Synergically increased expression of CD36, CLA-1 and CD68, but not of SR-A and LOX-1, with the progression to foam cells from macrophages.
Several species of scavenger receptors have so far been identified. However, it remains unclear which receptors are more crucial for the foam cell formation and progression. In the present study, we compared five major scavenger receptors (SR-A, CD36, CLA-1, CD68, and LOX-1) in their levels of expression at the different stages of foam cells derived from THP-1 cells. The expression of all scavenger receptors examined was up-regulated by the stimulation with TPA for 48 hours, despite the expressions of SR-A, CD36 and LOX-1 being very low before the treatment with TPA. Four to 7 days after the removal of TPA, the levels of CD36, CLA-1 and CD68 were increased significantly. In contrast, the expression of SR-A was suppressed significantly, and no change was observed in that of LOX-1. Furthermore, when the transformed macrophages were incubated with oxidized LDL, in which the uptake of [3H] cholesteryl oleoyl ether-labeled OxLDL was linear up to 7 days after the addition of OxLDL, the expression of CD36, CLA-1 and CD68 were greatly enhanced. This enhancement was more prominent than that without oxidized LDL, and the enhancement was sustained throughout the experimental period. On the other hand, SR-A was not up-regulated, and LOX-1 was down-regulated. We thus propose that CD36, CLA-1 and CD68, but not SR-A and LOX-1, may play crucial roles in the progression of macrophages to foam cells, which is a key step for the initiation of atherosclerosis.
Tsukamoto
Kayo
K
Department of Internal Medicine, Teikyo University School of Medicine, Tokyo, Japan.
Kinoshita
Makoto
M
Kojima
Kyoko
K
Mikuni
Yoko
Y
Kudo
Mikiko
M
Mori
Masaki
M
Fujita
Mineko
M
Horie
Eiko
E
Shimazu
Nobuko
N
Teramoto
Tamio
T
D015703:Antigens, CD / Q000235:genetics* / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000235:genetics* / Q000378:metabolism; D018955:CD36 Antigens / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D002784:Cholesterol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005487:Foam Cells / Q000166:cytology* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007948:Leukemia, Monocytic, Acute; D008077:Lipoproteins, LDL / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D011971:Receptors, Immunologic; D011973:Receptors, LDL / Q000235:genetics / Q000378:metabolism; D018110:Receptors, Lipoprotein / Q000235:genetics* / Q000378:metabolism; D051131:Receptors, Oxidized LDL; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B; D051127:Scavenger Receptors, Class E; D014316:Tritium; D014407:Tumor Cells, Cultured; D000097382:CD68 Molecule
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018955:CD36 Antigens; D002784:Cholesterol; D008077:Lipoproteins, LDL; D011971:Receptors, Immunologic; D011973:Receptors, LDL; D018110:Receptors, Lipoprotein; D051131:Receptors, Oxidized LDL; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B; D051127:Scavenger Receptors, Class E; D014316:Tritium; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C495137:OLR1 protein, human; C495124:SCARB1 protein, human; C099252:oxidized low density lipoprotein; C023511:cholesteryl oleyl ether