Lysophosphatidylcholine: a chemotactic factor for human monocytes and its potential role in atherogenesis.
Native low density lipoprotein (LDL) does not affect monocyte/macrophage motility. On the other hand, oxidatively modified LDL inhibits the motility of resident peritoneal macrophages yet acts as a chemotactic factor for circulating human monocytes. We now show that lysophosphatidylcholine (lyso-PtdCho), which is generated by a phospholipase A2 activity during LDL oxidation, is a potent chemotactic factor for monocytes. It is not chemotactic for neutrophils or for resident macrophages. Platelet-activating factor, after treatment with phospholipase A2, becomes chemotactic for monocytes, whereas the intact factor is not. Synthetic 1-palmitoyl-lyso-PtdCho showed chemotactic activity comparable to that of the lyso-PtdCho fraction derived from oxidized LDL. The results suggest that lyso-PtdCho in oxidized LDL may favor recruitment of monocytes into the arterial wall during the early stages of atherogenesis. Generation of lyso-PtdCho, either from LDL itself or from membrane phospholipids of damaged cells, could play a more general role in inflammatory processes throughout the body.
Quinn
M T
MT
Department of Medicine, University of California, San Diego, La Jolla 92093.
Parthasarathy
S
S
Steinberg
D
D
D000818:Animals; D001161:Arteriosclerosis / Q000209:etiology*; D002634:Chemotaxis, Leukocyte; D005487:Foam Cells / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008244:Lysophosphatidylcholines / Q000502:physiology*; D008264:Macrophages / Q000502:physiology*; D009000:Monocytes / Q000502:physiology*; D010084:Oxidation-Reduction; D010741:Phospholipases A / Q000494:pharmacology; D054467:Phospholipases A2; D010972:Platelet Activating Factor / Q000494:pharmacology; D011817:Rabbits; D013329:Structure-Activity Relationship
D008244:Lysophosphatidylcholines; D010972:Platelet Activating Factor; D010741:Phospholipases A; D054467:Phospholipases A2