Cellular and molecular mechanisms of embryonic haemangiogenesis and lymphangiogenesis

Vascular diseases are the leading cause of morbidity and mortality in developed nations. Therapeutic haemangiogenesis and lymphangiogenesis may present a chance for curative intervention. Recently we have learned that physiologic and pathologic angiogenesis in the human adult are controlled by molecules that are already functioning during embryogenesis, and the lessons we can learn from studying embryos may be useful for future clinical studies. Here we review cellular and molecular mechanisms of embryonic haemangiogenesis and lymphangiogenesis. The focus lies on the endothelial cell and the surrounding peri-endothelial cells, the growth factors and receptors that control their development, proliferation, maintenance, regression and differentiation. Our rapidly expanding knowledge of the molecules expressed in endothelial cells justifies expanded functional studies in future.