Abstract
Increased production of plasminogen activator inhibitor-1 (PAI-1) in plaques plays a role in the pathogenesis of atherosclerosis. This study was conducted to investigate the effect of blockade of Rho/Rho-kinase signaling on the synthesis of PAI-1 in cultured human peripheral blood monocytes. HMG-CoA reductase inhibitors (statins) and inhibitors of Rho and Rho-kinase were added to monocyte cultures. The levels of PAI antigen and mRNA were determined by Western blotting and RT-PCR, respectively, and PAI-1 expression was assessed by immunohistochemistry. We performed pull-down assays to determine the activity of Rho by measuring the GTP-bound form of Rho A. In unstimulated and lipopolysaccharide (LPS)-stimulated cultured monocytes, statins reduced the levels of PAI-1 antigen and mRNA. The suppressive effects of statins on PAI-1 synthesis were reversed by geranylgeranylpyrophosphate (GGPP) and were mimicked by C3 exoenzyme. Immunohistochemistry confirmed the role of lipid modification by GGPP in suppressive effect of statins in PAI-1 synthesis. Pull-down assays demonstrated that statins decreased the levels of the GTP-bound form of Rho A. Our findings suggest that statins decrease the activity of Rho by inhibiting geranylgeranylation. Moreover, Rho-kinase inhibitors, Y-27632 and fasudil, suppressed the synthesis of PAI-1 in this culture system. We show that inhibition of Rho/Rho-kinase signaling downregulates the synthesis of PAI-1 in human monocytes.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / analogs & derivatives*
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / pharmacology
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ADP Ribose Transferases / pharmacology
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Amides / pharmacology
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Arteriosclerosis / etiology
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Base Sequence
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Botulinum Toxins*
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Cells, Cultured
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Enzyme Inhibitors / pharmacology
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Humans
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Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology
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Intracellular Signaling Peptides and Proteins
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Monocytes / drug effects
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Monocytes / metabolism*
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Plasminogen Activator Inhibitor 1 / biosynthesis*
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Plasminogen Activator Inhibitor 1 / genetics
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Polyisoprenyl Phosphates / pharmacology
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Pravastatin / pharmacology
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Protein Prenylation / drug effects
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Protein Serine-Threonine Kinases / antagonists & inhibitors
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Protein Serine-Threonine Kinases / metabolism*
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Pyridines / pharmacology
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Signal Transduction / drug effects
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rho GTP-Binding Proteins / metabolism*
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rho-Associated Kinases
Substances
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Amides
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Enzyme Inhibitors
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Hydroxymethylglutaryl-CoA Reductase Inhibitors
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Intracellular Signaling Peptides and Proteins
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Plasminogen Activator Inhibitor 1
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Polyisoprenyl Phosphates
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Pyridines
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RNA, Messenger
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Y 27632
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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cerivastatin
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ADP Ribose Transferases
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exoenzyme C3, Clostridium botulinum
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Protein Serine-Threonine Kinases
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rho-Associated Kinases
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Botulinum Toxins
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rho GTP-Binding Proteins
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Pravastatin
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geranylgeranyl pyrophosphate
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fasudil