Vascular endothelial growth factor B controls endothelial fatty acid uptake

The vascular endothelial growth factors (VEGFs) are major angiogenic regulators and are involved in several aspects of endothelial cell physiology. However, the detailed role of VEGF-B in blood vessel function has remained unclear. Here we show that VEGF-B has an unexpected role in endothelial targeting of lipids to peripheral tissues. Dietary lipids present in circulation have to be transported through the vascular endothelium to be metabolized by tissue cells, a mechanism that is poorly understood. Bioinformatic analysis showed that Vegfb was tightly co-expressed with nuclear-encoded mitochondrial genes across a large variety of physiological conditions in mice, pointing to a role for VEGF-B in metabolism. VEGF-B specifically controlled endothelial uptake of fatty acids via transcriptional regulation of vascular fatty acid transport proteins. As a consequence, Vegfb(-/-) mice showed less uptake and accumulation of lipids in muscle, heart and brown adipose tissue, and instead shunted lipids to white adipose tissue. This regulation was mediated by VEGF receptor 1 and neuropilin 1 expressed by the endothelium. The co-expression of VEGF-B and mitochondrial proteins introduces a novel regulatory mechanism, whereby endothelial lipid uptake and mitochondrial lipid use are tightly coordinated. The involvement of VEGF-B in lipid uptake may open up the possibility for novel strategies to modulate pathological lipid accumulation in diabetes, obesity and cardiovascular diseases.