Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IL-6, a proinflammatory cytokine, has been implicated in the development of vascular diseases. We previously demonstrated that mechanical stress can initiate signaling pathways leading to smooth muscle cell (SMC) proliferation and apoptosis, but little is known concerning cyclic stress-induced inflammatory response. To explore the role of stretch in the upregulation of cytokine expression in SMCs we performed RNase protection assay for a panel of cytokines and found that mechanical stress resulted in a time-dependent induction of IL-6 mRNA but not other cytokines, e.g., IL-1alpha, IL-1beta, IL-6, IL-10, IL-12p35, IL-12p40, IL-18, IFN-gamma, and macrophage migration inhibitory factor (MIF). This induction also correlated with elevated IL-6 protein levels in the supernatant. Pretreatment of the cells with NF-kappaB inhibitors inhibited NF-kappaB activity and resulted in marked inhibition (50%) of IL-6 protein. Moreover, SMC lines stably expressing dominant-negative Ras (RasN17) or Rac (RacN17) exhibited a remarkable decrease in p38 MAPK activity and IL-6 mRNA induction by mechanical stress. Furthermore, a significant inhibition of 30 and 40% in IL-6 protein was observed in SMCs pretreated with inhibitors of p38 MAPK and ERK1/2, respectively, but not JNK. Interestingly, SMCs isolated from PKC-delta-deficient mice exhibited higher levels of IL-6 compared with wild-type cells. Finally, high levels of IL-6 expression were observed in atherosclerotic lesions of vein bypass grafts, which are related to altered biomechanical stress. Our findings demonstrate that biomechanical stress-induced IL-6 expression occurs via a mechanism that involves Ras/Rac/p38 MAPK/NF-kappaB/NF-IL6 signaling pathways, which is downregulated by PKC-delta, and suggest that modulation of this event contributes to the pathogenesis of atherosclerosis.
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PMID:Biomechanical stress induces IL-6 expression in smooth muscle cells via Ras/Rac1-p38 MAPK-NF-kappaB signaling pathways. 1568 96

Cigarette smoke, specifically the nicotine contained within, has been shown to cause ultrastructural changes in vascular endothelium resulting in the development of atherosclerosis. Our study examines the effects of nicotine on vascular smooth muscle cell (VSMC) migration and attempts to eludicidate the cellular mechanisms governing those effects. Bovine aortic VSMC were cultured in 10% fetal bovine serum (FBS) growth media and exposed to 10(-8) nicotine for varying periods of time. Boyden chamber chemotaxis assays and a scrape injury model using confluent cells were used to assess cell motility. Activation of the mitogen-activated protein kinases (MAPK), p38 and p44/42, was assessed using Western blotting methods. Nicotine, itself, did not cause significant VSMC migration. However, augmented migration was seen in nicotine-treated VSMCs (16.6+/-3-fold) and media (17.0+/-4-fold) with 10% FBS as chemoattractant. Inhibitors of p38 and p44/42 diminished this migration by 48.5+/-6% and 29.4+/-2%, respectively. Immunoblotting verified p38 and p44/42 activation with nicotine and inhibition with inhibitors of p38 and p44/42. Nicotine-treated endothelial cell (EC) conditioned media (CM) was shown to increase migration 20.3+/-l.l-fold. This chemotactic effect was diminished both with heat treatment and serial dilution. In conclusion, nicotine enhances the chemoatactiveness of VSMC. This migration is mediated via the MAPKs p38 and p44/42. Nicotine causes EC production of a chemoattractant molecule that enhances VSMC migration.
Atherosclerosis 2005 Feb
PMID:Nicotine induces mitogen-activated protein kinase dependent vascular smooth muscle cell migration. 1569 34

Regions in the vasculature that are exposed to steady laminar blood flow are protected from atherosclerosis as compared with regions where flow is disturbed. We found that flow decreased TNF-mediated VCAM1 expression by inhibiting JNK and p38. JNK inhibition correlated with inhibition of apoptosis signal-regulating kinase 1 (ASK1), a JNK and p38 activator. Thioredoxin-interacting protein (TXNIP) is a stress-responsive protein that inhibits thioredoxin (TRX) activity. Since thioredoxin inhibits ASK1, we hypothesized that changes in TXNIP-TRX-ASK1 interactions mediate the antiinflammatory effects of flow. To explore this, we used perfused vessels and cultured ECs. Exposure of rabbit aortae or ECs to normal flow (12 dyn/cm2, 24 hours) was associated with decreased TXNIP expression and increased TRX activity compared with exposure to low flow (0.4 dyn/cm2). Normal flow inhibited TNF activation of JNK/p38 and VCAM1 expression. In cultured ECs, reduction of TXNIP expression by small interfering RNA increased TRX binding to ASK1 and inhibited TNF activation of JNK/p38 and VCAM1 expression. Conversely, overexpression of TXNIP stimulated JNK and p38. In aortae from TXNIP-deficient mice, TNF-induced VCAM1 expression was inhibited. The data suggest that TXNIP and TRX are key components of biomechanical signal transduction and establish them as potentially novel regulators of TNF signaling and inflammation in ECs.
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PMID:Fluid shear stress inhibits vascular inflammation by decreasing thioredoxin-interacting protein in endothelial cells. 1569 99

Recent data have indicated that CRP (C-reactive protein) plays a role in atherosclerosis, in addition to being a marker for inflammatory diseases. IL-8 (interleukin-8), a CXC chemokine, is present in human coronary atheroma and promotes monocyte-endothelial cell adhesion. In the present study, we examined the effect of pitavastatin (NK-104), a synthetic statin (3-hydroxy-3-methylglutaryl CoA reductase inhibitor), on IL-8 production induced by CRP in human AoEC (aortic endothelial cells). We also investigated whether CRP can induce IL-8 production and if the activation of signalling pathways are functionally related. The concentrations of IL-8 in the media after stimulation with CRP were measured by ELISA, and the expression of IL-8 mRNA was assessed by Northern blot. The phosphorylation of MAPKs (mitogen-activated protein kinases) was determined by Western blot. The production of IL-8 induced by CRP (10 microg/ml) was enhanced significantly and was inhibited by pitavastatin. The expression of IL-8 mRNA was increased in a dose-dependent manner after stimulation with CRP (1-100 microg/ml), whereas expression of IL-8 mRNA induced by CRP (50 microg/ml) was significantly diminished by 5 microM pitavastatin. Furthermore, specific MAPK inhibitors (PD98059, SB203580 and SP600125) inhibited the expression of IL-8 mRNA induced by CRP (50 microg/ml). The phosphorylation of all three MAPKs [ERK (extracellular-signal-regulated kinase), p38 MAPK and JNK (c-Jun N-terminal kinase)] induced by CRP (10 microg/ml) was also significantly inhibited by pitavastatin. Our results suggest that CRP may play a role in atherosclerosis via IL-8 production and pitavastatin may prevent the progression of atherosclerosis not only by lowering plasma low-density lipoprotein cholesterol levels, but also by suppressing IL-8 production in endothelial cells through the inhibition of MAPK (ERK, p38 MAPK and JNK) pathways.
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PMID:Inhibitory effect of pitavastatin (NK-104) on the C-reactive-protein-induced interleukin-8 production in human aortic endothelial cells. 1570 Oct 58

The hypertrophy of vascular smooth muscle cells (VSMCs) is critical in vascular remodeling associated with hypertension, atherosclerosis, and restenosis. Recently, leptin has appeared to play a pivotal role in vascular remodeling. However, the mechanism by which leptin induces hypertrophy in vascular smooth muscle cells is still unknown. We studied the role of leptin as a potential hypertrophic factor in rat VSMCs. In the present study, leptin significantly increased [(3)H]leucine incorporation and the total protein/DNA ratio in VSMCs. The maximal hypertrophic effect was at 100ng/ml of leptin. Leptin induced phosphorylation and activation of p38 mitogen-activated protein (p38 MAP) kinase and of signal transducers and activators of transcription 3 in a concentration- and time-dependent manner. A p38 MAP kinase inhibitor SB203580 significantly inhibited leptin-induced hypertrophy, AG490 (a JAK2 inhibitor) partially inhibited it, and other MAP kinase inhibitors, PD98059 (an ERK inhibitor) and SP600125 (a JNK inhibitor), had no effect. These results indicate that leptin directly stimulates cellular hypertrophy via p38 MAP kinase in rat VSMCs.
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PMID:Leptin induces hypertrophy via p38 mitogen-activated protein kinase in rat vascular smooth muscle cells. 1572 Dec 67

Arsenic exposure is associated with an increased risk of atherosclerosis and vascular diseases. Although endothelial cells have long been considered to be the primary targets of arsenic toxicity, the underlying molecular mechanism remains largely unknown. In this study, we sought to explore the signaling pathway triggered by sodium arsenite and its implication for endothelial phenotype. We found that sodium arsenite produced time- and dose-dependent decreases in human umbilical vein endothelial cell viability. This effect correlated with the induction of p21Cip1/Waf1 (up to 10-fold), a regulatory protein of cell cycle and apoptosis. We also found that arsenite-stimulated EGF (ErbB1) and ErbB2 receptor transactivation, manifest as receptor tyrosine phosphorylation, appeared to be a proximal signaling event leading to p21Cip1/Waf1 induction, because both pharmacological inhibitors and knockdown of receptors by RNA interference blocked arsenite-induced p21Cip1/Waf1 upregulation. Arsenite-induced activation of JNK and p38 MAPK was distinct, with only JNK as a downstream target of the EGF receptor. Moreover, inhibition of JNK with SP-600125 or dominant negative MKK7 inhibited only p21Cip1/Waf1 induction, whereas the p38 MAPK inhibitor SB-203580 or dominant negative MKK4 inhibited both p21Cip1/Waf1 and p53 induction. Functionally, inhibition of p21Cip1/Waf1 induction prevented endothelial apoptosis due to arsenite treatment. Insofar as endothelial dysfunction promotes vascular disease, these data provide a mechanism for the increased incidence of cardiovascular disease due to arsenite exposure.
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PMID:EGF receptor-dependent JNK activation is involved in arsenite-induced p21Cip1/Waf1 upregulation and endothelial apoptosis. 1573 84

Inflammation and leukocyte activation/infiltration play a major role in the initiation and progression of cardiovascular diseases including atherosclerosis and heart failure. Acute p38 mitogen-activated protein kinase (MAPK) pathway inhibition attenuates tissue damage and leukocyte accumulation in myocardial ischemia/reperfusion injury, although its effect on the acute phase of leukocyte recruitment has not been elucidated. The purpose of this study was to test the hypothesis that acute treatment of rats with a selective p38 inhibitor, SB-239063, inhibits ischemia/reperfusion-induced leukocyte-endothelial adhesion in vivo. Male Sprague-Dawley rats were treated with either SB-239063 (10 mgkg(-1)), dexamethasone (3 mgkg(-1)) or vehicle 1h prior to ischemia. Postcapillary venules were observed microscopically in exteriorized, superfused cremaster tissue. Leukocytes were fluorescently labeled in vivo using intravenous rhodamine 6G. Leukocyte adhesion, rolling, and rolling velocities were quantitated prior to 30 min ischemia, and at several time points during a 90 min reperfusion period. Ischemia caused a 3-fold increase in adherent leukocytes 5 min following reperfusion, a response that was maintained throughout the monitoring period (90 min) in vehicle-treated animals. SB-239063, at a dose known to inhibit p38 MAPK activity in vivo (10 mgkg(-1)), had no effect on ischemia/reperfusion-induced leukocyte adhesion, the number of rolling leukocytes, rolling velocities during the reperfusion period or adhesion molecule expression (P-, E-selectin, VCAM-1, ICAM-1). In contrast, dexamethasone completely blocked leukocyte adhesion in response to ischemia/reperfusion, and reduced expression of E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). We conclude that p38 MAPK may not play a role in initial leukocyte recruitment in response to ischemia/reperfusion injury, but could affect leukocyte emigration, thereby resulting in increased leukocyte accumulation in ischemic-reperfused tissue.
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PMID:Role of p38 MAP kinase in postcapillary venule leukocyte adhesion induced by ischemia/reperfusion injury. 1574 61

Atherosclerotic plaque forms in regions of the vasculature exposed to disturbed flow. NF-kappaB activation by fluid flow, leading to expression of target genes such as E-selectin, ICAM-1, and VCAM-1, may regulate early monocyte recruitment and fatty streak formation. Flow-induced NF-kappaB activation is downstream of conformational activation of integrins, resulting in new integrin binding to the subendothelial extracellular matrix and signaling. Therefore, we examined the involvement of the extracellular matrix in this process. Whereas endothelial cells plated on fibronectin or fibrinogen activate NF-kappaB in response to flow, cells on collagen or laminin do not. In vivo, fibronectin and fibrinogen are deposited at atherosclerosis-prone sites before other signs of atherosclerosis. Ligation of integrin alpha2beta1 on collagen prevents flow-induced NF-kappaB activation through a p38-dependent pathway that is activated locally at adhesion sites. Furthermore, altering the extracellular matrix to promote p38 activation in cells on fibronectin suppresses NF-kappaB activation, suggesting a novel therapeutic strategy for treating atherosclerosis.
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PMID:The subendothelial extracellular matrix modulates NF-kappaB activation by flow: a potential role in atherosclerosis. 1580 8

Reactive oxygen species, such as superoxide anion (O2-) and hydrogen peroxide (H2O2), may act as second messengers of intracellular signaling and play a key role in the pathogenesis of atherosclerosis. The nuclear factor kappaB (NF-kappa B) is a redox-sensitive transcription factor that is involved in this process. The aim of the present study was to investigate the molecular mechanisms of action of statins on cultured vascular smooth muscle cells (VSMC) and monocytic cells (THP-1) under oxidative stress. In THP-1 and cultured VSMC, O2- caused an increase in NF-kappa B activation (P < 0.05) that was correlated with inhibitory I kappa B-alpha degradation. Atorvastatin or simvastatin decreased NF-kappa B activation induced by oxidative stress by around 50% in both cell types and was correlated with the I kappa B-alpha levels. In monocytes, O2- increased I kappa B kinase (IKK)-1 and IKK-2 activity (P < 0.05) and p38 and p42/44 activation and phosphorylation, which was reduced by statins. PD 98059 (p42/44 inhibitor) and SB20358 (p38 inhibitor) decreased NF-kappa B binding activity and prevented I kappa B-alpha degradation. However, we only observed a reduction in IKK-1 and IKK-2 activity with PD98059. Statins diminish NF-kappa B activation elicited by oxidative stress through the inhibition of IKK-1/-2, p38, and p42/44 activation. These data may help to further understand the molecular mechanisms of statins in cardiovascular disease.
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PMID:HMG-CoA reductase inhibitors reduce I kappa B kinase activity induced by oxidative stress in monocytes and vascular smooth muscle cells. 1582 43

Vascular smooth muscle cells (VSMCs) express functional interleukin-18 receptors (IL-18Rs), composed of alpha and beta subunits. These subunits are elevated in VSMCs of atherosclerotic plaques and can be induced by inflammatory agents in cultured VSMC. Because both IL-18 and Angiotensin II (Ang II) are implicated in atherosclerosis, our objective was to analyze the role of IL-18 signaling and potential cross-talk with Ang II in VSMC. We observed that IL-18 activated Src kinase, protein kinase C, p38 and JNK MAPKs, Akt kinase, transcription factors NF-kB and AP-1, and induced expression of pro-inflammatory cytokines in VSMC. Pretreatment of VSMC with Ang II enhanced IL-18-induced NF-kB activation and cytokine gene expression. Interestingly, Ang II directly increased mRNA and cell surface protein levels of the IL-18Ralpha subunit. Functional relevance in an organ culture model was demonstrated by the observation that incubation of intact mouse aortas ex vivo with Ang II also significantly increased IL-18Ralpha expression. Furthermore, Ang II significantly stimulated transcription from a minimal IL-18Ralpha promoter containing putative binding sites for STAT and AP-1. Ang II also increased in vivo recruitment of STAT-3 on the IL-18Ralpha promoter. Finally, dominant negative STAT-3 mutant blocked Ang II-induced IL-18Ralpha promoter activation in CHO cells overexpressing AT1a receptor and IL-18Ralpha mRNA expression in HVSMC. Thus, Ang II enhances IL-18 induced inflammatory genes by increasing IL-18Ralpha expression. These results illustrate a novel mechanism wherein Ang II- mediated increases in inflammatory genes and proatherogenic effects in the vasculature are enhanced by a vicious loop and cross-talk with the IL-18 signaling pathway.
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PMID:Angiotensin II enhances interleukin-18 mediated inflammatory gene expression in vascular smooth muscle cells: a novel cross-talk in the pathogenesis of atherosclerosis. 1586 Jul 56


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