Rho/Rho-Kinase Pathway Contributes to C-Reactive Protein–Induced Plasminogen Activator Inhibitor-1 Expression in Endothelial Cells

Abstract

Objective-Rho/Rho-kinase pathway plays pivotal roles in cardiovascular diseases including arteriosclerosis and hypertension. Recently it has become evident that C-reactive protein (CRP), a powerful marker for cardiovascular events, has direct proatherothrombotic effects on vascular cells. However, its molecular mechanism has not been fully investigated. We examined the involvement of Rho/Rho-kinase signaling in CRP-induced plasminogen activator inhibitor-1 (PAI-1) expression in bovine aortic endothelial cells (BAECs). Methods and Results-PAI-1 expression was determined by Western blotting. RhoA activation was determined by an affinity pull-down assay using Rho-binding fragment of rhotekin. NF-B activity was determined using the luciferase reporter gene. A ccumulating evidence suggests that inflammation plays a significant role in the development and progression of atherosclerosis. 1,2 Several plasma markers of inflammation have been evaluated as potential tools for the prediction of the risk of future cardiovascular events and, of these, the most reliable and accessible for clinical use is currently highsensitive C-reactive protein (CRP). 3,4 Recently, CRP was shown to elicit a multitude of effects on endothelial biology favoring proinflammatory and proatherosclerotic phenotypes. These include the expression of adhesion molecules, the stimulation of the release of inflammatory chemokine/cytokine, and the reduction of nitric oxide bioactivity and prostacyclin release in endothelial cells. 4,5 CRP was also able to increase the expression and activity of plasminogen activator inhibitor-1 (PAI-1), a member of the serine protease inhibitors and a marker of impaired fibrinolysis and atherothrombosis, in human aortic endothelial cells. 6 The atherothrombotic effects on PAI-1 expression by CRP were confirmed in vivo by the result that human CRP-transgenic mice (CRP-tg) showed a prothrombotic phenotype, as evidenced by higher rates of thrombotic occlusion after arterial injury. 7 CRP was also shown to possess similar proatherogenic properties toward vascular smooth muscle cells (VSMCs) and monocyte-macrophages, 5 strongly indicating that CRP is not only a biomarker of atherosclerotic events but is also a mediator of atherosclerosis.The molecular mechanisms involved in CRP-induced gene expression remain unknown, although one possible mechanism for this is via the activation of nuclear factor (NF)-B, 8 -10 a key mediator of atherosclerosis. 11,12 Rho/Rho-kinase signaling factors, initially identified as key molecules for Ca 2ϩ sensitization of smooth muscle contraction, 13,14 are known to be involved in the signal cascades related to inflammation including the NF-B pathway, 15 and several experimental models revealed the involvement of this signaling in the development of vascular remodeling and atherosclerosis. 16 The aim of the present investigation is to clarify whether the Rho/Rho-kinase signaling pathway is involved in PAI-1 expression by CRP in bovine aorta endothelial cells (BAECs). We demonstrated in this study tha...

Effect of Rosuvastatin on ROCK Activity, Endothelial Function, and Inflammation in Asian Patients with Atherosclerosis

“…Our experimental data showed a correlation between an anti-inflammatory effect measured as the reduction in hsCRP and ROCK inhibition (p<0.05) in the rosuvastatin 40 mg group. This result supports the hypothesis that the Rho/Rho-kinase pathway may be involved in CRP-induced atherothrombogenesis (32). ROCK inhibition mediates the anti-inflammatory effects of statins, and the clinical benefit is observed in patients with elevated CRP levels treated with intensive statin therapy (33).…”

HDL3, but not HDL2, stimulates plasminogen activator inhibitor-1 release from adipocytes: the role of sphingosine-1-phosphate

“…Analysis of endogenous sphingoid bases, sphingoid base-1-phosphates, and ceramide kinase (MAPK), protein kinase C (PKC), and Rho kinase (7)(8)(9)(10). Results from in vitro studies have shown that insulin and isolated lipoproteins, especially tri glyceride-rich lipoproteins, stimulate PAI-1 production by cultured endothelial cells and hepatocytes ( 11,12 ).…”

Endothelial Nitric Oxide Synthase Keeps Erection Regulatory Function Balance in the Penis

“…RhoA activation was assessed using a precipitation assay for RhoA-GTP in the membrane fraction, according to the manufacturer's instructions (Upstate Biotechnology, Lake Placid, NY). RhoA activation was expressed as a percentage of WT control RhoA activation [19].…”