bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of the aortic intima in young and old cebus and squirrel monkeys.
Authors: Hoover G A , Nicolosi R J , Camp R R , Hayes K C
Published: June 2011

To document naturally occurring aortic intimal changes with age in squirrel and Cebus monkeys, the aortic lipid class composition, histology, and fine structure were quantitatively compared in the two species at birth and in old age. The aortic intima plus inner media in the young squirrel monkey contained more lipid, particularly in the phospholipid and cholesterol ester fractions than in young Cebus. The lipid class composition of the old Cebus monkey aorta resembled that of the young Cebus. In the old squirrel monkey aorta, cholesteryl ester, and to a lesser extent, free cholesterol were increased over young levels, while the phospholipid concentration tended to be lower. The aortic cholesteryl ester:phospholipid ratio increased with age in both species, but the old Cebus monkey aorta maintained the ratio below unity at 0.3, whereas the old squirrel monkey aorta ratio was 2.5. The abdominal aorta of the old squirrel monkey tended to have more lipid in each class than the thoracic segment. Morphologically, the old Cebus monkey aortic intima was similar to the young Cebus in terms of the intima:media ratio, intimal cellularity, and the distribution of intimal components determined by points in electron micrographs. In both age groups the Cebus monkey aorta was characterized by diffuse intimal thickening without lipid deposits. In contrast, that old squirrel monkey aorta had a much greater intima:media ratio, especially in the abdominal aorta, and a greater intimal cellularity than the young squirrel monkey. The distribution of intimal components in electron micrographs of the old squirrel monkey aorta shifted to a predominance of extracellular lipid, smooth muscle cells, and collagen. Deposits of small dense granules, presumably the products of cellular breakdown, were observed in aortic intimas and medias of both species in old age. Thus, differences between Cebus and squirrel monkey aortic intimas were evident at birth. By old age, the Cebus monkey aortic intima remodeled without accumulating lipid, whereas the squirrel monkey developed aortic intimal lesions resembling human atherosclerosis.
Prevalence of severe arteriosclerosis obliterans in patients with diabetes mellitus. Relation to smoking and form of therapy.
Authors: Beach K W , Brunzell J D , Strandness D E
Published: June 2011

Noninvasive methods were used to determine the prevalence and severity of arteriosclerosis obliterans associated with diabetes in 674 subjects including 153 recruited as controls. A resting ankle systolic blood pressure that was less than 90% of the arm pressure indicated severe arteriosclerosis obliterans. Of the 71 subjects with severe disease, 64 (90%) had a history of smoking, which is significantly greater than the 60% overall smoking rate (p less than 0.001). In non-insulin-dependent diabetic smokers, the diet-treated subjects had 2.5 times the prevalence of severe arteriosclerosis obliterans as those treated with insulin (p = 0.01); the sulfonylurea-treated subjects had twice the prevalence of severe disease as those treated with insulin (p = 0.015).
Autoregulation of the modified low density lipoprotein receptor in human monocyte-derived macrophages.
Authors: Mazzone T , Chait A
Published: June 2011

Regulation of the macrophage receptor for modified low density lipoprotein (LDL) was evaluated using human monocyte-derived macrophages and acetyl LDL. Factors that regulate native LDL receptor activity in other cell types, such as the cholesterol content of the incubation medium, insulin, and platelet-derived growth factor had no effect on acetyl LDL degradation. Conditioned medium from mature macrophages significantly stimulated acetyl LDL degradation and enhanced cholesterol esterification by freshly isolated monocytes. Time course studies indicated that increasing time in culture was associated with increasing potency of the stimulating activity of macrophage-conditioned medium. These data suggest that a macrophage secretory product may be a prime modulator of modified LDL receptor activity on monocyte-macrophages, thus exerting an autocrine regulatory effect. The positive autoregulation of the human macrophage receptor for modified LDL could accelerate cellular cholesteryl ester accumulation and macrophage-derived foam cell formation.
Relation of diet to LDL cholesterol, VLDL cholesterol, and plasma total cholesterol and triglycerides in white adults. The Lipid Research Clinics Prevalence Study.
Authors: Gordon T , Fisher M , Ernst N , Rifkind B M
Published: June 2011

The association of diet with low density lipoprotein cholesterol (LDL-C) and total triglycerides, as well as with total and very low density lipoprotein cholesterol (VLDL-C), was investigated in a random sample of 4374 white participants aged 20 to 59 years seen by the Lipid Research Clinic Prevalence Study. Carbohydrate and total calories were negatively associated with LDL-C. There was also a statistically significant positive association of LDL-C with the percentage of total calories from fat. These three findings are generally consistent with what other cross-sectional studies have reported for the relation of diet with total cholesterol levels. The only diet variables significantly related to triglyceride levels in both men and women were the percentage of calories from fats, particularly polyunsaturated fatty acids (PFA), the P/S ratio, and the number of grams of PFA per day, all of which were inversely associated with the level of this lipid.
Dietary determinants of plasma cholesterol change in the recruitment phase of the Lipid Research Clinics Coronary Primary Prevention Trial.
Authors: Gordon D J , Salz K M , Roggenkamp K J , Franklin F A
Published: June 2011

We have investigated the relationship of diet to plasma lipid and lipoprotein levels in 6494 hypercholesterolemic (Type IIA) men who were instructed in an isocaloric, 400 mg cholesterol, 0.8 polyunsaturated-to-saturated fat ratio diet in the course of recruitment for the Lipid Research Clinics Coronary Primary Prevention Trial. Single 24-hour dietary recalls, plasma total and high density lipoprotein cholesterol, and total triglyceride determinations were obtained approximately 1 month before and 1 month after dietary instruction. Cross-sectional correlation analysis disclosed no significant association between diet and plasma cholesterol at entry. However, when diet-associated changes were similarly analyzed, weight loss, decreased intakes of saturated fat and cholesterol, and increased intake of polyunsaturated fat were all significantly and independently predictive of falls in plasma cholesterol, mainly in its low density lipoprotein fraction. The multiple correlation coefficient for the resultant four-variable regression model was 0.29. Diet-associated changes in plasma very low density lipoprotein cholesterol were less marked but in the same direction. These dietary changes were also weakly associated with a lowering of plasma high density lipoprotein cholesterol, while weight loss had an opposite effect of similar strength. When one takes into account the variability of dietary recall data, the observed diet-associated changes in plasma cholesterol were compatible with the findings of metabolic ward studies.
Differential Regulation of Macrophage Peroxisome Proliferator–Activated Receptor Expression by Glucose
Authors: Sartippour Maryam Radimeh , Renier Geneviève
Published: June 2011

Abstract
—Peroxisome proliferator–activated receptors (PPARs) are implicated in several metabolic disorders with altered glucose and lipid metabolism, including atherosclerosis and diabetes. In the present study, we evaluated the in vitro and ex vivo effects of high glucose concentrations on macrophage PPAR mRNA expression. Exposition of monocyte-derived macrophages isolated from healthy donors to a high glucose environment led to an increase in PPARα and PPARβ mRNA expression. In contrast, this treatment significantly decreased human macrophage PPARγ mRNA expression. Overexpression of PPARα and PPARβ mRNA and inhibition of PPARγ mRNA expression were also observed in monocyte-derived macrophages isolated from patients with type 2 diabetes. Because high glucose and PPARα agonists increase lipoprotein lipase (LPL) gene expression, the role of PPARα in the glucose-mediated upregulation of macrophage LPL gene expression was next evaluated. Incubation of murine J774 macrophages with high glucose concentrations increased the expression of PPARα at the mRNA and protein levels and enhanced nuclear protein binding to the peroxisome proliferator responsive element of the LPL promoter. Incubation of nuclear extracts in the presence of anti-PPARα and anti-PPARβ antibodies decreased glucose-stimulated nuclear protein binding to the peroxisome proliferator responsive element. These results demonstrate that glucose is an important regulator of macrophage PPAR expression and suggest a role of PPARα and PPARβ in the upregulation of macrophage LPL by glucose. Dysregulation of macrophage PPAR expression in type 2 diabetes may contribute, by altering arterial lipid metabolism and inflammatory response, to the accelerated atherosclerosis associated with diabetes.
Effect of Macrophage-Derived Mouse ApoE, Human ApoE3-Leiden, and Human ApoE2 (Arg158→Cys) on Cholesterol Levels and Atherosclerosis in ApoE-Deficient Mice
Authors: Van Eck Miranda , Herijgers Nicole , Van Dijk Ko Willems , Havekes Louis M. , Hofker Marten H. , Groot Pieter H. E. , Van Berkel Theo J. C.
Published: June 2011

Abstract
—The effect of monocyte/macrophage-derived wild-type mouse apolipoprotein E (apoE), human apoE3-Leiden, and human apoE2 on serum cholesterol levels and the development of atherosclerosis in apoE-deficient (
apoe–/–
) mice was investigated by using bone marrow transplantation (BMT). At 4 weeks after BMT, murine
apoe+/+
bone marrow reduced serum cholesterol levels by 87% in
apoe–/–
mice, whereas macrophage-derived human apoE3-Leiden and human apoE2 induced a maximal, transient reduction of 35% and 48%, respectively. At 4 months after BMT, atherosclerosis was 23-fold (
P
<0.001) reduced in
apoe+/+
→
apoe–/–
mice, whereas no significant reduction in apoE3-Leiden.
apoe–/–
→
apoe–/–
and apoE2.
apoe–/–
→
apoe–/–
mice could be demonstrated. A highly significant decrease in serum cholesterol levels (78% reduction) and atherosclerosis (21-fold,
P
<0.001) was found in apoE3-Leiden.
apoe–/–
animals expressing high levels of apoE in multiple tissues, whereas apoE2 was ineffective even at high concentrations. Furthermore, in contrast to apoE-deficient macrophages, cholesterol efflux from apoE2 or apoE3-Leiden macrophages was not impaired. In conclusion, apoE3-Leiden as well as apoE2 are less effective in reducing cholesterol levels and atherosclerosis in
apoe–/–
animals, compared with
apoe+/+,
with apoE2<apoE3-Leiden<
apoe+/+
, irrespective of the observed adequate efflux of cholesterol from macrophages expressing apoE2 and apoE3-Leiden, indicating that normalization of cholesterol efflux by macrophages is not accompanied by measurable effects on lesion growth.
Hyperexpression and Activation of Extracellular Signal–Regulated Kinases (ERK1/2) in Atherosclerotic Lesions of Cholesterol-Fed Rabbits
Authors: Hu Yanhua , Dietrich Hermann , Metzler Bernhard , Wick Georg , Xu Qingbo
Published: June 2011

Abstract
—A hallmark of hyperlipidemia-induced atherosclerosis is altered gene expression that initiates cell proliferation and (de)differentiation in the intima of the arterial wall. The molecular signaling that mediates this process in vivo has yet to be identified. Extracellular signal–regulated kinases (ERKs) are thought to play a pivotal role in transmitting transmembrane signals required for cell proliferation in vitro. The present studies were designed to investigate the activity, abundance, and localization of ERK1/2 in atherosclerotic lesions of cholesterol-fed rabbits. Immunofluorescence analysis revealed abundant and heterogeneous distribution of ERK1/2, mainly localized in the cap and basal regions of atheromas. A population of ERK-enriched cells was identified as α-actin–positive smooth muscle cells (SMCs). ERK1 and 2 were heavily phosphorylated on tyrosyl residues and coexpressed with proliferating cell nuclear antigen in atherosclerotic lesions. ERK1/2 protein levels in protein extracts from atherosclerotic lesions were 2- to 3-fold higher than the vessels of chow-fed rabbits, and their activities were elevated 3- to 5-fold over those of the normal vessel. SMCs derived from atherosclerotic lesions had increased migratory/proliferative ability and higher ERK activity in response to LDL stimulation compared with cells from the normal vessel. Inhibition of ERK activation by PD98059, a specific inhibitor of mitogen-activated protein kinase kinases (MEK1/2), abrogated LDL-induced SMC proliferation in vitro. Taken together, our findings support the proposition that persistent activation and hyperexpression of ERK1/2 may be a critical element to initiate and perpetuate cell proliferation during the development of atherosclerosis.
Influence of Folic Acid on Postprandial Endothelial Dysfunction
Authors: Wilmink Hanneke W. , Stroes Erik S. G. , Erkelens Willem D. , Gerritsen Wim B. , Wever Robert , Banga Jan-Dirk , Rabelink Ton J.
Published: June 2011

Abstract
—Triglyceride-rich lipoproteins that circulate postprandially are increasingly being recognized as potentially atherogenic. These particles also have been shown to cause endothelial dysfunction. We recently demonstrated that acute parenteral administration of folic acid restores endothelial function in vivo in patients with increased LDL cholesterol levels. In vitro data suggested that this effect could be mediated by a reduction of radical stress. In the present study, therefore, we evaluated the effect of an acute oral fat load on both endothelial function and oxygen radical production. Next, we studied whether 2 weeks of pretreatment with 10 mg folic acid PO could prevent these fat-induced changes. We conducted a prospective, randomized, placebo-controlled study to evaluate the effect of oral folic acid administration (10 mg/d for 2 weeks) on basal endothelial function as well as endothelial function on an acute fat load in 20 healthy volunteers 18 to 33 years old. Endothelial function was assessed as flow-mediated dilatation (FMD). Endothelium-independent dilatation was measured after sublingual nitroglycerin spray. Oxygen radical stress was assessed by measurement of the urinary excretion of the stable radical-damage end product malondialdehyde. During administration of placebo, FMD decreased significantly after an acute oral fat load, with a median from 10.6% (8.3% to 12.2%) to 5.8% (3.0% to 10.2%),
P
<0.05. During folic acid administration, FMD was unaffected by a fat load, with a median from 9.6% (7.1% to 12.8%) to 9.9% (7.5% to 14.1%),
P
=NS. The increase in malondialdehyde excretion in the urine after fat loading was also prevented during folic acid administration (absolute increase after an acute fat load during placebo, 0.11±0.1 μmol/L versus folic acid, 0.02±0.1 μmol/L,
P
<0.05). The response to the endothelium-independent vasodilator nitroglycerin remained unaltered throughout the study. Pretreatment with oral folic acid prevents the lipid-induced decrease in FMD as well as the lipid-induced increase in urinary radical-damage end products. Because these observations were made in healthy volunteers with normal folate and homocysteine levels, it is suggested that a higher folate intake in the general population may have vasculoprotective effects.
Autoantibodies Against Oxidized Low-Density Lipoprotein and Cardiolipin in Patients With Coronary Heart Disease
Authors: Erkkilä Arja T. , Närvänen Outi , Lehto Seppo , Uusitupa Matti I. J. , Ylä-Herttuala Seppo
Published: June 2011

Abstract
—Autoantibodies against oxidized low density lipoprotein (oxLDL) have been proposed to be independent predictors of atherosclerotic vascular disease. Because the levels of autoantibodies against oxLDL and cardiolipin might be modified by the presentation and severity of coronary heart disease (CHD), we measured their levels in patients with different manifestations of CHD (n=415, mean age 61 years, range 33 to 74 years) in a subset of the European Action on Secondary Prevention through Intervention to Reduce Events (EUROASPIRE) study. There were 109 patients with coronary artery bypass surgery, 106 patients with balloon angioplasty, 101 patients with acute myocardial infarction, and 99 patients with acute myocardial ischemia. Autoantibodies were measured by ELISA. Food records and fatty acid profiles of serum cholesteryl esters were used to evaluate dietary intake. Anti-oxLDL antibodies were significantly higher in the group with acute myocardial infarction than in other groups in men (coronary artery bypass surgery 1.91±1.41, balloon angioplasty 2.11±2.19, acute myocardial infarction 2.52±2.05, and acute myocardial ischemia 1.96±1.78;
P
=0.022, mean±SD) but not in women. The titers of anti-cardiolipin antibodies did not differ among the patient groups. Neither of the autoantibodies was associated with recurrent coronary events. Anti-oxLDL and anti-cardiolipin autoantibodies were not correlated with serum total cholesterol, high density lipoprotein cholesterol, or triglycerides, except that in women anti-oxLDL antibodies and triglycerides were positively correlated (
r
=0.225,
P
=0.011). In men, anti-cardiolipin antibodies were higher in the lowest quartiles of dietary intakes of vitamin E and polyunsaturated fat. Dietary intakes of vitamin E and polyunsaturated fat were correlated (
r
=0.588,
P
<0.001). In conclusion, autoantibodies against oxLDL were associated with myocardial infarction in men. Anti-cardiolipin autoantibodies were inversely correlated with dietary intakes of vitamin E and polyunsaturated fat in men with CHD.
The Private Hepatocyte Nuclear Factor-1α G319S Variant Is Associated With Plasma Lipoprotein Variation in Canadian Oji-Cree
Authors: Hegele Robert A. , Cao Henian , Harris Stewart B. , Hanley Anthony J. G. , Zinman Bernard , Connelly Philip W.
Published: June 2011

Abstract
—We previously showed an extremely strong association between type 2 diabetes and a private polymorphism, namely G319S, in the hepatocyte nuclear transcription factor (HNF)-1α. Because HNF-1α is involved in the transcription of several apolipoprotein genes, we tested for an association between the private
HNF1A
G319S variant and plasma lipoproteins in a sample of 55 unrelated Oji-Cree subjects with type 2 diabetes and 175 unrelated Oji-Cree subjects without type 2 diabetes. In Oji-Cree subjects with type 2 diabetes, we found that the
HNF1A
G319S genotype was significantly associated with lower plasma concentrations of total cholesterol, low density lipoprotein cholesterol, and apolipoprotein (apo) B. In Oji-Cree subjects without type 2 diabetes, we found that the
HNF1A
G319S genotype was significantly associated with higher plasma concentrations of high density lipoprotein cholesterol and apo AI. There were no associations with plasma triglycerides or lipoprotein(a). Regression analysis indicated that the
HNF1A
genotype accounted for ≈10% of the variation in the apo B–related traits in the diabetic subjects and for ≈5% of the variation in the apo AI–related traits in the nondiabetic subjects. Furthermore, the regression model indicated that the
HNF1A
S319 allele affected these traits in a dominant manner in subjects with and without type 2 diabetes. These findings provide the first evidence that a rare variant in a nuclear transcription factor is associated with variation in plasma lipoprotein traits.
Intravascular Free Tissue Factor Pathway Inhibitor Is Inversely Correlated With HDL Cholesterol and Postheparin Lipoprotein Lipase but Proportional to Apolipoprotein A-II
Authors: Kawaguchi Akito , Miyao Yuji , Noguchi Teruo , Nonogi Hiroshi , Yamagishi Masakazu , Miyatake Kunio , Kamikubo Yuichi , Kumeda Kousuke , Tsushima Motoo , Yamamoto Akira , Kato Hisao
Published: June 2011

Abstract
—To elucidate the distribution and clinical implications of tissue factor pathway inhibitor (TFPI) concentrations, we measured TFPI levels consisting of preheparin free, lipoprotein-bound (Lp-bound), and endothelial cell–anchor pools in 156 patients with coronary artery disease (average age, 61.2±9.1 years; range, 32 to 78 years) by heparin infusion (50 IU/kg) and compared them with the preheparin TFPI levels of 229 healthy subjects (average age, 59.6±9.4 years; range, 41 to 80 years). The patients had lower preheparin free TFPI and lower HDL cholesterol (HDL-C) levels than the healthy subjects with equivalent Lp-bound forms (free TFPI, 15.9±6.5 versus 19.2±8.1 ng/mL). In a partial correlation analysis, the preheparin free TFPI levels were shown to be inversely correlated with the HDL-C concentrations in both the patients (
r
=−0.454,
P
<0.001) and the healthy subjects (
r
=−0.136,
P
<0.05). As determined by comparison of preheparin and postheparin plasma, the patients generally showed preheparin free TFPI <10%, Lp-bound TFPI at 30%, and endothelial cell–anchor TFPI at 60%. When the patients were divided into 4 categories by their LDL cholesterol (LDL-C, 130 mg/dL) and HDL-C (40 mg/dL) levels to specify their coronary risks, the low–HDL-C groups had significantly increased preheparin and postheparin free TFPI levels and decreased postheparin LPL levels, whereas the high–LDL-C groups showed increased levels of Lp-bound TFPI. In a partial correlation analysis, we found a proportional relation between postheparin free TFPI and apolipoprotein A-II (
r
=0.5327) and between HDL-C and LPL (
r
=0.4906), whereas postheparin free TFPI was inversely correlated with HDL-C (
r
=−0.4280) and postheparin LPL (
r
=−0.4791). The inverse relationship between TFPI and LPL suggests that increased free TFPI concentrations as a compensatory response of the endothelium to prevent atherothrombotic processes compete with and displace LPL on endothelial surface, resulting in reduced LPL and low HDL-C.
Prospective Evaluation of the Risk Conferred by Factor V Leiden and Thermolabile Methylenetetrahydrofolate Reductase Polymorphisms in Pregnancy
Authors: Murphy Ronan P. , Donoghue Catherine , Nallen Ruth J. , D’Mello Melwyn , Regan Carmen , Whitehead Alexander S. , Fitzgerald Desmond J.
Published: June 2011

Abstract
—Factor V (FV) Leiden and thermolabile methylenetetrahydrofolate reductase (MTHFR) are 2 common polymorphisms that have been implicated in vascular thrombosis. We determined whether these mutations predicted an adverse outcome in pregnancy. Second, we looked for an interaction between these 2 mutations in patients with recurrent fetal loss or thrombosis in pregnancy. Primigravid subjects at their booking visit to the National Maternity Hospital (Holles Street, Dublin, Ireland) were screened for the polymorphisms. Thermolabile MTHFR and FV Leiden genotypes were detected by either restriction fragment length polymorphism or heteroduplex capillary chromatography. The carrier frequency of FV Leiden in the screened primigravid population was 2.7% (allele frequency 1.36%), all being heterozygous for the mutation. This value was lower than expected from previous studies in European populations. Forty-nine percent of the screened population (289 of 584) were heterozygous for thermolabile MTHFR, and 10.6% were homozygous (62 of 584). The frequency of the 2 polymorphisms was no higher in those who subsequently developed preeclampsia (n=12) or intrauterine growth retardation (n=9), and none of the screened population developed thrombosis. However, the frequency of FV Leiden was higher in patients who subsequently miscarried after the first trimester of pregnancy (allele frequency of 5.5%,
P
=0.0356). Among those positive for FV Leiden, 3 of 27 miscarried, compared with 24 of 572 of FV Leiden–negative patients (11% versus 4.2%). No interaction was found between the 2 mutations in the control or patient populations. In patients with a prior history of venous thrombosis, the carrier rate of FV Leiden was increased (4 of 33, allele frequency of 7.6%,
P
=0.0115). In contrast, the carrier frequency for thermolabile MTHFR was no higher, and there was no interaction between the 2 mutations. Neither mutation occurred at a significantly higher frequency in patients with a prior history of recurrent fetal loss. In conclusion, FV Leiden is a risk factor for thrombosis in pregnancy and possibly for second-trimester miscarriage independent of thermolabile MTHFR. However, prospective analysis suggests that the risk conferred by FV Leiden is low in a primigravid population. The thermolabile MTHFR genotype was not implicated in any adverse outcome.
Nitric Oxide–Induced Increase in p21
Sdi1/Cip1/Waf1
Expression During the Cell Cycle in Aortic Adventitial Fibroblasts
Authors: Gu Miaofen , Brecher Peter
Published: June 2011

Abstract
—This study was performed to investigate whether the expression of p21
Sdi1/Cip1/Waf1
, one of the cyclin-dependent kinase inhibitor proteins, could be regulated by nitric oxide (NO) and might account for the antiproliferative effect of NO. Quiescent adventitial fibroblasts were stimulated to proliferate by serum addition and by NO donors added during different phases of the cell cycle. [
3
H]Thymidine incorporation was markedly reduced by
S
-nitroso-
N
-acetyl-penicillamine (SNAP) added either with serum at quiescence or at later time point in the cell cycle. Northern and Western blot analyses showed that addition of SNAP either at quiescence or 15 hours after serum addition induced a rapid induction of p21 mRNA and protein. Immunoprecipitation studies and electrophoretic mobility shift analysis indicate that the treatment of cells with SNAP induced the phosphorylation of p53 (a tumor suppressor protein) and enhanced the ability of p53 to bind DNA when SNAP was added during the cell cycle. The increased expression of p21 mRNA or p53 activation during late G
1
or S phase was also caused by addition of 8-bromo-cGMP and effectively blocked by a specific inhibitor of the soluble guanylate cyclase. Furthermore, this response to SNAP was blocked by an inhibitor of protein kinase G. These studies implicate NO as a potential regulator of the cell cycle in aortic adventitial fibroblasts through a cGMP-mediated transcriptional mechanism involving the induction of p21.
Lifestyle and Hemostatic Risk Factors for Ischemic Heart Disease
Authors: Yarnell John W. G. , Sweetnam Peter M. , Rumley Ann , Lowe Gordon D. O.
Published: June 2011

Abstract
— We have recently shown that fibrin D-dimer, tissue plasminogen activator (tPA) antigen, von Willebrand factor antigen, fibrinogen, plasma viscosity, and white cell count are associated with subsequent ischemic heart disease (IHD) in men aged 49 to 65 years in the Caerphilly Study from South Wales. We now report the contribution of major lifestyle factors to plasma levels of these new risk predictors for IHD. Results were available for up to 2188 men. The contribution of factors associated with lifestyle (smoking, alcohol, body mass index, leisure and work activity, social class, and use of prescribed medicines) to variation in plasma levels of 8 hemostatic variables was examined. All results were adjusted for other lifestyle variables, age, and time of day. Most hemostatic variables increased with age and smoking habit. Increasing levels of alcohol consumption were associated with increases in tPA and plasminogen activator inhibitor (PAI-1) activity and with decreases in fibrinogen and white cell count. tPA, PAI-1, fibrinogen (nephelometric), and viscosity were positively associated with body mass index. Increasing levels of leisure activity were inversely associated with D-dimer, von Willebrand factor, nephelometric fibrinogen, and viscosity. Use of prescribed medicines (a marker for chronic illness) was associated with adverse levels of D-dimer, fibrinogen, plasma viscosity, and white cell count. tPA, PAI-1, and plasma viscosity were associated with blood pressure, cholesterol, and triglycerides but not with lipoprotein(a) or homocysteine. We conclude that several lifestyle factors are associated with hemostatic risk predictors for IHD. Lifestyle modifications may reduce IHD risk partly by altering hemostatic function; large intervention studies are required to test this hypothesis.
Determination of Temporal Expression Patterns for Multiple Genes in the Rat Carotid Artery Injury Model
Authors: Tai Julie T. N. , Brooks Eric E. , Liang Shoudan , Somogyi Roland , Rosete Jose D. , Lawn Richard M. , Shiffman Dov
Published: June 2011

Abstract
—Vascular injury induces extensive alteration to the extracellular matrix (ECM). These changes contribute to lesion formation and promote cell migration and proliferation. To elucidate ECM response to arterial injury, we used real-time polymerase chain reaction monitoring to quantitate the expression levels of 81 genes involved in the synthesis and breakdown of ECM as well as receptors and signaling proteins that communicate and respond to ECM molecules. The temporal regulation of gene expression in the carotid was measured at 1, 3, 5, 7, 9, 14, and 28 days postinjury. Among the 68 genes that showed detectable expression by our method, 47 (69%) were significantly induced or repressed over time, confirming the extensive ECM gene response in this model. More ECM-related genes (31) were regulated at day 1 than at any other time point, and the number of regulated genes decreased over time. However, 14 of the genes were still induced or repressed at day 28, indicating that return to preinjury expression patterns did not occur and no new steady state was achieved over 28 days. In spite of the large number of changes in gene expression, only a small number of expression patterns was observed, suggesting that ECM-related genes could potentially be coregulated.
Overexpression of Truncated IκBα Induces TNF-α–Dependent Apoptosis in Human Vascular Smooth Muscle Cells
Authors: Obara Hideaki , Takayanagi Atsushi , Hirahashi Junichi , Tanaka Katsunori , Wakabayashi Go , Matsumoto Kenji , Shimazu Motohide , Shimizu Nobuyoshi , Kitajima Masaki
Published: June 2011

Abstract—Dysregulation of apoptosis is one of the likely underlying mechanisms of neointimal thickening, a disorder in which proinflammatory cytokines may influence the function of vascular smooth muscle cells (VSMCs) and contribute to atherogenesis. One of these cytokines, tumor necrosis factor-α (TNF-α), induces 2 possibly conflicting pathways, 1 leading to the activation of nuclear factor-κB (NF-κB) and the other leading to caspase-mediated apoptosis. We investigated whether specific inhibition of NF-κB affects TNF-α–dependent apoptosis in human VSMCs. To inhibit NF-κB activation specifically, we constructed a recombinant adenovirus vector expressing a truncated form of the inhibitor protein IκBα (AdexIκBΔN) that lacks the phosphorylation sites essential for activation of NF-κB. The IκBΔN was overexpressed by adenoviral infection and was resistant to stimulus-dependent degradation. Electromobility gel shift and luciferase assays demonstrated that overexpression of IκBΔN inhibited NF-κB activation induced by TNF-α or interleukin-1β (IL-1β). In cells overexpressing IκBΔN, TNF-α dramatically induced apoptosis, whereas IL-1β had no effect. The induction was suppressed by treatment with a selective inhibitor of the caspase-3 family, Z-DEVD-fmk, and the overexpression of IκBΔN induced TNF-α–mediated caspase-3 and caspase-2 activity. These results indicate that overexpression of IκBΔN induces TNF-α–dependent apoptosis by efficient and specific suppression of NF-κB and upregulation of caspase-3 and caspase-2 activity in human VSMCs. Our findings suggest that adenovirus-mediated IκBΔN gene transfer may be useful in the treatment of disorders associated with inflammatory conditions, such as the response to vascular injury and atherosclerosis.
Expression of Human Apolipoprotein A-I/C-III/A-IV Gene Cluster in Mice Induces Hyperlipidemia but Reduces Atherogenesis
Authors: Vergnes Laurent , Baroukh Nadine , Ostos Maria A. , Castro Graciela , Duverger Nicolas , Nanjee M. Nazeem , Najib Jamila , Fruchart Jean-Charles , Miller Norman E. , Zakin Mario M. , Ochoa Alberto
Published: June 2011

Abstract
—The apolipoprotein (apo)A-I/C-III/A-IV gene cluster is involved in lipid metabolism and atherosclerosis. Overexpression of apoC-III in mice causes hypertriglyceridemia and induces atherogenesis, whereas overexpression of apoA-I or apoA-IV increases cholesterol in plasma high density lipoprotein (HDL) and protects against atherosclerosis. Each gene has been studied alone in transgenic mice but not in combination as the entire cluster. To determine which phenotype is produced by the expression of the entire gene cluster, transgenic mice were generated with a 33-kb human DNA fragment. The results showed that the transgene contained the necessary elements to direct hepatic and intestinal expression of the 3 genes. In the pooled data, plasma concentrations were 257±9, 7.1±0.5, and 1.0±0.2 mg/dL for human apoA-I, apoC-III, and apoA-IV, respectively (mean±SEM). Concentrations of these apolipoproteins were higher in males than in females. Human apoA-I and apoC-III concentrations were positively correlated, suggesting that they are coregulated. Transgenic mice exhibited gross hypertriglyceridemia and accumulation of apoB
48
–containing triglyceride-rich lipoproteins. Plasma triglyceride and cholesterol concentrations were correlated positively with human apoC-III concentration, and HDL cholesterol was correlated with apoA-I concentration. In an apoE-deficient background, despite being markedly hypertriglyceridemic, cluster transgenic animals compared with nontransgenic animals showed a 61% reduction in atherosclerosis. This suggests that apoA-I and/or apoA-IV can protect against atherosclerosis even in the presence of severe hyperlipidemia. These mice provide a new model for studies of the regulation of the 3 human genes in combination.
Role of the Angiotensin AT
1
Receptor in Rat Aortic and Cardiac PAI-1 Gene Expression
Authors: Chen Hong-Chi , Bouchie Julie L. , Perez Alexandra S. , Clermont Allen C. , Izumo Seigo , Hampe James , Feener Edward P.
Published: June 2011

Abstract
—Although the renin-angiotensin system has been implicated in increasing plasminogen activator inhibitor-1 (PAI-1) expression, the role of the angiotensin type 1 (AT
1
) receptor is controversial. This report examines the effects of angiotensin peptides, angiotensin-converting enzyme inhibition, and AT
1
antagonism on rat aortic and cardiac PAI-1 gene expression. In vitro, angiotensin (Ang) I, Ang II, and angiotensin Arg
2
-Phe
8
(Ang III) were potent agonists of PAI-1 mRNA expression in rat aortic smooth muscle cells (RASMCs), and stimulation of PAI-1 by these peptides was blocked by the AT
1
antagonist candesartan. Angiotensin Val
3
-Phe
8
(Ang IV) and angiotensin Asp
1
-Pro
7
(Ang [1-7]) did not affect PAI-1 expression in RASMCs. In neonatal rat cardiomyocytes, Ang II increased PAI-1 mRNA expression by 4-fold (
P
<0.01), and this response was completely blocked by AT
1
receptor antagonism. Continuous intrajugular infusion of Ang II into Sprague-Dawley rats for 3 hours increased aortic and cardiac PAI-1 mRNA expression by 17- and 9 fold, respectively, and these Ang II responses were completely blocked by coinfusion with candesartan. Aortic and cardiac PAI-1 expressions were compared in spontaneously hypertensive rats and Wistar-Kyoto rats. PAI-1 expression in the aorta and heart from spontaneously hypertensive rats was 5.8-fold and 2-fold higher, respectively, than in control Wistar-Kyoto rats (
P
<0.05). Candesartan treatment for 1 week reduced aortic and cardiac PAI-1 expression in spontaneously hypertensive rats by 94% and 72%, respectively (
P
<0.05), but did not affect vascular PAI-1 levels in Wistar-Kyoto rats. These results demonstrate a role for the AT
1
receptor in mediating the effects of Ang II on aortic and cardiac PAI-1 gene expression.
Genetic Modifiers of Atherosclerosis in Mice
Authors: Knowles Joshua W. , Maeda Nobuyo
Published: June 2011

Abstract
—Atherosclerosis is a complex, multifactorial disease with both genetic and environmental determinants. Experimental investigation of the effects of these determinants on the development and progression of atherosclerosis has been greatly facilitated by the use of targeted mouse models of the disease, particularly those resulting from the absence of functional genes for apolipoprotein E or the low density lipoprotein receptor (LDLR). This review focuses on the influence on atherosclerosis of combining apoE or LDLR deficiencies with factors affecting atherogenesis, including (1) inflammatory processes, (2) glucose metabolism, (3) blood pressure, and (4) coagulation and fibrinolysis. We also discuss the general problem of using the mouse to test the effects on atherogenesis of human polymorphic variations and future ways of enhancing the usefulness of these mouse models.
Thiol Oxidation Activates a Novel Redox-Regulated Coronary Vasodilator Mechanism Involving Inhibition of Ca
2+
Influx
Authors: Iesaki Takafumi , Wolin Michael S.
Published: June 2011

Abstract
—This study examines the mechanism of relaxation of isolated endothelium-removed bovine coronary arteries (BCAs) to the thiol oxidant diamide. BCAs precontracted with KCl or the thromboxane A
2
receptor agonist U46619 showed a concentration-dependent reversible relaxation on exposure to 10 μmol/L to 1 mmol/L diamide. This relaxation was enhanced by an inhibitor of glutathione reductase, and it was not altered by severe hypoxia, the presence of inhibitors of soluble guanylate cyclase, K
+
channels, tyrosine kinases, or probes that modulate levels of superoxide. The relaxation was almost eliminated when BCAs were precontracted with a phorbol ester that causes a contraction that is largely independent of extracellular Ca
2+
. The initial transient contraction elicited by 5-hydroxytryptamine in Ca
2+
-free solution was not altered by the presence of 1 mmol/L diamide; however, a subsequent tonic contraction on addition of CaCl
2
was inhibited by diamide. Diamide also inhibited contractions caused by the addition of CaCl
2
to Ca
2+
-free Krebs’ buffer containing Bay K8644 (an L-type Ca
2+
channel opener) or KCl. Relaxation to diamide was attenuated by L-type Ca
2+
channel blockers (nifedipine and diltiazem). Thus, thiol oxidation elicited by diamide appears to activate a novel redox-regulated vasodilator mechanism that seems to inhibit extracellular Ca
2+
influx.
Apolipoprotein Concentrations During Treatment and Recurrent Coronary Artery Disease Events
Authors: van Lennep Jeanine E. Roeters , Westerveld H. Tineke , van Lennep Henk W. O. Roeters , Zwinderman Aelko H. , Erkelens D. Willem , van der Wall Ernst E.
Published: June 2011

Abstract
—The effect of untreated total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) as cardiovascular risk factors in both primary and secondary prevention has been extensively investigated. The predictive value of on-treatment lipid and apolipoprotein levels on subsequent cardiovascular events is as yet uncertain. Eight hundred forty-eight patients (675 men and 173 women) with angiographically proven coronary artery disease (CAD) who received effective statin therapy (≥30% decrease of baseline TC) were studied. We analyzed the predictive value of on-treatment levels of TC, LDL-C, triglycerides (TG), apolipoprotein A-I (apoA-I) and apolipoprotein B (apoB) on subsequent myocardial infarction (MI) and all cause mortality. On-treatment LDL-C levels were 2.55±0.55 mmol/L and 2.58±0.62 mmol/L for men and women respectively. Age-adjusted Cox regression analysis showed that only on-treatment apoA-I was predictive for future CAD events in both men and women, whereas on-treatment HDL-C was exclusively predictive in women. On-treatment apoB levels were predictive for recurrent CAD events in the total population but not after separate analysis for men and women. On-treatment levels of TC, LDL-C, and TG did not predict subsequent events. Multivariate analysis showed that on-treatment apoA-I and apoB were the only significant predictors for future cardiovascular events. On-treatment levels of TC, LDL-C, and TG were no longer associated with increased risk of recurrent cardiovascular events in CAD patients treated to target levels, which justifies the current guidelines. However, on-treatment levels of apoB and in particular apoA-I (and HDL-C in women) were significantly predictive for MI and all-cause mortality and may therefore be more suitable for cardiovascular risk assessment in this population.
Normal Oxidative Stress and Enhanced Lipoprotein Resistance to In Vitro Oxidation in Hypertriglyceridemia
Authors: de Man Frits H. A. F. , Jonkers Iris J. A. M. , Schwedhelm Edzard , Smelt Augustinus H. M. , Onkenhout Willem , van Duyvenvoorde Wim , Buytenhek Rien , Leuven Jan A. Gevers , Troost Raphael , van der Laarse Arnoud , Princen Hans M. G.
Published: June 2011

Abstract
—Although there is evidence that hyperlipidemia and predominance of small dense low density lipoproteins (LDLs) are associated with increased oxidative stress, the oxidation status in patients with hypertriglyceridemia (HTG) has not been studied in detail. Therefore, we studied urinary levels of F
2
-isoprostanes (8-isoprostaglandin F
2α
and 2,3-dinor-5,6-dihydro-8-isoprostaglandin F
2α
) and susceptibility of very low density lipoproteins (VLDLs) and LDLs to oxidation ex vivo in 18 patients with endogenous HTG and 20 matched control subjects. In addition, the effects of 6 weeks of bezafibrate therapy were assessed in a double-blind, placebo-controlled, crossover trial. Urinary levels of F
2
-isoprostanes were similar in the HTG and normolipidemic group. Bezafibrate caused an increase in 8-isoprostaglandin F
2α
(762±313 versus 552±245 ng/24 h for bezafibrate and placebo therapy, respectively;
P
=0.03), whereas 2,3-dinor-5,6-dihydro-8-isoprostaglandin F
2α
levels tended to be increased (1714±761 versus 1475±606 ng/24 h for bezafibrate and placebo therapy, respectively;
P
=0.11). VLDLs and LDLs were more resistant to copper-induced oxidation in patients with HTG than in control subjects. Bezafibrate reversed the oxidation resistance to the normal range. In conclusion, these results indicate the following: (1) HTG is associated with normal in vivo oxidative stress and enhanced ex vivo resistance of lipoproteins to oxidation. (2) Bezafibrate reduces the resistance of lipoproteins to copper-induced oxidation and enhances oxidative stress in HTG patients.
Lipoprotein Promotes Caveolin-1 and Ras Translocation to Caveolae
Authors: Zhu Yi , Liao Hai-Ling , Wang Nanping , Yuan Yuan , Ma Kuo-Sheng , Verna Lynne , Stemerman Michael B.
Published: June 2011

Abstract
—To explore the role of LDL in caveolin-Ras regulation in human endothelial cells (ECs), we incubated confluent human umbilical vein endothelial cells (HUVECs) with LDL. This resulted in a high steady-state caveolin-1 (Cav-1) expression at both the mRNA and protein levels. LDL exposure appeared not to regulate the abundance of Cav-1. Immunofluorescence staining showed that Cav-1 protein migrated from the cytoplasm to the cell membrane after LDL exposure. Cav-1 protein and cholesterol partitioned mainly into the caveola fractions, and LDL increased both Cav-1 and cholesterol in these fractions. Ras protein in caveola fractions was also increased by LDL. Increased Ras was detected in Cav-1 immunoprecipitated samples, and conversely, increased Cav-1 was found in Ras-immunoprecipitated samples. We also demonstrated LDL-increased Ras activity in HUVECs by measuring the GTP/GTP+GDP ratio of Ras with [
32
P]orthophosphate labeling in the cells. Finally, we determined the binding of [
3
H]-labeled free cholesterol and recombinant H-Ras to Cav-1 fusion proteins in vitro. Both cholesterol and Ras bound to full-length GST–Cav-1, scaffolding domain (61–101), and C-terminal (135–178) Cav-1 fusion peptides. Addition of cholesterol enhanced Ras binding to the full-length and scaffolding domain of Cav-1 but not to the C-terminal Cav-1. These findings strongly suggest a role for Cav-1 in cholesterol trafficking and cholesterol-mediated intracellular signaling, which may mediate EC activation by LDL.
The Transcription Factor NF-κB and the Regulation of Vascular Cell Function
Authors: Rainer de Martin  , Hoeth Martina , Hofer-Warbinek Renate , Schmid Johannes A.
Published: June 2011

Abstract—A variety of pathophysiological situations that affect cells of the vasculature, including endothelial and smooth muscle cells, leads to the expression of genes such as adhesion molecules and chemokines that are dependent on members of the nuclear factor (NF)-κB family of transcription factors. The corresponding gene products mediate important biological functions such as immune and inflammatory reactions, smooth muscle cell proliferation, and angiogenesis. The beneficial and usually transient NF-κB–dependent gene expression may be exaggerated in pathological situations and results in damage to the vessel wall and impaired vascular cell function. In this review, we will capitalize on the favorable and adverse roles of NF-κB in the context of vascular disease, eg, chronic and localized inflammation, arteriosclerosis, and neoangiogenesis.
Role of p38 Mitogen-Activated Protein Kinase in Neointimal Hyperplasia After Vascular Injury
Authors: Ohashi Naohiro , Matsumori Akira , Furukawa Yutaka , Ono Koh , Okada Masaharu , Iwasaki Atsushi , Miyamoto Tadashi , Nakano Atsushi , Sasayama Shigetake
Published: June 2011

Abstract—p38 mitogen-activated protein kinase (MAPK) is involved in intracellular signals that regulate a variety of cellular responses during inflammation. However, the role of p38 MAPK in atherosclerosis, a chronic inflammatory disorder, remains uncertain. The aim of the present study was to examine the role of p38 MAPK in the development of neointimal hyperplasia in balloon-injured rat carotid arteries. Immunohistochemical studies indicated that p38 MAPK was rapidly activated in the majority of medial cells in injured arterial walls. Rats treated with FR167653, a selective inhibitor of p38 MAPK, at a dosage of 10 mg · kg–1· d–1, had a 29.4% lower intima-to-media ratio than the untreated controls at 14 days after balloon injury (P<0.05). The percentage of proliferating nuclear antigen–positive cells in the media at 48 hours was significantly lower in the FR167653-treated group than in the control group. Quantitative competitive reverse transcription–polymerase chain reaction analysis revealed that interleukin-1β mRNA expression in arteries was significantly inhibited by FR167653 (to 18.1% of control,P<0.05) at 8 hours after balloon injury. Moreover, p38 MAPK activation and interleukin-1β production by lipopolysaccharide-stimulated vascular smooth muscle cells were inhibited by FR167653 in a concentration-dependent manner in vitro. These results indicate that p38 MAPK is activated in vascular walls after injury and promotes neointimal formation and suggest that selective inhibition of p38 MAPK may be effective in the prevention of restenosis after percutaneous transluminal coronary angioplasty.