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

Vascular smooth muscle cells play a key role in the development of atherosclerosis. Culture of vascular smooth muscle A10 cells with high glucose for 4 weeks enhanced platelet-derived growth factor (PDGF)-induced BrdU incorporation. Since a long period of high glucose incubation was required for the effect, and it was inhibited by co-incubation with azaserine, the role of hexosamine biosynthesis in the development of atherosclerosis in diabetes was studied in A10 cells. Addition of glucosamine to the culture media enhanced PDGF-stimulated BrdU incorporation, and PDGF-induced tyrosine phosphorylation of the PDGF beta-receptor was increased by glucosamine treatment. Of the subsequent intracellular signaling pathways, PDGF-induced PDGF beta-receptor association with PLC gamma was not affected, whereas tyrosine phosphorylation of Shc, subsequent association of Shc with Grb2, and MAP kinase activation were relatively decreased. In contrast, PDGF-induced PDGF beta-receptor association with the p85 regulatory subunit of PI3-kinase and PI3-kinase activation were increased by 20% (P<0.01) and 36% (P<0.01), respectively. The intracellular signaling molecules responsible for the glucosamine effect were further examined using pharmacological inhibitors. Pretreatment with PLC inhibitor (U73122) had negligible effects, and MEK1 inhibitor (PD98059) showed only a slight inhibitory effect on the PDGF-induced BrdU incorporation. In contrast, pretreatment with PI3-kinase inhibitor (LY294002) significantly inhibited glucosamine enhancement of PDGF-induced BrdU incorporation. These findings suggest that glucosamine is involved in the development of atherosclerosis by enhancing PDGF-induced mitogenesis specifically via the PI3-kinase pathway.
Atherosclerosis 2001 Aug
PMID:Glucosamine enhances platelet-derived growth factor-induced DNA synthesis via phosphatidylinositol 3-kinase pathway in rat aortic smooth muscle cells. 1147 33

Atherosclerosis preferentially occurs in areas of turbulent flow and low fluid shear stress, whereas laminar flow and high shear stress are atheroprotective. Inflammatory cytokines, such as tumor necrosis factor-alpha (TNF), have been shown to stimulate expression of endothelial cell (EC) genes that may promote atherosclerosis. Recent data suggest that steady laminar flow decreases EC apoptosis and blocks TNF-mediated EC activation. EC apoptosis is likely important in the process termed "plaque erosion" that leads to platelet aggregation. Steady laminar flow inhibits EC apoptosis by preventing cell cycle entry, by increasing antioxidant mechanisms (e.g., superoxide dismutase), and by stimulating nitric oxide-dependent protective pathways that involve enzymes PI3-kinase and Akt. Conversely, our laboratory has identified nitric oxide-independent mechanisms that limit TNF signal transduction. TNF regulates gene expression in EC, in part, by stimulating mitogen-activated protein kinases (MAPK) which phosphorylate transcription factors. We hypothesized that fluid shear stress modulates TNF effects on EC by inhibiting TNF-mediated activation of MAP kinases. To test this hypothesis, we determined the effects of steady laminar flow (shear stress = 12 dynes/cm2) on TNF-stimulated activity of two MAP kinases: extracellular signal regulated kinase (ERK1/2) and c-Jun N-terminal kinase (JNK). Flow alone stimulated ERK1/2 activity, but decreased JNK activity compared to static controls. TNF (10 ng/ml) alone activated both ERK1/2 and JNK maximally at 15 minutes in human umbilical vein EC (HUVEC). Pre-exposing HUVEC for 10 minutes to flow inhibited TNF activation of JNK by 46%, but it had no significant effect on ERK1/2 activation. Incubation of EC with PD98059, a specific mitogen-activated protein kinase kinase inhibitor, blocked the flow-mediated inhibition of TNF activation of JNK. Flow-mediated inhibition of JNK was unaffected by 0.1 mM L-nitroarginine, 100 pM 8-bromo-cyclic GMP, or 100 microM 8-bromo-cyclic AMP. Transfection studies with dominant negative constructs of the protein kinase MEK1 and MEK5 suggested an important role for BMK1 in flow-mediated regulation of TNF signals. In summary, the atheroprotective effects of steady laminar flow on the endothelium involve multiple synergistic mechanisms.
 ...
PMID:Endothelial atheroprotective and anti-inflammatory mechanisms. 1179 13

Statins have been linked to a wide range of vascular benefits, many of them are likely to be due to attenuation of chronic vascular inflammation. Nuclear factor kappaB (NF-kappaB) is one of the key regulators of transcription of a variety of genes involved in immune and inflammatory responses. Therefore, we investigated the effect of statins on TNF-alpha-induced NF-kappaB signaling in human endothelial cells (EC). ECs were pre-incubated for 16 h with cerivastatin (10(-9) to 10(-7) M) or vehicle in the presence or absence of mevalonate, followed by stimulation with 20 ng/ml TNF-alpha. Statin-treatment prevented TNF-alpha-induced NF-kappaB binding activity, nuclear translocation of the NF-kappaB p65 subunit, as well as NF-kappaB controlled tissue factor (TF) gene transcription in cultured EC. IkappaBalpha phosphorylation and IkappaBalpha degradation, however, still occurred in statin-treated cells. TNF-alpha also activated phosphatidylinositol (PI)3-kinase, as reflected by phosphorylation of Akt. Statin treatment of cells abrogated TNF-alpha-induced Akt phosphorylation and p65 nuclear translocation. As observed with statins, inhibition of PI3-kinase activity by Ly294002 also blocked TNF-alpha-induced p65 translocation, but did not prevent IkappaBalpha phosphorylation nor IkappaBalpha degradation. These studies demonstrate that TNF-alpha-induced NF-kappaB activation is abrogated by statin treatment in HUVEC independently of the classical IKK-pathway but via inhibition of PI3-kinase/Akt signaling.
Atherosclerosis 2006 Apr
PMID:Statins prevent NF-kappaB transactivation independently of the IKK-pathway in human endothelial cells. 1605 Dec 51

Diabetes mellitus is one of the major risk factors for coronary artery disease (CAD). A recent study reported that glimepiride, a new third-generation sulfonylurea, inhibited the formation of atheromatous plaques in high-cholesterol fed rabbits. However, the mechanism by which glimepiride induces atheroprotection remains unknown. In the present study, we tested the hypothesis that glimepiride may stimulate NO production in vascular endothelial cells. Human coronary artery endothelial cells (HCAECs) were treated with glimepiride, glibenclamide or vehicle, and NO release was measured. Akt phosphorylation was evaluated by Western blot. The effects of LY294002, a specific PI3-kinase inhibitor, and antisense oligonucleotides directed to Akt, on glimepiride-induced NO production were examined. Glimepiride (0.1-10 microM), but not glibenclamide, induced NO production, significantly increasing it by 1.8-fold (n=6, p<0.05). LY294002 inhibited glimepiride-induced NO production by 68%. Akt was rapidly phosphorylated by glimepiride and antisense oligonucleotides directed to Akt completely inhibited glimepiride-induced NO production. These data demonstrate that glimepiride induces NO production in HCAECs by activating PI3-kinase and Akt, and also suggest that use of glimepiride in type 2 diabetes may show promise for preventing CAD in addition to lowering glucose levels.
Atherosclerosis 2005 Nov
PMID:Glimepiride induces nitric oxide production in human coronary artery endothelial cells via a PI3-kinase-Akt dependent pathway. 1621 90

Tissue factor (TF), formerly known as thromboplastin, is the key initiator of the coagulation cascade; it binds factor VIIa resulting in activation of factor IX and factor X, ultimately leading to fibrin formation. TF expression and activity can be induced in endothelial cells, vascular smooth muscle cells, and monocytes by various stimuli such as cytokines, growth factors, and biogenic amines. These mediators act through diverse signal transduction mechanisms including MAP kinases, PI3-kinase, and protein kinase C. Cellular TF is present in three pools as surface, encrypted, and intracellular protein. TF can also be detected in the bloodstream, referred to as circulating or blood-borne TF. Elevated levels of TF are observed in patients with cardiovascular risk factors such as hypertension, diabetes, dyslipidemia, and smoking as well as in those with acute coronary syndromes. TF may indeed be involved in the pathogenesis of atherosclerosis by promoting thrombus formation; in addition, it can induce migration and proliferation of vascular smooth muscle cells. As a consequence, therapeutic strategies have been developed to specifically interfere with the action of TF such as antibodies against TF, site-inactivated factor VIIa, or recombinant TF pathway inhibitor. Inhibition of TF action appears to be an attractive target for the treatment of cardiovascular diseases.
 ...
PMID:Tissue factor in cardiovascular diseases: molecular mechanisms and clinical implications. 1646 45

Increased tissue or serum levels of oxidized phospholipids have been detected in a variety of chronic and acute pathological conditions such as hyperlipidemia, atherosclerosis, heart attack, cell apoptosis, acute inflammation and injury. We have recently described signaling cascades activated by oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (OxPAPC)in the human pulmonary artery endothelial cells (EC) and reported potent barrier-protective effects of OxPAPC, which were mediated by small GTPases Rac and Cdc42. In this study we have further characterized signal transduction pathways involved in the OxPAPC-mediated endothelial barrier protection. Inhibitors of small GTPases, protein kinase A (PKA), protein kinase C (PKC), Src family kinases and general inhibitors of tyrosine kinases attenuated OxPAPC-induced barrier-protective response and EC cytoskeletal remodeling. In contrast, small GTPase Rho, Rho kinase, Erk-1,2 MAP kinase and p38 MAP kinase and PI3-kinase were not involved in the barrier-protective effects of OxPAPC. Inhibitors of PKA, PKC, tyrosine kinases and small GTPase inhibitor toxin B suppressed OxPAPC-induced Rac activation and decreased phosphorylation of focal adhesion kinase (FAK) and paxillin. Barrier-protective effects of OxPAPC were not reproduced by platelet activating factor (PAF), which at high concentrations induced barrier dysfunction, but were partially attenuated by PAF receptor antagonist A85783. These results demonstrate for the first time upstream signaling cascades involved in the OxPAPC-induced Rac activation, cytoskeletal remodeling and barrier regulation and suggest PAF receptor-independent mechanisms of OxPAPC-mediated endothelial barrier protection.
 ...
PMID:Signaling pathways involved in OxPAPC-induced pulmonary endothelial barrier protection. 1729 25

Intraplaque neovascularization contributes to the progression of atherosclerosis. Our aim is to understand the mobilization of cells and factors involved in this process. We investigated the localization of hepatocyte growth factor (HGF) and its receptor, c-Met, in human atherosclerotic plaques, together with the effects of HGF on pericyte migration in vitro. Atherosclerotic femoral arterial segments were collected and analysed from 13 subjects who were undergoing lower limb amputation. Pericytes were identified in human lesions using a 3G5 antibody. Immunohistochemical analysis localized HGF mainly around microvessels, in association with some, but not all, CD31-positive endothelial cells. c-Met expression was mainly associated with smooth muscle cells and pericytes, around some, but not all, microvessels within the atherosclerotic lesions; no detection was apparent in normal internal mammary arteries. Using RT-PCR, we demonstrated expression of HGF and c-Met in a rat pericyte cell-line, TR-PCT1, and in primary pericytes. HGF treatment of TR-PCT1 cells induced their migration, but not their proliferation, in a dose-dependent manner (10-100 ng/ml, p<0.01), an effect mediated by activation of the serine/threonine kinase Akt, shown by western blot analysis. Treating the cells with the PI3K inhibitors Wortmannin (0.1 microM) or LY294002 (10 microM) abolished these effects. This work demonstrates the expression of c-Met and HGF in human atherosclerotic arteries, in association with SM-actin-positive cells and CD-31-positive cells, respectively. HGF induces pericyte migration via PI3-kinase and Akt activation in vitro. HGF and c-Met may be involved in neovascularization during plaque development, and may recruit pericytes to neovessels. Since pericytes are thought to mechanically stabilize new blood vessels, these factors may function to protect against haemorrhage.
 ...
PMID:Hepatocyte growth factor and c-Met expression in pericytes: implications for atherosclerotic plaque development. 1740 87

In contrast to n-6 fatty acids like arachidonic acid (AA), the anti-inflammatory potential of n-3 fatty acids such as docosahexaenoic acid (DHA) has been demonstrated. We examined the phosphatidylinositol (PI)3-kinase dependent effects of AA versus DHA on monocyte rolling, adhesion and transmigration through inflammatory activated human umbilical venous endothelial cells (HUVEC) as well as on apoptosis, to investigate the impact on vascular inflammation. HUVEC were pre-incubated with AA, DHA or sham, and stimulated with VEGF, TNF-alpha or staurosporine. Rolling and adhesion were investigated by means of a parallel flow chamber; transmigration was performed in a static assay. Activation of PI3-kinase was measured as phosphorylation of protein kinase B (Akt). Apoptosis was determined by caspase-3 activity and annexin-V analysis. Pre-incubation of HUVEC with DHA markedly decreased TNF-alpha-induced monocyte rolling, adhesion, and transmigration, although expression of endothelial adhesion molecules was unchanged. In contrast, AA increased TNF-alpha-induced rolling. Both fatty acids did not alter TNF-alpha-mediated upregulation of the adhesion molecules ICAM-1, VCAM-1, and E-selectin. The divergent effects of AA and DHA were abrogated with PI3-kinase inhibitors. After pre-incubation with DHA, VEGF-, TNF-alpha- and staurosporine-induced phosphorylation of Akt was decreased when compared to AA. DHA pre-incubation significantly increased staurosporine-induced apoptosis. In addition, DHA in comparison to AA augmented staurosporine-mediated increase in caspase-3 activity. In conclusion, DHA-induced a reduction in rolling, adhesion and transmigration of monocytes through inflammatory activated HUVEC that is in part PI3-kinase dependent. PI3-kinase driven phosphorylation of Akt and apoptosis of HUVEC as contribution to the resolution of inflammation is differentially modulated by DHA versus AA.
Atherosclerosis 2008 Apr
PMID:Fatty acids differentially influence phosphatidylinositol 3-kinase signal transduction in endothelial cells: impact on adhesion and apoptosis. 1795 Feb 94

C-reactive protein (CRP) is an independent predictor of atherosclerosis and its complications. Monocytes/macrophages are implicated in this complex disease which is, among other mechanisms, characterised by angiogenesis. The aim of this study was to analyse whether CRP plays a role in VEGF-A regulation by monocytic cells. Our findings show that CRP up-regulates VEGF-A mRNA expression and protein excretion in THP-1 cells in a concentration- and time-dependent manner. Furthermore, we studied the signaling pathway underlying this effect. CRP increases VEGF-A expression via a PI3-kinase and an extracellular-signal-regulated kinase (ERK) 1/2 dependent pathway. Our results suggest that CRP could play a role in the angiogenesis process via immune cells such as monocytes.
Atherosclerosis 2008 Oct
PMID:C-reactive protein (CRP) increases VEGF-A expression in monocytic cells via a PI3-kinase and ERK 1/2 signaling dependent pathway. 1828 Apr 82

Endothelial cells (ECs) play an important role in hypoxia-induced vascular disorders. We investigated the acute hypoxia effect on endothelial expression of activating transcription factor 3 (ATF3), a stress-inducible transcription factor playing significant roles in cellular responses to stress. Bovine aortic ECs were subjected to acute hypoxia (1% O(2), pO(2)=8 mmHg) and ATF3 expression was examined. ECs exposed to hypoxia transiently induced ATF3 expression. A transient increase in the activation of c-Jun-NH(2)-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) in ECs was observed; however, only ECs pretreated with a specific inhibitor to JNK suppressed the hypoxia-induced ATF3 expression. ECs exposed to acute hypoxia transiently increased endothelial nitric oxide (eNOS) activity. Pre-treating ECs with a specific inhibitor to eNOS (l-NAME) or PI3-kinase significantly inhibited the hypoxia-induced JNK activation and ATF3 expression. ATF3 induction has been shown to inhibit matrix metalloproteinase-2 (MMP-2) expression. Consistently, ECs exposed to hypoxia attenuated the MMP-2 expression. This hypoxia-attenuated MMP-2 expression can be rescued by pre-treating ECs with an inhibitor of eNOS. These results suggest that the ATF3 induction by acute hypoxia is mediated by nitric oxide and the JNK pathway in ECs. Our findings provide a molecular basis for the mechanism in which ECs respond to acute hypoxia.
Atherosclerosis 2008 Dec
PMID:Acute hypoxia to endothelial cells induces activating transcription factor 3 (ATF3) expression that is mediated via nitric oxide. 1837 12


1 2 3 Next >>