RhoA-dependent PAI-1 gene expression induced in endothelial cells by monocyte adhesion mediates geranylgeranyl transferase I and Ca2+ signaling.
We investigated the role of RhoA activation and its mechanism in plasminogen activator inhibitor-1 (PAI-1) gene expression induced in endothelial cells by monocyte adhesion. Isolated human peripheral blood monocytes were added to cultured human coronary endothelial cells. Monocyte adhesion to endothelial cells increased PAI-1 expression at the transcriptional level and activated RhoA which was accompanied by an increase in the activity of geranylgeranyl transferase I (GGTase I), an enzyme responsible for geranylgeranylation, and actin stress fiber formation. Inhibition of RhoA by C3 exoenzyme or by adenovirus-mediated expression of N19RhoA, as well as by pravastatin, prevented the upregulation of PAI-1 induced by monocyte adhesion. GGTI-286, an inhibitor of GGTase I, prevented the monocyte-induced RhoA activation and PAI-1 expression in endothelial cells. Monocyte attachment induced an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in endothelial cells and Ca(2+) chelation prevented the increased promoter activity and expression of PAI-1 induced by monocyte adhesion. C3 exoenzyme and GGTI-286 also suppressed endothelial intracellular Ca(2+) mobilization and Ca(2+) entry induced by monocytes. The present study shows that GGTase I plays a role in the RhoA activation in endothelial cells induced by monocyte adhesion and that GGTase I-mediated Ca(2+) signaling may contribute to RhoA-dependent PAI-1 gene expression.
Sakamoto
Takayuki
T
First Department of Internal Medicine, Fukushima Medical University, Fukushima, Japan.
Ishibashi
Toshiyuki
T
Sugimoto
Koichi
K
Sakamoto
Nobuo
N
Ohkawara
Hiroshi
H
Niinuma
Miki
M
Nagata
Kenji
K
Kamioka
Masashi
M
Sugimoto
Naotoshi
N
Watanabe
Atai
A
Kurabayashi
Masahiko
M
Takuwa
Yoh
Y
Maruyama
Yukio
Y
D000199:Actins / Q000378:metabolism; D019883:Alkyl and Aryl Transferases / Q000378:metabolism*; D020013:Calcium Signaling; D002448:Cell Adhesion; D002478:Cells, Cultured; D018920:Coculture Techniques; D003599:Cytoskeleton / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D017035:Pravastatin / Q000494:pharmacology; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
D000199:Actins; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; C051321:SERPINE1 protein, human; D019883:Alkyl and Aryl Transferases; C083291:geranylgeranyltransferase type-I; D020742:rhoA GTP-Binding Protein; D017035:Pravastatin