Expression of retinoic acid-inducible gene-I (RIG-I) in macrophages: possible involvement of RIG-I in atherosclerosis.
OBJECTIVE
Retinoic acid-inducible gene-I (RIG-I) is one of the genes induced by interferon (IFN)-gamma which plays an important role in atherosclerosis. The aim of this study is to examine if RIG-I is involved in atherosclerosis.


METHODS
The expression of RIG-I in atherosclerotic lesions in human aorta was examined by immunohistochemical analysis. The expression of RIG-I in THP-1 monocytic cell line or human monocyte-derived macrophages was studied by western blot and RT-PCR analyses.


RESULTS
Intense immunoreactivity for RIG-I was detected in intimal macrophages in atherosclerotic lesions. IFN-gamma slightly enhanced the RIG-I expression in THP-1 cells. Treatment of the cells with phorbol 12-myristate 13-acetate, which induces the differentiation of the cells into macrophage-like cells, significantly enhanced the IFN-gamma -induced RIG-I expression. IFN-gamma also stimulated the expression of RIG-I in monocyte-derived macrophages.


CONCLUSIONS
These results suggest that RIG-I may be involved in differentiation and activation of macrophages, playing a role in atherosclerosis.
Imaizumi
Tadaatsu
T
Department of Vascular Biology, Hirosaki University School of Medicine, Hirosaki, Japan. timaizum@cc.hirosaki-u.ac.jp
Yagihashi
Norito
N
Kubota
Kosei
K
Yoshida
Hidemi
H
Sakaki
Hirotaka
H
Yagihashi
Soroku
S
Kimura
Hiroto
H
Satoh
Kei
K
D001011:Aorta / Q000378:metabolism / Q000473:pathology; D050197:Atherosclerosis / Q000378:metabolism* / Q000473:pathology; D015153:Blotting, Western; D002460:Cell Line; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism*; D011971:Receptors, Immunologic; D017539:Tunica Intima / Q000378:metabolism / Q000473:pathology
D011971:Receptors, Immunologic; D007371:Interferon-gamma; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases