation

Atherosclerosis. 2007 May;192(1):49-55. doi: 10.1016/j.atherosclerosis.2006.06.014. Epub 2006 Jul 25.

Abstract

Type 2 diabetes, a major risk factor for atherosclerosis, is associated with a cluster of lipid risk factors, many of which can be mechanistically linked with underlying dysregulated fatty acid metabolism and elevated plasma non-esterified fatty acids (NEFA). Thus, we tested the hypothesis that elevated NEFA dysregulates lipid metabolism at the levels of lipid synthesis and gene expression in THP-1 monocyte derived macrophages (MDM). THP-1 MDM incubated with oleic acid (OA) and a BODIPY-conjugated NEFA, accumulate, respectively, intracellular inclusions that are positive for oil red O and BODIPY-labeling. Parallel studies with [(14)C]OA show dose-dependent accumulation of intracellular (14)C-labeled neutral lipid, almost exclusively as triglyceride; the rate of [(3)H]OA uptake increases as THP-1 MDM convert to foam cells. Preincubation of THP-1 MDM with higher concentrations of OA (1.8mM versus 0.2mM) was associated with enhanced uptake of Ac-LDL, and increased expression of adipocyte fatty acid binding protein, FAT/CD36, and cyclooxygenase-2 (COX-2); COX-2 mass and activity also increased. These observations suggest a mechanistic link between sustained elevations in albumin-bound NEFA and foam cell formation that may be mediated by enhanced adipogenesis, increased uptake of modified LDL, and upregulated formation of eicosanoids, which may be proinflammatory.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / metabolism
  • Albumins / metabolism
  • CD36 Antigens / metabolism
  • Cell Line
  • Cyclooxygenase 2 / metabolism*
  • Fatty Acids, Nonesterified / metabolism*
  • Foam Cells / physiology*
  • Gene Expression Profiling
  • Humans
  • Lipid Metabolism
  • Macrophages / metabolism*
  • Molecular Sequence Data
  • Oleic Acid / metabolism

Substances

  • Albumins
  • CD36 Antigens
  • Fatty Acids, Nonesterified
  • Oleic Acid
  • Cyclooxygenase 2

Associated data

  • RefSeq/NM_000072
  • RefSeq/NM_000527
  • RefSeq/NM_000576
  • RefSeq/NM_000600
  • RefSeq/NM_000963
  • RefSeq/NM_001753
  • RefSeq/NM_004364
  • RefSeq/NM_005502
  • RefSeq/NM_005505
  • RefSeq/NM_006411
  • RefSeq/NM_006412
  • RefSeq/NM_012079
  • RefSeq/NM_032564
  • RefSeq/NM_032741