Lysophosphatidylcholine potentiates the mitogenic activity of modified LDL for human monocyte-derived macrophages.
The growth of murine peritoneal macrophages is induced by oxidized LDL (Ox-LDL), and lysophosphatidylcholine (lysoPC) plays an important role in its mitogenic activity. In the present++ study, Ox-LDL-induced macrophage growth was examined with human monocyte-derived macrophages. The cell growth of human macrophages was significantly induced by Ox-LDL but not by acetylated LDL (acetyl-LDL). The treatment of acetyl-LDL with phospholipase A2, however, led to a marked increase in its mitogenic activity, with a concomitant conversion of 75% of its phospholipids to lysoPC. The growth-stimulating activity became positive only when both acetyl-LDL and lysoPC were coincubated, although neither of them exhibited cell growth-promoting activity. These results suggest that Ox-LDL could stimulate the growth of human monocyte-derived macrophages, and lysoPC may play an essential role in the mitogenic activity of Ox-LDL.
Sakai
M
M
Department of Biochemistry, Kumamoto University School of Medicine, Kumamoto, Japan.
Miyazaki
A
A
Hakamata
H
H
Sato
Y
Y
Matsumura
T
T
Kobori
S
S
Shichiri
M
M
Horiuchi
S
S
D002455:Cell Division / Q000187:drug effects; D002460:Cell Line / Q000187:drug effects; D004357:Drug Synergism; D006801:Humans; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects*; D008934:Mitogens / Q000494:pharmacology*; D009000:Monocytes / Q000166:cytology*; D010084:Oxidation-Reduction; D010741:Phospholipases A / Q000494:pharmacology; D054467:Phospholipases A2; D002785:Sterol O-Acyltransferase / Q000037:antagonists & inhibitors
D008077:Lipoproteins, LDL; D008244:Lysophosphatidylcholines; D008934:Mitogens; C032629:acetyl-LDL; D002785:Sterol O-Acyltransferase; D010741:Phospholipases A; D054467:Phospholipases A2