Pharmacological suppression of hepcidin increases macrophage cholesterol efflux and reduces foam cell formation and atherosclerosis

Omar Saeed, Fumiyuki Otsuka, Rohini Polavarapu, Vinit Karmali, Daiana Weiss, Talina Davis, Brad Rostad, Kimberly Pachura, Lila Adams, John Elliott, W. Robert Taylor, Jagat Narula, Frank Kolodgie, Renu Virmani, Charles C. Hong, Aloke V. Finn

Research output: Contribution to journalArticle

99 Scopus citations

Abstract

Objective-: We recently reported that lowering of macrophage free intracellular iron increases expression of cholesterol efflux transporters ABCA1 and ABCG1 by reducing generation of reactive oxygen species. In this study, we explored whether reducing macrophage intracellular iron levels via pharmacological suppression of hepcidin can increase macrophage-specific expression of cholesterol efflux transporters and reduce atherosclerosis. Methods and Results-: To suppress hepcidin, increase expression of the iron exporter ferroportin, and reduce macrophage intracellular iron, we used a small molecule inhibitor of bone morphogenetic protein (BMP) signaling, LDN 193189 (LDN). LDN (10 mg/kg IP b.i.d.) was administered to mice, and its effects on atherosclerosis, intracellular iron, oxidative stress, lipid efflux, and foam cell formation were measured in plaques and peritoneal macrophages. Long-term LDN administration to apolipoprotein E-/-mice increased ABCA1 immunoreactivity within intraplaque macrophages by 3.7-fold (n=8; P=0.03), reduced Oil Red O-positive lipid area by 50% (n=8; P=0.02), and decreased total plaque area by 43% (n=8; P=0.001). LDN suppressed liver hepcidin transcription and increased macrophage ferroportin, lowering intracellular iron and hydrogen peroxide production. LDN treatment increased macrophage ABCA1 and ABCG1 expression, significantly raised cholesterol efflux to ApoA-1, and decreased foam cell formation. All preceding LDN-induced effects on cholesterol efflux were reversed by exogenous hepcidin administration, suggesting modulation of intracellular iron levels within macrophages as the mechanism by which LDN triggers these effects. Conclusion-: These data suggest that pharmacological manipulation of iron homeostasis may be a promising target to increase macrophage reverse cholesterol transport and limit atherosclerosis.

Original languageEnglish (US)
Pages (from-to)299-307
Number of pages9
JournalArteriosclerosis, thrombosis, and vascular biology
Volume32
Issue number2
DOIs
StatePublished - Feb 1 2012
Externally publishedYes

Keywords

  • ABC transporter
  • hemoglobin
  • macrophages
  • pharmacology
  • reactive oxygen species

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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    Saeed, O., Otsuka, F., Polavarapu, R., Karmali, V., Weiss, D., Davis, T., Rostad, B., Pachura, K., Adams, L., Elliott, J., Taylor, W. R., Narula, J., Kolodgie, F., Virmani, R., Hong, C. C., & Finn, A. V. (2012). Pharmacological suppression of hepcidin increases macrophage cholesterol efflux and reduces foam cell formation and atherosclerosis. Arteriosclerosis, thrombosis, and vascular biology, 32(2), 299-307. https://doi.org/10.1161/ATVBAHA.111.240101