Semin Liver Dis 2010; 30(3): 245-257
DOI: 10.1055/s-0030-1255354
© Thieme Medical Publishers

Macrophages: Master Regulators of Inflammation and Fibrosis

Thomas A. Wynn1 , Luke Barron1
  • 1Immunopathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
Further Information

Publication History

Publication Date:
21 July 2010 (online)

ABSTRACT

Macrophages are found in close proximity with collagen-producing myofibroblasts and indisputably play a key role in fibrosis. They produce profibrotic mediators that directly activate fibroblasts, including transforming growth factor-β1 and platelet-derived growth factor, and control extracellular matrix turnover by regulating the balance of various matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases. Macrophages also regulate fibrogenesis by secreting chemokines that recruit fibroblasts and other inflammatory cells. With their potential to act in both a pro- and antifibrotic capacity, as well as their ability to regulate the activation of resident and recruited myofibroblasts, macrophages and the factors they express are integrated into all stages of the fibrotic process. These various, and sometimes opposing, functions may be performed by distinct macrophage subpopulations, the identification of which is a growing focus of fibrosis research. Although collagen-secreting myofibroblasts once were thought of as the master “producers” of fibrosis, this review will illustrate how macrophages function as the master “regulators” of fibrosis.

REFERENCES

Thomas A Wynn, Ph.D. 

Immunopathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health

Bethesda, MD 20892

Email: twynn@niaid.nih.gov