bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of 347-Serine Mutation in Apoprotein A-IV on Plasma LDL Cholesterol Response to Dietary Fat
Authors: Jansen Sergio , Lopez-Miranda Jose , Salas Joaquin , Ordovas Jose M. , Castro Pedro , Marin Carmen , Ostos Maria A. , Lopez-Segura Fernando , Jimenez-Pereperez Jose A. , Blanco Angeles , Perez-Jimenez Francisco
Published: June 2011

AbstractLipid response to dietary fat and cholesterol is, to a large extent, genetically controlled. Apoprotein (apo) A-IV has been related to fat absorption and to the activation of some of the enzymes involved in lipid metabolism. One mutation has been described in the apo A-IV gene that causes substitution of Ser for Thr at position 347. To study the influence of this mutation on the plasma LDL cholesterol (LDL-C) response in diets of various fat content and fatty acid saturation, 41 healthy male subjects were studied, 25 of whom were homozygous for the Thr allele (347Thr) and the rest who were either homozygous (n=2) or heterozygous carriers of the Ser allele (347Ser). They consumed three consecutive diets, each of 4 weeks’ duration: one rich in saturated fat (SFA diet: 38% fat, 20% saturated), a National Cholesterol Education Program (NCEP) type 1 diet (28% fat, 10% saturated), and a third rich in monounsaturated fat (MUFA diet; 38% fat, 22% monounsaturated). Carriers of the 347Ser allele presented a greater decrease in total cholesterol (−0.7 vs −0.44 mmol/L,P<.034), LDL-C (−0.62 vs −0.31 mmol/L,P<.012), and apo B (−14 vs −8 mg/dL,P<.01) levels when they were switched from the SFA to the NCEP type 1 diet than homozygous carriers of the 347Thr allele. The change from the NCEP type 1 to the MUFA diet resulted in a greater increase in total cholesterol (0.18 vs −0.05 mmol/L,P<.028) and apo B (5 vs −1 mg/dL,P<.006) levels in the 347Ser than in the 347Thr individuals. In a previous study, we demonstrated that the G→A polymorphism at position −76 of the gene promoter of apo A-I affects the LDL-C response to dietary fat. We therefore decided to study the effect of the interaction between these mutations on this response. We found that both mutations have an additive effect on total cholesterol, LDL-C, and apo B dietary-induced changes. Our results suggest that total cholesterol and LDL-C response to dietary fat is influenced by the 347Ser mutation of apo A-IV.
Interactions Between Lifestyle-Related Factors and the ApoE Polymorphism on Plasma Lipids and Apolipoproteins
Authors: Boer Jolanda M. A. , Ehnholm Christian , Menzel Hans-Jurgen , Havekes Louis M. , Rosseneu Maryvonne , O’Reilly Denis St J. , Tiret Laurence , Group for the EARS
Published: June 2011

Abstract
To elucidate how the apolipoprotein (apo) E polymorphism and modifiable factors interact in explaining plasma lipid and apolipoprotein levels, we studied 1448 young adults (18 to 26 years old), participating in the European Atherosclerosis Research Study (EARS). Venous blood was collected after an overnight fast. Modifiable factors, eg, body mass index (BMI), waist-to-hip ratio (WHR), tobacco and alcohol consumption, and physical activity, were determined by using standardized protocols. Associations of modifiable factors with apoE levels were homogeneous across apoE phenotypes. In contrast, correlations of BMI with total cholesterol and apoB levels, as well as correlations between WHR and apoB, were significantly (
P
<.05 to
P
<.01) stronger in E2 carriers than in subjects with other phenotypes. Total cholesterol and apoB levels were comparable in E2 carriers in the upper tertile of BMI or WHR to those in E3/3 subjects, suggesting that the lowering effect of the E2 allele was no longer present. The inverse association between the plasma cholesteryl linoleate-to-oleate ratio, a marker for the dietary polyunsaturated-to-saturated fatty acid ratio, and triglycerides was also stronger in E2 carriers (−0.33 versus −0.17 in E3/3 and −0.24 in E4 carriers). Associations with other modifiable factors were notably consistent across apoE phenotypes. Gender and modifiable factors explained three times more (31%) of the interindividual variation in apoB levels in E2 carriers than in E3/3 subjects (9%) or E4 carriers (14%), mainly due to a larger variance explained by BMI. Our results suggest that the apoE polymorphism acts in a relatively uniform manner, independently of lifestyle. However, the associations of adiposity to total cholesterol and apoB levels appear to be stronger in apoE2 carriers.
Genetic Variation in Factor VII Associated with Variation in Plasma Lipoprotein(a) Concentration
Authors: Hegele Robert A. , Breckenridge W. Carl , Brunt J. Howard , Connelly Philip W.
Published: June 2011

Abstract
Cross-sectional and prospective studies have shown that individuals with high plasma lipoprotein(a) [Lp(a)] concentrations are at increased risk for coronary heart disease. Size polymorphism of the apolipoprotein(a) [apo(a)] glycoprotein accounts for ≈35% of the variation in plasma Lp(a) concentrations. However, there is no convincing evidence for associations between plasma Lp(a) and common genetic variation outside
APO(a)
, the gene that encodes apo(a). We tested for association of common genetic variation of candidate genes in lipid metabolism and also of F7 with variation of plasma Lp(a) concentrations in Alberta Hutterites. Variation at codon 353 of
F7
has been associated with variation in the plasma factor VII activity (FVIIc), with the 353Q allele associated with lower FVIIc and the 353R allele associated with higher FVIIc. We found significant associations between variation in plasma concentrations of Lp(a) and both apo(a) isoform size and
F7
codon 353 genotype (both
P
<.0001). The effects on plasma Lp(a) concentration of the alleles at codon 353 were additive. The average effects of the
F7
353Q and 353R alleles were, respectively, to decrease by 1.71 μg/mL and to increase by 0.301 μg/mL plasma Lp(a) concentration from the sample mean. This suggests that common genomic variation in
F7
is associated with variation in plasma Lp(a) concentration.
The II Genotype of the Angiotensin-Converting Enzyme Gene Delays the Onset of Acute Coronary Syndromes
Authors: Iwai Naoharu , Tamaki Shinji , Ohmichi Nobuyuki , Kinoshita Masahiko
Published: June 2011

AbstractThe DD genotype of the angiotensin-converting enzyme (ACE) gene has been reported to be a risk factor for myocardial infarction. However, this association has not been confirmed in some populations. We hypothesized that the discrepancies between these studies may be due to their definition of ischemic heart diseases. According to the genotype of the ACE gene, we analyzed the profiles of 320 patients who underwent coronary angiography for possible ischemic heart diseases. Of these, 23 patients had no significantly diseased vessels and no acetylcholine-induced vasospasm (normal acetylcholine responder [NAR]) (II, 7; ID, 14; DD, 2), 34 patients had no significantly diseased vessels and acetylcholine-induced vasospasm (paradoxical acetylcholine responder: [PAR]) (II, 15; ID, 18; DD, 1), 80 angina pectoris (AP) patients had significantly diseased vessels (II, 41; ID, 37; DD, 2), and 183 patients demonstrated myocardial infarction (MI) (II, 67; ID, 91; DD, 25). The frequency of the DD genotype was significantly lower in PAR and AP patients than in those with MI (P=.0344). Next we analyzed the length of time between the first anginal pain and the onset of myocardial infarction in the MI group. We obtained reliable information regarding this period in 149 of the 183 patients. This period was significantly shorter in the ID and DD groups than in the II group (P=.0022). Multiple regression analyses revealed that this period was significantly determined (P=.0003,R=.324) by the genotype of the ACE gene (II=1, ID+DD=2,P=.0003) and age (P=.034). The D allele of the ACE gene and lower age were associated with a shorter period. On the other hand, the genotype of the ACE gene had no significant effect on the number of significantly diseased (>50%) lesions. The frequency of the D allele in subjects with a rapid progression of MI was significantly higher than that in subjects with a prolonged history of stable AP (P<.0001). In summary, the II genotype of the ACE gene was associated with a longer period of time between the first anginal pain and the onset of myocardial infarction than the ID and DD genotypes of the ACE gene.
Expression of Matrix Metalloproteinases and Their Inhibitor TIMP-1 in the Rat Carotid Artery After Balloon Injury
Authors: Webb Karen E. , Henney Adriano M. , Anglin Sandra , Humphries Steve E. , McEwan Jean R.
Published: June 2011

Abstract
The temporal relationship of matrix metalloproteinases (MMPs) and a specific tissue inhibitor (TIMP-1) has been examined by reverse transcription-polymerase chain reaction and substrate zymography, after balloon catheter angioplasty of the rat carotid artery. The contralateral uninjured carotid artery was used as a comparative control. Of the MMPs examined, only MMP-2 (72-kDa gelatinase) was produced constitutively by normal uninjured arteries. After injury, MMP-2 mRNA levels fell compared with the uninjured arteries; by 24 hours, levels had increased 2-fold. Zymography showed that the inactive form of MMP-2 predominated in uninjured vessels, but after injury, the level of the active form was increased. MMP-9 (92-kDa gelatinase) mRNA levels and activity peaked at 6 hours after injury and were still detectable at 7 days. MMP-3 (stromelysin) expression was detectable at low levels as early as 2 hours after injury and showed an approximate 2-fold increase of expression at 7 days. The presence of the active protein paralleled the mRNA expression. The inhibitor TIMP-1 mRNA was first detected 6 hours after injury and showed a marked peak of expression at 24 hours; however, no expression was detected by 7 days. The presence of a constitutively expressed, low molecular weight caseinolytic enzyme (27 kDa) was observed, and the induction of a caseinolytic enzyme (30 kDa) was noted that was induced as early as 2 hours after injury, peaked at 6 hours, and was barely detectable by 7 days. These results demonstrate that the process of extracellular matrix breakdown by MMPs after balloon catheter-induced injury is controlled by a tightly regulated temporal response by the genes responsible for the production of these enzymes and their inhibitor and by post-translational activation of the proenzymes.
Acute Endothelin-Receptor Inhibition Does Not Attenuate Acetylcholine-Induced Coronary Vasoconstriction in Experimental Hypercholesterolemia
Authors: Hasdai David , Best Patricia J.M. , Cannan Charles R. , Mathew Verghese , Schwartz Robert S. , Holmes David R. , Lerman Amir
Published: June 2011

Abstract
—Endothelin (ET) may mediate the enhanced coronary vasoconstriction associated with hypercholesterolemia. We hypothesized that short-term inhibition of ET receptors attenuates the coronary epicardial vasoconstrictor response to acetylcholine in experimental hypercholesterolemia. ET-1 (group I, n=5; 5 ng · kg
−1
· min
−1
) and acetylcholine (group III, n=7; 10
−6
to 10
−4
mol/L) were given by intracoronary infusion in pigs. ET-1 and acetylcholine were also infused with the specific ETA-receptor blocker FR-139317 (5 μg · kg
−1
· min
−1
; group II, n=6; group IV, n=6). Acetylcholine was also infused with the combined ET-receptor blocker, bosentan (0.5 mg/kg plus 1 mg · kg
−1
· h
−1
, group V, n=5). The ETB-receptor agonist sarafotoxin 6c (5 ng · kg
−1
· min
−1
; n=4) was also infused. The percentage change in coronary artery diameter (%ΔCAD) to the infusions was measured at baseline and after 10 weeks of high-cholesterol diet in all animals. Sarafotoxin 6c mildly reduced %ΔCAD at baseline and 10 weeks (−10±2% and −12±3%, respectively). FR-139317 did not attenuate the epicardial vasoconstrictor response to ET-1 at baseline (%ΔCAD −18±8% for group I versus −12±6% for group II;
P
=NS) but did at 10 weeks (%ΔCAD −77±14% for group I versus −14±6% for group II;
P
<.05). FR-139317 did not affect the response to acetylcholine at baseline (%ΔCAD 5±2% for group III versus 7±3% for group IV,
P
=NS) or at 10 weeks (%ΔCAD −23±12% for group III versus −19±7% for group IV;
P
=NS). Bosentan did not affect the response to acetylcholine at baseline or 10 weeks. Short-term ET-receptor inhibition in experimental hypercholesterolemia attenuated the enhanced coronary epicardial vasoconstrictor effects of ET-1 but not acetylcholine-induced coronary epicardial vasoconstriction, suggesting that acetylcholine-induced coronary epicardial vasoconstriction may not be mediated by ET receptors.
Very-Low-Density Lipoprotein Response Element in the Promoter Region of the Human Plasminogen Activator Inhibitor-1 Gene Implicated in the Impaired Fibrinolysis of Hypertriglyceridemia
Authors: Eriksson Per , Nilsson Lennart , Karpe Fredrik , Hamsten Anders
Published: June 2011

Abstract
—Hypertriglyceridemia and impaired fibrinolytic function are linked to coronary heart disease and other atherothrombotic disorders. Triglyceride-rich lipoproteins may attenuate fibrinolysis by increasing the plasma levels of plasminogen activator inhibitor-1 (PAI-1). Furthermore, a common 4/5 guanosine (4G/5G) polymorphism in the promoter region of the PAI-1 gene has been indicated to influence plasma PAI-1 activity and to be involved in an allele-specific response to triglycerides. Herein we show by transfection assays that VLDLs induce transcription of the human PAI-1 promoter in endothelial cells. A VLDL response element (VLDLRE) is located to residues −672 to −657 in the promoter region by electromobility shift assay, methylation interference, and DNase I footprinting, and its activity is shown to be influenced by the common 4G/5G polymorphism located adjacent to and upstream of the binding site of a VLDL-inducible transcription factor. These findings may provide a molecular explanation to the link between VLDL and PAI-1 activity elevation in plasma and to the interaction between the 4G/5G polymorphism and plasma triglycerides.
Arterial Remodeling at the Reference Site After Angioplasty in the Atherosclerotic Rabbit Model
Authors: Kakuta Tsunekazu , Usui Michio , Coats William D. , Currier Jesse W. , Numano Fujio , Faxon David P.
Published: June 2011

Abstract
—Recent studies suggest that arterial remodeling plays an important role in restenosis and that remodeling at the reference site may also occur. To assess the chronic effect of the reference site remodeling on angioplasty results, we evaluated reference site remodeling in an experimental atherosclerotic restenosis model. Histological sections of iliac stenoses and their associated proximal reference segments from 50 atherosclerotic rabbits killed 4 weeks after angioplasty were analyzed. Lumen area (LA), external elastic lamina area (EEL), and intimal plus medial areas (I+M) were measured at the lesion (
L
) and reference (
R
) sites. Angiography was performed preangioplasty, immediately postangioplasty, and 4 weeks postangioplasty. Restenosis was defined as an angiographic loss/gain ratio of greater than 50% at follow-up angiography. Twenty-three lesions were restenotic (R+) and 32 were not (R−). There was no difference in reference site diameters (RD) between these two groups at the time of angioplasty. However, RDs were significantly smaller in the R+ group than in the R− group (1.24±0.18 versus 1.52±0.28 mm, n=55,
P
<.01) at 4-week follow-up. Morphometric analysis also showed a smaller LA
(R)
in the R+ group (0.85±0.27 versus 1.06±0.37 mm
2
, n=55,
P
<.02), whereas there was no difference in I+M
(R)
between the two groups. EEL
(R)
significantly correlated with EEL
(L)
, LA
(R)
, and I+M
(R)
in both groups combined (
r
=.53, n=55,
P
<.0001;
r
=.62, n=55,
P
<.0001; and
r
=.86, n=55,
P
<.0001, respectively). Remodeling can favorably and unfavorably affect both the lesion and the reference sites and appears to occur in parallel and proportionately at both sites. These data suggest that angiographic measurement of late percent stenosis using reference site diameters may lead to an underestimation of the percent luminal narrowing in restenotic lesions because unfavorable remodeling occurs in both the lesion and reference sites in restenotic vessels.
Apoptosis in the Atherosclerotic Plaque
Authors: Kockx Mark M.
Published: June 2011

Abstract
—Several laboratories have demonstrated the presence of apoptotic cell death in atherosclerotic plaques. Apoptosis occurs in at least 2 stages. The final “execution” phase, which includes DNA fragmentation, is brief (≈6 hours) and irreversible and can be detected by the terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling (TUNEL) technique. The TUNEL technique is only selective (rather than specific) for apoptotic nuclei, because these contain a far greater degree of DNA fragmentation than do nonapoptotic nuclei. Nonapoptotic cell nuclei that show high levels of RNA synthesis and splicing can also be labeled. This could explain the large variation in the reported percentages of TUNEL-positive nuclei in the plaques. Therefore, the TUNEL technique should be combined with additional techniques, such as markers of transcription and morphological criteria. Recent studies indicate that human fatty streaks differ from adaptive intimal thickenings by the presence of cells containing pro-apoptotic proteins. However, apoptotic cell death is present only in advanced atherosclerotic plaques that show a dense macrophage infiltration. This indicates that although both smooth muscle cells and macrophages within the human fatty streaks become susceptible to apoptosis, additional factors (mainly macrophage- and lipid-derived factors) are necessary to terminate the cell death pathway.
NO Inhibits Cytokine-Induced iNOS Expression and NF-κB Activation by Interfering With Phosphorylation and Degradation of IκB-α
Authors: Katsuyama Koichi , Shichiri Masayoshi , Marumo Fumiaki , Hirata Yukio
Published: June 2011

Abstract—Nitric oxide (NO) is known to have antiatherogenic and anti-inflammatory properties, but its effects on the cytokine-induced nuclear factor-kappa B (NF-κB) activation pathway in relation to the regulation of inducible nitric oxide synthase (iNOS) gene in vascular smooth muscle cells (VSMCs) remain elusive. To elucidate the roles of NO in the regulation of cytokine-induced NF-κB activation and consequent iNOS gene expression, we studied the effects of NO donors [(±)-(E)-ethyl-2-[(E)-hydroxyamino]-5-nitro-3-hexeneamide (NOR3) and sodium nitroprusside] on interleukin (IL)-1β–induced NF-κB activation and IκB-α degradation and subsequent iNOS expression in rat VSMCs. Northern blot and Western blot analyses demonstrated that NO donors decreased IL-1β–induced iNOS mRNA and protein expression. Electrophoretic mobility shift assay using synthetic oligonucleotide corresponding to the downstream NF-κB site of rat iNOS promoter as a probe showed that NOR3 inhibited IL-1β–induced NF-κB activation and its nuclear translocation, as demonstrated with immunocytochemical study. These effects were independent of guanylate cyclase activation; an inhibitor of soluble guanylate cyclase (1H-oxadiazolo-1,2,4-[4,3-α]quinoxaline-1-one) had no effect on NOR3-induced inhibition of NF-κB activation or iNOS mRNA expression by IL-1β, and a cGMP derivative (8-bromo-cGMP) failed to mimic the effects of NO donors. Western blot analysis using anti–IκB-α and anti–phospho-IκB-α antibodies revealed that IL-1β induced a transient degradation of IκB-α preceded by a rapid appearance of phosphorylated IκB-α, both of which were completely blocked by NOR3. A proteasome inhibitor (MG115) blocked IL-1β–induced transient degradation of IκB-α and stabilized the appearance of phosphorylated IκB-α stimulated by IL-1β. NOR3 inhibited the appearance of IL-1β–induced phosphorylated IκB-α even in the presence of MG115. Our results indicate that an inhibitory action by NO on cytokine-induced NF-κB activation and iNOS gene expression is due to its direct blockade on phosphorylation and subsequent degradation of IκB-α via the cGMP-independent pathway in rat VSMCs.
Urokinase Receptor-Dependent Upregulation of Smooth Muscle Cell Adhesion to Vitronectin by Urokinase
Authors: Chang Alan W. , Kuo Alice , Barnathan Elliot S. , Okada S. Steve
Published: June 2011

Abstract
—The plasminogen activator system has been implicated in the modulation of the response to vascular injury. Although urokinase-type plasminogen activator (uPA) and its receptor (uPAR) may enhance matrix degradation as well as migration and invasion by smooth muscle cells (SMCs), their roles in cell adhesion are uncertain. Therefore, we examined the ability of uPA and uPAR to modulate adhesion of cultured human vascular SMCs to various matrices. We demonstrated a dose-dependent stimulation of adhesion by single-chain uPA (scuPA) to vitronectin (maximum 1.55-fold [±0.04-fold] increase, 10 nmol/L,
P
<0.002) but not to laminin, collagen I, or collagen IV. Baseline adhesion to vitronectin was completely inhibited by both EDTA and RGD peptide but was restored to >40% of control in the presence of scuPA (
P
=0.001 and 0.046, respectively). Adhesion to vitronectin was also significantly enhanced by the amino-terminal fragment of uPA (
P
=0.007) and two-chain, high-molecular-weight uPA (
P
<0.01) but not by the low-molecular-weight fragment of uPA, which lacks the receptor-binding domain. Aprotinin, a plasmin inhibitor, had no effect on baseline or scuPA-stimulated adhesion, suggesting a plasmin-independent process. Preincubation of scuPA with soluble uPAR inhibited scuPA stimulation of adhesion by 88±14% (
P
=0.01), as did pretreatment of SMCs with phosphatidylinositol-specific phospholipase C, which removes glycophosphatidylinositol-anchored proteins, including uPAR. Antibodies to both α
v
β
3
and α
v
β
5
integrin inhibited baseline adhesion but not scuPA stimulation. Finally, coating plates with scuPA alone enabled cell adhesion, which could be inhibited by both soluble uPAR and anti-uPAR antibodies. These data suggest that uPA stimulates adhesion of SMCs specifically to vitronectin and that it is mediated by an interaction with uPAR. Upregulation of both proteins after vascular injury may facilitate migration through stimulation of both matrix degradation and cell adhesion.
The PAI-1 Gene Locus 4G/5G Polymorphism Is Associated With a Family History of Coronary Artery Disease
Authors: Margaglione Maurizio , Cappucci Giuseppe , Colaizzo Donatella , Giuliani Nicola , Vecchione Gennaro , Grandone Elvira , Pennelli Orazio , Di Minno Giovanni
Published: June 2011

Abstract
—A family history of ischemic events is a major determinant of coronary artery disease (CAD). Plasma levels of plasminogen activator inhibitor 1 (PAI-1) modulate this risk. A deletion/insertion polymorphism within the PAI-1 locus (4G/5G) affects the expression of this gene. We investigated the relationship between the PAI-1 4G/5G polymorphism in 1179 healthy employees of our institution and the occurrence of CAD in their first-degree relatives. A family history of documented ischemic coronary disease was assessed by a modified WHO questionnaire. The PAI-1 4G/5G polymorphism was evaluated by polymerase chain reaction and endonuclease digestion. The group with a first-degree relative who had suffered from a coronary ischemic episode had a higher number of homozygotes for the deleted allele (4G/4G) of the PAI-1 gene compared with subjects without such a family history (odds ratio [OR]=1.62, 95% confidence interval [CI]=1.17 to 2.25;
P
=.005). The frequency of the 4G allele was abnormally high as well (OR=1.29, 95% CI=1.04 to 1.60;
P
=.025). The individuals with a positive family history were older (
P
<.001) and exhibited a higher body mass index (
P
=.033) and total cholesterol levels (
P
<.001) than those without. In a multiple logistic regression analysis, age (
P
=.006) and PAI-1 4G/4G (
P
=.024) independently contributed to a family history of coronary heart disease, with 4G/4G carriers exhibiting a more frequent family history of CAD (OR=1.60). The PAI-1 4G/5G polymorphism to some extent thus accounts for the risk of CAD related to a family history for such an event. These findings support the hypothesis that the 4G variant is a transmissible coronary risk factor.
Plasminogen Activator Inhibitor-1 Activity Is Independently Related to Both Insulin Sensitivity and Serum Triglycerides in 70-Year-Old Men
Authors: Byberg Liisa , Siegbahn Agneta , Berglund Lars , McKeigue Paul , Reneland Richard , Lithell Hans
Published: June 2011

Abstract
—Increased levels of plasminogen activator inhibitor-1 (PAI-1) have been discussed as a part of the insulin resistance syndrome. However, it is not clear whether the relationship between PAI-1 and insulin resistance is independent of or mediated by increased triglycerides levels. The aim of this study was to investigate whether PAI-1 activity is associated with insulin sensitivity independently of serum triglycerides (sTG) and of other potential confounders. Seventy-year-old men (n=871), participating in a cohort study undergoing extensive metabolic investigations, had blood samples taken for determination of PAI-1 activity. Insulin sensitivity was determined by the euglycemic hyperinsulinemic clamp. In multivariate correlation and regression analyses, insulin sensitivity was a statistically significant determinant of PAI-1 activity (partial
r
=−.12;
P
<.001), independent of sTG, body mass index, waist-hip ratio, and other potential confounders. The levels of sTG were also independently related to PAI-1 activity (partial
r
=.18;
P
<.001). The relationships between PAI-1 and insulin sensitivity and sTG were independent of fasting glucose levels. Aggregation of risk factors of the insulin resistance syndrome was associated with increased activity of PAI-1 in men with normal glucose tolerance. We conclude that PAI-1 activity is related to insulin sensitivity and sTG, independently of each other and of other potential confounders, and that increased levels of PAI-1 should be regarded as a component of the insulin resistance syndrome.
−455G/A Polymorphism of the β-Fibrinogen Gene is Associated With the Progression of Coronary Atherosclerosis in Symptomatic Men
Authors: de Maat Moniek P. M. , Kastelein John J. P. , Jukema J. Wouter , Zwinderman Aeilko H. , Jansen Hans , Groenemeier Bjørn , Bruschke Albert V. G. , Kluft Cornelis
Published: June 2011

Abstract
—Increased plasma fibrinogen levels have been identified as a risk indicator for myocardial infarction, stroke, and thrombosis. Both environmental and genetic factors make an important contribution to plasma fibrinogen levels in humans. In the present study we evaluated, in patients with serum cholesterol levels between 4 and 8 mmol/L, the relation of plasma levels and polymorphisms of fibrinogen with coronary artery disease (CAD), cross-sectionally at baseline and after a 2-year follow-up period in which they received either a placebo or pravastatin. Higher plasma fibrinogen levels (3.9 g/L) were observed at baseline in patients with the −455AA genotype than in patients with the −455GA (3.2 g/L) and −455GG (3.1 g/L) genotypes of the −455G/A fibrinogen β gene polymorphism (
P
<.05). Plasma levels of fibrinogen were not related to the baseline angiographic variables (mean segment diameter [MSD] and minimum obstruction diameter [MOD]), nor to the quantitative changes in these angiographic variables. However, in the placebo group, patients with the −455AA genotype had more progression of CAD, expressed by a significantly greater decrease of the MSD and MOD, after the 2-year follow-up period than patients with the other genotypes. The −455G/A polymorphism was related to the progression of CAD, and pravastatin therapy seemed to offset this deleterious effect. We hypothesized that the −455A allele may promote a stronger acute-phase response in fibrinogen and that the resulting higher fibrinogen levels may form the pathogenetic basis for the stronger progression of coronary atherosclerosis. Experiments to verify this hypothesis are being proposed and advocated, in view of the possibility of identifying a genetic marker that can recognize a subgroup of patients with an increased risk who may benefit from early treatment with lipid-lowering or anticoagulant drugs.
Regulation of PDGF-B in Endothelial Cells Exposed to Cyclic Strain
Authors: Sumpio Bauer E. , Du Wei , Galagher Gary , Wang Xui-jie , Khachigian Levon M. , Collins Tucker , Gimbrone Michael A. , Resnick Nitzan
Published: June 2011

Abstract
—The present study was designed to examine the regulation by cyclic strain of endothelial cell (EC) platelet-derived growth factor-B chain (PDGF-B) expression. We demonstrate in this study that bovine aortic ECs subjected to 10% (but not 6%) average strain resulted in a 2.6-fold increase in PDGF-B steady state mRNA and immunoreactive protein. Nuclear runoff transcription assays confirmed the induction of PDGF-B transcripts. To address the regulation of PDGF-B gene expression by cyclic strain, we transfected bovine aortic ECs with a construct containing 450 bp of human PDGF-B promoter sequence coupled to chloramphenicol acetyltransferase (CAT), and found that subjecting these cells to 10% average strain resulted in a twofold increase in CAT activity by 4 hours. Analysis of nested 5′ deletions of the promoter transfected into ECs demonstrated a 55% drop-off in activity between position −313 and −153, with no induction of activity with the −101-bp minimal promoter. Since a shear stress response element (SSRE) is located at position −125, we tested the hypothesis that the SSRE site was necessary and/or sufficient for induction of PDGF-B activity with strain. Electromobility shift assays revealed that nuclear proteins from ECs exposed to strain for short intervals (30 minutes) bound to the PDGF-B SSRE. However, transfection of ECs with hybrid promoter constructs containing the SV40 sequence promoter downstream of the SSRE or the −153 PDGF-B promoter sequence bearing a mutation in the SSRE demonstrated that the SSRE was not necessary for inducible reporter gene expression in ECs exposed to cyclic strain.
Physical Activity Status and Adverse Age-Related Differences in Coagulation and Fibrinolytic Factors in Women
Authors: DeSouza Christopher A. , Jones Pamela Parker , Seals Douglas R.
Published: June 2011

Abstract
—Adverse changes in coagulation and fibrinolytic factors are thought to contribute to the increased risk of cardiovascular disease and atherothrombosis with age. We tested the hypothesis that such age-related changes in specific coagulation and fibrinolytic factors are absent in physically active women. Resting levels of plasma fibrinogen, tissue-type plasminogen activator (t-PA) antigen and activity, plasminogen activator inhibitor-1 (PAI-1) antigen and activity, and fibrin
d
-dimer were measured in 24 healthy premenopausal women: 11 sedentary (aged 28±1 years; Pre-S) and 13 physically active (aged 30±1 years; Pre-PA) and in 27 healthy postmenopausal women: 14 sedentary (aged 61±1 years; Post-S) and 13 physically active (aged 58±1 years; Post-PA). Post-S had higher (
P
<.05) fibrinogen, t-PA antigen, PAI-1 antigen, PAI-1 activity, and fibrin
d
-dimer levels and lower t-PA activity than Pre-S. Post-PA demonstrated lower (
P
<.01) plasma fibrinogen, t-PA antigen, PAI-1 antigen, and PAI-1 activity and higher (
P
<.01) t-PA activity levels than Post-S. In addition, plasma fibrin
d
-dimer levels tended (
P
=.06) to be lower in Post-PA than in Post-S. Although plasma levels of fibrinogen and fibrin
d
-dimer in Post-PA were lower than in Post-S, they were higher (
P
<.05) than in Pre-PA. Importantly, however, the fibrinolytic profile of Post-PA did not differ from that of Pre-PA. The results of the present study demonstrate that the adverse age-associated differences in plasma fibrinogen concentrations and the endogenous fibrinolytic system in sedentary healthy women are either attenuated or absent in highly physically active women. The smaller or absent age-related differences in coagulation and fibrinolytic factors in women who habitually exercise may represent an important mechanism contributing to their lower age-related increase in both cardiovascular disease and atherothrombotic events. Future studies need to determine whether women who are moderately active would demonstrate the same favorable hemostatic profile.
Human Vascular Smooth Muscle Cells Express Receptors for CC Chemokines
Authors: Hayes Ian M. , Jordan Nicola J. , Towers Sarah , Smith Graham , Paterson Jacqui R. , Earnshaw Jonothan J. , Roach Alan G. , Westwick John , Williams Robert J.
Published: June 2011

Abstract—Arteriosclerotic lesions are characterized by the accumulation of T lymphocytes and monocytes and the proliferation of intimal smooth muscle cells. Expression of the chemokine monocyte chemoattractant protein-1 (MCP-1) has been observed in arteriosclerotic plaques and has been proposed to mediate the transendothelial migration of mononuclear cells. More recently, MCP-1 has been proposed to affect the proliferation and migration of vascular smooth muscle cells (VSMCs). We have used reverse transcription–polymerase chain reaction (RT-PCR) to investigate chemokine mRNA expression in human arteriosclerotic lesions obtained from surgical biopsy of diseased vascular tissue and show, in addition to MCP-1, expression of the chemokine macrophage inflammatory protein-1α (MIP-1α) at higher levels than in “normal” aortic tissue. We have also used RT-PCR to characterize the expression of known chemokine receptors by primary human VSMCs. Messenger RNA for the MIP-1α/RANTES receptor, CCR-1, and the MCP-1/MCP-3 receptor, CCR-2, was expressed by unstimulated VSMCs grown under serum-free culture conditions for 24 hours. The receptors CCR-3, CCR-4, CCR-5, CXCR-1, and CXCR-2 were not expressed by VSMCs. The presence of functionally coupled receptors for MIP-1α on VSMCs was demonstrated by specific binding of biotinylated MIP-1α and increases in intracellular Ca2+levels after exposure to this chemokine. Taken together, these results suggest that chemokines are likely to be involved in arteriosclerosis and may play a role in modulating the function of VSMCs in vivo.
Differential Involvement of Tyrosine and Serine/Threonine Kinases in Platelet Integrin α
IIb
β
3
Exposure
Authors: Hers Ingeborg , Donath José , van Willigen Gijsbert , Akkerman Jan Willem N.
Published: June 2011

Abstract
—The relative contributions of protein tyrosine kinases (PTKs) and protein kinase C isoenzymes (PKCs), a family of serine/threonine kinases, in integrin α
IIb
β
3
(glycoprotein IIb/IIIa) exposure are the subject of much controversy. In the present study we measured the effect of the PTK inhibitor herbimycin A and the PKC inhibitor bisindolylmaleimide I on
125
I-fibrinogen binding to α
IIb
β
3
and on aggregation/secretion induced by different agonists. Dose-response studies showed complete inhibition of α
IIb
β
3
exposure by 30 μmol/L (ADP stimulation) and 35 to 40 μmol/L (α-thrombin stimulation) herbimycin A. In contrast, inhibition of exposure by bisindolylmaleimide I varied from none (for ADP and epinephrine), to 30% (for platelet-activating factor), and to ≈80% (for α-thrombin). Studies with a submaximal dose of herbimycin A (≈50% inhibition of the ADP-response) and a maximal dose of bisindolylmaleimide I showed that optical aggregation had a similar sensitivity to the inhibitors as α
IIb
β
3
exposure with minimal interference by secreted ADP. Thus, the relative contributions of tyrosine and serine/threonine kinases in α
IIb
β
3
exposure and aggregation differ among the different agonists, with an exclusive role for PTKs in ADP- and epinephrine-induced responses and a role for both PTKs and PKCs in responses induced by platelet-activating factor and α-thrombin.
Familial HDL Deficiency Characterized by Hypercatabolism of Mature ApoA-I but Not ProApoA-I
Authors: Batal Rami , Tremblay Michel , Krimbou Larbi , Mamer Orval , Davignon Jean , Genest Jacques , Cohn Jeffrey S.
Published: June 2011

Abstract
—We have previously described patients with familial high density lipoprotein (HDL) deficiency (FHD) having a marked reduction in the plasma concentration of HDL cholesterol and apolipoprotein (apo) A-I but lacking clinical manifestations of Tangier disease or evidence of other known causes of HDL deficiency. To determine whether FHD in these individuals was associated with impaired HDL production or increased HDL catabolism, we investigated the kinetics of plasma apoA-I and apoA-II in two related FHD patients (plasma apoA-I, 17 and 37 mg/dL) and four control subjects (apoA-I, 126±18 mg/dL, mean±SD) by using a primed constant infusion of deuterated leucine. Kinetic analysis of plasma apolipoprotein enrichment curves demonstrated that mature plasma apoA-I production rates (PRs) were similar in patients and control subjects (7.9 and 9.1 versus 10.5±1.7 mg · kg
−1
· d
−1
). Residence times (RTs) of mature apoA-I were, however, significantly less in FHD patients (0.79 and 1.66 days) compared with controls (5.32±1.05 days). Essentially normal levels of plasma proapoA-I (the precursor protein of apoA-I) in FHD patients were associated with normal plasma proapoA-I PRs (7.8 and 10.4 versus 10.9±2.6 mg · kg
−1
· d
−1
) and proapoA-I RTs (0.18 and 0.15 versus 0.16±0.03 day). The RTs of apoA-II were, however, less in patients (3.17 and 2.92 days) than control subjects (7.24±0.71 days), whereas the PRs of apoA-II were similar (1.8 and 1.9 versus 1.7±0.2 mg · kg
−1
· d
−1
). Increased plasma catabolism of apoA-II in FHD patients was associated with the presence in plasma of abnormal apoA-II–HDL (without apoA-I). These results demonstrate that FHD in our patients is characterized, like Tangier disease, by hypercatabolism of mature apoA-I and apoA-II, but unlike Tangier disease, by essentially normal plasma catabolism and concentration of proapoA-I.
Minimally Oxidized Low-Density Lipoprotein Increases Expression of Scavenger Receptor A, CD36, and Macrosialin in Resident Mouse Peritoneal Macrophages
Authors: Yoshida Hiroshi , Quehenberger Oswald , Kondratenko Nonna , Green Simone , Steinberg Daniel
Published: June 2011

Abstract—Fully oxidized LDL (OxLDL) is believed to contribute to atherogenesis in part by virtue of uptake into macrophages via specific scavenger receptors. This phenomenon results in the formation of cholesterol-loaded foam cells, a major component of atherosclerotic lesions. The present study is directed at examining the effects of OxLDL and minimally oxidized LDL (MM-LDL) on scavenger receptor expression and activity in mouse peritoneal resident macrophages. Macrophages were preincubated with MM-LDL or OxLDL at concentrations of 25 or 50 μg/mL for 24 to 48 hours, after which their ability to bind and take up125I-OxLDL or125I-acetylated LDL (AcLDL) was determined. MM-LDL pretreatment induced a clear increase of cell association and degradation of125I-OxLDL and125I-AcLDL. Pretreatment with OxLDL also enhanced scavenger receptor activity, but to a lesser degree. Neither native LDL nor AcLDL had any effect. Scatchard analysis showed that preincubation with 50 μg/mL MM-LDL for 48 hours increased the Bmaxof125I-OxLDL and125I-AcLDL by 139% and 154%, respectively, without significantly changing their affinity. Lipids extracted from MM-LDL also significantly induced scavenger receptor activity, but to a lesser extent than did intact MM-LDL. MM-LDL pretreatment increased both mRNA levels and protein levels of scavenger receptor A, CD36, and macrosialin. On the other hand, OxLDL pretreatment increased expression of macrosialin only. These results, showing that MM-LDL can upregulate scavenger receptor expression in mouse resident peritoneal macrophages, suggest that clearance of OxLDL by macrophages in lesions is more effective, in part because the OxLDL precursor, MM-LDL, primes the macrophage for foam cell generation.
Low Expression of the Apolipoprotein B mRNA–Editing Transgene in Mice Reduces LDL Levels but Does Not Cause Liver Dysplasia or Tumors
Authors: Qian Xiaobing , Balestra Maureen E. , Yamanaka Shinya , Borén Jan , Lee Isabelle , Innerarity Thomas L.
Published: June 2011

Abstract
—Hepatic expression of apolipoprotein (apo) B mRNA–editing enzyme catalytic polypeptide 1 (APOBEC-1) has been proposed as a gene therapy approach for lowering plasma low density lipoprotein (LDL) levels. However, high-level expression of APOBEC-1 in transgenic mouse and rabbit livers causes liver dysplasia and hepatocellular carcinoma. To determine the physiological and pathological effects of low-level hepatic expression of APOBEC-1, we used a 52-kb rat APOBEC-1 genomic clone (RE4) to generate transgenic mice expressing low levels of APOBEC-1 (2 to 5 times those in nontransgenic mice). Liver function, liver histology, editing of apoB mRNA at the normal editing site (C
6666
), and abnormal editing at multiple sites (hyperediting) in these mice were compared with those in transgenic mice expressing intermediate (I-20) or high (I-28) levels of APOBEC-1 in the liver. Hyperediting of mRNA coding for the novel APOBEC-1 target 1 (NAT1) was also examined. In the high-expressing I-28 line, 50% of the mice had palpable tumors at 15 weeks of age, whereas in the intermediate-expressing I-20 line, 50% of the mice had evidence of liver tumors after 1 year. In contrast, low-expressing RE4 mice had normal liver function and histology and did not develop liver tumors when examined at 3 to 17 months of age. Moreover, hyperediting of apoB and NAT1 mRNA in the liver was robust in the I-20 mice but barely detectable in the RE4 mice. The low-level expression resulted in sufficient APOBEC-1 to edit essentially all apoB mRNA at the normal editing site, virtually eliminating apoB-100 and LDL in the plasma of RE4 mice. When RE4 mice were crossed with human apoB transgenic mice, which possess high plasma LDL concentrations, plasma LDL levels in the offspring were reduced to very low levels. These results indicates that long-term hepatic expression of APOBEC-1 at low levels sufficient to eliminate LDL does not cause apparent liver damage or liver tumors in transgenic mice. RE4 APOBEC-1 transgenic mice should prove valuable for studying the roles of apoB-containing lipoproteins in lipid metabolism and atherosclerosis.
Relationship Between Plasma Viscosity and the Severity of Coronary Heart Disease
Authors: Junker Ralf , Heinrich Jürgen , Ulbrich Hans , Schulte Helmut , Schönfeld Rainer , Köhler Ekkehart , Assmann Gerd
Published: June 2011

Abstract
—Several studies have indicated that plasma viscosity contributes to cardiovascular risk in men. So far, a significant relationship between plasma viscosity and the severity of coronary heart disease has not been found. Thus, the present study is the first to report on the relationship of plasma viscosity and the severity of coronary heart disease. In a collective of 1142 male myocardial infarction patients, plasma viscosity and additional laboratory parameters were determined. Atherosclerotic changes were quantified by coronary angiography. Patients were divided into groups without any, and with one to three stenosed vessels. We found a positive relationship between plasma viscosity and the severity of coronary heart disease, even after adjusting groups for age, fibrinogen, and use of diuretics. Mean plasma viscosity ranged from 1.141±0.035 mPa s in patients without stenosed vessels to 1.162±0.044 mPa s in patients who had three coronary vessels with stenoses >50%. Differences between the groups were significant (
P
<0.001 to 0.05), with two exceptions: differences between patients without any and with one stenosed vessel, as well as between patients with one and two stenosed vessels, did not reach the significance level. On the whole, we can give further support to the hypothesis that cardiovascular risk factors and coronary heart disease may be linked by plasma viscosity.
Norethindrone Acetate Enhances the Antiatherogenic Effect of 17β-Estradiol
Authors: Alexandersen Peter , Haarbo Jens , Sandholdt Irene , Shalmi Michael , Lawaetz Henrik , Christiansen Claus
Published: June 2011

Abstract
—The influence of progestogens in combination with 17β-estradiol (E2) on cardiovascular disease remains controversial. This study investigated the effect of norethindrone acetate (NETA) combined with E2 on aortic atherosclerosis. Eighty mature female rabbits were ovariectomized, then fed a cholesterol-rich diet (240 mg/d) for 14 weeks to induce aortic atherosclerosis. They were randomized to four equally large groups for the following 38-week intervention period. One group received placebo, another group oral E2 4 mg daily (E2), and the last two groups oral E2 4 mg daily combined with either NETA 1 mg (E2NETA1) or NETA 3 mg (E2NETA3). The cholesterol intake was reduced to a “maintenance” level of 80 mg/d during the intervention period. Total serum cholesterol and ultracentrifuged lipoproteins were analyzed enzymatically throughout the study. The cholesterol content in the aortic wall was 2.76±0.44 μmol/cm
2
(mean±SEM) in the E2NETA1 group, 1.77±0.37 μmol/cm
2
in the E2NETA3 group, 5.46±0.77 μmol/cm
2
in the E2 group, and 7.20±0.94 μmol/cm
2
in the placebo group (ANOVA
P
<0.0001). The difference (in the aortic cholesterol accumulation) between the E2 and each of the combined E2/NETA groups was statistically significant (
P
<0.01) but could only partly be explained by the differences in serum lipids and lipoproteins. In conclusion, NETA enhances the antiatherogenic effect of E2 in cholesterol-fed rabbits. This effect is only partially mediated through changes in serum lipids and lipoproteins.
Abdominal Obesity, Impaired Nonesterified Fatty Acid Suppression, and Insulin-Mediated Glucose Disposal Are Early Metabolic Abnormalities in Families With Premature Myocardial Infarction
Authors: Kooner Jaspal S. , Baliga Ragavendra R. , Wilding John , Crook David , Packard Christopher J. , Banks Linda M. , Peart Stanley , Aitman Timothy J. , Scott James
Published: June 2011

Abstract
—British Indian Asian men aged <40 years have a twofold to threefold increased risk of death from coronary heart disease (CHD) compared with British whites. Epidemiological studies have suggested an association between glucose intolerance and hyperinsulinemia with premature CHD in Indian Asians. We tested the association of insulin action with myocardial infarction (MI) by using the hyperinsulinemic-euglycemic clamp in 17 MI patients: 8 Punjabi Sikhs (PSMIs), 9 British whites (BWMIs), and 17 control subjects (9 PSCs and 8 BWCs). Metabolic factors associated with insulin resistance were investigated in 51 MI patients (24 PSMIs and 27 BWMIs) and 53 control subjects (28 PSCs and 25 BWCs). Familial aggregation of defective insulin action was examined by studying five pedigrees of Sikh survivors of MI. Sikh survivors of premature MI demonstrated impaired insulin-mediated glucose uptake (
P
<.001) by use of the clamp technique and nonesterified fatty acid (NEFA) suppression (
P
<.05) by using both clamp techniques and the oral glucose tolerance test, as compared with Sikh control subjects. White patients had impaired insulin-mediated glucose uptake but normal NEFA suppression. Metabolic factors usually associated with insulin resistance, including increased 2-hour post–oral glucose tolerance test triglycerides, smaller low density lipoprotein particle size, and increased plasminogen activator inhibitor-1, were present in white (all
P
<.05) but surprisingly absent in Sikh (all
P
>.05) MI patients compared with respective ethnic control subjects. Fasting glucose and total cholesterol levels did not differ between patients and control subjects. Abdominal obesity, impaired NEFA suppression after oral glucose, and fasting hyperinsulinemia were present in Sikh MI patients and their nondiabetic first-degree relatives compared with Sikh control subjects. PS survivors of premature MI demonstrated impaired insulin-mediated glucose disposal and NEFA suppression compared with ethnic control subjects. BWMI patients showed abnormalities of carbohydrate, but not of NEFA, metabolism compared with white control subjects. Defects of insulin action manifested as abdominal obesity, impaired NEFA suppression, and fasting hyperinsulinemia are present in Sikh MI patients and their asymptomatic, nondiabetic, first-degree relatives. We suggest that these defects may be early metabolic markers that predict risk of premature MI among PSs.