bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidized LDL and Lysophosphatidylcholine Stimulate Plasminogen Activator Inhibitor-1 Expression in Vascular Smooth Muscle Cells
Authors: Dichtl Wolfgang , Stiko Ann , Eriksson Per , Goncalves Isabel , Calara Federico , Banfi Cristina , Ares Mikko P. S. , Hamsten Anders , Nilsson Jan
Published: June 2011

Abstract
—Plasminogen activator inhibitor-1 (PAI-1) functions as an important regulator of fibrinolysis by inhibiting both tissue-type and urokinase-type plasminogen activator. PAI-1 is produced by smooth muscle cells (SMCs) in atherosclerotic arteries, but the mechanisms responsible for induction of PAI-1 in SMCs are less well understood. In cultured human aortic SMCs, PAI-1 mRNA expression and protein secretion were increased after incubation with oxidized low-density lipoprotein (LDL) and the lipid peroxidation product lysophosphatidylcholine, whereas the effects of native LDL on PAI-1 production and release were more variable and did not reach statistical significance. The effect of LDL on arterial expression of PAI-1 in vivo was also studied in an animal model. Intravenous injection of human LDL in Sprague-Dawley rats resulted in accumulation of apolipoprotein B in the aorta within 12 hours as assessed by immunohistochemical testing. Epitopes specific for oxidized LDL began to develop in the aorta 12 hours after injection of LDL and peaked at 24 hours; this peak was accompanied by intense expression of PAI-1 immunoreactivity in the media. Also, increased aortic expression of PAI-1 mRNA after LDL injection was detected by using in situ hybridization. The transcription factor activator protein-1, which is known to bind to the promoter of the PAI-1 gene, was activated in the aortic wall 24 hours after LDL injection as assessed by electrophoretic mobility shift assay. Pretreatment of LDL with the antioxidant probucol decreased expression of oxidized LDL and PAI-1 immunoreactivity and activator protein-1 induction in the aorta but did not affect expression of apolipoprotein B immunoreactivity. These findings demonstrate that LDL oxidation enhances secretion of PAI-1 from cultured SMCs and that a similar mechanism may be involved in vascular expression of PAI-1.
Systematic Review on the Risk and Benefit of Different Cholesterol-Lowering Interventions
Authors: Bucher Heiner C. , Griffith Lauren E. , Guyatt Gordon H.
Published: June 2011

Abstract
—Meta-analyses have investigated the efficacy of cholesterol-lowering interventions in relation to the underlying risk of coronary heart disease and the extent and duration of cholesterol reduction. We systematically reviewed the efficacy of antilipidemic interventions on major mortality outcomes in relation to drug classes. We searched MEDLINE and EMBASE from 1966 through October 1996 for randomized, controlled trials of any cholesterol-lowering interventions reporting mortality data. We included 59 trials involving 85 431 participants in the intervention and 87 729 participants in the control groups. We pooled these trials into 7 pharmacological categories of cholesterol-lowering interventions: statins (13 trials), fibrates (12 trials), resins (8 trials), hormones (8 trials), niacin acid (2 trials), n-3 fatty acids (3 trials), and dietary interventions (16 trials). Of the cholesterol-lowering interventions, only statins showed a large and statistically significant reduction in mortality from coronary heart disease (risk ratio, 0.66; 95% confidence interval [CI], 0.54 to 0.79) and from all causes (risk ratio, 0.75; 95% CI, 0.65 to 0.86). For both all-cause and cardiovascular mortality, the difference between statins and the combined estimate of the other classes of agents was unlikely to be due to chance (
P
<0.02 for both comparisons). Meta-regression analysis demonstrated that variability in results across trials could be largely explained on the basis of differences in the magnitude of cholesterol reduction. Statins have the largest effect on the reduction of cardiovascular and all-cause mortality, and this result recommends their use in preference to other antilipidemic agents. The greater effect of statins is likely due to the larger reduction in cholesterol.
Genetic Analysis of the Thermolabile Variant of 5,10-Methylenetetrahydrofolate Reductase as a Risk Factor for Ischemic Stroke
Authors: Harmon Dawn L. , Doyle Rachael M. , Meleady Raymond , Doyle Marguerite , Shields Denis C. , Barry Rosemary , Coakley Davis , Graham Ian M. , Whitehead Alexander S.
Published: June 2011

Abstract—Mild hyperhomocysteinemia is a risk factor for atherosclerotic vascular disease. Homozygosity for the C677T mutation in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) is frequently associated with hyperhomocysteinemia, particularly in individuals with low levels of serum folate, and has been directly associated with cardiovascular disease in certain populations. The purpose of this study was to establish whether the C677T mutation, which causes thermolabile MTHFR, is a risk factor for ischemic stroke in the Irish population. The homozygous C677T genotype has previously been associated with coronary heart disease in Ireland. We collected blood from 174 individuals (minimum age 60 years) who had suffered an ischemic stroke that was confirmed by computed tomography brain scan. Control subjects (n=183) aged ≥60 years, who had never suffered a stroke or transient ischemic attack, were recruited from hospitals and active retirement groups in the same geographical area. MTHFR genotypes were determined and other known risk factors for stroke were documented. In the control group, the frequency of subjects with the homozygous C677T genotype was 10.4%. In patients who had suffered ischemic stroke, the frequency was 15.5%. This difference was not statistically significant. The odds ratio of stroke for C677T homozygotes, with other genotypes as a reference group, was 1.59, 95% CI=0.85, 2.97. The data indicate that the homozygous C677T MTHFR genotype is at most a moderate risk factor for ischemic stroke.
Low-Density Lipoprotein Enhances Platelet Secretion Via Integrin-α
IIb
β
3
–Mediated Signaling
Authors: Hackeng Christian M. , Huigsloot Merei , Pladet Marc W. , Nieuwenhuis H. Karel , van Rijn Herman J. M. , Akkerman Jan-Willem N.
Published: June 2011

Abstract
—LDL is known to increase the sensitivity of human platelets for agonists and to induce aggregation and secretion independently at high concentrations, but its mechanism of action is largely obscure. To clarify how LDL increases platelet sensitivity, cells were incubated in lipoprotein-poor plasma and treated with collagen at a concentration that induced ≈20% secretion of
14
C-serotonin. Preincubation with LDL (30 minutes at 37°C) enhanced secretion in a dose-dependent manner to 60±14% at a concentration of 2 g LDL protein/L. Similar stimulation by LDL was seen when secretion was induced by the thrombin receptor–activating peptide. This enhancement was strongly reduced (1) in the presence of monoclonal antibody PAC1 against activated α
IIb
β
3
, a polyclonal antibody against α
IIb
, and in the presence of the fibrinogen peptides GRGDS and HHLGGAKQAGDV; (2) in α
IIb
β
3
-deficient platelets; and (3) after dissociation of α
IIb
β
3
. In contrast, binding of
125
I-LDL to normal platelets in the presence of PAC1, anti-α
IIb
, GRGDS, and HHLGGAKQAGDV, and to α
IIb
β
3
-deficient platelets was normal. LDL increased the surface expression of fibrinogen in lipoprotein-poor plasma and fibrinogen-free medium, suggesting that extracellular and granular fibrinogen bind to α
IIb
β
3
after platelet-LDL interaction. Platelets deficient in fibrinogen (<0.5% of normal) or von Willebrand Factor (<1% of normal) but containing normal amounts of other ligands for α
IIb
β
3
preserved responsiveness to LDL, indicating that occupancy of α
IIb
β
3
was not restricted to fibrinogen. Inhibition of protein kinase C (bisindolylmaleimide) diminished fibrinogen binding and sensitization by LDL; inhibition of tyrosine kinases (herbimycin A) left fibrinogen binding unchanged but diminished sensitization by LDL. We conclude that an increased concentration of LDL, such as observed in homozygous familial hypercholesterolemia, sensitizes platelets to stimulation by collagen and thrombin receptor–activating peptide via ligand-induced outside-in signaling through integrin-α
IIb
β
3
.
Expression of Tissue Inhibitor of Metalloproteinase-1, -2, and -3 During Neointima Formation in Organ Cultures of Human Saphenous Vein
Authors: Kranzhöfer A. , Baker A. H. , George S. J. , Newby A. C.
Published: June 2011

Abstract
—Degradation of the extracellular basement membrane is implicated in atherosclerosis, restenosis after angioplasty, and intimal thickening of vein grafts. Upregulation of metalloproteinase (MMP)-2 and MMP-9 accompanies neointima formation in cholesterol-fed rabbits, in rat and pig models of angioplasty, and in organ cultures of human saphenous veins. MMPs are inhibited by binding to tissue inhibitors of MMPs (TIMPs). Relatively little is known about their regulation in relationship to neointima formation; thus, we investigated TIMP expression in the organ culture model. Qualitative reverse transcriptase–polymerase chain reaction of mRNA extracted from veins showed that TIMP-1, TIMP-2, and TIMP-3 are each expressed before and after culture. Zymography revealed that TIMP-1 was the most abundant TIMP secreted and that its secretion increased dramatically between 0 to 2 and 12 to 14 days of culture. An enzyme-linked immunosorbent assay showed that TIMP-1 secretion increased from 3.2±1.5 (mean±SE) to 32±6 ng/mg wet weight per day (n=5,
P
<0.01). Immunocytochemical testing localized the increased expression of TIMP-1 to neointimal smooth muscle cells. Although less abundant, TIMP-2 secretion also increased from 0.8±0.3 to 4.7±0.2 ng/mg wet weight per day (n=5,
P
<0.001), and tissue levels increased from 33±7 to 150±70 ng/mg wet weight (
P
<0.05). TIMP-2 was also immunolocalized to neointimal smooth muscle cells and their surrounding matrix. TIMP-3 was not secreted but was detected variably and constitutively in tissue extracts (160±120 and 170±100 ng/mg wet weight [n=9] on days 2 and 14, respectively). TIMP-3 was found in the cells and extracellular matrix of the media and adventitia before culture and to a lesser extent in the neointima after 14 days of culture. Rates of total TIMP secretion on day 14 exceeded those of MMP-2 and MMP-9 (10.6±1.9 and 15.6±2.3 ng/mg wet weight per day, respectively). Consistent with this, in situ zymography showed that MMP gelatinase activity was highly localized to cell bodies in the media and neointima. Secretion of TIMP-1 and TIMP-2 is greatly increased during neointima formation in human saphenous veins. TIMP-1 is readily released, whereas TIMP-2 remains partially attached and TIMP-3 exclusively attached to the extracellular matrix. Regulation of TIMP expression is therefore an important determinant of net MMP activity during neointima formation, restricting it to the pericellular environment.
Determinants of Plasma Levels of Plasminogen Activator Inhibitor-1
Authors: Cesari Maurizio , Sartori Maria Teresa , Patrassi Giovanni M. , Vettore Silvia , Rossi Gian Paolo
Published: June 2011

Abstract
—We investigated whether plasma levels of the plasminogen activator inhibitor type 1 antigen (PAI-1:Ag) are genetically determined in monozygotic (MZ) and dizygotic (DZ) twins. Twenty-five pairs of healthy twins underwent measurements of PAI-1:Ag and other variables, including body mass index, mean blood pressure, plasma renin activity, insulin, and glucose. To ascertain the zygosity of twins, highly discriminating micro- and minisatellite systems with variable numbers of tandem repeats were analyzed by PCR amplification followed by polyacrylamide gel electrophoresis. Subjects were also genotyped for the 4G/5G polymorphism by PCR. Estimates of genetic variance and heritability were obtained for PAI-1:Ag, and for body mass index, mean blood pressure, plasma renin activity, glucose, and insulin by jointly examining data in a path analysis with TWINAN90. Results showed that 12 pairs of twins were MZ and 13 were DZ. All tests of genetic variance [within pair (WP): F=6.24,
P
=0.002; among component (AC): F=2.62,
P
=0.04; average absolute difference
t
test=3.00,
P
=0.004] showed significant genetic variance of PAI-1:Ag, but not of the other variables. Three tests of heritability (WP=0.837,
P
=0.002; AC=1.791,
P
<0.05; intraclass correlation: 1.180,
P
=0.001) consistently showed significant PAI-1:Ag heritability. Additive genetic influences (A), dominance genetic effect (D), and random environmental influences (E) accounted for 0.714, 0.154, and 0.132 of PAI-1:Ag variance, respectively. No effect of different 4G/5G genotypes was found. Thus, these results show significant genetic variance and heritability of PAI-1:Ag and suggest that A is more important than both D and E in determining PAI-1:Ag variance.
Resveratrol, a Polyphenolic Compound Found in Wine, Inhibits Tissue Factor Expression in Vascular Cells
Authors: Pendurthi Usha R. , Williams J. Todd , Rao L. Vijaya Mohan
Published: June 2011

Abstract—A number of studies suggest that moderate consumption of red wine may be more effective than other alcoholic beverages in decreasing the risk of coronary heart disease mortality. The phytochemical resveratrol found in wine, derived from grapes, has been thought to be responsible for cardiovascular benefits associated with wine consumption because it was shown to have antioxidant and antiplatelet activities. In the present investigation, we examined the effect of resveratrol on induction of tissue factor (TF) expression in vascular cells that were exposed to pathophysiological stimuli. The data presented herein show that resveratrol, in a dose-dependent manner, inhibited the expression of TF in endothelial cells stimulated with a variety of agonists, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNFα) and lipopolysaccharide (LPS). A similar inhibition of TF induction was also seen in LPS stimulated monocytes that were pretreated with resveratrol before their stimulation with LPS. In addition, resveratrol was shown to inhibit the LPS-induced expression of TNFα mRNA in endothelial cells and of TNFα and IL-1β mRNA in monocytes. Nuclear run-on analysis in endothelial cells showed that resveratrol inhibited TF expression at the level of transcription. However, resveratrol did not significantly alter the binding of the transcription factors c-Fos/c-Jun and c-Rel/p65, the transcription factors required for the induction of TF promoter in both endothelial cells and monocytes. Similarly, resveratrol had no significant effect on the binding of NF-κB in endothelial cells stimulated with IL-1β, TNFα, and LPS. Overall, our data show that resveratrol could effectively suppress the aberrant expression of TF and cytokines in vascular cells, but it requires further investigation to understand how resveratrol exerts its inhibitory effect.
Socioeconomic Status and Determinants of Hemostatic Function in Healthy Women
Authors: Wamala Sarah P. , Murray Mittleman A. , Horsten Myriam , Eriksson Margita , Schenck-Gustafsson Karin , Hamsten Anders , Silveira Angela , Orth-Gomér Kristina
Published: June 2011

Abstract
—Hemostatic factors are reported to be associated with coronary heart disease (CHD). Socioeconomic status (SES) is 1 of the determinants of the hemostatic profile, but the factors underlying this association are not well known. Our aim was to examine determinants of the socioeconomic differences in hemostatic profile. Between 1991 and 1994, we studied 300 healthy women, aged 30 to 65 years, who were representative of women living in the greater Stockholm area. Fibrinogen, factor VII mass concentration (FVII:Ag), activated factor VII (FVIIa), von Willebrand factor (vWF), and plasminogen activator inhibitor-1 (PAI-1) were measured. Educational attainment was used as a measure of SES. Low educational level and an unfavorable hemostatic profile were both associated with older age, unhealthful life style, psychosocial stress, atherogenic biochemical factors, and hypertension. Levels of hemostatic factors increased with lower educational attainment. Independently of age, the differences between the lowest (mandatory) and highest (college/university) education in FVII:Ag levels were 41 μg/L (95% confidence interval [CI], 15 to 66 μg/L,
P
=0.001), 0.26 g/L (95% CI, 0.10 to 0.42 g/L,
P
=0.001) in fibrinogen levels, and 0.11 U/mL (95% CI, 0.09 to 0.12 U/mL,
P
=0.03) in levels of vWF. The corresponding differences in FVIIa and PAI-1 were not statistically significant. With further adjustment for menopausal status, family history of CHD, marital status, psychosocial stress, lifestyle patterns, biochemical factors, and hypertension, statistically significant differences between mandatory and college/university education were observed in FVII:Ag (difference=34 μg/L; 95% CI, 2 to 65 μg/L,
P
=0.05) but not in fibrinogen (difference=0.03 g/L; 95% CI, −0.13 to 0.19 g/L,
P
=0.92) or in vWF (difference=0.06 U/mL; 95% CI, −0.10 to 0.22 U/mL,
P
=0.45). An educational gradient was most consistent and statistically significant for FVII:Ag, fibrinogen, and vWF. Age, psychosocial stress, unhealthful life style, atherogenic biochemical factors, and hypertension mediated the association of low educational level with elevated levels of fibrinogen and vWF. Psychosocial stress and unhealthful life style were the most important contributing factors. There was an independent association between education and FVII:Ag, which could not be explained by any of these factors.
Fibrinolytic Activation Markers Predict Myocardial Infarction in the Elderly
Authors: Cushman Mary , Lemaitre Rozenn N. , Kuller Lewis H. , Psaty Bruce M. , Macy Elizabeth M. , Sharrett A. Richey , Tracy Russell P.
Published: June 2011

Abstract
—Coagulation factor levels predict arterial thrombosis in epidemiological studies, but studies of older persons are needed. We studied 3 plasma antigenic markers of fibrinolysis, viz, plasminogen activator inhibitor-1 (PAI-1), fibrin fragment D
-
dimer, and plasmin-antiplasmin complex (PAP) for the prediction of arterial thrombosis in healthy elderly persons over age 65. The study was a nested case-control study in the Cardiovascular Health Study cohort of 5201 men and women ≥65 years of age who were enrolled from 1989 to 1990. Cases were 146 participants without baseline clinical vascular disease who developed myocardial infarction, angina, or coronary death during a follow-up of 2.4 years. Controls remained free of cardiovascular events and were matched 1:1 to cases with respect to sex, duration of follow-up, and baseline subclinical vascular disease status. With increasing quartile of
D-
dimer and PAP levels but not of PAI-1, there was an independent increased risk of myocardial infarction or coronary death, but not of angina. The relative risk for D
-
dimer above versus below the median value (≥120 μg/L) was 2.5 (95% confidence interval, 1.1 to 5.9) and for PAP above the median (≥5.25 nmol/L), 3.1 (1.3 to 7.7). Risks were independent of C-reactive protein and fibrinogen concentrations. There were no differences in risk by sex or presence of baseline subclinical disease. D-dimer and PAP, but not PAI-1, predicted future myocardial infarction in men and women over age 65. Relationships were independent of other risk factors, including inflammation markers. Results indicate a major role for these markers in identifying a high risk of arterial disease in this age group.
Enhanced Fatty Streak Formation in C57BL/6J Mice by Immunization With Heat Shock Protein-65
Authors: George Jacob , Shoenfeld Yehuda , Afek Arnon , Gilburd Boris , Keren Pnina , Shaish Aviv , Kopolovic Juri , Wick Georg , Harats Dror
Published: June 2011

Abstract
—Recent data suggest that the immune system is involved in atherogenesis. Thus, interest has been raised as to the possible antigens that could serve as the initiators of the immune reaction. In the current work, we studied the effects of immunization with recombinant heat shock protein-65 (HSP-65) and HSP-65–rich
Mycobacterium tuberculosis
(MT) on early atherogenesis in C57BL/6J mice fed either a normal chow diet or a high-cholesterol diet (HCD). A rapid, cellular immune response to HSP-65 was evident in mice immunized with HSP-65 or with MT but not in the animals immunized with phosphate-buffered saline (PBS) alone. Early atherosclerosis was significantly enhanced in HCD-fed mice immunized with HSP-65 (n=10; mean aortic lesion size, 45 417±9258 μm
2
) or MT (n=15; 66 350±6850 μm
2
) compared with PBS-injected (n=10; 10 028±3599 μm
2
) or nonimmunized (n=10; 9500±2120 μm
2
) mice. No fatty streak lesions were observed in mice fed a chow diet regardless of the immunization protocol applied. Immunohistochemical analysis of atherosclerotic lesions from the HSP-65– and MT-immunized mice revealed infiltration of CD4 lymphocytes compared with the relatively lymphocyte-poor lesions in the PBS-treated or nonimmunized mice. Direct immunofluorescence analysis of lesions from HSP-65– and MT-immunized mice fed an HCD exhibited extensive deposits of immunoglobulins compared with the fatty streaks in the other study groups, consistent with the larger and more advanced lesions found in the former 2 groups. This model, which supports the involvement of HSP-65 in atherogenesis, furnishes a valuable tool to study the role of the immune system in atherogenesis.
ApoA1 Reduces Free Cholesterol Accumulation in Atherosclerotic Lesions of ApoE–Deficient Mice Transplanted With ApoE–Expressing Macrophages
Authors: Boisvert William A. , Black Audrey S. , Curtiss Linda K.
Published: June 2011

Abstract—Along with apolipoprotein (apo) E, which promotes cholesterol efflux from foam cells, apoA1–containing high density lipoprotein (HDL) is thought to facilitate the transport of cholesterol from lesions. This role for apoA1 was tested in vivo by lethally irradiating apoE–deficient and apoE– plus apoA1–deficient mice and reconstituting them with bone marrow cells isolated from wild-type (WT) mice. ApoE, but not apoA1, was synthesized by the transplanted bone marrow–derived cells. Therefore, this transplantation procedure generated apoE–deficient animals with atherosclerotic lesions that contained both apoE and apoA1 (E/A1 mice) and apoE–deficient animals with lesions that contained apoE but no apoA1 (E/A1o mice). As shown previously, the transplanted WT macrophage–derived apoE dramatically lowered the plasma hypercholesterolemia in both groups. On feeding with an atherogenic diet after transplantation, plasma cholesterol levels were raised in both groups of mice, but the levels in the E/A1 mice at 20 weeks were 2- to 3-fold higher than in E/A1o mice. Immunohistochemical staining verified that apoE was abundant in lesions of both groups, whereas apoA1 was detected in the lesions of E/A1 mice only. Despite a 2- to 3-fold lower total plasma cholesterol in the E/A1o mice, the free cholesterol recovered from isolated aortas was ≈60% higher and the mean lesion area in serial sections of the aortic valves 45% larger. Therefore, apoA1 reduces free cholesterol accumulation in vivo in atherosclerotic lesions.
PPARγ Activation in Human Endothelial Cells Increases Plasminogen Activator Inhibitor Type-1 Expression
Authors: Marx Nikolaus , Bourcier Todd , Sukhova Galina K. , Libby Peter , Plutzky Jorge
Published: June 2011

Abstract—Plasminogen activator inhibitor type-1 (PAI-1) is a major physiological inhibitor of fibrinolysis, with its plasma levels correlating with the risk for myocardial infarction and venous thrombosis. The regulation of PAI-1 transcription by endothelial cells (ECs), a major source of PAI-1, remains incompletely understood. Adipocytes also produce PAI-1, suggesting possible common regulatory pathways between adipocytes and ECs. Peroxisomal proliferator-activated receptor-γ (PPAR)γ is a ligand-activated transcription factor that regulates gene expression in response to various mediators such as 15-deoxy-Δ12,14-prostaglandin J2(15d-PGJ2) and oxidized linoleic acid (9- and 13-HODE). The present study tested the hypotheses that human ECs express PPARγ and that this transcriptional activator regulates PAI-1 expression in this cell type. We found that human ECs contain both PPARγ mRNA and protein. Immunohistochemistry of human carotid arteries also revealed the presence of PPARγ in ECs. Bovine ECs transfected with a PPAR response element (PPRE)–luciferase construct responded to stimulation by the PPARγ agonist 15d-PGJ2in a concentration-dependent manner, suggesting a functional PPARγ in ECs. Treatment of human ECs with 15d-PGJ2, 9(S)-HODE, or 13(S)-HODE augmented PAI-1 mRNA and protein expression, whereas multiple PPARα activators did not change PAI-1 levels. Introduction of increasing amounts of a PPARγ expression construct in human fibroblasts enhanced PAI-1 secretion from these cells in proportion to the amount of transfected DNA. Thus, ECs express functionally active PPARγ that regulates PAI-1 expression in ECs. Our results establish a role for PPARγ in the regulation of EC gene expression, with important implications for the clinical links between obesity and atherosclerosis.
Relative Contribution of Insulin and Its Precursors to Fibrinogen and PAI-1 in a Large Population With Different States of Glucose Tolerance
Authors: Festa Andreas , D’Agostino Ralph , Mykkänen Leena , Tracy Russell P. , Zaccaro Daniel J. , Hales C. Nick , Haffner Steven M.
Published: June 2011

Abstract
—Hyperinsulinemia is associated with the development of coronary heart disease. However, the underlying mechanisms are still poorly understood. Hypercoagulability and impaired fibrinolysis are possible candidates linking hyperinsulinism with atherosclerotic disease, and it has been suggested that proinsulin rather than insulin is the crucial pathophysiological agent. The aim of this study was to investigate the relationship of insulin and its precursors to markers of coagulation and fibrinolysis in a large triethnic population. A strong and independent relationship between plasminogen activator inhibitor-1 (PAI-1) antigen and insulin and its precursors (proinsulin, 32-33 split proinsulin) was found consistently across varying states of glucose tolerance (PAI-1 versus fasting insulin [proinsulin],
r
=0.38 [
r
=0.34] in normal glucose tolerance;
r
=0.42 [
r
=0.43] in impaired glucose tolerance; and
r
=0.38 [
r
=0.26] in type 2 diabetes; all
P
<0.001). The relationship remained highly significant even after accounting for insulin sensitivity as measured by a frequently sampled intravenous glucose tolerance test. In a stepwise multiple regression model after adjusting for age, sex, ethnicity, and clinic, both insulin and its precursors were significantly associated with PAI-1 levels. The relationship between fibrinogen and insulin and its precursors was significant in the overall population (
r
=0.20 for insulin and proinsulin; each
P
<0.001) but showed a more inconsistent pattern in subgroup analysis and after adjustments for demographic and metabolic variables. Stepwise multiple regression analysis showed that proinsulin (split products) but not fasting insulin significantly contributed to fibrinogen levels after adjustment for age, sex, clinic, and ethnicity. Decreased insulin sensitivity was independently associated with higher PAI-1 and fibrinogen levels. In summary, we were able to demonstrate an independent relationship of 2 crucial factors of hemostasis, fibrinogen and PAI-1, to insulin and its precursors. These findings may have important clinical implications in the risk assessment and prevention of macrovascular disease, not only in patients with overt diabetes but also in nondiabetic subjects who are hyperinsulinemic.
Effects of Alcohol and Cholesterol Feeding on Lipoprotein Metabolism and Cholesterol Absorption in Rabbits
Authors: Latour Mickey A. , Patterson Bruce W. , Kitchens Robert Thomas , Ostlund Richard E. , Hopkins Daniel , Schonfeld Gustav
Published: June 2011

Abstract
—Alcohol fed to rabbits in a liquid formula at 30% of calories increased plasma cholesterol by 36% in the absence of dietary cholesterol and by 40% in the presence of a 0.5% cholesterol diet. The increase was caused almost entirely by VLDL, IDL, and LDL. Cholesterol feeding decreased the fractional catabolic rate for VLDL and LDL apoprotein by 80% and 57%, respectively, and increased the production rate of VLDL and LDL apoprotein by 75% and 15%, respectively. Alcohol feeding had no effect on VLDL apoprotein production but increased LDL production rate by 55%. The efficiency of intestinal cholesterol absorption was increased by alcohol. In the presence of dietary cholesterol, percent cholesterol absorption rose from 34.4±2.6% to 44.9±2.5% and in the absence of dietary cholesterol, from 84.3±1.4% to 88.9±1.0%. Increased cholesterol absorption and increased LDL production rate may be important mechanisms for exacerbation by alcohol of hypercholesterolemia in the cholesterol-fed rabbit model.
Induction of Monocyte Binding to Endothelial Cells by MM-LDL
Authors: Honda Henry M. , Leitinger Norbert , Frankel Matthew , Goldhaber Joshua I. , Natarajan Rama , Nadler Jerry L. , Weiss James N. , Berliner Judith A.
Published: June 2011

Abstract
—Treatment of human aortic endothelial cells (EC) with minimally oxidized LDL (or minimally modified LDL, MM-LDL) produces a specific pattern of endothelial cell activation distinct from that produced by LPS, tumor necrosis factor-α, and interleukin-1, but similar to other agents that elevate cAMP. The current studies focus on the signal transduction pathways by which MM-LDL activates EC to bind monocytes. We now demonstrate that, in addition to an elevation of cAMP, lipoxygenase products are necessary for the MM-LDL response. Treatment of EC with inhibitors of the lipoxygenase pathway, 5,8,11,14-eicosatetraynoic acid (ETYA) or cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC), blocked monocyte binding in MM-LDL-treated EC (MM-LDL=118±13%; MM-LDL+ETYA=33±4%; MM-LDL+CDC=23±4% increase in monocyte binding) without reducing cAMP levels. To further investigate the role of the lipoxygenase pathway, cellular phospholipids were labeled with arachidonic acid. Treatment of cells for 4 hours with 50 to 100 μg/mL MM-LDL, but not native LDL, caused a 60% increase in arachidonate release into the medium and increased the intracellular formation of 12(S)-HETE (≈100% increase). There was little 15(S)-HETE present, and no increase in its levels was observed. We demonstrated that 12(S)-HETE reversed the inhibitory effect of CDC. We also observed a 70% increase in the formation of 11,12-epoxyeicosatrienoic acid (11,12-EET) in cells treated with MM-LDL. To determine the mechanism of arachidonate release induced by MM-LDL, we examined the effects of MM-LDL on intracellular calcium levels. Treatment of EC with both native LDL and MM-LDL caused a rapid release of intracellular calcium from internal stores. However, several pieces of evidence suggest that calcium release alone does not explain the increased arachidonate release in MM-LDL-treated cells. The present studies suggest that products of 12-lipoxygenase play an important role in MM-LDL action on the induction of monocyte binding to EC.
Increased Serotonin Receptor Density and Platelet GPIIb/IIIa Activation Among Smokers
Authors: Markovitz Jerome H. , Tolbert Lelland , Winders Suzan E.
Published: June 2011

Abstract
—This study sought to determine whether depressive symptoms and/or platelet serotonin receptor (5HT
2A
) density are associated with increased platelet activation (PA) found among smokers. Flow cytometric detection of PA was used to study 36 smokers and 16 nonsmokers, aged 18 to 48 years. Subjects were tested at baseline and after either smoking 2 cigarettes (smokers) or a similar resting interval (nonsmokers). Assessment of PA included both platelet secretion and fibrinogen receptor (GPIIb/IIIa) binding. Platelet 5HT
2A
receptor binding and saturation were tested using [
3
H]LSD, and depressive symptoms were measured using the Beck Depression Inventory. Platelet 5HT
2A
receptor density was increased among smokers versus nonsmokers (82.7±67.7 versus 40.0±20.2 fmol/mg protein;
P
<0.005), and there was a dose-dependent relationship between receptor density and packs/d among smokers. Baseline wound-induced GPIIb/IIIa binding at 1 minute and GPIIb/IIIa binding in response to collagen stimulation in vitro was increased among smokers (
P
<0.05); there were no changes in PA among smokers after smoking, and platelet secretion was not elevated among smokers. Depressive symptoms were associated with 5HT
2A
receptor density among nonsmokers (
P
<0.005), but no such relationship was evident among smokers; PA was unrelated to 5HT
2A
receptor density in either group. The findings indicate that smoking is associated with increased platelet serotonin receptor density and with increased GPIIb/IIIa receptor binding, although these 2 factors are not related to each other or to depressive symptoms among smokers. Serotonergic dysfunction may be an important factor in the development of cardiovascular disease among smokers.
Continuous Perivascularl-Arginine Delivery Increases Total Vessel Area and Reduces Neointimal Thickening After Experimental Balloon Dilatation
Authors: Bosmans Johan M. , Vrints Chris J. , Kockx Mark M. , Bult Hidde , Cromheeke Kristel M. C. , Herman Arnold G.
Published: June 2011

Abstract—The aim of this study was to evaluate whether vascular remodeling and neointimal thickening occur after balloon dilatation of the nonatherosclerotic rabbit carotid artery, and whether both processes are influenced by continuous perivascular delivery ofl-arginine or the nitric oxide synthase inhibitorNG-nitro-l-arginine methyl ester (L-NAME). In the first experiment, histological and morphometric evaluation of arteries was performed at different time points after balloon dilatation: 10 minutes (n=7), and 1 (n=7), 2 (n=9), 3 (n=20), or 10 (n=5) weeks. Neointimal thickening progressively contributed to luminal narrowing for at least 10 weeks after angioplasty. During the first 2 weeks after dilatation, a significant decrease of the total vessel area was measured. Ten weeks after dilatation, both the neointimal and total vessel area were increased without further changing of the luminal area. In the second experiment, endothelial injured rabbits were randomly assigned to receive 2 weeks of continuous local perivascular physiological salt solution (n=6),l-arginine (n=8), or L-NAME (n=7), starting immediately after balloon dilatation (ie, local drug delivery during the first phase of the biphasic vascular remodeling process). Perivascularl-arginine delivery significantly reduced the neointimal area, despite an increased number of neointimal Ki-67-positive smooth muscle cells. Both the luminal area and total vessel area were significantly increased. Seruml-arginine levels remained unchanged. L-NAME administration had no effect on the neointimal area, nor on the luminal and total vessel area. Neointimal formation and biphasic vascular remodeling occur after experimental balloon dilatation of the nonatherosclerotic rabbit carotid artery, and can be influenced by continuous local perivascular delivery ofl-arginine.
Enzymatically Modified, Nonoxidized LDL Induces Selective Adhesion and Transmigration of Monocytes and T-Lymphocytes Through Human Endothelial Cell Monolayers
Authors: Klouche Mariam , May Andreas E. , Hemmes Monika , Meßner Martina , Kanse Sandip M. , Preissner Klaus T. , Bhakdi Sucharit
Published: June 2011

Abstract—Circulating monocytes and T lymphocytes extravasate through the endothelium at sites of developing atheromatous lesions, where they tend to accumulate and mediate the progression of the disease. We have previously demonstrated the presence of an enzymatically degraded, nonoxidized form of LDL (E-LDL) in early human fatty streaks, which possesses major biological properties of an atherogenic lipoprotein. The effects of E-LDL on human endothelial cells have now been studied with respect to adhesion and transmigration of monocytes and T lymphocytes. E-LDL induced a rapid and dose-dependent selective adhesion of monocytes and T lymphocytes to endothelial cell monolayers within 30 minutes of incubation. Maximal increases in the number of adherent monocytes (8-fold) and of adherent T lymphocytes (4-fold) were observed after treatment with 50 μg/mL E-LDL. E-LDL was more active than oxidized LDL (ox-LDL), whereas native LDL produced only minor adhesive effects. Both E-LDL and ox-LDL enhanced transmigration of monocytes and of T lymphocytes through endothelial monolayers. Again, E-LDL was more potent than ox-LDL, inducing transmigration to a similar extent asN-formyl-Met-Leu-Phe. In endothelial cells, E-LDL stimulated upregulation of intercellular adhesion molecule-1 (ICAM-1), platelet-endothelial cells adhesion molecule-1 (PECAM-1), P-selectin, and E-selectin with distinct kinetics. Analyses with blocking antibodies indicated that ICAM-1 and P-selectin together mediated approximately 70% of cell adhesion, whereas blocking of PECAM-1 had no effect on adhesion but reduced transmigration to less than 50% of controls. E-LDL also upregulated expression of ICAM-1 in human aortic smooth muscle cells, and this correlated with increased adhesion of T lymphocytes. E-LDL is thus able to promote the selective adhesion of monocytes and T lymphocytes to the endothelium, stimulate transmigration of these cells, and foster their retention in the vessel wall by increasing their adherence to smooth muscle cells. These findings underline the potential significance of E-LDL in the pathogenesis of atherosclerosis.
Depletion of Preβ
1
LpA1 and LpA4 Particles by Mast Cell Chymase Reduces Cholesterol Efflux From Macrophage Foam Cells Induced by Plasma
Authors: Lee Miriam , von Eckardstein Arnold , Lindstedt Leena , Assmann Gerd , Kovanen Petri T.
Published: June 2011

Abstract
—Exposure of the LpA1-containing particles present in HDL
3
and plasma to a minimal degree of proteolysis by the neutral protease chymase from exocytosed rat mast cell granules (granule remnants) leads to a reduction in the high-affinity component of cholesterol efflux from macrophage foam cells. In this study, we demonstrate for the first time, a role for mast cell chymase in the depletion of the lipid-poor minor components of HDL that are specifically involved in reverse cholesterol transport as initial acceptors of cellular cholesterol. Thus, addition of proteolytically active granule remnants or human skin chymase to cholesterol-loaded macrophages of mouse or human origin incubated with human apoA1, ie, a system in which preβ
1
LpA1 is generated, resulted in a sharp reduction in the high-affinity cholesterol efflux promoted by apoA1. As determined by nondenaturing 2-dimensional polyacrylamide gradient gel electrophoresis, the granule remnants effectively depleted the preβ
1
LpA1, but not the αLpA1, in HDL
3
and in plasma during incubation at 37°C for <1 hour. Incubation of plasma with granule remnants for 1 hour also led to near disappearance of the LpA4–1 and LpA4–2 particles, but did not affect the distribution of the apoA2-containing lipoproteins present in the plasma. We conclude that the reduced ability of granule remnant-treated HDL
3
and granule remnant-treated plasma to induce cholesterol efflux from macrophage foam cells is caused by selective depletion by mast cell chymase of quantitatively minor A1- and A4-containing subpopulations of HDL. Because these particles, ie, preβ
1
LpA1 and LpA4, are efficient acceptors of cholesterol from cell surfaces, their depletion by mast cells may block the initiation of reverse cholesterol transport in vivo and thereby favor foam cell formation in the arterial intima, the site of atherogenesis.
Structural, Functional, and Hemodynamic Changes of the Common Carotid Artery With Age in Male Subjects
Authors: Schmidt-Trucksäss Arno , Grathwohl Dominik , Schmid Andreas , Boragk Raffael , Upmeier Christine , Keul Joseph , Huonker Martin
Published: June 2011

Abstract
—Aging of the common carotid artery (CCA) is associated with different principal structural, functional, and hemodynamic changes, which are often influenced by several atherosclerotic risk factors, so that it is difficult to estimate the exclusive effect of aging on this process. Studies dealing with vascular aging of the CCA usually assess only single, dimensional, or functional parameters, although it is likely that there are interactions and probably differences between them. Moreover, regional vascular blood flow characteristics are often not taken into consideration. Therefore, the aim of the study was to assess the age-related multiparametric changes of the CCA properties with ultrasound in 69 male subjects between the ages of 16 and 75 (42.4±16.5 years), who were screened for the absence of major atherosclerotic risk factors or existing vascular disease. As a result, the intima media thickness (0.052 mm/10 y) and diastolic diameter (0.17 mm/10 y) increased nearly linearly with age (
r
=0.60,
P
<0.001; and
r
=0.46,
P
<0.001, respectively). The absolute diastolic/systolic diameter change diminished by 0.10 mm/10 y (
r
=−0.73,
P
<0.001) and peak expansion velocity dropped by 0.12 cm/s per 10 years (
r
=−0.62,
P
<0.001) highly significantly with age. The peak blood flow velocity decreased continuously with age (
r
=−0.67,
P
<0.00) by 9.3 cm/s per 10 years. According to multiple regression analysis, peak blood flow velocity seems to reflect the changes of several structural and functional parameters in one; intima-media thickness was determined by diastolic arterial diameter and age as independent variables. The data indicate that a multiparametric assessment may contribute to a better understanding of vascular aging and might be the basis for further studies to evaluate the association of atherosclerotic risk factors and/or major vascular disease with local changes in the CCA.
Omega-3 Fatty Acids in Adipose Tissue and Risk of Myocardial Infarction
Authors: Guallar Eliseo , Aro Antti , Jiménez F. Javier , Martín-Moreno José M. , Salminen Irma , van’t Veer Pieter , Kardinaal Alwine F. M. , Gómez-Aracena Jorge , Martin Blaise C. , Kohlmeier Lenore , Kark Jeremy D. , Mazaev Vladimir P. , Ringstad Jetmund , Guillén José , Riemersma Rudolph A. , Huttunen Jussi K. , Thamm Michael , Kok Frans J.
Published: June 2011

Abstract
—Omega-3 fatty acids have potential antiatherogenic, antithrombotic, and antiarrhythmic properties, but their role in coronary heart disease remains controversial. To evaluate the association of omega-3 fatty acids in adipose tissue with the risk of myocardial infarction in men, a case-control study was conducted in eight European countries and Israel. Cases (n=639) included patients with a first myocardial infarction admitted to coronary care units within 24 hours from the onset of symptoms. Controls (n=700) were selected to represent the populations originating the cases. Adipose tissue levels of fatty acids were determined by capillary gas chromatography. The mean (±SD) proportion of α-linolenic acid was 0.77% (±0.19) of fatty acids in cases and 0.80% (±0.19) of fatty acids in controls (
P
=0.01). The relative risk for the highest quintile of α-linolenic acid compared with the lowest was 0.42 (95% confidence interval [CI] 0.22 to 0.81,
P
-trend=0.02). After adjusting for classical risk factors, the relative risk for the highest quintile was 0.68 (95% CI 0.31 to 1.49,
P
-trend=0.38). The mean proportion of docosahexaenoic acid was 0.24% (±0.13) of fatty acids in cases and 0.25% (±0.13) of fatty acids in controls (
P
=0.14), with no evidence of association with risk of myocardial infarction. In this large case-control study we could not detect a protective effect of docosahexaenoic acid on the risk of myocardial infarction. The protective effect of α-linolenic acid was attenuated after adjusting for classical risk factors (mainly smoking), but it deserves further research.
Pleiotropy and Genotype by Diet Interaction in a Baboon Model for Atherosclerosis
Authors: Mahaney Michael C. , Blangero John , Rainwater David L. , Mott Glen E. , Comuzzie Anthony G. , MacCluer Jean W. , VandeBerg John L.
Published: June 2011

Abstract
—We investigated dietary effects on pleiotropic relationships among 3 HDL cholesterol (C) subfractions (HDL
1
-C, HDL
2
-C, and HDL
3
-C; levels quantified by gradient gel electrophoresis) for 942 pedigreed baboons (
Papio hamadryas
) who were fed a basal (Chow) diet and a high cholesterol, saturated fat (HCSF) challenge diet. Using multivariate maximum likelihood methods we estimated heritabilities for all 6 traits, genetic and environmental correlations (ρ
G
and ρ
E
) between them, and the additive genetic variance of each subfraction’s response to the diets. On the Chow diet, genetic correlations between the 3 subfractions were significant, and we observed complete pleiotropy between HDL
1
-C and HDL
3
-C (ρ
G
=−0.81). On the HCSF diet, only the genetic correlation between HDL
1
-C and HDL
3
-C (ρ
G
=−0.61) was significant. Genetic correlations between individual subfractions on the Chow and HCSF diets did not differ significantly from 1.0, indicating that the same additive genes influenced each subfraction’s levels regardless of diet. However, the additive genetic variance of response to the diets was highly significant for HDL
1
-C and HDL
2
-C, but not for HDL
3
-C. Similar sets of genes influence variation in the 3 HDL subfractions on the Chow diet, and the same set influences variation in each subfraction on the HCSF diet. However, the expression of genes influencing HDL
1
-C and HDL
2
-C is altered by the HCSF diet, disrupting the pleiotropy observed between the 3 subfractions on the Chow diet.
17β-Estradiol Reduces Glycoxidative Damage in the Artery Wall
Authors: Walsh Barbara A. , Busch Bonnie L. , Mullick Adam E. , Reiser Karen M. , Rutledge John C.
Published: June 2011

Abstract
—Glycoxidative damage in the vasculature has been linked to atherosclerotic cardiovascular disease. Estrogens protect against the development and progression of atherosclerosis. Because estrogens are potent antioxidants that also effect glucose metabolism, part of their protection against atherosclerosis could be through attenuation of glycoxidative damage in the vascular wall. In this study, we tested the hypothesis that chronic estradiol administration is associated with decreased levels of glycoxidative damage in arterial walls. We harvested and examined iliac arteries from ovariectomized, 8-month-old rats that had been implanted for 6 months with 1 of the following subcutaneous hormone pellets: low estradiol (2.5 mg estradiol), high estradiol (25 mg estradiol), P
4
(200 mg progesterone), low estradiol and P
4
, placebo (no hormone), or control (no implant). Using pentosidine as a biomarker of glycoxidative damage, we found that all vessels from rats receiving estradiol (low estradiol, high estradiol, and low estradiol+P
4
) exhibited a 50% reduction in glycoxidative damage compared with P
4
, placebo, and control vessels (
P
<0.05). Consistent with this finding, we observed that estradiol-treated rats had a 30% decrease in tissue levels of hydroperoxides, a marker of oxidative stress. Finally, estradiol-treated rats had a small, but significant, decrease in plasma glucose levels (
P
<0.01). In summary, we report the novel finding that chronic estrogen administration is associated with significant decreases in glycoxidative damage and oxidative stress in the arterial wall. It seems likely that these actions may constitute a mechanism by which estrogen attenuates the progression of atherosclerosis.