Ectopic Fatty Acid–Binding Protein 4 Expression in the Vascular Endothelium is Involved in Neointima Formation After Vascular Injury

BackgroundFatty acid‐binding protein 4 (FABP4) is expressed in adipocytes, macrophages, and endothelial cells of capillaries but not arteries. FABP4 is secreted from adipocytes in association with lipolysis, and an elevated circulating FABP4 level is associated with obesity, insulin resistance, and atherosclerosis. However, little is known about the link between FABP4 and endovascular injury. We investigated the involvement of ectopic FABP4 expression in endothelial cells in neointima hyperplasia after vascular injury. Methods and ResultsFemoral arteries of 8‐week‐old male mice were subjected to wire‐induced vascular injury. After 4 weeks, immunofluorescence staining showed that FABP4 was ectopically expressed in endothelial cells of the hyperplastic neointima. Neointima formation determined by intima area and intima to media ratio was significantly decreased in FABP4‐defficient mice compared with that in wild‐type mice. Adenovirus‐mediated overexpression of FABP4 in human coronary artery endothelial cell...