Related Experiment Videos
Macrophage-derived angiogenesis factors
C Sunderkötter1, M Goebeler, K Schulze-Osthoff
1Institute of Experimental Dermatology, University of Münster, Germany.
Abstract:
A majority of angiogenic factors has been shown to be produced by macrophages. This review will give a concise description of their biochemical nature, their isolation from macrophages and their angiogenic activity. Among the factors with mitogenic effects on endothelial cells are basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF-alpha) and very probably insulin-like growth factor-1 (IGF-1). Other secretory products such as angiotropin and human angiogenic factor (HAF) are nonmitogenic but promote angiogenesis by inducing migration of endothelial cells. Prostaglandins, platelet-derived growth factor (PDGF), granulocyte-macrophage- and granulocyte-colony stimulating factor (GM-CSF, G-CSF), interleukin 6 (IL-6) and angiotensin converting enzyme (ACE) have also been shown to be angiogenic, but their mode of action is still to be clearly defined. As the extracellular matrix appears to be involved in the control of angiogenesis, macrophage-derived factors that can alter this structure via degradation or via the clotting system will also be discussed. Tumor necrosis factor alpha (TNF-alpha), interleukin 1 (IL-1) and transforming growth factor-beta (TGF-beta) have complex actions on endothelial cells, and can partially inhibit angiogenesis. Among the factors which solely inhibit neovascularization are the interferons. As it is not known whether all of these factors play a role in angiogenesis in vivo attempts to detect them in situ during the course of neovascularization will be described. Finally macrophages will be discussed as cells that may not be mandatory for each phase of the angiogenic process but whose angiogenic capabilities are comprehensive and unsurpassed by any other cell.
Insights
Macrophages are key producers of angiogenic factors, influencing blood vessel growth through various secreted molecules. This review details these factors, their roles in promoting or inhibiting angiogenesis, and their detection in vivo.
Area of Science:
- Cell Biology
- Molecular Biology
- Immunology
Background:
- Macrophages are a primary source of angiogenic factors, crucial for blood vessel formation.
- Understanding these factors is vital for research into angiogenesis and related diseases.
Purpose of the Study:
- To review the biochemical nature, isolation, and angiogenic activity of macrophage-derived factors.
- To discuss factors that promote (mitogenic and non-mitogenic) and inhibit angiogenesis.
- To explore the role of extracellular matrix interactions and in vivo detection of these factors.
Main Methods:
- Literature review of biochemical and cellular studies on macrophage-derived angiogenic factors.
- Analysis of factors affecting endothelial cell proliferation, migration, and extracellular matrix.
- Discussion of in situ detection methods for angiogenic factors during neovascularization.
Main Results:
- Identified mitogenic factors (e.g., bFGF, TGF-α, IGF-1) and non-mitogenic factors (e.g., angiotropin, HAF) produced by macrophages.
- Highlighted other angiogenic factors (e.g., prostaglandins, PDGF, cytokines, ACE) with less defined mechanisms.
- Noted inhibitory factors (e.g., TNF-α, IL-1, TGF-β, interferons) and the role of extracellular matrix modulation.
Conclusions:
- Macrophages possess comprehensive and potent angiogenic capabilities, influencing neovascularization through diverse secreted factors.
- While not essential for every stage, macrophages play a significant, multifaceted role in angiogenesis.
- Further in vivo studies are needed to fully elucidate the roles of these factors in physiological and pathological angiogenesis.