SPION primes THP1 derived M2 macrophages towards M1-like macrophages

• Published in: Biochemical and biophysical research communications 2013-11, Vol.441 (4), p.737-742
• Main Authors: Laskar, Amit, Eilertsen, Jonas, Li, Wei, Yuan, Xi-Ming
• Format: Article
• Language: English
• Subjects: B7-2 Antigen - analysis; Cathepsin L; Cathepsin L - metabolism; Cell Differentiation - drug effects; Cell Polarity - drug effects; Cells, Cultured; Dextrans - pharmacology; Ferric Compounds - pharmacology; Ferritin; Ferritins - metabolism; Humans; Immunoglobulin G - immunology; Inflammation - metabolism; Iron-oxide nanoparticles; M1 and M2 macrophages; Macrophages - cytology; Macrophages - drug effects; Macrophages - metabolism; Magnetite Nanoparticles; Oxysterols; Phagocytosis - drug effects; Plaque, Atherosclerotic - metabolism; Sterols - pharmacology; Tetradecanoylphorbol Acetate - analogs & derivatives; Tetradecanoylphorbol Acetate - pharmacology; Tumor Necrosis Factor-alpha - analysis; Up-Regulation
• ISSN: 0006-291X; 1090-2104; 1090-2104
• DOI: 10.1016/j.bbrc.2013.10.115

•Monocyte differentiation alters cellular ferritin and cathepsin L levels.•Ferritin and cathepsin L are associated with plasticity in macrophages.•Iron in SPION induces a phenotypic shift in M2 macrophages.•Atherogenic oxysterols reduce phagocytic activity in macrophage subtypes. Potentially, cellular iron regulates functional plasticity in macrophages yet; interaction of functionally polarized macrophages with iron-oxide nanoparticles has never been studied. We found that monocyte differentiation alters cellular ferritin and cathepsin L levels and induces functional polarization in macrophages. Iron in super paramagnetic iron-oxide nanoparticle (SPION) induces a phenotypic shift in THP1 derived M2 macrophages towards a high CD86+ and high TNF α+ macrophage subtype. This phenotypic shift was accompanied by up-regulated intracellular levels of ferritin and cathepsin L in M2 macrophages, which is a characteristic hallmark of M1 macrophages. Atherogenic oxysterols reduce phagocytic activity in macrophage subtypes, and thus these cells may escape detection by iron-oxide nanoparticles (INPs) in-vivo.