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)

Regulation of expression of the genes for the low density lipoprotein receptor (LDLR) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) is of central importance in the control of cholesterol metabolism and thus in influencing the concentration of low density lipoprotein in the plasma. This can be studied by investigating the effects of factors (hormones, drugs, etc.) on the levels of mRNA for these genes. An RNase protection assay is reported for measurement of the levels of mRNA for the LDLR and HMGR. Several probes have been developed for these genes, together with probes for the "housekeeping" genes, beta-actin and glyceraldehyde-3-phosphate dehydrogenase. Various conditions in the assay have been examined and optimised, e.g. conditions for solution hybridization and RNase digestion and the use of "sense" RNA standards. The assay allows accurate measurement of approximately 2 x 10(7) copies of LDLR and HMGR mRNAs, which is equivalent to the number of copies present in approximately 1 x 10(6) human dermal fibroblasts and approximately 5 x 10(5) Hep G2 liver hepatoma cells cultured in 10% fetal calf serum. The average number of copies of mRNA per cell was estimated in fibroblasts and Hep G2 cells under various conditions of regulation of the LDLR and revealed the following: [table: see text] Under the chosen conditions 10 copies per cell was the detection limit for the assay. The effect of these treatments on the number of copies of mRNA per cell for beta-actin and glyceraldehyde-3-phosphate dehydrogenase was also determined.
Atherosclerosis 1991 Sep
PMID:A sensitive RNase protection assay for the quantitation of the mRNAs for the LDL receptor and HMG-CoA reductase in human total RNA. Effects of treatments on cells in culture designed to up- and down-regulate expression of the LDL receptor. 182 10

The phenotype of smooth muscle cells (SMCs) in the aortic media of 7 human fetuses (14-20 weeks of gestation) was examined with transmission electron microscopy, immunofluorescence microscopy, and gel electrophoresis of the cytoskeletal and cytocontractile proteins. Ultrastructurally, virtually all medial cells were identified as SMCs having a poorly differentiated phenotype with a cytoplasm rich in rough endoplasmic reticulum and organelles, and with only a few myofilaments. All medial cells stained intensely with antibodies to vimentin, but only in a 20-week-old fetus could we find a few SMCs staining with antibodies to desmin. Nor was desmin detectable with SDS gel electrophoresis followed by immunoblotting, while clear bands corresponding to vimentin, myosin, and actin were present. In isoelectric focusing and two-dimensional gel electrophoresis beta-actin was the most prominent of the 3 actin isoforms in all cases. The present results show that SMCs in the media of fetal human aorta have a poorly differentiated phenotype, which morphologically and biochemically resembles that previously described in the aorta of fetal and newborn rat, in the arterial intima after endothelial injury, in atherosclerotic lesions, and after spontaneous modulation of medial SMCs in culture.
Atherosclerosis 1988 Nov
PMID:Characterization of the phenotype of smooth muscle cells in human fetal aorta on the basis of ultrastructure, immunofluorescence, and the composition of cytoskeletal and cytocontractile proteins. 321 79

Although little is known about the endothelial cell function of human saphenous vein coronary artery bypass grafts, there is evidence to suggest that receptor-activated, endothelial-dependent relaxation mediated by nitric oxide is impaired. This study examines the expression and function of endothelial cell constitutive nitric oxide synthase (cNOS) of aortocoronary vein bypass grafts and human saphenous veins obtained from 10 patients undergoing repeat coronary artery bypass grafting for recurrent ischemic symptoms. Following precontraction with norepinephrine (10(-5) M), responses to acetylcholine (receptor-mediated, endothelium-dependent), calcium ionophore (A23187; receptor-independent, endothelium-dependent), and sodium nitroprusside (endothelium-independent) were assessed. Following total RNA extraction using phenol/guanidinium isothiocyanate from specimens of human saphenous vein and vein graft, a quantitative RNase Protection Assay (RPA) was performed using a cRNA riboprobe corresponding to a fragment of the human endothelial cell cNOS gene. Histologically, the vein grafts showed both intimal hyperplasia development and focal atherosclerosis formation compared to the saphenous veins. Scanning electron microscopy of the saphenous veins and the vein grafts showed an intact endothelium. Precontracted vein grafts did not relax in response to acetylcholine; in contrast, the saphenous vein relaxed in a dose-dependent manner to reach a maximal relaxation of 19 +/- 4% precontracted tension. Saphenous veins and vein grafts relaxed in response to A23187 with maximal relaxation of 92 +/- 5 and 73 +/- 13%, respectively. Both vessels relaxed in a dose dependent manner to sodium nitroprusside. RPA normalized to beta-actin showed similar levels of expression of endothelial cell cNOS equivalent to 1 pg of sense RNA in both the saphenous vein and vein graft.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Constitutive nitric oxide synthase is expressed and nitric oxide-mediated relaxation is preserved in retrieved human aortocoronary vein grafts. 754 Jul 1

Hyperlipidemia, especially hypercholesterolemia, may contribute to glomerulosclerosis as it does to atherosclerosis. Low density lipoprotein (LDL) stimulates the production of extracellular matrix by mesangial cells in culture as well as the proliferation of mesangial cells. This study was carried out to examine the effects of LDL on the type IV collagen (CIV) production by cultured rat mesangial cells (CRMC). Subconfluent CRMC monolayers which were grown in RPMI with 20% lipid-free fetal calf serum for 48 h were challenged with LDL (0, 50, 100, 150 and 200 micrograms/ml) for another 48 h. LDL was prepared from normal human plasma. Mesangial cell proliferation was examined by [3H]-thymidine uptake. Production of CIV was evaluated as the expression of CIV on the cell surface by flow-cytometric analysis. The collagen synthesis was measured by the [3H]-proline uptake. Total RNA was extracted from CRMC at 6 and 24 h of incubation with 150 micrograms/ml LDL, and Northern blotting and hybridization was performed with cDNAs for alpha 1-CIV, for 72-kD collagenase and for tissue inhibitor of metalloproteinase (TIMP)-2. The amount of total mRNA was corrected with beta-actin mRNA. Mesangial cell proliferation increased in all concentrations studied and had a peak value of 221% with 150 micrograms/ml of LDL. Expression of CIV increased by 30-60% in 100-200 micrograms/ml of LDL. Collagen synthesis also increased by 50-70% in 150-200 micrograms/ml of LDL. The mRNA ratio (procollagen alpha 1(IV)/beta-actin) increased to 133% at 24 h. The mRNA ratio (TIMP-2/beta-actin) increased to 137% at 24 h. mRNA ratios at 6 h showed no change.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of low density lipoprotein on type IV collagen production by cultured rat mesangial cells. 793 24

Monokines, such as interleukin-1, have been implicated in the pathogenesis of several pathologic processes, including the initiation and progression of atherosclerosis. Since estrogen has been identified as a modulator of atherosclerosis progression, we sought to examine the effect of estrogen on the inducible expression of interleukin-1 beta (IL-1 beta) and interleukin-1 alpha (IL-1 alpha) mRNA in the monocytic cell line, THP-1. Cells were treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) (50 ng/ml) for 48 or 96 h to induce differentiation. Some cells were treated with lipopolysaccharide (LPS) (10 micrograms/ml) in the last 3 h and/or 10(-9) M ethinyl estradiol (estrogen) in the last 20 h. Total cellular RNA was isolated, and cDNA was synthesized and amplified using the polymerase chain reaction (PCR) using two sets (pairs) of 32P-labeled primers, one for IL-1 beta (product size 388 bp) and the second for the internal control, beta-actin (1126 bp), or to detect another cytokine mRNA, a set of primers for IL-1 alpha (product size 420 bp) and beta-actin. The PCR products were separated on a 3.0% agarose gel and the ratio of radioactivity incorporated into cytokine PCR products and beta-actin products was determined to assess the relative changes in the relative levels of cytokine to beta-actin mRNA abundance in response to various inducers. Treatment with TPA for 48 h induced expression of IL-1 beta mRNA, an effect that was enhanced two fold by LPS.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The inducible expression of THP-1 cell interleukin-1 mRNA: effects of estrogen on differential response to phorbol ester and lipopolysaccharide. 818 19

Smooth muscle cell differentiation and proliferation are increasingly seen to be intimately tied to the etiology of atherosclerosis and hypertension. To determine the role of PKC alpha in the regulation of smooth muscle cell differentiation and proliferation, the rat embryonic smooth muscle cell line A7r5 was transfected with an expression vector containing the full-length PKC alpha cDNA. Neomycin-resistant clones which exhibited increased PKC alpha levels compared to wild-type cells were selected. The A7r5 cells overexpressing PKC alpha had altered morphology and decreased growth rates compared to wild-type cells and cells transfected only with the neomycin resistance gene. Electrophoretic mobility shift assays showed that nuclear extracts from overexpressing clones gave a different pattern of protein-DNA binding to an AP-1 consensus oligonucleotide compared to wild-type cells. In contrast to the growth characteristics of these clones, their levels of cell differentiation marker proteins such as vinculin and desmin were not affected by PKC alpha overexpression. Moreover, the smooth muscle-specific differentiation marker alpha-actin was markedly reduced, while beta-actin levels were found to remain unchanged. Northern blot analysis confirmed that alpha-actin downregulation occurred at the RNA level. Western blot analysis revealed that A7r5 cells have five different PKC isoforms and that these isoform protein levels were not changed by PKC alpha overexpression. These findings suggest that PKC alpha regulates growth and differentiation of A7r5 smooth muscle cells and that these changes might result from altered expression/function of AP-1 transcription factors.
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PMID:Effects of protein kinase C alpha overexpression on A7r5 smooth muscle cell proliferation and differentiation. 934 91

Diabetes mellitus is a major risk factor for atherosclerosis. In atherosclerotic lesions, arterial smooth muscle cells (SMC) change from a contractile to a synthetic phenotype characterized by active proliferation. A similar phenotype modulation occurs in vitro when isolated arterial SMC are grown in culture and is characterized by both changes in cell morphology and a typical switch in actin isoform expression. In this study, we examined the influence of streptozotocin (STZ)-induced diabetes on the differentiation state and the phenotype modulation of cultured rat aortic SMC. We used transmission electron microscopy to study the fine structure of STZ-diabetic and non-diabetic SMC in primary culture and immunological methods for the determination of the proportions of alpha-smooth muscle actin (alpha-SM) and nonmuscle beta-actin (beta-NM) isoforms. Cultured STZ-diabetic SMC exhibited a large cytoplasmic volume, rich in rough endoplasmic reticulum, when compared with cultured non-diabetic SMC. alpha-SM, organized in stress fibers, was less homogeneously and abundantly distributed and by contrast, beta-NM was more abundant in STZ-diabetic than in non-diabetic SMC. Cytofluorimetric analyses demonstrated that the alpha-SM content was reduced in freshly STZ-diabetic SMC. Furthermore, during logarithmic growth of cultured SMC, the decrease of alpha-SM was more important in STZ-diabetic than in non-diabetic SMC. Immunoblotting of actin isoforms confirmed that expression of beta-NM was more important in STZ-diabetic than in non-diabetic SMC even in freshly isolated cells. The results suggest that SMC from STZ-diabetic rats express a more dedifferentiated state and undergo a more rapid phenotypic modulation in primary cultures than SMC from non-diabetic rats. Therefore, diabetes could induce changes in the phenotype of arterial SMC which might be associated with the onset or progression of the atherogenic process.
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PMID:Phenotype modulation in primary cultures of aortic smooth muscle cells from streptozotocin-diabetic rats. 974 13

Hypertension is a major side effect of cyclosporin (CsA). While the mechanism(s) responsible are unclear, CsA-induced endothelial dysfunction and CsA-induced hypertension have been attributed to the CsA effect on the endothelial-derived factors controlling vasomotor tone. Endothelial nitric oxide (NO) is crucial in the maintenance of a state of basal vasodilation, and recent studies have suggested an NO-mediated counterregulatory mechanism protective from CsA-induced vasoconstriction. Our study evaluates endothelial nitric oxide synthase (ecNOS) gene status (PCR analysis) and plasma levels of NO metabolites (ELISA) in kidney and heart transplant patients under chronic CsA treatment with CsA-induced hypertension. Since CsA increases superoxide production, which metabolises NO, plasma hydroperoxides from cholesterol esters and from triglycerides and peroxynitrite were also evaluated (HPLC) as an index of the presence of superoxides and of "oxidative stress". Quantification of monocyte ecNOS mRNA and NO metabolites plasma levels from patients and controls (C) demonstrated NO system upregulation in patients notwithstanding the hypertension. The mean ecNOS to beta-actin ratio was 1.80 +/- 0.85 in patients vs 0.40 +/- 0.09 in C (P < 0.04). NO metabolites were 34.03 +/- 14.32 microM in patients vs 11.53 +/- 5.64 microM in C (P < 0.001). Hydroperoxides from cholesterol esters and from triglycerides were also increased in patients, 3.4 +/- 1.4 vs 1.3 +/- 0.6 integrated area units (i. a. u.), P < 0.007 and 10.6 +/- 6.4 vs 1.3 +/- 0.8 i. a. u., P < 0.008, respectively, as well as the peroxynitrite plasma level, 0.32 +/- 0.11 microM/l vs undetectable in C. This study confirms a CsA-induced NO system upregulation in transplanted patients. However, the NO-mediated counterregulatory system to CsA-induced vasoconstriction, present in normals, could be canceled in patients by CsA-induced superoxide (O2-) and free radical production which, by increasing NO metabolism, could contribute to CsA-induced vasoconstriction and hypertension and predispose to atherosclerosis.
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PMID:Cyclosporin-induced endothelial dysfunction and hypertension: are nitric oxide system abnormality and oxidative stress involved? 1111 45

Osteopontin (OPN) is a soluble secreted phosphoprotein that binds with high affinity to several integrins and it has been found at the site of atherosclerotic lesions. However, the role of OPN expression in vivo is still poorly understood. To investigate the physiological role of OPN in detail, we generated transgenic mice (Tg) overexpressing the OPN gene under control of the cytomegalovirus enhancer/chicken beta-actin promoter. We detected OPN mRNAs in almost all tissues of 3 lines of Tg mice by Northern blotting. The serum levels of OPN were significantly higher in Tg than in non-Tg mice (782+/-107 versus 182+/-44 ng/mL; P<0.001). Compared with non-Tg mice, a 73% (88+/-6 versus 51+/-7 microm; P<0.001) and 94% (126+/-15 versus 73+/-11 microm; P<0.0001) increase in the medial thickness of the aorta was determined in Tg mice at 16 and 32 weeks after birth. However, we found no evidence of inflammatory cells adhering to endothelial cells, intimal hyperplasia, or calcification in any region of Tg mice without artery injury. We then investigated the effect of cuff-induced injury to the femoral artery. The intimal thickening in Tg mice increased 2.9-fold more than that in non-Tg mice (4.9+/-1.9 versus 1.7+/-0.4 microm; P=0.022). The expression of OPN induces both medial thickening without injury and neointimal formation after injury, thus suggesting that OPN plays a role in the development of atherosclerosis, vascular remodeling, and restenosis after angioplasty in vivo.
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PMID:Osteopontin plays an important role in the development of medial thickening and neointimal formation. 1211 25

Atherosclerotic cardiovascular disease results from complex interactions among multiple genetic and environmental factors. Thus, it is important to elucidate the influence of each factor on cholesterol metabolism. For this purpose, transgenic/gene-targeting technology is a powerful tool for studying gene functions. However, this technology has several disadvantages such as being time consuming and expensive. Accordingly, we established new animal models using in vivo gene transfer technology. In this study, we examined the feasibility of the creation of a new animal model for the study of atherosclerosis. We hypothesized that apolipoprotein (apo) E-deficient mice can be created by systemic administration of antisense apo E oligodeoxynucleotides (ODN) coupled to the HVJ-liposome complex. Initially, we examined the localization and cellular fate of FITC-labeled antisense ODN administered intravenously. FITC-labeled ODN transfection by the HVJ-liposome method resulted in fluorescence in the liver, spleen and kidney, but not in other organs such as brain. Moreover, fluorescence with the HVJ-liposome method was sustained for up to 2 weeks after transfection, which resulted in a striking difference from transfection of ODN alone or ODN in liposomes without HVJ, which showed rapid disappearance of fluorescence (within 1 day). Given these unique characteristics of the HVJ-liposome method, we next examined transfection of antisense apo E ODN by intravenous administration. Transfection of antisense apo E ODN resulted in a marked reduction of apo E mRNA levels in the liver, but no change in apo B and beta-actin mRNA levels. In mice fed a normal diet, a transient increase in cholesterol and triglyceride levels was observed in the antisense apo E-treated group, but they returned to normal levels by 6 days after transfection. Similar findings were also found in mice fed a high cholesterol diet. Neither scrambled nor mismatched ODN resulted in any increase in cholesterol. To make chronic hypercholesterolemic mice, we therefore performed repeated injections of apo E antisense ODN. Whenever antisense apo E ODN were injected, mice showed a transient increase in cholesterol and triglyceride. Cumulative administration of antisense apo E ODN resulted in a sustained increase in cholesterol for up to 3 weeks after the last transfection. Finally, mice treated with repeated injections of antisense apo E every week developed sustained hypercholesterolemia and hypertriglyceridemia until withdrawal of injections. Apolipoprotein-deficient mice created by intravenous administration of antisense ODN are a promising new animal model to help understand the role of apolipoprotein in vivo and develop a new drug therapy targeting apolipoprotein.
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PMID:Apolipoprotein E-deficient mice created by systemic administration of antisense oligodeoxynucleotides: a new model for lipoprotein metabolism studies. 1242 45


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