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)

In this study we asked whether the well-known atherosclerosis resistance of rats might be reduced with aging. Two groups of young, adult and aged Wistar rats, one of which was kept on a standard, low-cholesterol (CT) diet, and the other one was fed a 2% CT diet for 2 months were enrolled. Potential modifications in the phenotypic profile of aortic smooth muscle (SM) were assessed by SDS-gel electrophoresis, Western blotting and immunofluorescence procedures using a panel of monoclonal antibodies to myosin isoforms, cytoskeletal and extracellular matrix proteins. With development and aging, the expression of 196-kD non-muscle-type myosin heavy-chain isoform (MyHC), the EIIIA fibronectin variant and keratins was downregulated, whereas that of the 204- and 200-kD SM-type MyHC isoforms, SM-type alpha-actin and desmin did not change. The levels of hypercholesterolemia achieved in this model did not substantially modify the distribution of the downregulated markers, except for the subendothelial grouping of immature SM cells in aged rats. Morphometric measurements indicated a slight increase of medial cross-sectional area accompanied by a decrease in total SM cell number, both with aging and with hypercholesterolemia. In no circumstance was the presence of atherosclerotic lesions histologically detectable. Bromo-deoxyuridine (BrdU) incorporation analysis revealed a marked age-dependent decline in DNA synthesis and the formation of binucleated cells in aged aortas. This pattern was not influenced by hypercholesterolemia, except in aged rats where BrdU-positive SM cells are almost doubled. Our data indicate that aging and hypercholesterolemia cannot affect the phenotypic stability of rat SM cells and confirm that the change from a fully differentiated to an immature state is a general prerequisite to allow the development of atherosclerotic lesions in mammalian species.
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PMID:Atherosclerosis resistance in rats correlates with lack of expansion of an immature smooth muscle cell population. 925 93

The exceptionally strong independent association found between Lp(a) lipoprotein [Lp(a)] levels and atherosclerotic disorders indicate that Lp(a) is a factor of considerable importance in the pathogenesis of atherosclerosis. The association between Lp(a) and diabetes, rheumatoid arthritis and renal diseases suggest that Lp(a) may be involved in immunological mechanisms. Lp(a) has a great tendency to aggregate and bind to glucosaminoglycans, fibrin and fibronectin and is preferentially retained in the extracellular matrix during development of atherosclerosis and is in vitro phagocytosed by macrophages, probably as small aggregates. It was previously found that the Lp(a) level is significantly related to the HLA class II genotype in male patients with early coronary artery disease. In this paper additional results of interleukin determinantions in relation to HLA type and Lp(a) levels are presented and discussed. It is suggested that an autoimmune process, perhaps triggered by a concomitant intracellular infection may occur, especially in patients with inherited high Lp(a) levels in combination with certain inherited HLA class II genotypes.
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PMID:Indications of an autoimmune component in LP(a) associated disorders. 909 40

The effects of serotonin on migration of cultured rat aortic smooth muscle cells (SMC) were studied to clarify the role of this substance in the pathogenesis of atherosclerosis. Serotonin alone did not stimulate SMC migration but stimulated it at physiological concentrations in the presence of other migration factors such as SMC-derived migration factor, platelet-derived migration factor and fibronectin. Checker-board analysis revealed that the serotonin effect was chemotactic. Moreover, serotonin effects were completely abolished by a selective inhibitor of the 5-HT2 receptor (MCI-9042), indicating that serotonin effects were mediated through the 5-HT2 receptor pathway. Finally, serotonin effects were also abolished by a phospholipase C inhibitor, U73122, suggesting that the 5-HT2 receptor mediated signal of serotonin was transduced by PLC. The results suggest that platelet-derived serotonin plays some role in the SMC dominant neointima formation.
Atherosclerosis 1997 Jul 25
PMID:Serotonin (5-hydroxytryptamine, 5-HT) enhances migration of rat aortic smooth muscle cells through 5-HT2 receptors. 924 58

In vascular smooth muscle cells (SMCs), proliferation and migration contribute to lesion formation after arterial injury. In the cell cycle, several cyclin-dependent kinases (cdks) inhibitors are implicated in the regulating of cyclin-cdk activity such as p21Cip1, p16Ink4 and p27Kip1. Although Cip1 inhibits SMC proliferation, its effects on SMC migration are unknown. To test the hypothesis that Cip1 inhibits SMCs migration and proliferation, we transfected the Cip1 gene into a strain of rabbit aortic SMCs (SM3 cells). Both the spreading and the attachment of Cip1-transfected SM3 cells to extracellular matrices (ECMs) were inhibited compared to that of vector-transfected cells. In the modified Boyden's chamber assay the effect of fibronectin on the migratory activity of Cip1-transfected SM3 cells was significantly less than that of vector transfected cells in response to PDGF-BB. These data suggested that Cip1 inhibited both the migration and proliferation of SMC.
Atherosclerosis 1997 Jul 11
PMID:Inhibition of smooth muscle cell migration by the p21 cyclin-dependent kinase inhibitor (Cip1). 924 59

Vessel wall subendothelial extracellular matrix, a dense mesh formed of collagens, fibronectin, laminin, and proteoglycans, has important roles in lipid and lipoprotein retention and cell adhesion. In atherosclerosis, vessel wall heparan sulfate proteoglycans (HSPG) are decreased and we therefore tested whether selective loss of HSPG affects lipoprotein retention. A matrix synthesized by aortic endothelial cells and a commercially available matrix (Matrigel; , Rutherford, NJ) were used. Treatment of matrix with heparinase/heparitinase (1 U/ml each) increased LDL binding by approximately 1.5-fold. Binding of lipoprotein (a) [Lp(a)] to both subendothelial matrix and Matrigel(R) increased 2-10-fold when the HSPG were removed by heparinase treatment. Incubation of endothelial cells with oxidized LDL (OxLDL) or lysolecithin resulted in decreased matrix proteoglycans and increased Lp(a) retention by matrix. The effect of OxLDL or lysolecithin on endothelial PG was abolished in the presence of HDL. The decrease in matrix HSPG was associated with production of a heparanase-like activity by OxLDL-stimulated endothelial cells. To test whether removal of HSPG exposes fibronectin, a candidate Lp(a) binding protein in the matrix, antifibronectin antibodies were used. The increased Lp(a) binding after HSPG removal was inhibited 60% by antifibronectin antibodies. Similarly, the increased Lp(a) binding to matrix from OxLDL-treated endothelial cells was inhibited by antifibronectin antibodies. We hypothesize that atherogenic lipoproteins stimulate endothelial cell production of heparanase. This enzyme reduces HSPG which in turn promotes Lp(a) retention.
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PMID:Subendothelial retention of lipoprotein (a). Evidence that reduced heparan sulfate promotes lipoprotein binding to subendothelial matrix. 925 86

The effect of aminoguanidine (AG) on the expression of adhesion molecules on nonactivated human umbilical vein endothelial cells (HUVEC) was investigated in vitro. Nonactivated HUVEC cultivated on long-term glycated fibronectin (FN) as compared to native FN showed a significant upregulation of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and CD31 which could be further promoted by long-term glycated bovine serum albumin. AG, at a concentration of 0.01 mol/l, caused an upregulation of ICAM-1 of 48 +/- 17.4% in HUVEC cultivated on gelatin. In contrast, VCAM-1 and E-selectin remained unaffected. At this concentration, formation of advanced glycation end products (AGE) was inhibited by 57%, as determined immunologically, and by 50%, as verified by AGE-specific fluorescence. A hypothesis concerning the upregulation of ICAM-1 by AG as compared to VCAM-1 is proposed relating to its relative redox insensitivity. Our results demonstrate that the beneficial effect of AG in reducing the risk of accelerated development of atherosclerosis in diabetic patients by inhibiting formation of AGE on matrix proteins such as FN might be hampered by its tendency to upregulate ICAM-1 on endothelial cells.
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PMID:Effects of aminoguanidine on adhesion molecule expression of human endothelial cells. 934 1

To assess the pathologic findings observed in the setting of post-transplant graft atherosclerosis, we have studied 18 endomyocardial biopsies (EMB) from 18 heart-transplanted patients collected at the same time that a coronary angiography (CA) showed changes consistent with graft atherosclerosis. Twenty-two EMB from patients with heart transplant with normal CA were used as controls. In spite of the small size of the sample, the number of acute rejection (AR) episodes correlated with the appearance of graft atherosclerosis (p < 0.001). Heart biopsies in graft atherosclerosis showed myointimal proliferation, thickening and folding of the wall of precapillary arteries, myocyte hypertrophy, and interstitial and perivascular fibrosis. Type III and type IV collagen, laminin, and fibronectin were increased in areas of interstitial and perivascular fibrosis, as well as in the vessel's wall. Fibronectin accumulation was more evident in the subendothelium and inner media of affected vessels. These changes were never found all together in control biopsies. Even though the inespecificity of some of those findings, we conclude that chronic graft atherosclerosis in a heart transplant may be suspected by endomyocardial biopsy when most of these alterations are seen together, especially if small precapillary arteries are present in the specimen.
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PMID:Role of endomyocardial biopsy in the diagnosis of chronic rejection in human heart transplantation. 936 35

Hyperhomocysteinemia is associated with severe, premature atherosclerosis and thromboembolism. The mechanisms involved in the atherogenic and thrombotic complications of hyperhomocysteinemia are not understood. It has been suggested that hyperhomocysteinemia predisposes to atherosclerosis by injuring the vascular endothelium. Whether hyperhomocysteinemia is independently associated with changed endothelial function, either in the absence or the presence of clinically manifest atherosclerotic disease, is, however, not known. Therefore we investigated, both in patients with peripheral arterial occlusive disease and in healthy individuals, whether plasma protein markers of endothelial function differed between subjects with, and subjects without hyperhomocysteinemia. We studied 80 individuals under the age of 56 years: healthy individuals with (n = 20) and without (n = 20) hyperhomocysteinemia and patients with peripheral arterial occlusive disease with (n = 20) and without (n = 20) hyperhomocysteinemia. The following endothelium-derived proteins were measured as markers of endothelial cell function: von Willebrand factor (vWf) and von Willebrand factor propeptide (vWf: AgII), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), cellular fibronectin (cFN) and thrombomodulin (TM). In addition we assessed C-reactive protein (CRP). vWf, vWf: AgII, tPA and CRP were significantly higher in the patients with peripheral arterial occlusive disease than in the healthy individuals. No differences in marker protein plasma levels were found between individuals with, and those without hyperhomocysteinemia, apart from vWf, which was significantly raised in hyperhomocysteinemic as compared to normohomocysteinemic patients. We did not find any evidence for an independent association between hyperhomocysteinemia and protein markers of endothelial cell function in healthy subjects.
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PMID:Endothelial marker proteins in hyperhomocysteinemia. 940 14

The proliferation of intrinsic glomerular cells and the accumulation of extracellular matrix proteins are principal histopathological features seen in glomerular injury. Because of the marked similarity between the cellular and molecular events that occur in both atherosclerosis and glomerulosclerosis and the commonly accepted hypothesis that lipoproteins are implicated in the pathogenesis of glomerulosclerosis, we examined the effect of three atherogenic lipoproteins, low-density lipoprotein (LDL), oxidized (ox)-LDL, and minimally modified (mm)-LDL on the synthesis and secretion of extracellular matrix (ECM) proteins by mesangial cells. The incubation of SV-40 transformed murine mesangial cells with LDL (25-100 microg/ml) increased the synthesis and secretion of both fibronectin and laminin in a dose-dependent manner. Similarly, oxidized forms of LDL (25-100 micro/ml) increased fibronectin and laminin synthesis and secretion dose dependently. However, both oxidatively modified forms of LDL had a greater effect on increasing ECM protein synthesis than their native counterpart. Northern blot analysis showed a dose-dependent increase in mRNA transcripts for fibronectin and laminin in response to the incubation of mesangial cells with LDL, ox-LDL, and mm-LDL. Similar to the ECM protein expression data, the oxidatively modified forms of LDL had more pronounced effects on the gene expression of both fibronectin and laminin. These data show that both LDL and, perhaps more importantly, its oxidatively modified forms stimulate mesangial cells to upregulate both the gene expression and synthesis and secretion of ECM proteins, supporting a role for atherogenic lipoproteins in the pathobiology of glomerular injury.
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PMID:Oxidative modification of low-density lipoprotein enhances mesangial cell protein synthesis and gene expression of extracellular matrix proteins. 965 42

Degradation of extracellular matrix (ECM) proteins in the aorta is a critical step for the development of atherosclerosis. Expression of matrix metalloproteinase (MMP)-12 (macrophage elastase), an elastin-degrading proteinase in the MMP family, was investigated in the thoracic aorta of rabbits fed a 1% cholesterol-containing diet for 16 weeks. In the atherosclerotic lesions, MMP-12 was produced abundantly at both the mRNA and protein levels, whereas no expression was observed in the normal rabbit aortas. The principal source of MMP-12 was macrophage foam cells (MFCs) that had infiltrated the atherosclerotic intima; this was demonstrated in both in vitro culture studies of MFCs purified from atherosclerotic lesions and immunohistochemical studies of aortic lesions. Additional biochemical studies using recombinant rabbit MMP-12 revealed that MMP-12 digested elastin, type IV collagen, and fibronectin and also activated MMP-2 and MMP-3. Expression of MMP-12 by human macrophage cell lines was increased by stimulation with acetylated low-density lipoprotein, implying augmentation of MMP-12 production during foam cell formation. Increased expression of MMP-12 in atherosclerotic lesions, concomitant with foam cell generation, which triggers the acceleration of ECM breakdown, is likely to be a critical step in the initiation and progression of the atherosclerotic cascade.
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PMID:Expression and localization of matrix metalloproteinase-12 in the aorta of cholesterol-fed rabbits: relationship to lesion development. 966 71


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