Perspective on the osteoclast: an angiogenic cell?
Frank C Cackowski1, G David Roodman
1University of Pittsburgh School of Medicine, Hematology-Oncology, Pittsburgh, Pennsylvania, USA.
Annals of the New York Academy of Sciences
|December 7, 2007
Summary
Osteoclasts, bone-resorbing cells, may actively promote new blood vessel growth (angiogenesis). This review examines evidence supporting osteoclasts as proangiogenic cells, considering factors like their secretions and proximity to blood vessels.
Area of Science:
- Bone Biology
- Angiogenesis Research
- Cellular Interactions
Background:
- Recent in vitro studies suggest osteoclasts stimulate angiogenesis.
- Understanding the role of bone cells in vascularization is crucial for bone health and disease.
- Osteoclasts are primarily known for bone resorption.
Purpose of the Study:
- To review evidence supporting the hypothesis that osteoclasts directly stimulate angiogenesis.
- To discuss the feasibility of osteoclasts acting as proangiogenic cells.
Main Methods:
- Literature review of existing studies on osteoclasts and angiogenesis.
- Analysis of proangiogenic factors produced by osteoclasts.
- Comparison with the known angiogenic effects of macrophages.
- Evaluation of the impact of nitrogen-containing bisphosphonates on angiogenesis.
- Consideration of the physical interactions between osteoclasts and endothelial cells.
Main Results:
- Evidence suggests osteoclasts produce proangiogenic factors.
- Macrophages, which share developmental origins with osteoclasts, are known to be proangiogenic.
- Nitrogen-containing bisphosphonates, which inhibit osteoclasts, also exhibit antiangiogenic effects.
- Osteoclasts are in close physical proximity to endothelial cells in bone microenvironments.
Conclusions:
- The hypothesis that osteoclasts can be proangiogenic cells is feasible.
- Osteoclasts may play a direct role in stimulating angiogenesis.
- Further research is warranted to elucidate the precise mechanisms of osteoclast-mediated angiogenesis.
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