Transfer of very low density lipoprotein-associated phospholipids to activated human platelets.
LDL-associated phospholipids (PLs) may be transferred into platelets. In this work, we characterized the role of VLDLs as PL donors. VLDL transferred radiolabeled PLs to platelets in a temperature- and concentration-dependent manner. LPL stimulated this process through its action on VLDL lipolysis, because it was abolished by tetrahydrolipstatin. LPL also stimulated the platelet production of thromboxane B2 (TXB2). Both LPL actions were inhibited in the presence of fatty acid-free albumin, suggesting that they were attributable to fatty acids generated during VLDL lipolysis. To study the relationship between PL transfers and platelet activation, we performed incubations in the presence of HDL, a physiological acceptor of PL released from VLDL. HDL antagonized the transfer of PL from VLDL to platelets but had no effect on the production of TXB2, suggesting that PL transfers were driven by platelet activation. Confirming this idea, thrombin stimulated both the production of TXB2 and the transfers of PL. In conclusion, VLDL can transfer PL to platelets. These transfers are stimulated by LPL and thrombin through their action on platelet activation. They might be enhanced in pathologies characterized by increased VLDL concentrations.
Ibrahim
Salam
S
Unité Mixte de Recherche 585 Institut National de la Santé et de la Recherche Médicale/Institut National des Sciences Appliquées de Lyon-Lyon, Pathophysiology of Lipids and Membranes, Villeurbanne, France.
Djimet-Baboun
Anaël
A
Pruneta-Deloche
Valérie
V
Calzada
Catherine
C
Lagarde
Michel
M
Ponsin
Gabriel
G
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D007783:Lactones / Q000494:pharmacology; D008071:Lipoprotein Lipase / Q000378:metabolism; D008075:Lipoproteins, HDL / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000378:metabolism; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D000077403:Orlistat; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010742:Phospholipid Ethers / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D015539:Platelet Activation; D012709:Serum Albumin / Q000378:metabolism; D013696:Temperature; D013917:Thrombin / Q000378:metabolism; D013929:Thromboxane B2 / Q000378:metabolism
C096875:1-palmitoyl-2-arachidonyl-glycero-3-phosphoethanolamine; D004791:Enzyme Inhibitors; D007783:Lactones; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D010714:Phosphatidylethanolamines; D010742:Phospholipid Ethers; D010743:Phospholipids; D012709:Serum Albumin; D015060:1,2-Dipalmitoylphosphatidylcholine; D013929:Thromboxane B2; C043051:1-O-hexadecyl-2-arachidonyl-sn-glycero-3-phosphocholine; D000077403:Orlistat; D008071:Lipoprotein Lipase; D013917:Thrombin