Plasma phospholipid transfer activity is essential for increased atherogenesis in PLTP transgenic mice: a mutation-inactivation study.
Plasma phospholipid transfer protein (PLTP) interacts with HDL particles and facilitates the transfer of phospholipids from triglyceride (TG)-rich lipoproteins to HDL. Overexpressing human PLTP in mice increases the susceptibility to atherosclerosis. In human plasma, high-active and low-active forms of PLTP exist. To elucidate the contribution of phospholipid transfer activity to changes in lipoprotein metabolism and atherogenesis, we developed mice expressing mutant PLTP, still able to associate with HDL but lacking phospholipid transfer activity. In mice heterozygous for the LDL receptor, effects of the mutant and normal human PLTP transgene (mutPLTP tg and PLTP tg, respectively) were compared. In PLTP tg mice, plasma PLTP activity was increased 2.9-fold, resulting in markedly reduced HDL lipid levels. In contrast, in mutPLTP tg mice, lipid levels were not different from controls. Furthermore, hepatic VLDL-TG secretion was stimulated in PLTP tg mice, but not in mutPLTP tg mice. When mice were fed a cholesterol-enriched diet, atherosclerotic lesion size in PLTP tg mice was increased more than 2-fold compared with control mice, whereas in mutPLTP tg mice, there was no change. Our findings demonstrate that PLTP transfer activity is essential for the development of atherosclerosis in PLTP transgenic mice, identifying PLTP activity as a possible target to prevent atherogenesis, independent of plasma PLTP concentration.
Samyn
Hannelore
H
Department of Cell Biology and Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands.
Moerland
Matthijs
M
van Gent
Teus
T
van Haperen
Rien
R
Metso
Jari
J
Grosveld
Frank
F
Jauhiainen
Matti
M
van Tol
Arie
A
de Crom
Rini
R
D000818:Animals; D050197:Atherosclerosis / Q000235:genetics* / Q000378:metabolism; D004195:Disease Models, Animal; D008079:Lipoproteins, VLDL / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D049294:Phospholipid Transfer Proteins / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism
D008079:Lipoproteins, VLDL; D049294:Phospholipid Transfer Proteins; D012333:RNA, Messenger; C510091:phospholipid transfer protein, mouse