Managing macrophages in rheumatoid arthritis by reform or removal

Curr Rheumatol Rep. 2012 Oct;14(5):445-54. doi: 10.1007/s11926-012-0272-4.

Abstract

Macrophages play a central role in the pathogenesis of rheumatoid arthritis (RA). There is an imbalance of inflammatory and antiinflammatory macrophages in RA synovium. Although the polarization and heterogeneity of macrophages in RA have not been fully uncovered, the identity of macrophages in RA can potentially be defined by their products, including the co-stimulatory molecules, scavenger receptors, different cytokines/chemokines and receptors, and transcription factors. In the last decade, efforts to understand the polarization, apoptosis regulation, and novel signaling pathways in macrophages, as well as how distinct activated macrophages influence disease progression, have led to strategies that target macrophages with varied specificity and selectivity. Major targets that are related to macrophage development and apoptosis include TNF-α, IL-1, IL-6, GM-CSF, M-CSF, death receptor 5 (DR5), Fas, and others, as listed in Table 1. Combined data from clinical, preclinical, and animal studies of inhibitors of these targets have provided valuable insights into their roles in the disease progression and, subsequently, have led to the evolving therapeutic paradigms in RA. In this review, we propose that reestablishment of macrophage equilibrium by inhibiting the development of, and/or eliminating, the proinflammatory macrophages will be an effective therapeutic approach for RA and other autoimmune diseases.

Publication types

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

MeSH terms

  • Animals
  • Antirheumatic Agents / pharmacology
  • Antirheumatic Agents / therapeutic use*
  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Arthritis, Rheumatoid / drug therapy*
  • Arthritis, Rheumatoid / immunology
  • Clinical Trials as Topic
  • Disease Models, Animal
  • Humans
  • Macrophage Activation / drug effects*
  • Macrophage Activation / immunology
  • Macrophages / drug effects*
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mice
  • Mice, Transgenic
  • Synovial Membrane / drug effects*
  • Synovial Membrane / immunology
  • TNF-Related Apoptosis-Inducing Ligand / metabolism

Substances

  • Antirheumatic Agents
  • TNF-Related Apoptosis-Inducing Ligand