Vascular heterogeneity and specialization in development and disease

Blood and lymphatic vessels have essential roles in physiology and disease. The endothelial cells that line these vessels specialize to fulfil the needs of the tissue that they pervade. Recent studies in animal models have provided insights into the mechanisms underlying vessel type- and organ-specific specialization, which is crucial for the understanding of several diseases. Blood and lymphatic vessels pervade almost all body tissues and have numerous essential roles in physiology and disease. The inner lining of these networks is formed by a single layer of endothelial cells, which is specialized according to the needs of the tissue that it supplies. Whereas the general mechanisms of blood and lymphatic vessel development are being defined with increasing molecular precision, studies of the processes of endothelial specialization remain mostly descriptive. Recent insights from genetic animal models illuminate how endothelial cells interact with each other and with their tissue environment, providing paradigms for vessel type- and organ-specific endothelial differentiation. Delineating these governing principles will be crucial for understanding how tissues develop and maintain, and how their function becomes abnormal in disease.