Table 1 Activation status of synovial macrophages and/or circulating monocytes in rheumatoid arthritis
From: Cells of the synovium in rheumatoid arthritis. Macrophages
Class of overexpressed molecules | Molecules | Known or potential function |
|---|---|---|
Class II major histocompatibility complex (overexpressed on Mφ) | HLA-DR | Presentation of antigens relevant to disease initiation or severity [93] (Stuhlmuller B, et al., unpublished data) (reviewed in [2]) |
Cytokines and growth factors | For example, TNF-α, IL-1, IL-6, IL-10, IL-13, IL-15, IL-18, migration inhibitory factor, granulocyte macrophage colony-stimulating factor, and thrombospondin-1 | Mediation and regulation of local and systemic inflammation and tissue remodelling (reviewed in [2,24,39,52]) |
Chemokines and chemoattractants | For example, IL-8, macrophage inflammatory protein-1, monocyte chemoattractant protein-1, and CXCL13 | Mediation and regulation of monocyte migration Stimulation of angiogenesis (reviewed in [69]) |
Metalloproteases (MMPs) | MMP-9 and MMP-12 | Tissue degradation and post-injury tissue remodelling [94,95] |
Tissue inhibitors of MMP (TIMPs) | TIMP-1 | Attempt to control excessive tissue destruction [96] |
Acute-phase reactants | For example, C-reactive protein and A-SAA (serum amyloid A) | Integrated hormone-like activation of hepatocytes by synovial Mφ and fibroblasts (mostly via IL-6) [97] (reviewed in [2]) |
Other molecules | Neopterin | Produced by interferon-gamma-stimulated monocytes/Mφ Induces/enhances cytotoxicity and apoptosis Acts as antioxidant [98,99] |
|  | Cryopyrin | Produced by TNF-α-stimulated Mφ Regulates nuclear factor-kappa-B and caspase-1 activation [100] |