Endogenous NO blockade enhances tissue factor expression via increased Ca2+ influx through MCP-1 in endothelial cells by monocyte adhesion.
OBJECTIVE
Ca2+ plays an important role in tissue factor (TF) gene expression. We investigated the role of endogenous nitric oxide (NO) in the induction of TF expression in endothelial cells (ECs) by monocyte adhesion and the mechanisms of NO action.


RESULTS
Inhibition of endogenous NO by Nomega-nitro-L-arginine methyl ester (L-NAME) enhanced TF promoter activity and protein expression induced in human coronary ECs by monocyte adhesion, as well as EC surface TF activity. L-NAME also induced monocyte chemoattractant protein-1 (MCP-1) expression, which was blocked by an NO donor, NOC18. Exogenous MCP-1 enhanced TF expression induced by monocyte adhesion, whereas adenovirus-mediated expression of the mutant MCP-1, 7ND, abolished the L-NAME enhancement of TF expression induced by monocyte adhesion. Monocyte attachment to L-NAME-treated ECs increased Ca2+ influx, which was prevented by NOC18, anti-MCP-1 antibody or 7ND. These results indicate that the binding of increased MCP-1 induced by endogenous NO blockade to CCR2 mediated the enhancement of Ca2+ influx only when monocytes adhered to ECs, which upregulated TF expression in ECs triggered by monocyte adhesion.


CONCLUSIONS
MCP-1/CCR2 may play a role in Ca2+ influx-dependent TF regulation in the monocyte-EC interaction in the impairment of NO synthesis.
Sakamoto
Takayuki
T
First Department of Internal Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
Ishibashi
Toshiyuki
T
Sakamoto
Nobuo
N
Sugimoto
Koichi
K
Egashira
Kensuke
K
Ohkawara
Hiroshi
H
Nagata
Kenji
K
Yokoyama
Keiko
K
Kamioka
Masashi
M
Ichiki
Toshihiro
T
Sugimoto
Naotoshi
N
Kurabayashi
Masahiko
M
Suzuki
Koji
K
Takuwa
Yoh
Y
Maruyama
Yukio
Y
D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology; D002448:Cell Adhesion / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D003331:Coronary Vessels / Q000166:cytology; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018014:Gene Transfer Techniques; D006801:Humans; D009000:Monocytes / Q000166:cytology* / Q000276:immunology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013925:Thromboplastin / Q000378:metabolism*
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D013925:Thromboplastin; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester