Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet-derived growth factor (PDGF) controls migration and proliferation of mesenchymal cells and is thought to be involved in the pathophysiology of different diseases such as arteriosclerosis and tumorigenesis. In order to investigate the role of PDGF in rat models for such diseases, sufficient amounts of PDGF antagonists are needed. For this purpose we expressed the extracellular domain (ectodomain) of the rat PDGF receptor beta (PDGFR beta) in insect cells using a baculovirus vector. A hydrophilic octapeptide was added onto the N-terminus of the receptor ectodomain to follow its expression with specific anti-FLAG antibodies. The FLAG tag was also utilized to design a rapid two-step purification protocol. Purified FLAG-tagged rat PDGFR beta ectodomain had an affinity to PDGF-BB identical to the untagged ectodomain as determined by Scatchard analysis. FLAG-tagged PDGFR beta ectodomain in solution, however, did not compete for PDGF-BB binding to full length cellular receptors at concentrations expected for an high affinity antagonist.
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PMID:Expression of a rat PDGF receptor beta ectodomain generates a low affinity ligand antagonist. 845 May 8

Vein graft failure within the first month after bypass surgery is largely because of thrombosis. However, systemic study of thrombus formation in vein grafts is still lacking, and few effective techniques are available to prevent this event. Herein, we analyzed the kinetics of thrombosis and tested the effectiveness of locally applied aspirin on prevention of the disease in a mouse model. En face analysis of vein grafts revealed that 67+/-12% and 54+/-17% of the surface areas were covered by microthrombi at 1 and 3 days, respectively. Thrombus generation was also identified by labeling of platelets and fibrin, which occurred in 35 grafts examined at 1 and 3 days and 1, 2, 4, and 8 weeks. In a fifth of grafts, the thrombus occluded the vessel lumen by > or =1/4. Furthermore, a significant loss of endothelial cells was evidenced by beta-gal staining for vein grafts in transgenic mice expressing LacZ gene controlled by TIE2-endothelial specific gene promoter. Following thrombosis, neointimal lesions were significantly increased by 4-fold 2 weeks after the operation. When vein grafts were treated locally with aspirin in pluronic gel-127, the thrombus area was significantly reduced (P<0.005) at 1, 4, and 8 weeks. Interestingly, neointimal lesions were markedly reduced in the local, but not oral, aspirin-treated group at 4 and 8 weeks by 50% to 70% (P<0.005). The mechanism of reduced lesions by locally applied aspirin involved the protection of vein graft endothelium. Thus, we provide strong evidence that thrombus formation occurs before the development of neointimal lesions in vein grafts and that local aspirin treatment successfully reduces vein graft arteriosclerosis through endothelial protection, resulting in reduction of thrombosis.
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PMID:Thrombosis and neointima formation in vein grafts are inhibited by locally applied aspirin through endothelial protection. 1511 16

The steady-state level of peptide hormones represents a balance between their biosynthesis and proteolytic processing by convertases and their catabolism by proteolytic enzymes. Low levels of neuropeptide Y, somatostatin and corticotropin-releasing factor, described in Alzheimer disease (AD), were related to a defect in proteolytic processing of their protein precursors. In contrast the abundance of beta-amyloid peptides, the major protein constituents of senile plaques is likely related to inefficient catabolism. Therefore, attention is mainly focused on convertases that generate active peptides and counter-regulatory proteases that are involved in their catabolism. Some well-described proteases such as NEP are thought to be involved in beta-amyloid catabolism. The search of other possible candidates represents a primary effort in the field. A variety of vascular risk factors such as diabetes, hypertension and arteriosclerosis suggest that the functional vascular defect contributes to AD pathology. It has also been described that beta-amyloid peptides potentiate endothelin-1 induced vasoconstriction. In this review, we will critically evaluate evidence relating proteases implicated in amyloid protein precursor proteolytic processing and beta-amyloid catabolism.
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PMID:Abnormalities of peptide metabolism in Alzheimer disease. 1618 Oct 81

Inducible NO synthase (iNOS) is expressed by macrophages and smooth muscle cells in atherosclerotic lesions. Previously, we have established a mouse model for vein graft arteriosclerosis by grafting autologous jugular veins or vena cava to carotid arteries. Using this model, we studied the role of iNOS in the development of vein graft arteriosclerosis in iNOS(-/-) mice. Four weeks after grafting, neointimal hyperplasia of vein grafts in iNOS(-/-) mice was increased 2-fold compared with that of wild-type controls. Neointimal lesions contained mainly MAC-1+ macrophages and alpha-actin+ smooth muscle cells (SMCs) in both vein grafts of iNOS(-/-) and iNOS(+/+) mice. Immunofluorescence analysis revealed that increased iNOS expression in neointimal macrophages and SMCs of wild-type, but not iNOS(-/-), mice coincided with increased vascular endothelial growth factor (VEGF) expression in vein grafts. When vein grafts were performed in iNOS(-/-)/TIE2-LacZ transgenic mice expressing LacZ gene only in endothelial cells, the number of beta-galactosidase+ cells in iNOS(-/-) vein grafts were significantly decreased. Furthermore, treatment with the NOS inhibitor NG-nitro-L-arginine methyl ester resulted in delayed endothelial progenitor cell attachment, whereas L-arginine intake through drinking water enhanced endothelial repair. Interestingly, local application of VEGF to iNOS(-/-) vein grafts restored endothelial progenitor homing and reduced neointimal lesions, whereas the VEGF receptor inhibitor SU1498 increased the lesion formation. Additionally, iNOS-deficient SMCs showed a low level of VEGF production in response to interleukin 1beta stimulation. Thus, iNOS deficiency accelerates neointima formation by abrogating VEGF production and endothelial progenitor cell attachment and differentiation.
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PMID:Accelerated arteriosclerosis of vein grafts in inducible NO synthase(-/-) mice is related to decreased endothelial progenitor cell repair. 1648 25

Sphingosine 1-phosphate (S1P) has been shown to regulate expression of several genes in vascular smooth muscle cells (VSMCs) and contributes to arteriosclerosis. However, the mechanisms regulating epidermal growth factor receptor (EGFR) expression by S1P in aortic VSMCs remain unclear. Western blotting and RT-PCR analyses showed that S1P induced EGFR mRNA and protein expression in a time- and concentration-dependent manner, which was attenuated by inhibitors of MEK1/2 (U0126) and phosphatidylinositide 3-kinase (PI3K; wortmannin), and transfection with dominant negative mutants of ERK and Akt, respectively. These results suggested that S1P-induced EGFR expression was mediated through p42/p44 MAPK and PI3K/Akt pathways in VSMCs. In accordance with these findings, S1P stimulated phosphorylation of p42/p44 MAPK and Akt which was attenuated by U0126 and wortmannin, respectively. Furthermore, S1P-induced EGFR upregulation was blocked by a selective NF-kappaB inhibitor helenalin. Immunofluorescent staining and reporter gene assay revealed that S1P-induced activation of NF-kappaB was blocked by wortmannin, but not by U0126, suggesting that activation of NF-kappaB was mediated through PI3K/Akt. Moreover, S1P-induced EGFR expression was inhibited by an AP-1 inhibitor curcumin and tanshinone IIA. S1P-stimulated AP-1 subunits (c-Jun and c-Fos mRNA) expression was attenuated by U0126 and wortmannin, suggesting that MEK and PI3K/ERK cascade linking to AP-1 was involved in EGFR expression. Upregulation of EGFR by S1P may exert a phenotype modulation of VSMCs. This hypothesis was supported by pretreatment with AG1478 or transfection with shRNA of EGFR that attenuated EGF-stimulated proliferation of VSMCs pretreated with S1P, determined by XTT assay. These results demonstrated that in VSMCs, activation of Akt/NF-kappaB and ERK/AP-1 pathways independently regulated S1P-induced EGFR expression in VSMCs. Understanding the mechanisms involved in S1P-induced EGFR expression on VSMCs may provide potential therapeutic targets in the treatment of arteriosclerosis.
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PMID:Sphingosine 1-phosphate induces EGFR expression via Akt/NF-kappaB and ERK/AP-1 pathways in rat vascular smooth muscle cells. 1790 69

Smooth muscle cell (SMC) migration plays an important role in normal angiogenesis and is relevant to disease-related vascular remodeling in conditions such as brain arteriovenous malformations, pulmonary hypertension, arteriosclerosis, and restenosis after angioplasty. In this present study, we showed that tanshinone IIA, the major lipid-soluble pharmacological constituent of Salvia miltiorrhiza BUNGE, inhibits human aortic smooth muscle cell (HASMC) migration and MMP-9 activity. Tanshinone IIA significantly inhibited IkappaBalpha phosphorylation and p65 nuclear translocation through inhibition of AKT phosphorylation. Tanshinone IIA inhibited TNF-alpha-induced ERK and c-jun phosphorylation, but not other MAPKs such as JNK and p38. Tanshinone IIA also inhibited NF-kappaB and AP-1 DNA-binding. Moreover, tanshinone IIA inhibited the migration of TNF-alpha-induced HASMCs. Our results provide evidence that tanshinone IIA has multiple effects in the inhibition of HASMC migration and may offer a therapeutic approach to block HASMC migration.
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PMID:Tanshinone IIA from Salvia miltiorrhiza BUNGE inhibits human aortic smooth muscle cell migration and MMP-9 activity through AKT signaling pathway. 1797 38

Endothelial dysfunction, a well recognized marker of cardiovascular risk, is an early event in arteriosclerosis process. Diabetes mellitus, hypertension and dyslipidemia, known risk factors for coronary disease have been associated with endothelial dysfunction, which improves after the control of these factors. Statins have additional benefits on endothelial function not related to decreasing cholesterol levels, known as pleiotropic effects. Most recently it has been reported the effect of statins promoting bone marrow-derived mononuclear cells. These cells are positive for CD34 and KDR superficial markers of endothelial cellular lineage, which is consistent with the hypothesis that they constitute the endothelial progenitor cells. Circulating endothelial progenitor cells are involved in the repair process of the endothelium after endothelial-cell injury in myocardial ischemia, angina and other stressful situations. Recent studies have demonstrated an inverse relationship between the EPC count in peripheral blood and risk of developing a cardiovascular event. In addition, circulating EPC correlates with the presence of endothelial dysfunction and could play a role as a surrogate biologic marker in vascular function. The effect of statins on endothelial progenitor cells might contribute to improve endothelial function leading to a decrease in vascular risk, independently of their impact on LDL cholesterol. In this paper, we review the role of statins in EPC mobilization, its effect in endothelial function restoration and the relevance of this finding in cardiovascular risk. We also review future therapeutic implications.
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PMID:The role of endothelial progenitor cells and statins in endothelial function: a review. 1797 88

Angiogenesis is essential for tumor growth, metastasis, arteriosclerosis as well as embryonic development and wound healing. Its process is dependent on cell proliferation, migration and capillary tube formation in endothelia cells (ECs). High levels of reactive oxygen species (ROS) such as superoxide and H2O2 are observed in various cancer cells. Accumulating evidence suggests that ROS function as signaling molecules to mediate various growth-related responses including angiogenesis. ROS-dependent angiogenesis can be regulated by endogenous antioxidant enzymes such as SOD and thioredoxin. Vascular endothelial growth factor (VEGF), one of the major angiogenesis factor, is induced in growing tumors and stimulates EC proliferation and migration primarily through the VEGF receptor type2 (VEGFR2, Flk1/KDR). Major source of ROS in ECs is a NADPH oxidase which consists of Nox1, Nox2, Nox4, Nox5, p22phox, p47phox and the small G-protein Rac1. NADPH oxidase is activated by various growth factors including VEGF and angiopoietin-1 as well as hypoxia and ischemia, and ROS derived from this oxidase are involved in VEGFR2 autophosphorylation, and diverse redox signaling pathways leading to induction of transcription factors and genes involved in angiogenesis. Dietary antioxidants appear to be effective for treatment of tumor angiogenesis. The aim of this review is to provide an overview of the recent progress on role of ROS derived from NADPH oxidase and redox signaling events involved in angiogenesis. Understanding these mechanisms may provide insight into the NADPH oxidase and redox signaling components as potential therapeutic targets for tumor angiogenesis.
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PMID:Reactive oxygen species and angiogenesis: NADPH oxidase as target for cancer therapy. 1840 51

The thrombin/proteinase-activated receptors (PARs) have been shown to regulate smooth muscle cell proliferation, migration, and vascular maturation. Thrombin up-regulates expression of several proteins including cyclooxygenase (COX)-2 in vascular smooth muscle cells (VSMCs) and contributes to vascular diseases. However, the mechanisms underlying thrombin-regulated COX-2 expression in VSMCs remain unclear. Western blotting, RT-PCR, and EIA kit analyses showed that thrombin induced the expression of COX-2 mRNA and protein and PGE(2) release in a time-dependent manner, which was attenuated by inhibitors of PKC (GF109203X and rottlerin), c-Src (PP1), EGF receptor (EGFR; AG1478) and MEK1/2 (U0126), or transfection with dominant negative mutants of PKC-delta, c-Src or extracellular regulated kinase (ERK) and ERK1 short hairpin RNA interference (shRNA). These results suggest that transactivation of EGFR participates in COX-2 expression induced by thrombin in VSMCs. Accordingly, thrombin stimulated phosphorylation of ERK1/2 which was attenuated by GF109203X, rottlerin, PP1, GM6001, CRM197, AG1478, or U0126, respectively. Furthermore, this up-regulation of COX-2 mRNA and protein was blocked by selective inhibitors of AP-1 and NF-kappaB, curcumin and helenalin, respectively. Moreover, thrombin-stimulated activation of NF-kappaB, AP-1, and COX-2 promoter activity was blocked by the inhibitors of c-Src, PKC, EGFR, MEK1/2, AP-1 and NF-kappaB, suggesting that thrombin induces COX-2 promoter activity mediated through PKC(delta)/c-Src-dependent EGFR transactivation, MEK-ERK1/2, AP-1, and NF-kappaB. These results demonstrate that in VSMCs, activation of ERK1/2, AP-1 and NF-kappaB pathways was essential for thrombin-induced COX-2 gene expression. Understanding the regulation of COX-2 expression and PGE(2) release by thrombin/PARs system on VSMCs may provide potential therapeutic targets of vascular inflammatory disorders including arteriosclerosis.
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PMID:PKC-delta/c-Src-mediated EGF receptor transactivation regulates thrombin-induced COX-2 expression and PGE(2) production in rat vascular smooth muscle cells. 1845 14

Overexpression of plasminogen activator inhibitor-1 (SERPINE1, PAI-1), the major physiological inhibitor of pericellular plasmin generation, is a significant causative factor in the progression of vascular disorders (e.g. arteriosclerosis, thrombosis, perivascular fibrosis) as well as a biomarker and a predictor of cardiovascular-disease associated mortality. PAI-1 is a temporal/spatial regulator of pericellular proteolysis and ECM accumulation impacting, thereby, vascular remodeling, smooth muscle cell migration, proliferation and apoptosis. Within the specific context of TGF-beta1-initiated vascular fibrosis and neointima formation, PAI-1 is a member of the most prominently expressed subset of TGF-beta1-induced transcripts. Recent findings implicate EGFR/pp60c-src-->MEK/ERK1/2 and Rho/ROCK-->SMAD2/3 signaling in TGF-beta1-stimulated PAI-1 expression in vascular smooth muscle cells. The EGFR is a direct upstream regulator of MEK/ERK1/2 while Rho/ROCK modulate both the duration of SMAD2/3 phosphorylation and nuclear accumulation. E-box motifs (CACGTG) in the PE1/PE2 promoter regions of the human PAI-1 gene, moreover, are platforms for a MAP kinase-directed USF subtype switch (USF-1-->USF-2) in response to growth factor addition suggesting that the EGFR-->MEK/ERK axis impacts PAI-1 expression, at least partly, through USF-dependent transcriptional controls. This paper reviews recent data suggesting the essential cooperativity among the EGFR-->MAP kinase cascade, the Rho/ROCK pathway and SMADs in TGF-beta1-initiated PAI-1 expression. The continued clarification of mechanistic controls on PAI-1 transcription may lead to new targeted therapies and clinically-relevant options for the treatment of vascular diseases in which PAI-1 dysregulation is a major underlying pathogenic feature.
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PMID:Integration of non-SMAD and SMAD signaling in TGF-beta1-induced plasminogen activator inhibitor type-1 gene expression in vascular smooth muscle cells. 1913 20


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