Expression of HDL receptor, CLA-1 in human smooth-muscle cells and effect of interferon-gamma on its regulation.
High-density lipoprotein (HDL) exerts antiatherogenic effects by various mechanisms. The protective effect of HDL is thought to involve the reverse transport of cholesterol from cells in the arterial wall to the liver for disposal. We previously identified human scavenger receptor BI (hSR-BI/CLA-1) as a receptor for human HDL, but did not examine the expression of hSR-BI/CLA-1 in smooth-muscle cells. In this present study, a human aortic intima smooth-muscle cell line immortalized with SV 40 DNA was established, and the expression of hSR-BI/CLA-1 in this cell line analyzed by Western blot and RT-PCR. HSR-BI/CLA-1 mRNA and protein were detected in both this cell line and primary human aortic smooth-muscle cells. A cytokine, interferon-gamma (IFN-gamma) inhibited the hSR-BI/CLA-1 protein expression, but not mRNA expression. This observation confirmed that selective cholesterol ester uptake from HDL was inhibited by IFN-gamma. These results indicated that hSR-BI/CLA-1 may be expressed in human smooth-muscle cells, and the expression may be modulated by IFN-gamma. HSR-BI/CLA-1 on smooth-muscle cells could play an important role in atherogenesis.
Imachi
H
H
First Department of Internal Medicine, Kagawa Medical University, Japan.
Murao
K
K
Cao
W M
WM
Ohyama
T
T
Sato
M
M
Sasaguri
Y
Y
Ishida
T
T
Takahara
J
J
D001013:Aorta, Thoracic / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015153:Blotting, Western; D002352:Carrier Proteins; D002478:Cells, Cultured; D008076:Cholesterol, HDL / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D008075:Lipoproteins, HDL / Q000378:metabolism; D008565:Membrane Proteins; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism*; D016601:RNA-Binding Proteins; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000235:genetics; D018110:Receptors, Lipoprotein / Q000096:biosynthesis* / Q000235:genetics; D051116:Receptors, Scavenger; D011994:Recombinant Proteins; D051122:Scavenger Receptors, Class B; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D002352:Carrier Proteins; D008076:Cholesterol, HDL; D016207:Cytokines; D008075:Lipoproteins, HDL; D008565:Membrane Proteins; D016601:RNA-Binding Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D011994:Recombinant Proteins; C495124:SCARB1 protein, human; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D016212:Transforming Growth Factor beta; C031616:high density lipoprotein receptors; C075197:high density lipoprotein binding protein; D007371:Interferon-gamma