bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymorphisms of the Tissue Factor Pathway Inhibitor (TFPI) Gene in Patients With Acute Coronary Syndromes and in Healthy Subjects
Authors: Moatti Didier , Seknadji Patrick , Galand Colette , Poirier Odette , Fumeron Frédéric , Desprez Sophie , Garbarz Michel , Dhermy Didier , Arveiler Dominique , Evans Alun , Luc Gerald , Ruidavets Jean-Bernard , Ollivier Véronique , Hakim Jacques , Aumont Marie Claude , de Prost Dominique
Published: June 2011

Abstract
—Mutations of the gene encoding tissue factor pathway inhibitor (TFPI), an inhibitor of TF-induced activation of the coagulation cascade, were screened for in 130 patients and 142 healthy controls to determine whether these variants contribute to acute coronary syndromes or modify plasma TFPI levels. The following 3 new polymorphisms were identified: 384T→C in exon IV, which does not change the corresponding amino acid (tyrosine 57); −33C→T in intron 7 (the T/T, C/T, and C/C genotypes were found in ≈50%, 40%, and 10% of subjects in both groups); and 874G→A in exon IX (GTG→ATG), which predicts a valine to methionine change (V264M) in the carboxy-terminus tail of TFPI. The V264M polymorphism was found in 9.2% of the cases and 4.9% of the controls; the associated odds ratio (OR) for acute coronary syndromes was 2.0 (95% confidence interval [CI], 0.7 to 5.1). The OR increased to 3.6 (95% CI, 0.8 to 15.7) and 3.2 (95% CI, 0.9 to 11.8) in nonsmokers and patients without other risk factors, respectively. The possible link between the V264M polymorphism and coronary heart disease was checked in a large case-control study of myocardial infarction (Etude Cas-Témoins de l’Infarctus du Myocarde [the ECTIM Study]). The results showed no link between the V264M polymorphism and coronary syndromes. Interestingly, however, 5 patients heterozygous for the V264M polymorphism had significantly lower plasma TFPI levels than did 13 patients with the most common genotype. Although our present results do not support an association between TFPI polymorphisms and acute coronary syndromes, the possibility that 1 of them, especially the exon IX polymorphism, is associated with subtypes of myocardial infarction or to evolutive particularities that were not assessed in this study, cannot be excluded and is currently being evaluated.
Dietary Restriction of Saturated Fat and Cholesterol Decreases HDL ApoA-I Secretion
Authors: Vélez-Carrasco Wanda , Lichtenstein Alice H. , Welty Francine K. , Li Zhengling , Lamon-Fava Stefania , Dolnikowski Gregory G. , Schaefer Ernst J.
Published: June 2011

Abstract
—We examined the mechanisms responsible for the decrease in HDL cholesterol (HDL-C) levels after the consumption of a diet low in total fat, saturated fat, and cholesterol. Twenty-one subjects with a mean age of 58±12 years were placed on a baseline isocaloric diet (15% protein, 49% carbohydrate, 36% fat, and 150 mg/1000 kcals of cholesterol) and then switched to an NCEP Step 2 diet (15% protein, 60% carbohydrate, 25% fat, and 45 mg/1000 kcals of cholesterol). After 6 or 24 weeks on each diet, subjects received a 15-hour primed-constant infusion of [5,5,5–
2
H
3
]-L-leucine. HDL apoA-I and apoA-II tracer curves were determined by gas chromatography-mass spectrometry and fitted to a monoexponential equation. Compared with the baseline diet, consumption of the Step 2 diet lowered HDL-C mean levels by 15% (1.03±0.23 to 0.88±0.16 mmol/L,
P
<0.001), apoA-I by 12% (1.25±0.15 to 1.10±0.13 g/L,
P
<0.001) and the TC/HDL-C ratio by 5% (0.145±0.04 to 0.137±0.03). No significant changes were observed in apoA-II levels and HDL particle size with diet. HDL apoA-I fractional catabolic rate did not change (0.219±0.052 to 0.220±0.043 pools/day,
P
=0.91) but HDL apoA-I secretion rate decreased by 8% (12.26±3.07 to 10.84±2.11 mg · kg
−1
· day
−1
,
P
=0.03) during consumption of the Step 2 diet. There was no effect of diet on apoA-II fractional catabolic rate or secretion rate. Our results indicate that the decrease in HDL-C and apoA-I levels during the isocaloric consumption of a Step 2 diet paralleled the reductions in apoA-I secretion rate.
Acute Effects of Intravenous Infusion of ApoA1/Phosphatidylcholine Discs on Plasma Lipoproteins in Humans
Authors: Nanjee M. N. , Doran J. E. , Lerch P. G. , Miller N. E.
Published: June 2011

Abstract
—To investigate the metabolism of nascent HDLs, apoA1/phosphatidylcholine (apoA1/PC) discs were infused IV over 4 hours into 7 healthy men. Plasma total apoA1 and phospholipid (PL) concentrations increased during the infusions. The rise in plasma apoA1 was greatest in small preβ-migrating particles not present in the infusate. Total HDL unesterified cholesterol (UC) also increased simultaneously. After stopping the infusion, the concentrations of apoA1, PL, HDL UC, and small preβ HDLs decreased, whereas those of HDL cholesteryl ester (CE) and large α-migrating apoA1 containing HDLs increased. ApoB-containing lipoproteins became enriched in CEs. Addition of apoA1/PC discs to whole blood at 37°C in vitro also generated small preβ HDLs, but did not augment the transfer of UC from erythrocytes to plasma. We conclude that the disc infusions increased the intravascular production of small preβ HDLs in vivo, and that this was associated with an increase in the efflux and esterification of UC derived from fixed tissues. The extent to which the increase in tissue cholesterol efflux was dependent on that in preβ HDL production could not be determined. Infusion of discs also reduced the plasma apoB and apoA2 concentrations, and increased plasma triglycerides and apoC3. Thus, nascent HDL secretion may have a significant impact on preβ HDL production, reverse cholesterol transport and lipoprotein metabolism in humans.
Role of Endothelial Nitric Oxide Synthase in Endothelial Cell Migration
Authors: Murohara Toyoaki , Witzenbichler Bernhard , Spyridopoulos Ioakim , Asahara Takayuki , Ding Bo , Sullivan Alison , Losordo Douglas W. , Isner Jeffrey M.
Published: June 2011

Abstract
—Endothelium-derived nitric oxide (NO) and its precursor
l
-arginine have been implied to promote angiogenesis, but little is known about the precise mechanism. The inhibition of endogenous NO formation by
N
ω
-nitro
-l
-arginine methyl ester (
l
-NAME) (1 mmol/L) but not its inactive enantiomer
d
-NAME (1 mmol/L) inhibited endothelial cell sprouting from the scratched edge of the cultured bovine aortic endothelial cell monolayer. Inhibition of endogenous NO release by
l
-NAME was confirmed by amperometric measurement using an NO-specific electrode. In the modified Boyden chamber,
l
-NAME (1 mmol/L) significantly inhibited endothelial cell migration, whereas
l
-NAME did not affect endothelial DNA synthesis as assessed by analysis of [
3
H]thymidine incorporation. We then examined alteration of endothelial cell adhesion molecule expression after the inhibition of NO by
l
-NAME in cultured human umbilical vein endothelial cells. In both normoxic and hypoxic conditions,
l
-NAME (1 mmol/L) inhibited surface expression of integrin αvβ3, which is an important integrin facilitating endothelial cell survival and angiogenesis. However,
l
-NAME did not affect the expression of platelet endothelial cell adhesion molecule-1, intercellular adhesion molecule-1, vascular endothelial adhesion molecule-1, gap junction protein connexin 43, and VE-cadherin, which have been reported to potentially affect angiogenesis. In summary, inhibition of endothelial NO synthase by
l
-NAME attenuated endothelial cell migration but not proliferation in vitro. Furthermore, endogenous endothelium-derived NO maintains the functional expression of integrin αvβ3, a mediator for endothelial migration, survival, and angiogenesis. Endothelium-derived NO, thus, may play an important role in mediating angiogenesis by supporting endothelial cell migration, at least partly, via an integrin-dependent mechanism.
Nitric Oxide Production Is Reduced in Patients With Chronic Renal Failure
Authors: Wever Robert , Boer Peter , Hijmering Michel , Stroes Erik , Verhaar Marianne , Kastelein John , Versluis Kees , Lagerwerf Fija , van Rijn Herman , Koomans Hein , Rabelink Ton
Published: June 2011

Abstract
—In patients with chronic renal failure (CRF), atherosclerosis is a major cause of cardiovascular morbidity and mortality. Generally, atherosclerosis has been associated with a reduced bioavailability of nitric oxide (NO). Experimental studies have indicated the presence of enhanced NO degradation by reactive oxygen species as well as decreased NO production as possible causes for this reduced NO bioavailability. So far, the question whether or not NO production is impaired in patients with CRF has never been investigated. Therefore, we measured whole body NO production in 7 patients with CRF, and in 7 matched healthy subjects. To assess the relative importance of a dysfunction of NO synthase (NOS), we compared the NO production of these patients to that of 2 other groups known to have endothelial dysfunction, ie, 7 patients with familial hypercholesterolemia (FH) who did not yet have signs of clinical cardiovascular disease (all nonsmokers), and 5 cigarette smokers. These groups were also compared with 7 nonsmoking, age-matched healthy subjects. Whole body NO production, determined as in vivo arginine-to-citrulline conversion, was assessed by giving an intravenous infusion of [
15
N
2
]-arginine as a substrate for NOS and measuring isotopic plasma enrichment of [
15
N]-citrulline by LC-MS. NO production in the CRF patients (0.13±0.02 μmol · kg
–1
· h
–1
) was significantly lower (
P
<0.05) than in the corresponding control group (0.23±0.09 μmol · kg
–1
· h
–1
). NO production also tended to be lower in the FH patients (0.16±0.04 μmol · kg
–1
· h
–1
), but the difference with the corresponding control group did not reach significance (0.22±0.06 μmol · kg
–1
· h
–1
). In the group of smokers, NO production was similar to that in nonsmokers (0.22±0.09 μmol · kg
–1
· h
–1
). In conclusion, it is demonstrated for the first time that basal whole body NO production is reduced in patients with CRF. This finding implies that therapeutic interventions to endothelial dysfunction in these patients should be primarily directed toward improvement of NO production. The finding of only a tendency toward reduction of NO production in patients with FH and the absence of a reduction in cigarette smokers suggests that other mechanisms such as enhanced NO degradation may be involved in the decrease of NO bioavailability in these groups.
Endothelial Cell Dysfunction and Arterial Wall Hypertrophy Are Associated With Disturbed Carbohydrate Metabolism in Patients at Risk for Cardiovascular Disease
Authors: Thalhammer Christoph , Balzuweit Beate , Busjahn Andreas , Walter Clemens , Luft Friedrich C. , Haller Hermann
Published: June 2011

Abstract
—To investigate the effects of fasting and postprandial glucose on endothelial cell function and intima-media thickness, we studied 60 men with cardiovascular risk factors. Postischemic, endothelium-dependent vasodilatation was measured after 3 minutes of ischemia at the radial artery with high-resolution echo tracking. Common carotid artery intima-media thickness was measured by B-mode ultrasound. Glucose tolerance was determined by a 75-g oral glucose load. Fasting glucose levels were inversely correlated with postischemic, endothelium-dependent vasodilatation (
r
=−0.24,
P
<0.05) and directly correlated with intima-media thickness (
r
=0.26,
P
<0.05). However, postischemic, endothelium-dependent vasodilatation and intima-media thickness were not correlated. All subjects with normal postischemic, endothelium-dependent vasodilatation also had a normal intima-media thickness, whereas some subjects with impaired postischemic, endothelium-dependent vasodilatation also had a normal intima-media thickness. Multiple regression analysis revealed a profound influence of age on intima-media thickness to the exclusion of all other variables. The same age-adjusted analysis for postischemic, endothelium-dependent vasodilatation accepted fasting glucose, followed by 2-hour postprandial glucose, as variables, but no others. Subjects with fasting glucose values >100 mg/dL showed reduced postischemic, endothelium-dependent vasodilatation (59 versus 120 μm,
P
<0.05) and a higher intima-media thickness (right: 0.76 versus 0.62 mm,
P
<0.05; left: 0.78 versus 0.63 mm,
P
<0.05) compared with those with fasting glucose values <100 mg/dL. Subjects with 2-hour postprandial glucose values >125 mg/dL had no reduced postischemic, endothelium-dependent vasodilatation compared with subjects with a 2-hour postprandial glucose >125 mg/dL; however, their intima-media thickness (right: 0.66 versus 0.62 mm; left: 0.68 versus 0.62 mm;
P
<0.05 for both) was greater. Thus, high fasting rather than postprandial glucose values are associated with both postischemic, endothelium-dependent vasodilatation and increased intima-media thickness. Postischemic endothelium-dependent vasodilatation may precede increased intima-media thickness.
Lovastatin Decreases the Receptor-Mediated Degradation of Acetylated and Oxidized LDLs in Human Blood Monocytes During the Early Stage of Differentiation Into Macrophages
Authors: Hrboticky N. , Draude G. , Hapfelmeier G. , Lorenz R. , Weber P. C.
Published: June 2011

Abstract—3-Hydroxy-3-methylglutaryl–coenzyme A reductase inhibitors are used therapeutically to upregulate the LDL receptor-mediated removal of plasma cholesterol by the liver. Several lines of evidence indicate that these drugs also exert direct effects on the metabolism of native and modified LDL in extrahepatic cells. We studied the effects of lovastatin (LOV) on the degradation of native, acetylated, and oxidized LDL, and on levels of mRNA encoding for the LDL, types I and II class A macrophage scavenger, and CD36 receptors in human blood monocytes at different stages of their maturation into adherent macrophages. LOV (10 μmol/L) reduced the degradation of acetylated LDL when added to freshly isolated cells cultured for 2 (81±4% of control,P<0.05) and 5 (76±6%, of control,P<0.05) days. The degradation of oxidized LDL was also reduced in cells treated with LOV for 2 days after seeding (51±3% of control,P<0.001) but not in 5-day-old cells. LOV had no significant effect on the degradation of either acetylated or oxidized LDL when added to fully matured macrophages allowed to differentiate under control conditions for 7 days before incubations with 10 μmol/L LOV for an additional 2 days. In contrast, LOV increased the degradation of native LDL in these cells at all 3 stages of cell differentiation. LOV also reduced class A types I and II macrophage scavenger receptor and CD36 mRNA levels in 2- and 5-day-old cells but not in the more mature macrophages. These data suggest that 3-hydroxy-3-methylglutaryl–coenzyme A inhibitors may reduce the expression and function of the class A types I and II macrophage scavenger receptor and CD36 in monocytes, during the early stages of their differentiation into adherent macrophages. These effects, if operative in vivo, may slow down the development of the atherosclerotic plaque and thus contribute to the beneficial effects of these drugs.
Reduced Postprandial Serum Paraoxonase Activity After a Meal Rich in Used Cooking Fat
Authors: Sutherland Wayne H. F. , Walker Robert J. , de Jong Sylvia A. , van Rij André M. , Phillips Vicki , Walker Heather L.
Published: June 2011

Abstract
—Paraoxonase is an enzyme associated with HDL in human serum that hydrolyzes oxidized phospholipids and inhibits LDL oxidation, which is an important step in atherogenesis. In animals, addition of oxidized lipids to the circulation reduces paraoxonase activity, and diets rich in oxidized fat accelerate the development of atherosclerosis. The current randomized, crossover study was designed to compare the effect of a meal rich in oxidized lipids in the form of fat that had been used for deep-frying in a fast food restaurant and a control meal rich in the corresponding unused fat on postprandial serum paraoxonase (arylesterase) activity and peroxide content of LDL and its susceptibility to copper ion catalyzed oxidation in 12 healthy men. Four hours into the postprandial period, serum paraoxonase activity had decreased significantly after the used fat meal (−17%,
P
=0.005) and had increased significantly after the meal rich in unused fat (14%,
P
=0.005). These changes were significantly (
P
=0.003) different. A time-course study indicated that serum paraoxonase activity remained lower than baseline for up to 8 hours after the used fat meal. Serum apoA1 concentration tended to decrease after the unused fat meal and tended to increase after the used fat meal. These changes were different at a marginal level of significance (
P
=0.07). Also, a significantly (
P
=0.03) greater decrease in apoA1 content of postprandial HDL was recorded after the unused fat meal. The peroxide content of LDL tended to decrease after the used fat meal and tended to increase after the control meal. These changes were significantly (
P
=0.04) different. Susceptibility of isolated LDL to copper ion oxidation and plasma levels of malondialdehyde were unchanged during the study. These data suggest that in the postprandial period after a meal rich in used cooking fat, the enzymatic protection of LDL against accumulation of peroxides and atherogenic oxidative modification may be reduced, possibly due to factors associated with apoA1, without acutely affecting the intrinsic resistance of LDL to in vitro oxidation.
Dietary β-Carotene and α-Tocopherol Combination Does Not Inhibit Atherogenesis in an ApoE–Deficient Mouse Model
Authors: Shaish Aviv , George Jacob , Gilburd Boris , Keren Pnina , Levkovitz Hana , Harats Dror
Published: June 2011

Abstract
—Although lipid oxidation plays a major role in atherogenesis, the role of antioxidants in the prevention and treatment of the process is not clear. Apolipoprotein (apo) E–deficient mice develop spontaneous atherosclerotic lesions in major arteries. The presence of oxidized lipoprotein epitopes in the lesion suggests that oxidation reactions are involved in atherogenesis in this mouse model, but the inhibitory effect of antioxidants on atherogenesis in the model is controversial. To test the effect of dietary antioxidants on atherogenesis, male apoE-deficient mice (n=15) were fed a standard chow diet supplemented with 0.05% α-tocopherol and 0.05% all-trans β-carotene. A control group (n=15) received no antioxidant supplement. At the end of the trial, mice consuming vitamins had 5× more plasma vitamin E but undetectable β-carotene levels. However, liver levels of the β-carotene metabolite, retinyl palmitate, were higher in antioxidant-treated mice compared with control mice. The antioxidants had no effect on lipoprotein or on plasma anti–oxidatively modified low density lipoproteins (anti-oxLDL) antibody levels. The vitamins had a small but insignificant effect on lipoprotein resistance to ex vivo oxidation, determined by a longer lag period of conjugated diene formation. Atherosclerosis, determined by the lesion size at the aortic sinus, was insignificantly suppressed in antioxidant-treated mice (mean area±SE, 20 000±7129 versus 13 281±5861 μm
2
;
P
=0.40). The aortic atherosclerotic lesion area was similar in both experimental groups (2.55±0.65% and 2.08±0.5% of total aortic area in the control and antioxidant group, respectively;
P
=0.58). The results of the current study suggest that moderate levels of synthetic antioxidant vitamins have no effect on atherogenesis in apoE-deficient mice.
Angiotensin Induces Inflammatory Activation of Human Vascular Smooth Muscle Cells
Authors: Kranzhöfer Roger , Schmidt Joachim , Pfeiffer Carolein A. H. , Hagl Siegfried , Libby Peter , Kübler Wolfgang
Published: June 2011

Abstract—Multiple data suggest that the renin-angiotensin system contributes to the pathogenesis of atherosclerosis. The atherogenic effect of the renin-angiotensin system can only in part be explained by the influence of its effector angiotensin II on blood pressure, smooth muscle cell (SMC) growth, or antifibrinolytic activity. Because chronic inflammation of the vessel wall is a hallmark of atherosclerosis, we hypothesized that angiotensin II may elicit inflammatory signals in vascular SMCs. Human vascular SMCs were stimulated with angiotensin. Inflammatory activation was assessed by determination of interleukin-6 (IL-6) release into the culture medium, detection of IL-6 mRNA by RT-PCR, and demonstration of activation of nuclear factor-κB in electrophoretic mobility shift assays. Angiotensin II concentration-dependently (1 nmol/L to 1 μmol/L) stimulated IL-6 production by SMCs via activation of the angiotensin II type 1 receptor (demonstrated by the inhibitory action of the receptor antagonist losartan). Angiotensin I increased IL-6 production by SMCs, too. This effect was inhibited by captopril and ramiprilat, suggesting conversion of angiotensin I to angiotensin II by angiotensin-converting enzyme in SMCs. Steady-state mRNA for IL-6 was augmented after stimulation with angiotensin II, suggesting regulation of angiotensin-induced IL-6 release at the pretranslational level. Moreover, the proinflammatory transcription factor nuclear factor-κB, which is necessary for transcription of most cytokine genes, was also activated by angiotensin II. Pyrrolidine dithiocarbamate suppressed angiotensin II–induced IL-6 release, a finding compatible with involvement of reactive oxygen species as second messengers in cytokine production mediated by angiotensin. The data demonstrate the ability of angiotensin to elicit an inflammatory response in human vascular SMCs by stimulation of cytokine production and activation of nuclear factor-κB. Inflammatory activation of the vessel wall by a dysregulated renin-angiotensin system may contribute to the pathogenesis of atherosclerosis.
Effect of Cyclosporine on Arterial Balloon Injury Lesions in Cholesterol-Clamped Rabbits
Authors: Andersen Henrik Ørbæk , Hansen Birgit Fischer , Holm Pernille , Stender Steen , Nordestgaard Børge Grønne
Published: June 2011

Abstract
—Restenosis after balloon dilatation of stenosed coronary arteries is a major clinical problem. Because T lymphocytes occur in neointima and because cyclosporine inhibits T-lymphocyte proliferation, we tested the hypothesis that cyclosporine would attenuate neointimal proliferation after balloon dilation injury. Rabbits with a balloon-injured aorta, randomized to cyclosporine in the human therapeutic range (n=13) or vehicle (n=14) were followed up for 5 weeks; as a control for the effect of cyclosporine, half the rabbits received in addition an aorta allograft. Rabbits were clamped at a human plasma cholesterol level of 5 to 7 mmol/L. Cyclosporine did not affect aorta cholesterol accumulation or neointimal proliferation in balloon-injured aortas; however, it attenuated both in transplanted aortas. Likewise, cyclosporine had no effect on endothelial cells at balloon-injured sites, but protected these cells in the transplanted aortas. Infiltration of smooth muscle cells, T lymphocytes, and macrophages were unaffected by cyclosporine in balloon-injured aortas; however, in transplanted aortas, cyclosporine reduced the relative number of T lymphocytes and macrophages but increased the relative number of smooth muscle cells. Finally, in balloon-injured aortas, cyclosporine did not affect expression of vascular adhesion molecule-1, intercellular adhesion molecule-1, or major histocompatibility complex II, but all these cellular activation markers were attenuated by cyclosporine in transplanted aortas. These results suggest that cyclosporine does not attenuate neointimal proliferation after balloon dilatation, and that T lymphocyte—mediated immune responses are not involved in neointimal proliferation after balloon dilatation.
Increased Secretion of Tissue Inhibitors of Metalloproteinases 1 and 2 From the Aortas of Cholesterol Fed Rabbits Partially Counterbalances Increased Metalloproteinase Activity
Authors: Zaltsman A. B. , George S. J. , Newby A. C.
Published: June 2011

Abstract
—The balance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) plays an important role in extracellular matrix turnover and thereby modulates atherosclerotic plaque development. MMP-1, -2, -3, and -9 activity is increased by atherosclerosis, but the status of TIMPs is less clear. We therefore compared secretion of TIMPs-1 and -2 from cultured aortic explants derived from arch, middle, and distal portions of thoracic aortas of normal rabbits and rabbits fed a 1% cholesterol diet for 8 weeks, using reverse zymography of conditioned media. Cholesterol feeding significantly increased secretion of TIMP-1 from arch and middle portions (both 2.6-fold), accompanied by 2.0- and 2.7-fold increases in TIMP-2, respectively. Atherosclerotic aortas exhibited increased immunoreactive TIMP-1 and TIMP-2 in endothelial cells, smooth muscle cells, and macrophages. Staining of extracellular matrix was also prominent within the noncellular boundary region between fibrous cap and the lipid core, and within the lipid core. Increased TIMP-2 staining was also found in the media subjacent to the lipid core. In situ gelatin zymography demonstrated excess MMP activity within the plaque with partial inhibition in the lipid core base and subjacent media, consistent with the distribution of TIMPs. Casein zymography and in situ zymography demonstrated that increased caseinolytic activity was confined to the pericellular zones of macrophages within the lipid core, again consistent with its restriction by TIMPs. In summary, atherosclerosis increases TIMP expression, which counterbalances, in part, increased MMP activity.
Inherited Prothrombotic Conditions and Premature Ischemic Stroke
Authors: Margaglione Maurizio , D’Andrea Giovanna , Giuliani Nicola , Brancaccio Vincenzo , De Lucia Domenico , Grandone Elvira , De Stefano Valerio , Tonali Pietro A. , Di Minno Giovanni
Published: June 2011

Abstract
—At a young age, ischemic stroke is an uncommon event in which prothrombotic factors are likely to play an important role. In 202 referred cases, 105 men and 97 women, median age 39 years (range, 3 to 50), with a history of ischemic stroke and in 1036 age frequency-matched apparently healthy individuals from the same ethnic background, we have investigated whether inherited prothrombotic conditions increase the risk of ischemic stroke. Neither abnormal plasma levels of natural anticoagulants and fibrinogen nor significant increase of the prothrombin A
20210
allele was found in stroke cases compared with controls. Hypertension (odds ratio [OR], 22.61), male sex (OR, 2.30), smoking (OR, 2.78) and alcohol habits (OR, 0.14), a personal history of venous thromboembolism (OR, 4.53), a family history of stroke (OR, 1.93), high circulating levels of fibrinogen (
P
=0.0190), and total cholesterol (
P
=0.101) were all independently associated with ischemic stroke. Compared with noncarriers, carriers of the factor V (FV) Leiden mutation (OR, 2.56), and to a lesser extent, of the methylenetetrahydrofolate reductase (MTHFR) TT genotype (OR, 1.60), had an independent higher estimated risk of having a history of ischemic stroke. The relationship with the FV Leiden mutation was greater in women (OR, 3.95). Thus, in addition to established determinants, FV Leiden mutation is independently associated with the occurrence of ischemic stroke in this setting. The greater association in women suggests the possibility of an interaction of this genotype with female hormones.
The Relationship of Fibrinogen and Factors VII and VIII to Incident Cardiovascular Disease and Death in the Elderly
Authors: Tracy Russell P. , Arnold Alice M. , Ettinger Walter , Fried Linda , Meilahn Elaine , Savage Peter
Published: June 2011

Abstract
—Little is known about the prospective associations of fibrinogen, factor VII, or factor VIII with cardiovascular disease (CVD) and mortality in the elderly. At baseline in the Cardiovascular Health Study (5888 white and African American men and women; aged ≥65 years), we measured fibrinogen, factor VIII, and factor VII. We used sex-stratified stepwise Cox survival analysis to determine relative risks (RRs) for CVD events and all-cause mortality (up to 5 years of follow-up), both unadjusted and adjusted for CVD risk factors and subclinical CVD. After adjustment, comparing the fifth quintile to the first, fibrinogen was significantly associated in men with coronary heart disease events (RR=2.1) and stroke or transient ischemic attack (RR=1.3), and also with mortality within 2.5 years of follow-up (RR=5.8) and later (RR=1.7). Factor VIII was significantly associated in men with coronary heart disease events (RR=1.5) and mortality (RR=1.8), and in women with stroke/transient ischemic attack (RR=1.4). For both factors, values were higher in those who died, whether causes were CVD-related or non–CVD-related, but highest in CVD death. Factor VII exhibited associations with incident angina (RR=1.44) in men and with death in women (RR, middle quintile compared with first=0.66). However, in general, factor VII was not consistently associated with CVD events in this population. We conclude that, if confirmed in other studies, the measurement of fibrinogen and/or factor VIII may help identify older individuals at higher risk for CVD events and mortality.
Angiotensin-Converting Enzyme Gene Polymorphism and Carotid Wall Thickening in a Community Population
Authors: Hung Joseph , McQuillan Brendan M. , Nidorf Mark , Thompson Peter L. , Beilby John P.
Published: June 2011

Abstract
—The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene has been associated with an increased risk of coronary heart disease, but whether it is a risk factor for underlying atherosclerosis remains unclear. Therefore, we examined to see whether the ACE gene deletion polymorphism was associated with carotid wall thickening and atherosclerotic plaque formation in a large randomly selected community population. A total of 1111 subjects, aged 27 to 77 years, with an equal male:female ratio and equal numbers in each age decile, were randomly selected from the Perth community population. Mean common carotid intima-medial wall thickness (IMT) and focal plaque formation were assessed by high-resolution B-mode ultrasound. The ACE gene
I/D
polymorphism was detected by PCR. The distribution of the ACE genotypes conformed to the Hardy-Weinberg equilibrium (
DD
, 31.0%;
ID
, 48.4%; and
II
, 20.6%). The
D
allele was strongly correlated in a codominant fashion with plasma ACE activity (
r
s
=0.53,
P
<0.0001), and accounted for 33% of the total variance in circulating ACE activity. No significant differences among the ACE genotypes were found with respect to age, sex, and conventional risk variables, including a history of hypertension and vascular disease. The average mean IMT and prevalence of increased IMT and focal plaque were not significantly different among genotypes in the overall population or in the subset (n=852) who were conventionally low risk by Framingham coronary heart disease risk score. Logistic regression analysis selected age, systolic blood pressure, pack-years of smoking, LDL cholesterol level, waist/hip ratio, and history of hypertension, but not the
D
allele, as multivariate predictors of increased IMT and carotid plaque formation. We conclude that, although the ACE
I/D
polymorphism is strongly related to ACE activity, it is not a risk predictor of carotid wall thickening or focal plaque formation when examined in a large randomly selected community population.
Hepatic Lipase (
LIPC
) Promoter Polymorphism in Men With Coronary Artery Disease
Authors: Shohet Ralph V. , Vega Gloria L. , Anwar Azam , Cigarroa Joaquin E. , Grundy Scott M. , Cohen Jonathan C.
Published: June 2011

Abstract
—Hepatic lipase is an important determinant of plasma HDL concentration and LDL subclass distribution and may therefore influence susceptibility to coronary artery disease (CAD). To assess the effect of genetic variation in hepatic lipase activity on CAD susceptibility, we determined the frequency of the −514T allele of hepatic lipase in white men with CAD and in controls who did not have CAD. In men with CAD, postheparin plasma hepatic lipase activity was 15% to 20% lower in heterozygotes and 30% lower in homozygotes for the −514T allele. Allele frequencies were similar in cases and controls, however, and were consistent with Hardy-Weinberg expectation in both groups. This finding was confirmed in a second group comprising cases with premature symptomatic CAD and controls who were free of disease. These data indicate that a primary decrease in hepatic lipase activity of as much as 30% does not influence susceptibility to CAD in white men.
Hypoxia/Hypoxemia-Induced Activation of the Procoagulant Pathways and the Pathogenesis of Ischemia-Associated Thrombosis
Authors: Yan Shi-Fang , Mackman Nigel , Kisiel Walter , Stern David M. , Pinsky David J.
Published: June 2011

Abstract—Although oxygen deprivation has long been associated with triggering of the procoagulant pathway and venous thrombosis, blood hypoxemia and stasis by themselves do not lead to fibrin formation. A pathway is outlined through which diminished levels of oxygen activate the transcription factor early growth response-1 (Egr-1) leading to de novo transcription/translation of tissue factor in mononuclear phagocytes and smooth muscle cells, which eventuates in vascular fibrin deposition. The procoagulant response is magnified by concomitant suppression of fibrinolysis by hypoxia-mediated upregulation of plasminogen activator inhibitor-1. These data add a new facet to the biology of thrombosis associated with hypoxemia/stasis and imply that interference with mechanisms causing Egr-1 activation in response to oxygen deprivation might prevent vascular fibrin deposition occurring in ischemia without directly interfering with other pro/anticoagulant pathways.
Similarities and Differences in Smooth Muscle α-Actin Induction by TGF-β in Smooth Muscle Versus Non–Smooth Muscle Cells
Authors: Hautmann Martina B. , Adam Paul J. , Owens Gary K.
Published: June 2011

Abstract
—Transforming growth factor-β (TGF-β) has been shown to stimulate smooth muscle (SM) α-actin expression in smooth muscle cells (SMCs) and non-SMCs. We previously demonstrated that the 2 CArG boxes A and B and a novel TGF-β control element (TCE) located within the first 125 bp of the SM α-actin promoter were required for TGF-β inducibility of SM α-actin in SMCs. The aims of the present study were (1) to determine whether the TCE exhibits SMC specificity or contributes to TGF-β induction of SM α-actin expression in non-SMCs (ie, endothelial cells and fibroblasts) and (2) to determine whether TGF-β can induce expression of multiple TCE-containing SMC differentiation marker genes, such as SM22α, h
1
calponin, and SM myosin heavy chain (SM MHC) in non-SMCs. Results of transient transfection assays demonstrated that mutation of CArG A, CArG B, or the TCE within a 125-bp promoter context completely abolished TGF-β inducibility of SM α-actin in endothelial cells and fibroblasts. However, in contrast to observations in SMCs, inclusion of regions upstream from −155 completely repressed TGF-β responsiveness in non-SMCs. Electrophoretic mobility shift assays showed that TGF-β enhanced binding of a serum response factor to the CArG elements and the binding of an as-yet-unidentified factor to the TCE in endothelial cells and fibroblasts, but to a much lesser extent compared with SMCs. TGF-β also stimulated expression of the SMC differentiation marker SM22α in non-SMCs. However, in contrast to SMCs, TGF-β did not induce expression of h
1
calponin and SM MHC in non-SMCs. In summary, these results suggest a conserved role for CArG A, CArG B, and the TCE in TGF-β–induced expression of SM α-actin in SMCs and non-SMCs that is modified by a complex interplay of positive- and negative-acting
cis
elements in a cell-specific manner. Furthermore, observations that TGF-β stimulated expression of several early but not late differentiation markers in non-SMCs indicate that TGF-β alone is not sufficient to induce transdifferentiation of non-SMCs into SMCs.
9-cis Retinoic Acid Induces Monocyte Chemoattractant Protein-1 Secretion in Human Monocytic THP-1 Cells
Authors: Zhu Lingyu , Bisgaier Charles L. , Aviram Michael , Newton Roger S.
Published: June 2011

Abstract—Monocyte migration and activation are regulated by monocyte chemoattractant protein-1 (MCP-1). Prior studies have shown MCP-1 expression is modulated by a variety of ligands that act through extracellular receptors. In the current study, we show 9-cis retinoic acid (RA), a ligand for the nuclear hormone receptor retinoid X receptor (RXR) and retinoic acid receptor (RAR), markedly induces the expression of MCP-1. In human THP-1 monocytic leukemia cells cultured with RA (0.05 to 500 nmol/L), MCP-1 expression was induced rapidly, significantly, and dose-dependently by as much as 165-fold. MCP-1 RNA level was also increased in RA-treated cells. Expression of PPARγ, a heterodimer partner of RXR, is also markedly induced by RA in THP-1 cells. However,BRL49653, a PPARγ ligand, failed to induce MCP-1 secretion either alone or to modify the expression level induced by RA. In contrast,BRL49653significantly increased MCP-1 (biotinylated MCP-1) binding to THP-1 cells, whereas RA had no effect. Other peroxisome proliferator activated receptor (PPAR) ligands, 15d-PGJ2and troglitazone (PPARγ), Wy14,643 (PPARα), and PD195599 (PPARβ) inhibited the induction of MCP-1 by RA. RA’s effect on MCP-1 expression in human elutriated monocytes were similar to that observed in the THP-1 cells. These studies identify RA as a nuclear signal for MCP-1 induction in undifferentiated human monocytic cells. These studies also suggest monocyte MCP-1 expression induced through RA may modulate cell migration.
Phosphatidylinositol 3-Kinase Is Required for Growth Factor–Induced Amino Acid Uptake by Vascular Smooth Muscle Cells
Authors: Higaki Masahide , Shimokado Kentaro
Published: June 2011

Abstract
—Although accumulating evidence suggests that phosphatidylinositol 3-kinase (PI3K) is a common signaling molecule for growth factor–induced amino acid uptake by the cell, the role of PI3K in the uptake of different amino acids was not tested under the same conditions. In this study, we asked whether PI3K mediates platelet-derived growth factor (PDGF) –stimulated uptake of different amino acids that are taken up through 3 major amino acid transporters expressed in rat vascular smooth muscle cells and other cell types and whether PI3K mediates amino acid uptake stimulated with different growth factors and vasoactive substances. PDGF increased the uptake of [
3
H]leucine, [
3
H]proline, and [
3
H]arginine in a dose- and time-dependent fashion. Two different PI3K inhibitors, wortmannin (100 nmol/L) and LY294002 (10 μmol/L), completely inhibited the amino acid uptake stimulated by PDGF. Chinese hamster ovary cells expressing both PDGF receptor-β and a dominant-negative PI3K did not increase their leucine uptake when stimulated with PDGF, whereas the same cells expressing only PDGF receptor-β did. Transforming growth factor-β, as well as insulin-like growth factor-I and angiotensin II, increased leucine uptake by vascular smooth muscle cells. Wortmannin and LY294002 inhibited this increase. We also found that transforming growth factor-β stimulated PI3K activity and the phosphorylation of Akt, a downstream signaling molecule of PI3K. A similar effect of PI3K inhibitors on amino acid uptake was observed in Swiss 3T3 cells. We conclude that PI3K mediates the uptake of different amino acids by vascular smooth muscle cells and other cell types stimulated with a variety of growth factors, including transforming growth factor-β. Our findings suggest that PI3K may play an important role in vascular pathophysiology by regulating amino acid uptake.
Chronic Endothelin-1 Improves Nitric Oxide–Dependent Flow-Induced Dilation in Resistance Arteries From Normotensive and Hypertensive Rats
Authors: Henrion Daniel , Iglarz Marc , Lévy Bernard I.
Published: June 2011

Abstract—Endothelin-1 (ET-1) is released on stimulation by shear stress of the vascular wall. In several pathological situations, an involvement of ET-1 is suspected. Nevertheless, the effect of a chronic increase in circulating ET-1 on vascular tone in resistance arteries is not yet fully understood. We investigated the response to tensile stress (pressure-induced myogenic tone) and shear stress (flow-induced dilation, FD) of rat mesenteric resistance arteries cannulated in an arteriograph. Intraluminal diameter was measured continuously. Rats (normotensive Wistar-Kyoto rats [WKYs] and spontaneously hypertensive rats [SHRs]) were treated for 2 weeks with ET-1 (5 pmol · kg−1· min−1SC; n=8 to 16 per group). Systolic arterial blood pressure increased significantly in ET-1–treated rats (171±7 versus 196±6 mm Hg in WKYs and 216±8 versus 245±6 mm Hg in SHRs,P<0.05). Passive arterial diameter in isolated resistance arteries ranged from 78±9 to 169±4 μm in WKYs and from 62±6 to 149±7 μm in SHRs (pressure from 10 to 150 mm Hg). Myogenic tone was not significantly affected by chronic ET-1. Flow (9 to 150 μL/min) significantly increased the arterial diameter by 2±0.5 to 22±2 μm in WKYs and by 1.3±0.7 to 8.3±0.8 μm in SHRs (P<0.001 versus WKYs). The NO synthesis blockerNG-nitro-l-arginine methyl ester (L-NAME; 100 μmol/L) attenuated FD in WKYs (eg, 22±2 versus 15±3 μm after L-NAME, flow=150 μL/min) and, to a lesser extent, in SHRs (P<0.001 versus WKYs). The cyclooxygenase inhibitor indomethacin (3 μmol/L) attenuated the remaining FD in WKYs (eg, 15±3 versus 8±3 μm, flow=150 μL/min) and in SHRs (eg, 7.5±0.5 versus 5.0±0.6 μm). Chronic ET-1 significantly increased FD in SHRs but not in WKYs. In both strains, NO-dependent FD was significantly increased by chronic ET-1. Furthermore, indomethacin-sensitive FD was increased by chronic ET-1 in SHRs only. Thus, chronic ET-1 increased NO-dependent FD in resistance mesenteric arteries from both WKYs and SHRs and increased indomethacin-sensitive FD in SHRs only.
Different Effects of Photodynamic Therapy and γ-Irradiation on Vascular Smooth Muscle Cells and Matrix
Authors: Heckenkamp Joerg , Leszczynski Dariusz , Schiereck Jan , Kung Justin , LaMuraglia Glenn M.
Published: June 2011

Abstract
—γ-Irradiation (γ-RT) and photodynamic therapy (PDT) are known to inhibit intimal hyperplasia. The common mechanism is that both modalities produce free radicals, but unlike γ-RT, PDT generates them through the absorption of light by photosensitizers. The purpose of this in vitro study was to assess the differences that PDT and γ-RT have on the fibroproliferative response after vascular injury by comparing their effects on vascular smooth muscle cells (SMCs) and on the extracellular matrix (ECM). Mitochondrial activity (tetrazolium salt), proliferation ([
3
H]thymidine incorporation), and the mechanisms of cell death (terminal deoxynucleotidyl transferase–mediated dUTP biotin nick end labeling [TUNEL] staining) were used to assess differences between PDT (100 J/cm
2
) and γ-RT (10 or 20 Gy) on SMC injury. The different effects on bioregulatory molecules were investigated by quantitating the proliferation of SMCs cultured with conditioned medium and on treated ECM. PDT of SMCs reduced proliferation and mitochondrial activity (0.5±0.75% and 1.7±4.25%, respectively,
P
<0.0001), whereas γ-RT of SMCs decreased cell proliferation but did not affect metabolic activity. Stimulation with calf serum of γ-RT–treated SMCs did not affect proliferation but increased mitochondrial enzyme activity (160±11%,
P
<0.0005). The conditioned medium, derived from PDT- but not γ-RT–treated SMCs, did not stimulate effector SMC proliferation compared with γ-RT–treated SMCs (16±4.1% versus 80±16.8%,
P
<0.0001). Apoptosis was the principle cytotoxic mechanism after PDT, whereas γ-RT cells were growth arrested but viable. PDT of the ECM reduced effector SMC proliferation compared with controls and γ-RT cells (18±6.5% versus 100±17.7% and 84±8.9%, respectively,
P
<0.0001). These data suggest that γ-RT and PDT may inhibit restenosis but by different mechanisms. The effects of PDT are more diverse and may result in improved outcome while avoiding the teratogenic exposure due to ionizing irradiation.
Cholesterol Oxidation Products Induce Vascular Foam Cell Lesion Formation in Hypercholesterolemic New Zealand White Rabbits
Authors: Rong James X. , Shen Lijiang , Chang Yi H. , Richters Arnis , Hodis Howard N. , Sevanian Alex
Published: June 2011

Abstract
—Circulating cholesterol oxidation products (ChOx) have long been implicated in the etiology of early atherosclerosis; however, direct in vivo evidence elucidating their role in atherogenesis is only recently becoming available. This study investigated ChOx effects on vascular lesion formation in New Zealand White rabbits under controlled hypercholesterolemic conditions. By closely monitoring plasma cholesterol levels and adjusting dietary cholesterol intake during a 78-day period, total plasma cholesterol exposures (cumulative plasma cholesterol levels over time) were controlled between 27 000 and 34 000 mg/dL×day (final plasma cholesterol concentration, 467±77 mg/mL), representing a threshold range for sudanophilic lesion formation in the aorta. Twenty injections of a ChOx mixture (70 mg per injection) were made bearing an oxysterol composition similar to that found in circulating oxidatively modified low density lipoprotein. At sacrifice, the ChOx-injected rabbits (n=5) had (1) significantly higher plasma ChOx levels, (2) significantly increased cholesterol content in the aortas, mainly as esterified cholesterol, and (3) significantly greater sudanophilic lesion size and frequency in the aortas compared with vehicle-injected control rabbits (n=5). The aortic cholesterol content and extent of sudanophilic lesion area were correlated significantly with total plasma ChOx exposure (
P
<0.003 and
P
<0.0001, respectively) but not with total cholesterol exposure. The results indicate that for moderate experimental hypercholesterolemia, a situation more relevant to physiological hypercholesterolemia in humans, circulating ChOx may play an important role in inducing formation of early atherosclerotic lesions. Because ChOx are often present in cholesterol-containing diets, foam cell lesion formation induced by ChOx rather than cholesterol cannot be overlooked.
Coronary and Aortic Calcification Among Women 8 Years After Menopause and Their Premenopausal Risk Factors
Authors: Kuller Lewis H. , Matthews Karen A. , Sutton-Tyrrell Kim , Edmundowicz Daniel , Bunker Clareann H.
Published: June 2011

Abstract
—In the Healthy Women Study, the relationship between cardiovascular risk factors measured premenopausally at age 48, use of hormone therapy, and coronary and aortic calcification at age 58 were evaluated among 169 women. Approximately 63% of women had no coronary calcification, but only 29% had no aortic calcification. Coronary calcification and aortic calcification were positively correlated with each other. There was a very strong association between low density lipoprotein cholesterol (LDL-C) level and coronary calcification. Among women with premenopausal levels of LDL-C <100 mg/dL, only 9% had a coronary calcium score ≥101 compared with 30% of women with an LDL-C >160 mg/dL. Only 5% of women with a high density lipoprotein cholesterol (HDL-C) level >60 mg/dL had high coronary scores. The level of HDL
2
-C was especially strongly inversely related to coronary calcium scores. Cigarette smoking was a very important determinant of both high aortic and high coronary calcium scores. Other risk factors associated with greater coronary calcium were higher systolic blood pressure, triglycerides levels, and blood glucose. Use of hormone replacement therapy was associated with less coronary calcium (NS). For both hormone replacement therapy users and nonusers, the levels of LDL-C and HDL-C measured premenopausally were predictors of coronary and aortic calcium scores. Thus, risk factors evaluated premenopausally are powerful predictors of coronary and aortic calcification, a marker of atherosclerosis, measured 8 years after menopause, 11 years later in these women.