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)

Inflammation may contribute to the pathogenesis of atherosclerosis. On the basis of previous reports that human atherosclerotic lesions contain alpha-defensins, a class of cationic proteins released by activated neutrophils, the study was designed to ask whether defensins modulate the binding and catabolism of low-density lipoprotein (LDL) by human vascular cells. The results of the study demonstrated that defensin stimulated the binding of (125)I-LDL to cultured human umbilical vein endothelial cells, smooth muscle cells, and fibroblasts approximately 5-fold in a dose-dependent and saturable manner. Defensin and LDL formed stable complexes in solution and on cell surfaces. Stimulation of LDL binding by defensin was not inhibited by antibodies against the LDL-receptor (LDL-R), or by recombinant receptor-associated protein, which blocks binding of ligands to the alpha(2)-macroglobulin receptor/LDL-R-related protein and other LDL-R family members. Furthermore, defensin stimulated the binding, endocytosis, and degradation of LDL by fibroblasts lacking LDL-R. Stimulation of LDL degradation by defensin was inhibited approximately 75% by low concentrations of heparin (0.2 units/mL) and was similarly reduced in CHO cells lacking heparan-sulfate-containing proteoglycans. The effect of defensin was substantially increased in cells overexpressing the core protein of the syndecan-1 heparan sulfate proteoglycan. The alpha-defensins released from activated neutrophils may provide a link between inflammation and atherosclerosis by changing the pattern of LDL catabolism from LDL-R to the less efficient LDL-R-independent, proteoglycan-dependent pathway. (Blood. 2000;96:1393-1398)
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PMID:The alpha-defensins stimulate proteoglycan-dependent catabolism of low-density lipoprotein by vascular cells: a new class of inflammatory apolipoprotein and a possible contributor to atherogenesis. 1094 83

Heparan sulfate proteoglycans (HSPGs) are key constituents of subendothelial extracellular matrix that play an important role in the assembly and structure of the basement membrane, regulation of basement membrane permeability, growth factor activity and cellular adhesion. Vascular HSPGs decrease during inflammation, atherosclerosis and diabetes. Recent studies showed that HSPGs are negatively regulated by atherogenic molecules and positively regulated by antiatherogenic agents. Extracellular matrix HSPG, perlecan, appears to be a key target of regulation by these agents. At least two levels of regulation appear to control perlecan HSPG in matrix; a change in core protein expression or a change in heparan sulfate metabolism. Atherogenic levels of low-density lipoprotein (LDL), oxidized LDL and lysolecithin decrease not only perlecan core protein synthesis but also enhance heparan sulfate degradation by stimulating endothelial secretion of heparanase. ApoE and apoE-HDL, in contrast, increase perlecan core protein as well as sulfation of heparan sulfate. Increased perlecan in endothelial cells was associated with increased antithrombin-binding and antiproliferative heparan sulfates. Moreover, modulation of perlecan appears to have a direct effect on smooth muscle cell growth. Thus, lipoprotein modulation of vascular perlecan may play a key role in the modulation of atherogenesis.
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PMID:Lipoprotein modulation of subendothelial heparan sulfate proteoglycans (perlecan) and atherogenicity. 1115 Jul 31

A link between certain infectious microorganisms and an increased risk of atherosclerotic disease has been suggested. By analyzing the data of subjects who had undergone general health-screening tests, a possible association between carotid atherosclerosis and seropositivity of antibody against hepatitis C virus (HCV) has been previously reported. In the present study, a possible link between carotid atherosclerosis and HCV core protein positivity was assessed, because it is postulated to be a better marker of viremia and thus persistent infection. Of the 1992 enrolled subjects, 496 (25%) had carotid artery plaque, and 25 (1.3%) were positive for HCV core protein. Carotid artery plaque was positive in 480/1967 (24%) and 16/25 (64%) of the core protein-negative and core protein-positive subjects, respectively (p<0.0001 by chi(2) test). Serum concentrations of transaminases were higher in core protein-positive subjects, but albumin concentrations were not significantly different between the 2 groups. Multivariate logistic regression analysis showed that HCV core protein positivity is an independent predictor of carotid plaque with an odds ratio of 5.61 (95% confidence interval 2.06-15.26, p<0.001). These data further support the possible link between persistent HCV infection and carotid atherosclerosis in the subjects without severe liver dysfunction.
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PMID:Association between hepatitis C virus core protein and carotid atherosclerosis. 1252 Jan 47

Hyperglycemia is an independent risk factor for diabetes-associated cardiovascular disease. One potential mechanism involves hyperglycemia-induced changes in arterial wall extracellular matrix components leading to increased atherosclerosis susceptibility. A decrease in heparan sulfate (HS) glycosaminoglycans (GAG) has been reported in diabetic arteries. The present studies examined the effects of high glucose on in vitro production of proteoglycans (PG) by aortic endothelial cells. Exposure of cells to high glucose (30 vs. 5 mM glucose) resulted in decreased [(35)S] sodium sulfate incorporation specifically into secreted HSPG. Differences were not due to hyperosmolar effects and no changes were observed in CS/DSPG. Enzymatic procedures, immunoprecipitation and Western analyses demonstrated that high glucose induced changes specifically in the HSPG, perlecan. In double-label experiments, lower sulfate incorporation in high-glucose-treated cells was accompanied by lower [(3)H] glucosamine incorporation into GAG but not lower [(3)H] serine incorporation into PG core proteins. Size exclusion chromatography demonstrated that GAG size was unchanged and GAG sulfation was not reduced. These results indicate that the level of regulation of perlecan by high glucose is posttranslational, involving a modification in molecular structure, possibly a decrease in the number of HS GAG chains on the core protein.
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PMID:High-glucose-induced structural changes in the heparan sulfate proteoglycan, perlecan, of cultured human aortic endothelial cells. 1505 91

Smooth muscle cells (SMC) of the rat carotid arterial media proliferate and migrate in response to injury during the formation of a neointima. The interaction of fibroblast growth factor (FGF-2), which is released at the site of injury, with heparan sulfate proteoglycans (HSPGs) is necessary to induce signaling, which elicits an FGF-dependent mitogenic response by arterial smooth muscle cells, and also serves as a mechanism for storage of the growth factor within the extracellular matrix. However, whether these interactions are critical during neointimal formation has not been directly tested. In this study, a model of FGF-2-dependent medial SMC mitogenic response in balloon-injured rat carotid artery was used to test the effect of degradation of vessel wall heparan sulfate on subsequent SMC proliferation. Treatment of balloon-catheterized rat carotid arteries with chondroitin ABC lyase and/or heparin lyases eliminated heparan sulfates in the vessel wall, as determined by immunoperoxidase staining. In contrast, the distribution in the carotid vessel wall of the large core protein of perlecan, a major vessel wall HSPG that binds FGF-2, is not decreased. The effect of glycosaminoglycan digestion in situ on medial SMC proliferation in response to a bolus injection of FGF-2 after injury was determined by measuring the percentage of SMC nuclei that incorporated 5-bromo-2'-deoxyuridine (BrdU) 48 h after injury. Enzymatic removal of heparan sulfate reduced BrdU incorporation into medial SMC by 60-70% (P < 0.001) at 48 h after injury. Moreover, pre-incubation of FGF-2 with heparin prior to injection restored SMC replication to the levels present in injured vessels treated with buffer alone (P < 0.01). These experiments indicate that endogenous HSPGs are essential to promote FGF-2-driven medial SMC proliferation following injury, and that heparinase treatment can abrogate FGF-2-dependent responses in vivo.
Atherosclerosis 2004 Jul
PMID:Removal of heparan sulfate by heparinase treatment inhibits FGF-2-dependent smooth muscle cell proliferation in injured rat carotid arteries. 1518 46

The accumulation of extracellular matrix components such as proteoglycans is a hallmark of an atherosclerotic lesion. A large heparan sulfate proteoglycan, perlecan, dramatically increases in the advanced lesion, and vascular smooth muscle cells are the cell type responsible for the accumulation. In this study, we investigated the effects of thrombin on the proteoglycan synthesis in cultured human coronary smooth muscle cells to determine the interrelationship between the accumulation of proteoglycans and the procoagulant state of blood in atherosclerosis. The cells were metabolically labeled with [(35)S]sulfate or (35)S-labeled amino acids in the presence of thrombin, and the labeled proteoglycans were characterized by Sepharose CL-4B molecular sieve chromatography and DEAE-Sephacel ion-exchange chromatography. The glycosaminoglycan M(r) and composition were analyzed by Sepharose CL-6B chromatography, and the core protein M(r) was determined by SDS-polyacrylamide gel electrophoresis before and after digestion with chondroitinase ABC or papain. The results indicate that thrombin increases the cell layer-associated heparan sulfate proteoglycan with a core protein size of approximately 400 kDa without any change in the length of the glycosaminoglycan chains when the cell density is high. The heparan sulfate proteoglycan was identified as perlecan by Western blot analysis. In addition, quantitative reverse transcription-polymerase chain reaction showed that thrombin elevated the steady-state level of perlecan mRNA but not that of versican, decorin, and syndecan-1 mRNAs, although that of biglycan mRNA was moderately elevated. Furthermore, the percentage of disaccharide units that compose perlecan heparan sulfate chains remained unaffected by thrombin. Therefore, it is suggested that thrombin induces the perlecan core protein synthesis without influencing the formation of the heparan sulfate chains in human coronary smooth muscle cells at a high cell density. The regulation of proteoglycan synthesis by thrombin may be involved in the accumulation of perlecan in advanced lesions of atherosclerosis.
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PMID:Induction of synthesis of a large heparan sulfate proteoglycan, perlecan, by thrombin in cultured human coronary smooth muscle cells. 1571 25

Steatosis is a common feature of chronic hepatitis C, and may be caused directly by the virus, as in genotype 3 infection, or be associated with host metabolic factors. The interaction of hepatitis C virus core protein with the lipoprotein secretion pathways causes the characteristic alterations of lipid metabolism observed in hepatitis C virus-related steatosis. Several pathogenic mechanisms are likely involved into the pathogenesis of hepatitis C virus-related steatosis, including hyper-homocysteinaemia, hypoadiponectinaemia and insulin resistance. Steatosis is a major determinant of the liver damage progression in chronic hepatitis C (CHC), and negatively affects the response rate to the interferon (IFN)-based anti-viral treatment. Moreover, recent evidence suggests that steatosis may contribute to liver carcinogenesis. Chronic hepatitis C is a recognized risk factor for type 2 diabetes and it could be implicated into the pathogenesis of atherosclerosis. The role of hepatitis C virus (HCV)-related steatosis in these epidemiological associations remains to be determined.
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PMID:Review article: hepatitis C virus-associated steatosis--pathogenic mechanisms and clinical implications. 1622 74

Heparan sulfate in the extracellular matrix of the artery wall has been proposed to possess anti-atherogenic properties by interfering with lipoprotein retention, suppression of inflammation, and inhibition of smooth muscle cell growth. Previously, the amount of heparan sulfate in atherosclerotic lesions from humans and animals has been shown to be reduced but the identity or identities of the heparan sulfate molecules being down regulated in this disease are not known. In this study, atherosclerotic lesions were retrieved from 44 patients undergoing surgery for symptomatic carotid stenosis. Normal iliac arteries from organ donors were used as controls. Analysis of the specimens by gene microarray showed a selective reduction in perlecan gene expression, whereas, expression of the other heparan sulfate proteoglycans in the artery wall, agrin and collagen XVIII, remained unchanged. Expression of the large chondroitin sulfate proteoglycan, versican, also remained unchanged. Real-time PCR confirmed the decrease in perlecan gene expression and the unchanged expression of versican. The findings were supported by immunohistochemical analysis demonstrating a reduced accumulation of both perlecan core protein and heparan sulfate in carotid lesions. The study demonstrates a reduction of perlecan mRNA-expression and protein deposition in human atherosclerosis, which in part explains the low levels of heparan sulfate in this disease.
Atherosclerosis 2007 Feb
PMID:Reduced perlecan expression and accumulation in human carotid atherosclerotic lesions. 1662 Aug 36

Proteoglycans are important components of the extracellular matrix of all tissues. Proteoglycans are comprised of a core protein and one or more covalently attached glycosaminoglycan (GAG) chains. The major chondroitin sulfate (CS) and dermatan sulfate (DS) proteoglycans are aggrecan, versican, biglycan and decorin. Cells synthesize GAGs of natural or basal lengths and the GAG chains are subject to considerable growth factor, hormonal and metabolic regulation to yield longer GAG chains with altered structure and function. The mechanism by which the CS/DS GAG chains are polymerized is unknown. Recent work has identified several monosaccharide transferases which when co-expressed yield GAG polymers and the length of the polymers depends upon the pair of enzymes coexpressed. The further extension of these chains is regulated by signaling pathways. Inhibition of these latter pathways may be a therapeutic target to prevent the elongation which is associated with increased binding of atherogenic lipids and the disease process of atherosclerosis.
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PMID:Biosynthesis of natural and hyperelongated chondroitin sulfate glycosaminoglycans: new insights into an elusive process. 1923 87

Platelet-derived growth factor (PDGF) receptor signalling is implicated in cardiovascular diseases such as atherosclerosis and restenosis. PDGF expression levels are elevated in atherosclerotic lesions and play a key role in migration and proliferation of vascular smooth muscle cells in the neointima. PDGF stimulates glycosaminoglycan elongation on vascular proteoglycans biglycan and decorin, a process implicated in the aetiology of atherosclerosis. We investigated the ability of the specific kinase inhibitor Ki11502 to inhibit PDGF beta receptor phosphorylation and proteoglycan synthesis in human vascular smooth muscle cells. Ki11502 inhibited PDGF-mediated tyrosine phosphorylation of the PDGF beta receptor autophosphorylation site and at least six other receptor-associated proteins. Ki11502 also caused a concentration-dependent inhibition of PDGF-stimulated [(3)H]-thymidine incorporation. Total proteoglycan synthesis was assessed as incorporation of [(35)S]-sulfate. PDGF-induced a two-fold increase in [(35)S]-sulfate incorporation into proteoglycans secreted over 24h and was inhibited in a concentration-dependent manner by Ki11502. PDGF treatment resulted in a statistically significant (P<0.01) increase in total proteoglycan core protein secretion. Treatment of cells with Ki11502 (300 nM) had no effect on basal core protein secretion and completely abolished the PDGF-stimulated component. Analysis of isolated cleaved glycosaminoglycan chains by size-exclusion chromatography demonstrated that PDGF stimulated the synthesis and secretion of proteoglycans with elongated glycosaminoglycan chains and this effect was inhibited by Ki11502. Inhibition was also seen in the length of xyloside-glycosaminoglycan chains. The results demonstrate that Ki11502 is a potent and selective inhibitor of PDGF beta receptor phosphorylation, proliferation and proteoglycan synthesis in human vascular smooth muscle cells.
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PMID:Characterisation of Ki11502 as a potent inhibitor of PDGF beta receptor-mediated proteoglycan synthesis in vascular smooth muscle cells. 1981 54


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