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)

The modulation of vascular smooth muscle cells (VSMCs) from the quiescent phenotype to the proliferative and migratory phenotype is a critical event in the pathogenesis of atherosclerosis. To-date several growth factors, including platelet-derived growth factor, PDGF, have been shown to induce VSMC proliferation and migration. To further understand the mechanism of PDGF-induced VSMC activation, quiescent human coronary artery SMC were treated with PDGF, and the genes that displayed transcriptional changes within 3 and 8 h were identified using differential display RT-PCR, real-time PCR, nucleotide sequencing and bioinformatics. Eleven genes that were highly upregulated or down-regulated at 3 and/or 8 h by PDGF, designated growth-factor regulated VSMC genes (GRSG1-11), were analyzed. GRSG5 and GRSG9-1 were identified as cortactin and cytochrome c oxidase subunit II, respectively. The remaining nine GRSGs were novel. GRSG3, 4, 5 and 9-2 showed wide tissue distribution whereas GRSG10-1, 10-2, and 11 were tissue specific. Cortactin was localized by immunohistochemical staining to the neointima and fibrous cap of human coronary artery atherosclerotic plaques. Domain analysis of open reading frames suggest that the novel GRSGs may participate in signaling, metabolic, translational or migrational processes during PDGF-induced VSMC activation.
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PMID:mRNA differential display identification of vascular smooth muscle early response genes regulated by PDGF. 1632 58

Inflammation contributes to the pathogenesis of atherosclerosis. Proinflammatory cytokines, including interleukin-1 (IL-1), may be involved in the local inflammation occurring in the vessel wall. Vascular smooth muscle cells express the unprocessed IL-1beta precursor molecule. Invading leukocytes, such as monocytes or polymorphonuclear granulocytes (PMN) may activate the IL-1beta precursor during atherogenesis. Thus, we investigated the capacity of PMN to process IL-1beta and IL-18 precursors. Processing was analyzed using Western blot and bioassay for IL-1-activity was performed. As few as 80 to 400 PMN/mL detectably processed preIL-1beta. PMN also cleaved the caspase-1 substrate preIL-18. The preIL-1beta and preIL-18 cleavage products were located at the same apparent molecular weight as those resulting from cleavage by monocyte-derived caspase-1. PMN expressed caspase-1 mRNA and immunoreactive protein. The N-terminus of the preIL-1beta cleavage product expressed the sequence expected for caspase-1 cleavage. The cleavage product was active in the bioassay for IL-1 activity, and the caspase-1 inhibitor YVAD blocked processing. We have shown previously that SMC can block processing of preIL-1 by caspase-1. In contrast, SMC do not block processing of PARP by caspase-3. Here, we show that SMC also inhibited the PMN-mediated processing of recombinant and native preIL-1beta or preIL-18 depending on the cell number, whereas EC or fibroblasts did not block processing. Our results indicate that PMN can activate preIL-1beta in a caspase-1-like fashion. During inflammatory processes, PMN may activate preIL-1beta released from SMC, thereby altering IL-1-mediated cardiovascular functions, including contractility, apoptosis, and cytokine production.
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PMID:Neutrophils process interleukin-1beta and interleukin-18 precursors in a caspase-1-like fashion--processing is inhibited by human vascular smooth muscle cells. 1661 59

CXCL16 is a transmembrane non-ELR CXC chemokine that signals via CXCR6 to induce aortic smooth muscle cell (ASMC) proliferation. While bacterial lipopolysaccharide (LPS) has been shown to stimulate CXCL16 expression in SMC, its effects on CXCR6 are not known. Here, we demonstrate that LPS upregulates CXCR6 mRNA, protein, and surface expression in human ASMC. Inhibition of TLR4 with neutralizing antibodies or specific siRNA interference blocked LPS-mediated CXCR6 expression. LPS stimulated both AP-1 (c-Fos, c-Jun) and NF-kappaB (p50 and p65) activation, but only inhibition of AP-1 attenuated LPS-induced CXCR6 expression. Using dominant negative expression vectors and siRNA interference, we demonstrate that LPS induces AP-1 activation via MyD88, TRAF6, ERK1/2, and JNK signaling pathways. Furthermore, the flavoprotein inhibitor diphenyleniodonium chloride significantly attenuated LPS-mediated AP-1-dependent CXCR6 expression, as did inhibition of NOX4 NADPH oxidase by siRNA. Finally, CXCR6 knockdown inhibited CXCL16-induced ASMC proliferation. These results demonstrate that LPS-TLR4-NOX4-AP-1 signaling can induce CXCR6 expression in ASMC, and suggest that the CXCL16-CXCR6 axis may be an important proinflammatory pathway in the pathogenesis of atherosclerosis.
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PMID:TLR4-NOX4-AP-1 signaling mediates lipopolysaccharide-induced CXCR6 expression in human aortic smooth muscle cells. 1687 Jan 45

Connective tissue growth factor (CTGF) is expressed in atherosclerotic plaques. It is generally recognized that CTGF contributes to atherosclerosis by stimulating vascular smooth muscle cell (VSMC) proliferation and extracellular matrix production during the development of atherosclerosis. Recent studies indicate that CTGF may also contribute to plaque destabilization as it induces apoptosis and stimulates MMP-2 expression in VSMCs. Thiazolidinediones (TZDs), a new class of insulin sensitizing drugs for type 2 diabetes, inhibit atherosclerosis. However, their effect on CTGF expression in atherosclerotic plaques remains unknown. In this study, male LDL receptor-deficient mice were fed high-fat diet for 4 months to induce the formation of atherosclerotic plaques and then given the high-fat diet with or without pioglitazone for the next 3 months. At the end of the 7-month study, CTGF expression in aortic atherosclerotic lesions was examined. Results showed that CTGF expression was increased in mice fed the high-fat diet by seven-fold as compared to that in mice fed normal chow, but the treatment with pioglitazone significantly inhibited the high-fat diet-induced CTGF expression. To verify these in vivo observations, in vitro studies using human aortic SMC were conducted. Quantitative real-time PCR and Western blot showed that pioglitazone inhibited TGF-beta-stimulated CTGF expression. In conclusion, the present study has demonstrated that pioglitazone inhibits CTGF expression in mouse advanced atherosclerotic plaques and in cultured human SMCs, and hence unveiled a possible mechanism potentially involved in the inhibition of atherosclerosis by TZD.
Atherosclerosis 2007 May
PMID:Pioglitazone inhibits connective tissue growth factor expression in advanced atherosclerotic plaques in low-density lipoprotein receptor-deficient mice. 1690 90

Over-proliferation of SMC (smooth muscle cell) is one characteristics of atherosclerosis. One well accepted mechanism is that the decrease of ECs (endothelial cells) induced by over apoptosis leads to endothelial dysfunction, which in turn results in over-proliferation of SMC. Obviously, the mechanism works after endothelial apoptosis. Compared with necrosis, apoptosis is time and energy consuming. The question is why the cell ends in the form of apoptosis instead of necrosis. From the evolutionary standpoint, apoptosis has some useful functions other than removing the damaged or unwanted cells. Recent studies showed that cells nearby the apoptotic ones began to proliferate and differentiate before apoptosis and the apoptotic signals could induce the near cells to proliferate without the death of cells. Apparently, some mechanism in apoptosis results in the proliferation of cells. So, we hypotheses that endothelial apoptosis can directly induce the over-proliferation of SMC.
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PMID:In atherogenesis, the apoptosis of endothelial cell itself could directly induce over-proliferation of smooth muscle cells. 1701 Nov 40

Loss of the differentiated (contractile) phenotype of vascular smooth muscle cells (VSMCs) heightens their migratory activity. Integrins, as the main integrators of cell-extracellular matrix, regulate different aspects of cell behavior including migration and differentiation. alpha 8 beta 1 Integrin being expressed in cell types with contractile abilities is downregulated during VSMC phenotype modulation. In this report the ability of alpha 8 beta 1 integrin to induce the characteristics of the contractile phenotype as well as suppression of VSMC migratory activity was investigated. Forced expression of alpha 8 integrin in passage-5 rat VSMCs resulted in lower migratory activity. Western blot and immunoconfocal studies revealed that alpha 8 integrin overexpression was associated with the reappearance of VSMC contractile hallmarks including upregulation of contractile markers, assembly of stress fibres, and increased number of focal adhesions. alpha 8 Integrin overexpression in fibroblast-like Rat1 cells also induced SMC-like characteristics. alpha 8 Integrin-induced reappearance of the contractile hallmarks in de-differentiated VSMCs was impaired by RhoA inhibitors. These results provide evidences that alpha 8 integrin overexpression may assist phenotype-modulated VSMCs to revert to the contractile phenotype possibly via RhoA signaling pathway. Our findings suggest a dynamic role for alpha 8 beta 1 integrin to induce contractile phenotype as well as suppression of VSMC migration, a key player during arterial stenosis.
Atherosclerosis 2007 Dec
PMID:alpha 8 Integrin overexpression in de-differentiated vascular smooth muscle cells attenuates migratory activity and restores the characteristics of the differentiated phenotype. 1727 6

We investigated the influence of apolipoprotein E deficiency and Western-type diet feeding on the development and composition of neointimal lesions induced by periadventitial carotid placement of a non-occlusive collar in mice. ApoE-/- and wild-type mice were fed a Western-type diet or chow diet for 4 weeks before collar surgery. Diets were continued after collar placement for 6 or 12 weeks. Compared to sham-operated arteries, collared carotids showed significant neointima formation, lumen loss, and outward remodeling in both apoE-/- and wild-type mice. These changes were not affected by either the genotype or the diet. Conversely, significant differences in neointima composition were detected between the two genotypes, with apoE-/- mice showing greater lipid deposition and lower SMC accumulation compared to wild-type mice, independent of the dietetic regimen. Altogether, the results of the present study indicate that although lesion composition may be influenced by genotype, neointima formation and arterial remodeling in the murine perivascular carotid collar model occur independent of the exposure to atherogenic diet or the presence of a sensitized genotype such as apoE-/-. The murine perivascular carotid collar model would thus be suitable for investigating neointima formation, arterial remodeling, and their potential pharmacological modulation in the setting of different genetic and dietary conditions.
Atherosclerosis 2007 Nov
PMID:Perivascular carotid collar placement induces neointima formation and outward arterial remodeling in mice independent of apolipoprotein E deficiency or Western-type diet feeding. 1748 95

Chlamydia pneumoniae infection may play a role in the pathogenesis of atherosclerosis. In this study, an oligonucleotide microarray was utilized to examine the transcriptional response of human aortic smooth muscle cells (AoSMC) to C. pneumoniae infection. Alteration of mRNA expression in 71 out of 780 genes was detected at 24 h after infection. Among the down-regulated genes, platelet-derived growth factor receptor-beta (PDGFR-beta) was identified as a target for further analysis because the PDGF system is involved in the fibroproliferative response of SMC in atherogenesis. Reverse transcriptase PCR analysis demonstrated that C. pneumoniae inhibits the up-regulation of PDGFR-beta mRNA occurring in AoSMC after mock infection. PDGFR-beta protein synthesis was examined by immunoblotting and fluorescence-activated cell sorting. Compared with mock-infected cells, the amount of receptor protein was reduced at 24, 48, and 72 h after infection. Diminished PDGFR-beta synthesis in infected cultures was accompanied by the suppression of AoSMC growth following PDGF-BB stimulation. The interference of C. pneumoniae with PDGFR-beta expression may result in decreased SMC proliferation in atherosclerotic plaques, thereby affecting the development and stability of advanced lesions.
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PMID:Chlamydia pneumoniae infection of aortic smooth muscle cells reduces platelet-derived growth factor receptor-beta expression. 1772 56

Atherosclerosis is an inflammatory disease characterized by a large amount of hyperproliferation and poorly differentiated or undifferentiated smooth muscle cells in atherosclerotic plaque. Cancer cells differ from normal cells in many aspects, including hyperproliferation and loss of differentiation. So the research on tumor may shed light on the treatment of atherosclerosis. Given that Kruppel-like factor 4 (KLF4) has an important function in tumor development and progression, it may be associated with the formation and development of atherosclerosis. Recently, KLF4 expression has been documented in vascular endothelial cells. KLF4, which is normally not expressed in differentiated SMC in vivo, was rapidly up-regulated in response to vascular injury. In addition, KLF4 is a critical regulator in macrophage activation. Endothelial dysfunction, macrophage activation and VSMC phenotype switching are critical component elements in development of atherosclerosis. Herein we hypothesize that KLF4 is an important regulator in different phase of atherosclerosis and may be a novel target of prevention and cure of atherosclerosis. Further investigation is needed to approach the concrete signaling pathways about KLF4.
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PMID:KLF4: a novel target for the treatment of atherosclerosis. 1786 9

The lesions of atherosclerosis represent a series of highly specific cellular and molecular responses. Low density lipoprotein (LDL), which may be modified by oxidation, glycation, aggregation, association with proteoglycans, or incorporation into immune complexes, is a major cause of injury to the endothelium and vascular smooth muscle cells (VSMC).The major major cell types involved in atherogenesis, macrophages and VSMC, are activated by pro-inflammatory stimuli including modified LDL. Modified LDL induces inflammatory responses in macrophages, migration and proliferation of SMC, and triggers foam cell formation. Scavenger receptors, including LOX-1, play a key role in foam cell formation by mediating the uptake of modified LDL. LOX-1 expression is detected in endothelial cells of early atherosclerosis lesions of human carotid arteries. Advanced lesions showed LOX-1 expression not only in endothelial cells but also in macrophages and more frequently in VSMC, and may be involved in foam cell transformation in macrophages and VSMC. The metabolic abnormalities that characterize diabetes, particularly hyperglycemia, free fatty acids, and insulin resistance, provoke molecular mechanisms that alter the function and structure of blood vessels. These include increased oxidative stress, intracellular signal transduction disturbances, and activation of the receptor for advanced glycation end products (R-AGE). Data showed that LOX-1 expression is enhanced by proatherogenic factors relevant to human diabetes, including high glucose, oxLDL, advance glycation end products, and C-reactive protein. LOX-1 expression increased also through oxygen species (ROS), endothelin-1 (ET-1), tumor necrosis factor-alpha (TNF-alpha), shear stress, activation of protein kinase-C (PKC), angiotensin-II (ANG-II), and through inflammatory pathways.
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PMID:The expression and down stream effect of lectin like-oxidized low density lipoprotein 1 (LOX-1) in hyperglycemic state. 1793 9


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