Effects of histamine and interleukin-4 synthesized in arterial intima on phagocytosis by monocytes/macrophages in relation to atherosclerosis.
We investigated the localization of histidine decarboxylase (HDC), which is the rate-limiting enzyme that generates histamine from histidine, in human aorta/coronary artery. RT-PCR and immunohistochemical staining revealed that the HDC gene was expressed in monocytes/macrophages and T cells in the arterial intima but not in smooth muscle cells in either the arterial intima or the media. A luciferase promoter assay with U937 and Jurkat cells demonstrated that interleukin-4 (IL-4) inhibited the expression of the HDC gene. In contrast, among a scavenger receptor family, IL-4 as well as histamine up-regulated U937 cells to express the LOX-1 gene but not the SR-A gene, which genes encode receptors that scavenge oxidized lipids. These findings suggest that histamine synthesized in the arterial wall participates in the initiation and progression of atherosclerosis and that IL-4 can act as an important inhibitory and/or stimulatory factor in the function of monocytes/macrophages modulated by histamine in relation to the process of atherosclerosis.
Higuchi
S
S
Department of Orolaryngology, School of Medicine, University of Occupational and Environmental Health, 101 Iseigaoka, Yahatanashi, Kitakyushu 807-8555, Japan.
Tanimoto
A
A
Arima
N
N
Xu
H
H
Murata
Y
Y
Hamada
T
T
Makishima
K
K
Sasaguri
Y
Y
D001161:Arteriosclerosis / Q000378:metabolism*; D015152:Blotting, Northern; D003001:Cloning, Molecular; D017930:Genes, Reporter; D006632:Histamine / Q000494:pharmacology*; D006640:Histidine Decarboxylase / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015847:Interleukin-4 / Q000378:metabolism / Q000494:pharmacology*; D019169:Jurkat Cells; D008156:Luciferases / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D009000:Monocytes / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010587:Phagocytosis; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014162:Transfection; D017539:Tunica Intima / Q000378:metabolism*; D020298:U937 Cells; D015854:Up-Regulation
D015847:Interleukin-4; D006632:Histamine; D008156:Luciferases; D006640:Histidine Decarboxylase; D010100:Oxygen