Glycosylphosphatidylinositol-specific phospholipase D influences triglyceride-rich lipoprotein metabolism

2005; doi:10.1152/ajpendo.00593.2004.—Glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) is a minor HDL-associated protein. Because many minor HDL-associated proteins exchange between different lipoprotein classes during the postprandial state and are also involved in triglyceride (TG) metabolism, we hypothesized that GPI-PLD may play a role in the metabolism of TG-rich lipoproteins. To test this hypothesis, we examined the distribution of GPI-PLD among lipoprotein classes during a fat tolerance test in C57BL/6 and LDL receptor-deficient (LDLR/) mice fed either a chow or high-fructose diet. In the fasting state in wild-type mice fed a chow diet, GPI-PLD was only present in HDL, whereas in LDLR/ mice GPI-PLD was present in HDL and intermediate-density lipoproteins (IDL)/LDL. During the fat tolerance test, there was no change in total serum GPI-PLD levels in either model; however, a significant amount of GPI-PLD appeared in both VLDL (0.5–1 % of total GPI-PLD) an