Angiogenesis in Inflammatory Bowel Disease

The etiology of inflammatory bowel diseases (IBD) is not precisely defined, however they display environmental factors, genetic predisposition, gut microbiota involvement, and abnormal immunity.Angiogenesis seems to be an integral part of IBD. Impaired intestinal barrier probably express an initiating or early feature in the disease. A disruption of epithelial barrier leads to penetration of microtiota and other antigens into the mucosa leading to an enhanced immune response, whereas the vascular barrier damage is related to endothelium activation and pathological angiogenesis which promote inflammation. Angiogenesis is a very complex phenomenon which including endothelial and immune cells, growth factors, cytokines, adhesion molecules, intestinal microbiota, and signal transduction. It seems that intestinal microvasculature hemostasis turns to prothrombotic state, and microthrombi formation enhance ischemia. The angiogenic process in IBD is in part regulated by intestinal microbiota. Antiangiogenic therapy is a novel and significant approach for IBD treatment. Biologic anti-inflammatory therapy of IBD simultaneously attenuates angiogenesis to a similar degree. However expression of VEGF and other grow factors may have dual and opposing effect probably related to stage of the disease. Thus anti- angiogenic treatment in IBD patients is still controversial and clinical trials should be performed using anti-angiogenic drugs.