Our lab studies the role of endothelial cells in lipid metabolism. The lipolytic processing of triglyceride-rich lipoproteins in the bloodstream by lipoprotein lipase (LPL) is the central event in plasma lipid metabolism. Acting inside capillaries, LPL cleaves lipoprotein triglycerides, releasing fatty acids that are taken up by tissues and either used for fuel or stored in cytosolic lipid droplets. LPL is synthesized by parenchymal cells (e.g. myocytes and adipocytes) and secreted into the interstitial spaces, but to be functional in processing triglycerides in the plasma, it must be transported to the capillary lumen. The endothelial cell protein GPIHBP1 serves as the LPL transporter, capturing LPL and moving it across endothelial cells to the capillary lumen. When GPIHBP1 is absent, LPL cannot reach the capillary lumen, leading to severe hypertriglyceridemia (in both humans and mice).
