Mechanisms of Disease: angiogenesis in inflammatory diseases.

Angiogenesis, the development of new vessels, is an important process in health and disease. The perpetuation of neovascularization in inflammatory diseases, such as rheumatoid arthritis, spondyloarthropathies and some systemic autoimmune diseases, might facilitate the ingress of inflammatory cells into the synovium and, therefore, stimulate pannus formation. Disorders associated with perpetuated neovascularization are considered to be angiogenic inflammatory diseases. Several angiogenic mediators, including growth factors, cytokines, matrix metalloproteinases, matrix macromolecules, cell adhesion receptors, chemokines and chemokine receptors, have been implicated in the process of capillary formation. There is a regulatory network in inflamed tissues that is involved in the upregulation or downregulation of angiogenesis. Endogenous angiostatic factors downregulate neovascularization and might act as angiostatic agents. Furthermore, angiogenesis might be targeted by several specific approaches that could be therapeutically used to control inflammatory diseases.