Atheroprotective effects of methotrexate on reverse cholesterol transport proteins and foam cell transformation in human THP-1 monocyte/macrophages

Arthritis Rheum. 2008 Dec;58(12):3675-83. doi: 10.1002/art.24040.


Objective: To determine whether methotrexate (MTX) can overcome the atherogenic effects of cyclooxygenase 2 (COX-2) inhibitors and interferon-gamma (IFNgamma), both of which suppress cholesterol efflux protein and promote foam cell transformation in human THP-1 monocyte/macrophages.

Methods: Message and protein levels of the reverse cholesterol transport proteins cholesterol 27-hydroxylase and ATP-binding cassette transporter A1 (ABCA1) in THP-1 cells were evaluated by real-time polymerase chain reaction and immunoblot, respectively. Expression was evaluated in cells incubated in the presence or absence of the COX-2 inhibitor NS398 or IFNgamma, with and without MTX. Foam cell transformation of lipid-laden THP-1 macrophages was detected with oil red O staining and light microscopy.

Results: MTX increased 27-hydroxylase message and completely blocked NS398-induced down-regulation of 27-hydroxylase (mean +/- SEM 112.8 +/- 13.1% for NS398 plus MTX versus 71.1 +/- 4.3% for NS398 alone; P < 0.01). MTX also negated COX-2 inhibitor-mediated down-regulation of ABCA1. The ability of MTX to reverse inhibitory effects on 27-hydroxylase and ABCA1 was blocked by the adenosine A2A receptor-specific antagonist ZM241385. MTX also prevented NS398 and IFNgamma from increasing transformation of lipid-laden THP-1 macrophages into foam cells.

Conclusion: This study provides evidence supporting the notion of an atheroprotective effect of MTX. Through adenosine A2A receptor activation, MTX promotes reverse cholesterol transport and limits foam cell formation in THP-1 macrophages. This is the first reported evidence that any commonly used medication can increase expression of antiatherogenic reverse cholesterol transport proteins and can counteract the effects of COX-2 inhibition. Our results suggest that one mechanism by which MTX protects against cardiovascular disease in rheumatoid arthritis patients is through facilitation of cholesterol outflow from cells of the artery wall.

Publication types

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

MeSH terms

  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters / genetics*
  • ATP-Binding Cassette Transporters / metabolism
  • Adenosine / metabolism
  • Antirheumatic Agents / pharmacology*
  • Atherosclerosis / drug therapy
  • Atherosclerosis / prevention & control
  • Cells, Cultured
  • Cholestanetriol 26-Monooxygenase / genetics*
  • Cholestanetriol 26-Monooxygenase / metabolism
  • Cholesterol / metabolism
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Down-Regulation / drug effects
  • Down-Regulation / immunology
  • Drug Interactions
  • Foam Cells / cytology
  • Foam Cells / drug effects*
  • Foam Cells / metabolism
  • Humans
  • Interferon-gamma / pharmacology
  • Macrophages / cytology
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Methotrexate / pharmacology*
  • Monocytes / cytology
  • Monocytes / drug effects
  • Monocytes / metabolism
  • RNA, Messenger / metabolism
  • Receptor, Adenosine A2A / metabolism


  • ABCA1 protein, human
  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters
  • Antirheumatic Agents
  • Cyclooxygenase 2 Inhibitors
  • RNA, Messenger
  • Receptor, Adenosine A2A
  • Interferon-gamma
  • Cholesterol
  • CYP27A1 protein, human
  • Cholestanetriol 26-Monooxygenase
  • Adenosine
  • Methotrexate