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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A method is presented for growing large numbers of pure isolated smooth muscle cells from adult human, monkey, and rabbit blood vessels in primary culture. In the first few days in culture these cells closely resembled those in vivo and could be induced to contract with angiotensin II, noradrenaline and mechanical stimulation. They stained intensely with antibodies against smooth muscle actin and myosin. Fibroblasts and endothelial cells did not stain with these antibodies thereby allowing the purity of each batch of cultures to be monitored. This was consistently found to be better than 99%. The smooth muscle cells modified or "dedifferentiated" after about 9 days in culture to morphologically resemble fibroblasts. At this stage cells could no longer be induced to contract and did not stain with the myosin antibodies. Intense proliferation of these cells soon resulted in a confluent monolayer being formed at which stage some differentiated characteristics returned. The modification of "dedifferentiation" process could be inhibited by the presence of a feeder layer of fibroblasts or endothelial cells, or the addition of cAMP to the culture medium. Smooth muscle cells which had migrated from explants in primary culture, and cells in subculture, had morphological and functional properties of "dedifferentiated" cells at all times. The advantages of differentiated rather than "dedifferentiated" smooth muscle cells in culture for the study of mitogenic agents in atherosclerosis is discussed.
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PMID:Comparison of vascular smooth muscle cells from adult human, monkey and rabbit in primary culture and in subculture. 40 16

Blood cells express a cell membrane protein, termed homologous restriction factor 20 (HRF20) and identical to CD59, that can inhibit complement C5b-9 insertion into their membranes. In this report, we investigated by immunohistochemistry whether CD59 was present on cells in human atherosclerotic lesions since membranous C5b-9(m) has been found in lesions. Using a monoclonal anti-CD59 antibody, a cellular CD59 staining pattern was apparent in nearly all lesion specimens. CD59 stain co-localised with macrophage (CD14), T lymphocyte (CD7), endothelial cell (anti-factor VIII related antigen) and smooth muscle cell cytoskeletal-specific antigens (anti-alpha actin and muscle myosin). Endothelial cells always exhibited a more intense stain than the other cell types. CD59 antigen was not localised to any one area of the lesions. Usually CD59-positive cells occurred in clusters rather than as randomly spaced individual cells. CD59 did not stain all cells of the lesion and in particular did not appear to stain all smooth muscle cells. Areas of CD59-negative cells were sometimes observed to exhibit a cellular C5b-9 staining pattern. C5b-9 deposits were also observed in CD59-positive regions. Normal saphenous vein stained strongly for CD59 at the endothelial lining and weakly in the media. Capillaries in atherosclerotic intima always stained strongly for CD59. We conclude that HRF20 is constitutively expressed on endothelium and is under regulatory control in smooth muscle cells. Cellular C5b-9 attack in atherosclerotic lesions is therefore most likely to occur on smooth muscle cells.
Atherosclerosis 1992 Oct
PMID:CD59 (homologous restriction factor 20), a plasma membrane protein that protects against complement C5b-9 attack, in human atherosclerotic lesions. 128 30

To study the functional characteristics of smooth muscle cell (SMC) phenotypes, we have investigated myosin expression, cell proliferation, collagen production and low-density lipoprotein (LDL) receptor activity in intimal SMCs of normal human aorta during their growth in primary culture. By staining with rabbit antibodies to smooth muscle myosin (ASMM) 3 cell types could be distinguished in culture: homogeneously stained cells, cells with discontinuous myosin fibrils and myosin-negative cells. The ratio of cell types greatly changed with culture growth: on days 5, 7 and 14 it was 82:1:17%, 70:5:25% and 10:30:60%, respectively. After 5-6 days of culture intimal SMCs began to proliferate and DNA-synthesizing nuclei were seen 1.5-4.3 times more frequently in myosin-negative cells than in cells with homogeneous myosin distribution. At that time the number of cells reacted with monoclonal antibody (MAb) to an epitope shared collagen types I and III started to increase. By double immunofluorescence staining it was shown that the cultured cells containing both ASMM and MAb markers were found 2.0-4.8 times more rarely than MAb-positive staining in myosin-negative cells. During the first 5 days in culture LDL binding and uptake were diminished in intimal cells with intercellular lipid inclusions independently of their myosin staining pattern, but their activity increased with culture growth. Thus, SMCs from human aortic intima change their phenotype on days 6 and 7 in primary culture as manifested by alteration of myosin expression, increased cell proliferation, collagen production and LDL receptor activity. Changes in myosin expression, however, are not an essential prerequisite for cell proliferation and collagen production.
Atherosclerosis 1992 Oct
PMID:Phenotype related changes of intimal smooth muscle cells from human aorta in primary culture. 146 51

Smooth muscle cell (SMC) proliferation is a poorly understood process that plays a critical role in several pathological states, including atherosclerosis and hypertension. Recent work suggests that the oncogene c-myb and myosin, a ubiquitous cytoskeletal protein, may be directly involved in this process. We have used antisense nonmuscle myosin heavy chain (NMMHC) or c-myb phosphorothiolate oligonucleotides to inhibit proliferation of SMCs in vitro. The suppression of growth is accompanied by reductions in the concentrations of NMMHC and c-myb mRNAs as well as decreases in the levels of the corresponding proteins. The specificity of the antiproliferative effect is underscored by the absence of any detectable growth inhibition with sense NMMHC or c-myb phosphorothiolate oligonucleotides, an antisense c-myb mismatch phosphorothiolate oligonucleotide, or an antisense thrombomodulin phosphorothiolate oligonucleotide. Furthermore, the treatment of SMCs with antisense phosphorothiolate oligonucleotides for as little as 2 hours causes maximal inhibition of cell growth over the next 72 hours. Under these conditions, SMCs attain normal rates of growth over the following 48 hours, which shows that proliferation is suppressed in a reversible fashion by antisense phosphorothiolate oligonucleotides. These experiments indicate that both c-myb and nonmuscle myosin play critical roles in SMC proliferation and that reductions of either mRNA by antisense phosphorothiolate oligonucleotides arrest the process.
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PMID:Antisense nonmuscle myosin heavy chain and c-myb oligonucleotides suppress smooth muscle cell proliferation in vitro. 155 Dec 7

Two monoclonal antimyosin antibodies, Western blotting experiments, and immunofluorescence procedures were used to investigate myosin isoform expression in normal and atherosclerotic aortas of adult rabbits. The SM-E7 antibody reacted with the two myosin heavy chain (MHC) isoforms of smooth muscle (SM) type (SM-MHC-1 and SM-MHC-2) expressed in the adult rabbit aorta. The NM-G2 antibody recognized an epitope shared by the nonmuscle (NM) myosin heavy chains (NM-MHC) present in fibroblasts, macrophages, lymphocytes, and platelets. Two smooth muscle cell (SMC) populations were identified in the medial layer of normal adult aorta, namely cells that contained SM myosin exclusively and cells that showed the coexistence of SM and NM myosin isoforms. The size of the cell population with double myosin isoform content increased markedly during experimental atherogenesis and represented by far the predominant SMC phenotype in the atherosclerotic plaque. Western blotting analysis performed on crude extracts from the atherosclerotic plaque showed the presence of SM-MHC-1 and NM-MHC isoforms in this tissue. Co-expression of SM and NM myosin at the molecular and the cellular level were found in aortic tissue during the early stages of development. These results indicate that in experimental atherosclerosis, the accumulation in the plaque of SMC with an "immature" pattern of myosin isoform expression is accompanied by similar modifications in the differentiation pattern of SMC of the underlying media.
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PMID:Myosin isoform expression and smooth muscle cell heterogeneity in normal and atherosclerotic rabbit aorta. 170 Aug 96

The ultrastructure and the expression of cytoskeletal and contractile proteins were studied in the intimal cells of human coronary arteries (CA) taken at autopsy from 38 trauma victims aged 1 to 70 years. All intimal smooth muscle cells (SMC) of the CA from 2-4-year old children contained desmin, vimentin, myosin, and actin. In the normal intima of adolescents aged 14-16 years, only did some SMC contain desmin whereas in that of adults, they had no desmin, but expressed all other proteins. For example, some atherosclerotic plaques of CA exhibited desmin-positive SMC and smooth muscle myosin-free cells. The ultrastructure of SMC of atherosclerotic plaques showed profound polymorphism. In addition to typical SMC, the plaques displayed modified cells having a developed endoplasmic reticulum and Golgi complex. The fact that the atherosclerotic plaques have cells differing in ultrastructural features and protein expression, which is specific to an earlier period of the body development suggests phenotypic changes in the cells and the latter acquiring new functions that are of great significance in the pathogenesis of atherosclerosis.
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PMID:[Phenotype changes in smooth muscle cells of human coronary arteries during aging and during development of atherosclerosis]. 179 63

This paper deals with some changes at the cardiac and aortic levels observed in normotensive rats and in hypertensive rats and turkeys by using two different beta-blockers, namely propranolol and oxprenolol. Chronic treatment with propranolol induced in the heart of normotensive rats a shift in the ventricular myosin pattern toward the "slow" V2 and V3 isoforms which are characterized by a reduced oxygen consumption. Oxprenolol treatment did not modify the blood pressure levels in the renal hypertensive rats nor in the spontaneously hypertensive turkeys. Nevertheless, in both experimental models a substantial modification of the media and intima, respectively, took place. In untreated hypertensive and normal rats the thickness of the aortic media was significantly higher than that of the treated ones, therefore suggesting a direct effect of oxprenolol on the smooth muscle cells of the aortic media. In the spontaneously hypertensive turkeys the atherosclerotic plaques appeared to be more frequent and thicker than those found in the oxprenolol-treated animals. These two experiments demonstrate that beta-blockers can prevent the development of hypertrophy of the media and decrease both the incidence and severity of intimal proliferations independently of blood pressure control. It therefore appears that the well-known myocardial protective effect played by beta-blockers, which mainly consists of a reduced myocardial oxygen consumption, is certainly obtained by reducing blood pressure and heart rate but also by changing the contractile protein pattern. In addition, an indirect myocardial protective effect could be exerted by beta-blockers at the vascular level by preventing medial hypertrophy and the development of atherosclerosis.
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PMID:Cardioprotection by beta-blockers: molecular and structural aspects in experimental hypertension. 197 39

We evaluated the ability of the Ca2+ channel blocker nifedipine to influence the severity of atherosclerotic lesions and the pattern of aortic smooth muscle cell (SMC) differentiation in cholesterol-fed New Zealand White rabbits. The animals were fed a 1% cholesterol-enriched diet for 12 weeks. After 4 weeks of the diet, some rabbits were given nifedipine (20 mg b.i.d.) for another 8 weeks without discontinuation of the cholesterol-enriched diet (experiment 1). Another group of rabbits was treated with nifedipine from the beginning of the cholesterol-enriched diet for the entire 12 weeks (experiment 2). The severity of ahterosclerotic lesions was determined by computerized planimetry, and qualitative effects of nifedipine on SMCs were studied by monoclonal antibodies specific for smooth muscle and nonmuscle myosins. In the aortic media of normal rabbits, these antibodies can identify an SMC population with an "immature" type of myosin pattern; a marked increase in the number of these cells is observed during atherogenesis. In experiment 1, we observed a marked decrease of medial SMCs with the immature type of myosin pattern, without any significant reduction in atherosclerosis severity. In experiment 2, disappearance of the previously mentioned medial SMC population was accompanied by a dramatic slowing of intimal lesion development. These results indicate that nifedipine treatment is effective in reducing atherosclerotic lesions only when given from the beginning of a cholesterol-enriched diet. Delay of nifedipine administration until the fourth week of the cholesterol-enriched diet fails to halt progression of the disease. The observed antiatherosclerotic activity can be attributable to a direct effect of the drug on the medial SMC population, which increases during the course of experimental atherogenesis.
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PMID:A nifedipine-sensitive smooth muscle cell population is present in the atherosclerotic rabbit aorta. 206 44

The pattern of immunocytochemical staining with antibodies to caeruloplasmin, myosin, myoglobin and C-reactive protein seen in myocardium taken from deaths with macroscopic evidence of myocardial infarction and/or significant coronary artery atherosclerosis and from deaths with neither of these lesions has been correlated with H&E, PTAH and HBFP staining of myocardium and circumstances of each death indicative of antemortem hypoxia and/or ischaemia. Loss of staining with these antibodies correlated well with fuchsinorrhagia and both techniques are more sensitive than H&E and PTAH staining in the detection of early ischaemic/hypoxic damage to myocardium. However, their sensitivity is such that they appear to detect agonal changes and, therefore, cannot be used for specific diagnosis of early myocardial infarction.
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PMID:Further evaluation of immunocytochemical staining in the diagnosis of early myocardial ischaemic/hypoxic damage. 233 27

The manifestations of cardiac involvement in hypertension include: (1) the development of hypertensive heart disease characterized by left ventricular hypertrophy (LVH), and (2) the consequences of coronary atherosclerosis, as angina pectoris, myocardial infarction, and sudden cardiac death. Whereas the former is directly related to increased blood pressure, the latter are sequelae of atherosclerosis per se, and hypertension acts only as a risk factor in this regard. This can partially explain why antihypertensive treatment is effective in diminishing the incidence of congestive heart failure, which is the final consequence of LVH, but is not very effective in preventing coronary complications. It is generally accepted about LVH that increased arterial pressure is the major stimulus to cardiac hypertrophy in hypertension; however, there are a lot of both quantitative and qualitative events suggesting that other factors beside blood pressure levels can modulate the development of LVH, in particular neurohumoral influences. From a morphological point of view, hypertrophy of the cardiac muscle is defined as an increase in the size of existing myocardial fibers. In most experimental models, myocardial hypertrophy is associated with myosin isoenzymatic changes, consisting in a shift from the faster migrating isoenzyme V1 to V3, a form that migrates more slowly. However these changes do not occur in all animal species and particularly in humans. In the hypertrophied human ventricle, a decreased ATPase activity of myofibrils was observed, probably related to changes in myosin light chains. Presently the changes in ATPase activity and in ventricular contractility do not still have a clear molecular basis in humans.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Heart and hypertension. 252 4


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