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)

Benzo[a]pyrene (B[a]P) is a polycyclic aromatic hydrocarbon with atherogenic and carcinogenic properties. The role of B[a]P in carcinogenesis is well established, and thought to exert via enzymatic activation into reactive metabolites that are capable of binding to the DNA leading to uncontrolled proliferation. However, the mechanism underlying the atherogenic properties of B[a]P is still unclear. Therefore, the effects of chronic B[a]P exposure on atherosclerotic plaque development in apolipoprotein E knockout (apoE-KO) mice were studied. ApoE-KO mice were orally treated with 5 mg/kg/bw B[a]P once per week for 12 or 24 consecutive weeks. Levels of reactive B[a]P metabolites in the arterial tree (from the aortic arch until the iliac artery bifurcations) were high as shown by the level of B[a]P DNA-binding products measured in DNA isolated from the entire aorta (38.9 +/- 4.8 adducts/10(8) nucleotides). Analysis of atherosclerotic lesions in the aortic arch showed no influence of B[a]P on location or number of lesions. Moreover, no increased levels of p53 nuclear protein accumulation or cell proliferation, as detected by immunohistochemistry, were seen in the plaques of the B[a]P-exposed animals. However, the effects of B[a]P on advanced lesions were obvious: advanced plaques were larger and more prone to lipid core development and plaque layering at both 12 and 24 weeks (P < 0.05). In the B[a]P-exposed animals advanced plaques contained more T-lymphocytes and macrophages than in the control animals at both end points (P < 0.05). These data suggest that B[a]P does not initiate atherosclerosis in apoE-KO mice, but accelerates the progression of atherosclerotic plaques via a local inflammatory response.
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PMID:Chronic exposure to the carcinogenic compound benzo[a]pyrene induces larger and phenotypically different atherosclerotic plaques in ApoE-knockout mice. 1469 24

Ligation of endothelial cell (EC) CD40 induces the expression of several proinflammatory cytokines as well as angiogenesis factors, including vascular endothelial growth factor (VEGF). Moreover, despite the reported importance of CD40 in cell-mediated immunity, little is known of the CD40-induced signaling pathways in EC. In this study, we have investigated the function of the Ras signaling pathway(s) for CD40-induced overexpression of VEGF. EC were transiently transfected with a full-length VEGF promoter-luciferase construct and a dominant-inhibitory mutant of Ras (Ras17N). Following transfection, ligation of CD40 with soluble CD40 ligand resulted in a significant increase in VEGF transcriptional activation, and the inhibitory mutant of Ras blocked this CD40-induced VEGF overexpression. Using EMSA and Western blot analysis, we demonstrated that CD40-dependent binding of nuclear protein(s) to the VEGF promoter and CD40-induced VEGF protein expression in EC were also inhibited by the Ras mutant. Immunoprecipitation studies revealed that ligation of CD40 on EC promoted an increased association of Ras with its effector molecules Raf, Rho, and phosphatidylinositol 3-kinase (PI3K). But, cotransfection of effector-loop mutants of Ras determined that only PI3K was functional for Ras-induced VEGF transcription. Also, wortmanin and a dominant-inhibitory mutant of PI3K inhibited CD40-induced overexpression of VEGF. Together these findings demonstrate that both Ras and PI3K are intermediaries in CD40-induced regulation of VEGF in EC. We believe our findings are of importance in several chronic inflammatory diseases, including atherosclerosis and allograft rejection associated with both CD40-CD40 ligand signaling as well as VEGF expression and function.
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PMID:The CD40-induced signaling pathway in endothelial cells resulting in the overexpression of vascular endothelial growth factor involves Ras and phosphatidylinositol 3-kinase. 1518 29

Platelet-derived growth factors (PDGFs) play an integral role in normal tissue growth and maintenance as well as many human pathological states including atherosclerosis, fibrosis, and tumorigenesis. The PDGF family of ligands is comprised of A, B, C, and D chains. Here, we provide the first functional characterization of the PDGF-C promoter. We examined 797 bp of the human PDGF-C promoter and identified several putative recognition elements for Sp1, Ets Egr-1, and Smad. The proximal region of the PDGF-C promoter bears a remarkable resemblance to a comparable region of the PDGF-A promoter (1). Binding and transient transfection analysis in primary vascular smooth muscle cells revealed that PDGF-C, like PDGF-A, is under the transcriptional control of the zinc finger nuclear protein Egr-1 (early growth response-1). Electrophoretic mobility shift analysis using both smooth muscle cell nuclear extracts and recombinant protein revealed that Egr-1 and Sp1 bind this region of the PDGF-C promoter (Oligo C, -35 to -1). Egr-1 competes with Sp1 for overlapping binding sites even when the former is at a stoichiometric disadvantage. Reverse transcriptase PCR and supershift analysis demonstrate that fibroblast growth factor-2 (FGF-2) stimulates both Egr-1 and PDGF-C mRNA expression in a time-dependent and transient manner and that FGF-2-inducible Egr-1 binds the proximal PDGF-C promoter. FGF-2-inducible PDGF-C expression was completely abrogated using catalytic DNA (DNAzymes) targeting Egr-1 but not by its scrambled counterpart. Moreover, using pharmacological inhibitors we demonstrate the critical role of ERK but not JNK in FGF-2-inducible PDGF-C expression. These findings thus demonstrate that PDGF-C transcription, activated by FGF-2, is mediated by Egr-1 and its upstream kinase ERK.
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PMID:Fibroblast growth factor-2 induction of platelet-derived growth factor-C chain transcription in vascular smooth muscle cells is ERK-dependent but not JNK-dependent and mediated by Egr-1. 1524 55

A nuclear protein, high mobility group box 1 (HMGB1), is released passively by necrotic cells, and actively by macrophages/monocytes in response to exogenous and endogenous inflammatory stimuli. After binding to the receptor for advanced glycation end products (RAGE) or toll-like receptor 4 (TLR4), HMGB1 activates vascular endothelial cells and macrophages/monocytes to express proinflammatory cytokines, chemokines and adhesion molecules. Pharmacological suppression of its activities or release is protective against lethal endotoxemia and sepsis, establishing HMGB1 as a critical mediator of lethal systemic inflammation. In light of the pathogenic role of inflammation in cardiovascular diseases, we propose that HMGB1, a proinflammatory cytokine derived from both injured endothelium and activated macrophages/monocytes, could contribute to the progression of atherosclerosis and other cardiovascular diseases.
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PMID:Role of HMGB1 in cardiovascular diseases. 1648 50

The abnormal growth of vascular smooth muscle cells (VSMCs) plays an important role in vascular diseases, including atherosclerosis and restenosis after angioplasty. Although (-)-epigallocatechin-3-O-gallate (EGCG) has antiproliferative effects on various cells, relatively a little is known about precise mechanisms of the inhibitory effects of EGCG on SMCs. In this study, the inhibitory effects of EGCG on attachment, proliferation, migration, and cell cycle of rat aortic SMCs (RASMCs) with serum stimulation were investigated. Also, the involvement of nuclear factor-kappaB (NF-kappaB) during these inhibitions by EGCG was examined. EGCG treatment resulted in significant (p<0.05) inhibition in attachment and proliferation of RASMCs induced by serum. While non-treated RASMCs migrated into denuded area in response to serum and showed essentially complete closure after 36 h, EGCG-treated cells covered only 31% of the area even after 48 h of incubation. Furthermore, EGCG treatment resulted in an appreciable cell cycle arrest at both G0/G1- and G2/M-phases. The immunoblot analysis revealed that the constitutive expression of NF-kappaB/p65 nuclear protein in RASMCs was lowered by EGCG in both the cytosol and the nucleus in a dose-dependent manner. These results suggest that the EGCG-caused inhibitory effects on RASMCs may be mediated through NF-kappaB down-modulation.
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PMID:Inhibitory effects of epigallocatechin-3-O-gallate on serum-stimulated rat aortic smooth muscle cells via nuclear factor-kappaB down-modulation. 1667 5

The intracellular mechanism responsible for the mitogenic effects of lysophosphatidylcholine (LPC) is unclear. Import of proteins from the cytoplasm into the cell nucleus is integral to the regulation of gene expression and cell growth. We hypothesized that LPC exerts its intracellular effects through alterations in nuclear protein import. Rabbit aortic smooth muscle cells incubated with LPC induced a significant increase in cell proliferation in both quiescent cells (63.2+/-6.48% of control) and cells grown in 1% fetal bovine serum (FBS) (28.3+/-7.35% of control). Vascular smooth muscle cells were preincubated with LPC then microinjected with a marker protein for nuclear import. A significant stimulation of nuclear protein transport was observed. Using a conventional nuclear protein import assay in permeabilized cells, a significant stimulation of import (72.3+/-5.2% of control) was again observed when the cytosolic nuclear import cocktail was treated with LPC. This effect was not observed with other lysophosphatidyl species. LPC also activated the extracellular signal-regulated kinase (ERK) 1/2 mitogen-activated protein kinase (MAPK) pathway, and this was blocked by 2'-amino-3'-methoxyflavone (PD98059), which inhibits the activation of ERK 1/2. The stimulation of nuclear import was also blocked by PD98059. LPC-induced MAPK activation augmented GTP hydrolysis by RanGAP, a RanGTPase activating protein and a critical regulatory component of nuclear protein import, and this stimulation was again blocked by PD98059. We conclude that LPC alters gene expression and cell proliferation through striking effects on nuclear protein import via a MAP kinase-induced activation of RanGAP. This may play an important role in cancer and atherosclerosis and other disorders involving accelerated cell growth/proliferation.
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PMID:RanGAP-mediated nuclear protein import in vascular smooth muscle cells is augmented by lysophosphatidylcholine. 1710 74

The Leu33Pro polymorphism of the gene encoding beta(3) integrin (ITGB3) is associated with acute coronary syndromes and influences platelet aggregation. Three common promoter polymorphisms have also been identified. The aims of this study were to (1) investigate the influence of the ITGB3 -400C/A, -425A/C and -468G/A promoter polymorphisms on reporter gene expression and nuclear protein binding and (2) determine genotype and haplotype associations with platelet alpha(IIb)beta(3) receptor density. Promoter haplotypes were introduced into an ITGB3 promoter-pGL3 construct by site directed mutagenesis and luciferase reporter gene expression analysed in HEL and HMEC-1 cells. Binding of nuclear proteins was assessed by electrophoretic mobility shift assay. The association of ITGB3 haplotype with platelet alpha(IIb)beta(3) receptor density was determined in 223 subjects. Species conserved motifs were identified in the ITGB3 promoter in the vicinity of the three polymorphisms. The GAA, GCC, AAC, AAA and ACC constructs induced approximately 50% increased luciferase expression relative to the GAC construct in both cell types. Haplotype analysis including Leu33Pro indicated five common haplotypes; no associations between ITGB3 haplotypes and receptor density were found. However, the GCC-Pro33 haplotype was associated with significantly higher vWF activity (128.6 [112.1-145.1]%) compared with all other haplotypes (107.1 [101.2-113.0]%, p=0.02). In conclusion, the GCC-Pro33 haplotype was associated with increased vWF activity but not with platelet alpha(IIb)beta(3) receptor density, which may indicate ITGB3 haplotype influences endothelial function.
Atherosclerosis 2008 Jun
PMID:Beta3 integrin haplotype influences gene regulation and plasma von Willebrand factor activity. 1804 6

High mobility group box 1 (HMGB1) is a non-histone nuclear protein which is released from the nucleus of activated macrophages into the extracellular space in response to stimuli such as endotoxin or necrosis. The HMGB1 functions as a potent proinflammatory cytokine in the extracellular spaces. Recently, HMGB1 has been implicated in the progression of atherosclerosis. However, the association between HMGB1 and the development of atherosclerosis is poorly understood. Therefore, we examined whether serotonin (5-HT), a key factor involved in the development of atherosclerosis, induced HMGB1 release in human umbilical vein endothelial cells (HUVECs). We found that 5-HT induced the release of HMGB1 but not of ERK1/2 and JNK from HUVECs via the 5-HT receptor (5-HT1B)/p38 mitogen-activated protein kinase (MAPK) signaling pathway. The p38MAPK inhibitor SB203580 and the 5-HT1B antagonist GR55526 markedly inhibited HMGB1 release from 5-HT-stimulated HUVECs. The vascular endothelial growth factor (VEGF) derived from activated macrophages in atherosclerotic lesions also plays an important role in the progression of atherosclerosis. We found that HMGB1 induced VEGF production in macrophage-like RAW264.7 cells. HMGB1 induced the activation of p38MAPK, ERK1/2 and Akt. The PI3-kinase inhibitor LY294002 significantly inhibited VEGF production in HMGB1-stimulated macrophages, while other kinase inhibitors did not. These results suggest that HMGB1 release may contribute as a risk factor in the development and progression of atherosclerosis.
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PMID:Induction of high mobility group box 1 release from serotonin-stimulated human umbilical vein endothelial cells. 1894 84

Proteins enter the nucleus through the nuclear pore complex. Once in the nucleus, some proteins, such as transcriptional regulators, can turn genes on or off, and change the composition of the cell and its function to meet the demands of its environment. This process of protein import into the nucleus is highly controlled and regulated by the expression or function of single cargoes, transport receptors, or the transport channels themselves. Thus, these components of the import process have an impact on transport capacity, which subsequently affects gene expression, signal transduction, and cell growth and development. With such a key position in the process of cell growth, it is reasonable to hypothesize that alterations in nuclear protein transport may play an important role in pathological cell conditions that have abnormal cell growth as a central feature. Indeed, there are now sufficient data to demonstrate that alterations in nuclear protein transport participate in alterations in cell proliferation and hypertrophy. Further study is needed to provide definitive proof that changes in nuclear protein import directly participate in the pathogenesis of diseases such as hypertension, atherosclerosis, cancer, viral infection, and diabetes. However, the data to date have, on select occasions, led to a clear association of alterations in nuclear transport with disease states. Furthermore,this research has led to the important identification of new targets within the process of nuclear protein import that hold therapeutic promise to inhibit viral replication, to improve drug delivery during cancer therapy, and, in general, to modify cell growth and viability during disease conditions.
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PMID:Therapeutic targeting of nuclear protein import in pathological cell conditions. 1980 78

Atherosclerosis is a complex fibroproliferative-inflammatory process triggered by vascular injury. Transcription factors play an important role in the control of genes that effect critical changes in the vessel wall. Recent evidence indicates an emerging role for activation transcription factor 4 (ATF4), a master regulator for evolutionarily conserved mammalian stress response pathways, in cardiovascular pathologic settings. For example, in endothelial cells, ATF4 is induced by atherogenic factors such as oxidised phospholipids and homocysteine, and in monocytes, ATF4 is activated by hypoxia. In this context, ATF4 is thought to regulate pro-inflammatory signalling cascades and subsequent apoptosis. ATF4 is induced in aortic smooth muscle cells by fibroblast growth factor 2 and in the intact vessel wall following balloon angioplasty. Our own work indicates that ATF4 knockdown blocks injury-inducible intimal proliferation. Furthermore, studies in ATF4-deficient mice have established a role for ATF4 in diet-induced diabetes and hyperlipidaemia. In this article, we will review recent developments on the regulation of this intriguing nuclear protein and its transcriptional roles in the context of vascular injury and related disease.
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PMID:Activation transcription factor-4 and the acute vascular response to injury. 2030 12


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