bluuebunny/crossref_metadata_2025 huggingface dataset:
Tissue Prothrombin
Authors: McBane Robert D. , Miller Randall S. , Hassinger Nancy L. , Chesebro James H. , Nemerson Yale , Owen Whyte G.
Published: June 2011

Abstract
Immunohistochemical analysis of surgically obtained porcine tissue samples reveals ubiquitous staining for prothrombin in organs rich in smooth muscle content and universal staining of smooth muscle in tissue vasculature. The native character of tissue prothrombin is verified first by chromogenic substrate hydrolysis and hirudin inhibition after incubation of tissue extracts with taipan snake venom and phospholipid. Western analysis of tissue extracts confirms the native zymogen molecular weight. In addition, prothrombin purified in good yield from porcine uterus is activated by
Echis carinatus
venom which, like taipan venom, is 4-carboxyglutamic acid-sensitive. After correction for blood (gross heme) and interstitial fluid (albumin), excess functional prothrombin is observed in extracts of tissues having abundant smooth muscle. In contrast with factor X, the yield of prothrombin purified from porcine uterus greatly exceeds that attributable to contamination by whole blood. Northern blot analysis from selected bovine tissues extracted for polyadenylated messenger RNA is equivocal for prothrombin mRNA with the exception of liver, which is positive. It is concluded that functionally intact prothrombin is widely distributed among tissues owing to smooth muscle content, although the mechanism of emplacement and physiologic significance of prothrombin in these tissues remains unclear.
Identification of Osteoglycin as a Component of the Vascular Matrix
Authors: Shanahan Catherine M. , Cary Nathaniel R. B. , Osbourn Jane K. , Weissberg Peter L.
Published: June 2011

AbstractUsing differential cDNA screening, we demonstrated that the bone-associated glycoprotein osteoglycin was highly expressed in differentiated adult rat vascular smooth muscle cells (VSMCs) but downregulated in VSMCs that had undergone proliferation in vitro. Further experiments in vitro revealed that osteoglycin gene expression was downregulated by a number of cytokines expressed in vivo (often in association with vascular injury) including basic fibroblast growth factor, transforming growth factor-β, platelet-derived growth factor, and angiotensin II. In the normal adult rat carotid artery, osteoglycin was expressed in both the media and adventitia. However, osteoglycin mRNA expression was substantially increased in the adventitia and neointima 14 days after balloon injury, implying a role for this protein in vessel remodeling. Northern analysis of mRNA from neonatal rat aortas demonstrated upregulation of osteoglycin mRNA at week 2, after VSMC proliferation had ceased and when matrix modeling was maximal. In situ hybridization studies in human coronary arteries showed that osteoglycin mRNA was expressed by normal medial VSMCs but was downregulated in a subset of intimal VSMCs. Osteoglycin was not expressed in the VSMCs of adventitial vessels but was expressed in a subset of adventitial cells. This expression pattern contrasted with that of SM22α, a contractile protein marker of VSMC differentiation, which was highly expressed in the media of all vessels. These data indicate that osteoglycin is a new marker of differentiated VSMCs and may be an essential component of the normal vascular matrix.
Peroxidation of LDL From Combined-Hyperlipidemic Male Smokers Supplied With ¯-3 Fatty Acids and Antioxidants
Authors: Brude Ingeborg R. , Drevon Christian A. , Hjermann Ingvar , Seljeflot Ingebjørg , Lund-Katz Sissel , Saarem Kristin , Sandstad Berit , Solvoll Kari , Halvorsen Bente , Arnesen Harald , Nenseter Marit S.
Published: June 2011

Abstract
The effects of marine ¯-3 polyunsaturated fatty acids (FAs) and antioxidants on the oxidative modification of LDL were studied in a randomized, double-blind, placebo-controlled trial. Male smokers (n=41) with combined hyperlipidemia were allocated to one of four groups receiving supplementation with ¯-3 FAs (5 g eicosapentaenoic acid and docosahexaenoic acid per day), antioxidants (75 mg vitamin E, 150 mg vitamin C, 15 mg β-carotene, and 30 mg coenzyme Q
10
per day), both ¯-3 FAs and antioxidants, or control oils. LDL and human mononuclear cells were isolated from the patients at baseline and after 6 weeks of supplementation. LDL was subjected to cell-mediated oxidation by the patients’ own mononuclear cells, as well as to Cu
2+
-catalyzed and 2,2′-azobis-(2-amidinopropane hydrochloride) (AAPH)–initiated oxidation. Extent of LDL modification was measured as lag time, the formation rate of conjugated dienes (CDs), the maximum amount of CDs formed, formation of lipid peroxides, and the relative electrophoretic mobility of LDL on agarose gels. Dietary supplementation with ¯-3 FAs increased the concentration of total ¯-3 FAs in LDL and reduced the concentration of vitamin E in serum. The ¯-3 FA–enriched LDL particles were not more susceptible to Cu
2+
-catalyzed, AAPH-initiated, or autologous cell–mediated oxidation than control LDL. In fact, enrichment with ¯-3 FAs significantly reduced the formation rate of CDs when LDL was subjected to AAPH-induced oxidation. Supplementation with moderate amounts of antioxidants significantly increased the concentration of vitamin E in serum and increased the resistance of LDL to undergo Cu
2+
-catalyzed oxidation, measured as increased lag time, reduced formation of lipid peroxides, and reduced relative electrophoretic mobility compared with control LDL. Supplementation with ¯-3 FAs/antioxidants showed oxidizability of LDL similar to that of control LDL and ¯-3 FA–enriched LDL. In conclusion, ¯-3 FAs neither rendered the LDL particles more susceptible to undergo in vitro oxidation nor influenced mononuclear cells’ ability to oxidize autologous LDL, whereas moderate amounts of antioxidants protected LDL against oxidative modification.
Inhibition of HMG-CoA Reductase by Atorvastatin Decreases Both VLDL and LDL Apolipoprotein B Production in Miniature Pigs
Authors: Burnett John R. , Wilcox Lisa J. , Telford Dawn E. , Kleinstiver Sandra J. , Barrett P. Hugh R. , Newton Roger S. , Huff Murray W.
Published: June 2011

Abstract
In the present studies, the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor atorvastatin was used to test the hypothesis that inhibition of cholesterol biosynthesis in vivo with a consequent reduction in the availability of hepatic cholesterol for lipoprotein synthesis, would (1) reduce very low density lipoprotein (VLDL) apolipoprotein B (apoB) secretion into the plasma, (2) reduce the conversion of VLDL apoB to LDL apoB, and (3) reduce LDL apoB direct synthesis. ApoB kinetic studies were carried out in six control miniature pigs and in six animals after 21 days of administration of atorvastatin (3 mg/kg per day). Pigs were fed a fat- (34% of calories; polyunsaturated to monounsaturated to saturated ratio, 1:1:1) and cholesterol- (400 mg/d cholesterol; 0.1%; 0.2 mg/kcal) containing pig chow–based diet. Atorvastatin treatment significantly reduced plasma total cholesterol, LDL cholesterol, total triglyceride, and VLDL triglyceride concentrations by 16%, 31%, 19%, and 28%, respectively (
P
<.01). Autologous
131
I-VLDL,
125
I-LDL, and [
3
H]leucine were injected simultaneously into each pig, and apoB kinetic data were analyzed using multicompartmental analysis (
saam ii
). The VLDL apoB pool size decreased by 29% (0.46 versus 0.65 mg/kg;
P
=.002), which was entirely due to a 34% reduction in the VLDL apoB production rate (PR) (1.43 versus 2.19 mg/kg per hour;
P
=.027). The fractional catabolic rate (FCR) was unchanged. The LDL apoB pool size decreased by 30% (4.74 versus 6.75 mg/kg;
P
=.0004), which was due to a 22% reduction in the LDL apoB PR (0.236 versus 0.301 mg/kg per hour;
P
=.004), since the FCR was unchanged. The reduction in LDL apoB PR was primarily due to a 34% decrease in conversion of VLDL apoB to LDL apoB; however, this reduction was not statistically significant (
P
=.114). Hepatic apoB mRNA abundance quantitated by RNase protection assay was decreased by 13% in the atorvastatin-treated animals (
P
=.003). Hepatic and intestinal LDL receptor mRNA abundances were not affected. We conclude that inhibition of hepatic HMG-CoA reductase by atorvastatin reduces both VLDL and LDL apoB concentrations, primarily by decreasing apoB secretion into the plasma and not by an increase in hepatic LDL receptor expression. This decrease in apoB secretion may, in part, be due to a reduction in apoB mRNA abundance.
Prevalence of Double Pre-Beta Lipoproteinemia in Hyperlipidemic Patients Is Influenced by Gender, Menopausal Status, and ApoE Phenotype
Authors: Cohn Jeffrey S. , Giroux Louise-Marie , Fortin Louis-Jacques , Davignon Jean
Published: June 2011

Abstract
Double pre-beta lipoproteinemia (DPBL) is a plasma lipoprotein phenotype characterized by the presence of two agarose gel electrophoretic populations of very low density lipoproteins (VLDLs,
d
<1.006 g/mL), ie, normal pre–β-migrating VLDL and slow pre–β VLDL. Slow pre–β VLDL represents remnant lipoproteins derived from the hydrolysis of triglyceride (TG)-rich lipoproteins (TRLs), and thus DPBL is a characteristic of plasma remnant lipoprotein accumulation. To determine the prevalence of DPBL in our lipid clinic population, patients (n=2501) were selected who (1) had an unambiguous VLDL electrophoretic phenotype and could be classified as having either DPBL (DPBL+), β-migrating VLDL (β-VLDL+), or an absence of both (DPBL/β-VLDL −/−) and (2) had hypercholesterolemia (HC: plasma cholesterol ≥6.2 mmol/L, n=1017), hypertriglyceridemia (HTG: plasma TG ≥2.3 mmol/L but <15 mmol/L, n=554) or combined hyperlipidemia (HC+HTG, n=930). Patients with TG <2.3 mmol/L and cholesterol <5.2 mmol/L acted as control subjects (n=343). Using a commercially available agarose gel electrophoresis system, we identified 220 hyperlipidemic patients (8.8%) with DPBL (versus <1% of control). The prevalence of DPBL was higher in (1) male than in female patients (10.7% versus 6.7%), (2) postmenopausal than in premenopausal females (7.3% versus 4.1%), and (3) patients with HC+HTG than in those with HTG or HC alone (15.8% versus 8.3% versus 2.7%, respectively). Patients with an ε2 allele had a higher prevalence of DPBL; ie, 26.9% of apoE 3/2 and 26.2% of apoE 4/2 patients had DPBL compared with 6.5%, 6.8%, and 7.4% of apoE 3/3, 4/3, and 4/4 patients, respectively. DPBL patients consistently had increased levels of VLDL-C and (LDL+HDL)-TG and decreased levels of LDL-C, and their plasma lipid profiles were intermediate between those of β-VLDL+ and DPBL/β-VLDL−/− patients. These results demonstrate that male sex, postmenopausal status in women, and the presence of an apoE 3/2 or apoE 4/2 phenotype are associated with an increased incidence of DPBL in hyperlipidemic patients.
17β-Estradiol Prevents Fatty Streak Formation in Apolipoprotein E–Deficient Mice
Authors: Elhage R. , Arnal J.-F. , Pieraggi M.-T. , Duverger N. , Fiévet C. , Faye J.-C. , Bayard F.
Published: June 2011

Abstract
The reality of the atheroprotective effect of estrogens is still a matter of debate, and its unknown mechanisms could involve favorable changes in blood lipids and lipoproteins and/or direct action at the level of the arterial wall. We used the recently developed animal model of atherosclerosis constituted by apolipoprotein E–deficient mice in an attempt to clarify these issues. Male and female animals, fed a low-fat chow diet, were treated with increasing doses of 17β-estradiol (E
2
) after castration and compared with testosterone treated and uncastrated (intact) animals. Total serum cholesterol, LDL-cholesterol, and HDL-cholesterol concentrations decreased under E
2
treatment in each sex and were weakly correlated with lesion area. However, a highly significant correlation between lesion area and serum E
2
levels also suggested a direct action of E
2
on cells of the vascular wall. A dose-response curve analysis revealed that these activities were sex-dependent, with females being nearly twice as sensitive to E
2
as males. It also revealed that the atheroprotective activity was recruited at higher E
2
concentrations than those needed by other E
2
target tissues such as uterus or functions such as apoA-1 and LDL production and/or clearance rates.
Reduced Progression of Atherosclerosis in Apolipoprotein E–Deficient Mice Following Consumption of Red Wine, or Its Polyphenols Quercetin or Catechin, Is Associated With Reduced Susceptibility of LDL to Oxidation and Aggregation
Authors: Hayek Tony , Fuhrman Bianca , Vaya Jacob , Rosenblat Mira , Belinky Paula , Coleman Raymond , Elis Avishay , Aviram Michael
Published: June 2011

Abstract
The effect of consuming red wine, or its major polyphenol constituents catechin or quercetin, on the development of atherosclerotic lesions, in relation to the susceptibility of plasma LDL to oxidation and to aggregation, was studied in atherosclerotic apolipoprotein E deficient (E°) mice. Forty E° mice at the age of 4 weeks were divided into four groups, 10 mice in each group, and were supplemented for up to 6 weeks in their drinking water with placebo (1.1% alcohol); catechin or quercetin (50 μg/d per mouse), or red wine (0.5 mL/d per mouse). Consumption of catechin, quercetin, or red wine had no effect on plasma LDL or HDL cholesterol levels. The atherosclerotic lesion area was smaller in the treated mice by 39%, 46%, and 48%, respectively, in comparison with E° mice that were treated with placebo. In accordance with these findings, cellular uptake of LDL derived after catechin, quercetin, or red wine consumption was found to be reduced by 31%, 40%, and 52%, respectively. These results were associated with reduced susceptibility to oxidation (induced by different modes such as copper ions, free radical generator, or macrophages) of LDL isolated after red wine or quercetin and, to a lesser extent after catechin consumption, in comparison with LDL isolated from the placebo group. Similar results were obtained when LDL was preincubated in vitro with red wine or with the polyphenols prior to its oxidation. Even in the basal oxidative state (not induced oxidation), LDL isolated from E° mice that consumed catechin, quercetin, or red wine for 2 weeks was found to be less oxidized in comparison with LDL isolated from E° mice that received placebo, as evidenced by 39%, 48%, and 49% reduced content of LDL-associated lipid peroxides, respectively. This effect could be related to enhanced serum paraoxonase activity in the polyphenol-treated mice. LDL oxidation was previously shown to lead to its aggregation. The present study demonstrated that the susceptibility of LDL to aggregation was reduced in comparison with placebo-treated mice, by 63%, 48%, or 50% by catechin, quercetin, and red wine consumption, respectively, and this effect could be shown also in vitro. The inhibition of LDL oxidation by polyphenols could be related, at least in part, to a direct effect of the polyphenols on the LDL, since both quercetin and catechin were found to bind to the LDL particle via the formation of an ether bond. We thus conclude that dietary consumption by E° mice of red wine or its polyphenolic flavonoids quercetin and, to a lesser extent, catechin leads to attenuation in the development of the atherosclerotic lesion, and this effect is associated with reduced susceptibility of their LDL to oxidation and aggregation.
Common Genomic Variation in theAPOC3Promoter Associated With Variation in Plasma Lipoproteins
Authors: Hegele Robert A. , Connelly Philip W. , Hanley Anthony J. G. , Sun Fang , Harris Stewart B. , Zinman Bernard
Published: June 2011

AbstractWe hypothesized that common genomic variation that affected the expression and/or function of the products of theAPOC3,APOE,FABP2, andPON1genes would be associated with variation in biochemical phenotypes in a previously unstudied human sample. We determined genotypes of functional genomic variants ofAPOC3,APOE,FABP2, andPON1in 509 adult aboriginal Canadians from an isolated community in Northern Ontario. We tested for genotype associations with plasma lipoprotein traits. We found that (1) common variation at nucleotide −455 of theAPOC3promoter was associated with variation in plasma triglycerides (P=.006) and (2) common variation ofAPOEdetermining plasma isoforms of apo E was associated with variation in plasma apo B (P=.009). Analysis of subjects classed byAPOC3markers showed that homozygosity for presence of a C at nucleotide −455 and a T at nucleotide −482 was associated with significantly increased plasma triglycerides in both men and women. Furthermore, this allele was approximately twice as frequent in subjects within the highest quartile of plasma triglycerides as in subjects within the lowest quartile. Since the DNA variation detected by theAPOC3markers affects in vitro expression of the gene product, it is possible that the marker itself caused the associations. However, the associations could also have resulted from linkage disequilibrium with other functional variants inAPOC3or the closely linkedAPOA1and/orAPOA4genes.
Protein C Activation and Factor Va Inactivation on Human Umbilical Vein Endothelial Cells
Authors: Hockin Matthew F. , Kalafatis Michael , Shatos Marie , Mann Kenneth G.
Published: June 2011

Abstract
The inactivation of factor Va was examined on primary cultures of human umbilical vein endothelial cells (HUVECs), either after addition of activated protein C (APC) or after addition of α-thrombin and protein C (PC) zymogen. Factor Va proteolysis was visualized by Western blot analysis using a monoclonal antibody (αHVa
HC
No. 17) to the factor Va heavy chain (HC), and cofactor activity was followed both in a clotting assay using factor V–deficient plasma and by quantitation of prothrombinase function. APC generation was monitored using the substrate 6-(D-VPR)amino-1-naphthalenebutylsulfonamide (D-VPR-ANSNHC
4
H
9
), which permits quantitation of APC at 10 pmol/L. Addition of APC (5 nmol/L) to an adherent HUVEC monolayer (3.5×10
5
cells per well) resulted in a 75% inactivation of factor Va (20 nmol/L) within 10 minutes, with complete loss of cofactor activity within 2 hours. Measurements of the rate of cleavage at Arg
506
and Arg
306
in the presence and absence of the HUVEC monolayer indicated that the APC-dependent cleavage of the factor Va HC at Arg
506
was accelerated in the presence of HUVECs, while cleavage at Arg
306
was dependent on the presence of the HUVEC surface. Factor Va inactivation proceeded with initial cleavage of the factor Va HC at Arg
506
, generating an
M
r
75 000 species. Further proteolysis at Arg
306
generated an
M
r
30 000 product. When protein C (0.5 μmol/L), α-thrombin (1 nmol/L), and factor Va (20 nmol/L) were added to HUVECs an APC generation rate of 1.56±0.11×10
−14
mol/min per cell was observed. With APC generated in situ, cleavage at Arg
506
on the HUVEC surface is followed by cleavage at Arg
306
, generating
M
r
75 000 and
M
r
30 000 fragments, respectively. In addition, the appearance of two novel products derived from the factor Va HC are observed when thrombin is present on the HUVEC surface: the HC is processed through limited thrombin proteolysis to generate an
M
r
97 000 fragment, which is further processed by APC to generate an
M
r
43 000 fragment. NH
2
-terminal sequence analysis of the
M
r
97 000 fragment revealed that the thrombin cleavage occurs in the COOH-terminus of the intact factor Va HC since both the intact HC as well as the
M
r
97 000 fragment have the same sequence. Our data demonstrate that the inactivation of factor Va on the HUVEC surface, initiated either by APC addition or PC activation, follows a mechanism whereby cleavage is observed first at Arg
506
followed by a second cleavage at Arg
306
. The latter cleavage is dependent on the availability of the HUVEC surface. This mechanism of inactivation of factor Va is similar to that observed on synthetic phospholipid vesicles.
Common C-to-T Substitution at Position −480 of the Hepatic Lipase Promoter Associated With a Lowered Lipase Activity in Coronary Artery Disease Patients
Authors: Jansen Hans , Verhoeven Adrie J. M. , Weeks Lilian , Kastelein John J. P. , Halley Dicky J. J. , van den Ouweland Ans , Jukema J. Wouter , Seidell Jaap C. , Birkenhäger Jan C.
Published: June 2011

Abstract
We studied the molecular basis of low hepatic lipase (HL) activity in normolipidemic male patients with angiographically documented coronary artery disease (CAD). In 18 subjects with a lowered HL activity (<225 mU/mL), all nine exons of the HL gene and part of the promoter region (nucleotides −524 to +7) were sequenced. No structural mutations in the coding part of the HL gene were found, but 50% of the subjects showed a C-to-T substitution at nucleotide −480. Screening for the base substitution in 782 patients yielded an allele frequency of 0.213 (297 heterozygotes, 18 homozygotes). In a group of 316 nonsymptomatic control subjects, the allele frequency was 0.189, which is significantly less than in the CAD patients (
P
=.035). In the CAD patients, the C-to-T substitution was associated with a lowered lipase activity (heterozygotes −15%, homozygotes −20%). The patients were divided into quartiles on the basis of HL activity. Sixty percent (allele frequency 0.32) of the patients in the lowest quartile (HL activity <306 mU/mL) had the gene variant against 27% (allele frequency 0.14) in the highest quartile (HL activity >466 mU/mL). In the noncarriers, but not in the carriers, HL activity was related with plasma insulin, being increased at higher insulin concentration. Homozygous carriers had a significantly higher HDL cholesterol level than noncarriers (1.13±0.28 mmol/L versus 0.92±0.22 mmol/L,
P
<.02). Our results show that a C-to-T substitution at −480 of the HL promoter is associated with a lowered HL activity. The base substitution, or a closely linked gene variation, may contribute to the variation in HL activity and affect plasma lipoprotein metabolism.
Elevated Circulating Levels of Inflammatory Cytokines in Patients With Abdominal Aortic Aneurysm
Authors: Juvonen Jukka , Surcel Heljä-Marja , Satta Jari , Teppo Anna-Maija , Bloigu Aini , Syrjälä Hannu , Airaksinen Juhani , Leinonen Maija , Saikku Pekka , Juvonen Tatu
Published: June 2011

Abstract
The basic feature in the pathogenesis of abdominal aortic aneurysm (AAA) is the degradation of extracellular matrix components. This process is induced partly by cytokines secreted from inflammatory and mesenchymal cells. Circulating levels of inflammatory cytokines were studied in AAA patients and compared with subjects suffering from atherosclerotic disease only. Furthermore, the predictive value of cytokine concentrations was evaluated for aneurysm expansion rate. Circulating levels of interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were measured in 50 AAA patients (40 men, 10 women), 42 patients with coronary heart disease (CHD) (23 men, 19 women), and 38 controls whose angiogram was normal (17 men, 21 women). No differences in cytokine concentrations were found between the CHD patients and the controls. AAA disease was found to be associated with significantly higher IL- 1β and IL-6 concentrations in both male patients (median concentrations of 19.40 pmol/L and 6.45 pmol/L, respectively) and female patients (19.26 pmol/L and 7.99 pmol/L) than in either the CHD patients or the controls (
P
<.005). TNF-α levels were slightly higher in the AAA patients (1.64 pmol/L in the males and 1.59 pmol/L in the females) than in the other groups (
P
<.05). IFN-γ levels were elevated significantly in the female AAA patients (3.75 pmol/L) compared with levels found in the other female (
P
<.05) or male (
P
<.01) patient groups. The measured cytokine concentrations were not related to the size of the aneurysm or the maximal thickness of the thrombus within the aneurysm. IFN-γ concentration showed a significant positive correlation to the aneurysm expansion (
R
=.37,
P
<.02) and negative correlation to the concentration of aminoterminal propeptide of type III procollagen during 6-month follow up (
R
=−.42,
P
<.005). The results show that circulating levels of inflammatory cytokines are elevated in patients with AAA disease, suggesting that the production of these cytokines is increased in these patients compared with CHD patients and controls. Elevated INF-γ concentrations seem to predict an increased rate of expansion in AAA.
Effect of Phenotype on the Transcription of the Genes for Platelet-Derived Growth Factor (PDGF) Isoforms in Human Smooth Muscle Cells, Monocyte-Derived Macrophages, and Endothelial Cells In Vitro
Authors: Krettek Alexandra , Fager Gunnar , Lindmark Helena , Simonson Carolina , Lustig Florentyna
Published: June 2011

Abstract
Proliferation of arterial smooth muscle cells (ASMCs) contributes considerably to enlargement of the arterial wall during atherosclerosis. The platelet-derived growth factor (PDGF) is a well-known mitogen and chemoattractant for ASMCs. Quantitative reverse transcription–polymerase chain reaction showed that cells appearing in atherosclerotic lesions, such as ASMCs, endothelial cells, and monocytes/macrophages, expressed mRNAs for both PDGF A and B chains in vitro, with the highest expression in endothelial cells. On proliferation, ASMCs and endothelial cells upregulated PDGF A mRNA. Differentiation of macrophages increased the amount of both mRNAs. Thus, the regulation of PDGF A- and B-chain expression depends on cell types and phenotypic states of the cells, which have also been found in vivo in human atherosclerotic lesions. PDGF A can be produced as short and long isoforms. The latter binds with high affinity to glycosaminoglycans. Irrespective of phenotype, only the minor part of total PDGF A mRNA consisted of the long variant in ASMCs, while endothelial cells produced 40% of total PDGF A as the long form. The differentiation of macrophages increased the production of the long PDGF A mRNA from 10% to 40%. Thus, increasing numbers of stimulated cells in the atherosclerotic lesion may increase the transcription of PDGF isoforms, and particularly of the long PDGF A isoform. Together with increasing amounts of ASMC-derived proteoglycans in developing lesions, this may contribute to accumulation of PDGF in the arterial wall matrix, resulting in prolonged stimulation of ASMCs.
ChronicChlamydia pneumoniaeInfection Is Associated With a Serum Lipid Profile Known to Be a Risk Factor for Atherosclerosis
Authors: Laurila Aino , Bloigu Aini , Näyhä Simo , Hassi Juhani , Leinonen Maija , Saikku Pekka
Published: June 2011

Abstract Chlamydia pneumoniaeinfection has been associated with coronary heart disease. To evaluate the mechanisms of this association, we studied whether chronicC. pneumoniaeinfection affects serum lipid values similarly to acute infections. Triglyceride, total and HDL cholesterol concentrations, andC. pneumoniaeantibodies were measured from paired serum samples of 415 Finnish males taken 3 years apart. Chronic infection, defined as persistent IgG and IgA antibodies, was found in 20%, and the antibodies were negative (IgG<32 and IgA<16 in both samples) in 15% of the cases studied. The serum triglyceride and total cholesterol concentrations were higher in the subjects with a chronicC. pneumoniaeinfection than in the subjects with no antibodies (1.23 versus 1.03 mmol/L and 6.41 versus 6.31 mmol/L, respectively). The HDL cholesterol concentrations and the ratios of HDL cholesterol to total cholesterol were significantly decreased in the subjects with chronic infection (1.24 versus 1.36 mmol/L,P=.026; and 0.19 versus 0.22,P=.018, respectively). ChronicC. pneumoniaeinfection seems to be associated with a serum lipid profile considered to increase the risk of atherosclerosis. This finding supports the hypothesis that infections play a role in the pathogenesis of atherosclerosis.
Altered Transfer of Cholesteryl Esters and Phospholipids in Plasma From Alcohol Abusers
Authors: Liinamaa M. Johanna , Hannuksela Minna L. , Kesäniemi Y. Antero , Savolainen Markku J.
Published: June 2011

AbstractThe net mass transfer (NMT) of cholesteryl esters (CEs), triglycerides (TGs), and phospholipids (PLs) between lipoproteins was measured after incubation of fresh plasma for up to 2 hours from 18 male alcohol abusers and 17 male volunteer control subjects. In alcohol abusers the mean value of CE NMT was 3.7 nmol·mL−1·h−1from apolipoprotein B–containing lipoproteins (apoB-containing lipoproteins) to HDL and in control subjects 8.7 nmol · mL−1· h−1from HDL to apoB-containing lipoproteins. The NMT of PL was higher in alcohol abusers than in control subjects (35.0 vs 11.6 nmol·mL−1·h−1from apoB-containing lipoproteins to HDL, respectively), and plasma PL transfer protein (TP) activity was 33% higher (P<.05) in alcohol abusers than in control subjects. The lack of correlation between the NMTs and CETP and PLTP activities suggests that the NMT could more closely reflect the role of lipoprotein properties in reverse cholesterol transport in vivo, whereas in vitro activities reflect the total capacity of transfer but not its direction. The rate of CE NMT from HDL to apoB-containing lipoproteins was dependent on the VLDL TG concentration. Moreover, at low VLDL TG levels, the increased HDL cholesterol concentration in alcohol abusers reversed the direction of CE NMT. This situation could be reconstructed in the plasma of control subjects by adding autologous HDL or VLDL to mimic the lipoprotein profiles of the alcohol abusers. Addition of VLDL enhanced the CE NMT from HDL to apoB-containing lipoproteins, whereas addition of HDL had an opposite effect, and at higher HDL levels, even reversed the direction of CE NMT. In conclusion, the NMT of CE and PL in alcohol abusers differs from that in control subjects. The concentrations of HDL and VLDL seem to be the major determinants of the direction of CE NMT in alcohol abusers.
Vascular Superoxide Dismutase Deficiency Impairs Endothelial Vasodilator Function Through Direct Inactivation of Nitric Oxide and Increased Lipid Peroxidation
Authors: Lynch Sean M. , Frei Balz , Morrow Jason D. , Roberts L. Jackson , Xu Aiming , Jackson Terence , Reyna Ronald , Klevay Leslie M. , Vita Joseph A. , Keaney John F.
Published: June 2011

Abstract
Nitric oxide (NO) and superoxide are both constitutive products of the endothelium. Because NO is readily inactivated by superoxide, the bioactivity of endothelium-derived NO (EDNO) is dependent on local activity of superoxide dismutase (SOD). We examined the effects of chronic inhibition of copper-zinc SOD (CuZnSOD) using a rat model of dietary copper restriction. Male weanling Sprague-Dawley rats were fed a Cu-deficient diet and received either no Cu replacement (Cu-deficient) or Cu in the drinking water (Cu-sufficient). Compared with Cu-sufficient animals, Cu-deficiency was associated with a 68% reduction in CuZnSOD activity and a 58% increase in vascular superoxide as estimated by lucigenin chemiluminescence (both
P
<.05). Compared with Cu-sufficient animals, arterial relaxation in the thoracic aorta from Cu-deficient animals was 10-fold less sensitive to acetylcholine, a receptor-dependent EDNO agonist, but only 1.5-fold less sensitive to A23187, a receptor-independent EDNO agonist, and only 1.25-fold less sensitive to authentic NO (all
P
<.05). In contrast, acute inhibition of CuZnSOD with 10 mM diethyldithiocarbamate produced a more uniform reduction in sensitivity to acetylcholine (8-fold), A23187 (10-fold), and NO (4-fold; all
P
<.001). Cu-deficient animals demonstrated a 2.5-fold increase in plasma-esterified F
2
-isoprostanes, a stable marker of lipid peroxidation, that correlated inversely with arterial relaxation to acetylcholine (
R
=−.83;
P
<.0009) but not A23187 or authentic NO. From these findings, we conclude that chronic inhibition of CuZnSOD inhibits EDNO-mediated arterial relaxation through two mechanisms, one being direct inactivation of NO and the other being lipid peroxidation that preferentially interrupts receptor-mediated stimulation of EDNO.
Genotype Distribution of Estrogen Receptor Polymorphisms in Men and Postmenopausal Women From Healthy and Coronary Populations and Its Relation to Serum Lipid Levels
Authors: Matsubara Yumiko , Murata Mitsuru , Kawano Koichi , Zama Takeru , Aoki Nobuo , Yoshino Hideaki , Watanabe Gentaro , Ishikawa Kyozo , Ikeda Yasuo
Published: June 2011

AbstractThe cardiovascular protective effects of estrogen are known to be mediated by its beneficial effects on lipid metabolism and its direct actions on the vessel wall. The latter can be mediated by a specific receptor for estrogen present on smooth muscle cells and endothelial cells. The gene for the receptor (the classic estrogen receptor [ER]) has three known polymorphisms,PvuII,XbaI, and B-variant polymorphisms, which are reportedly associated with receptor expression and altered receptor function and with some disorders including breast cancer, hypertension, and spontaneous abortion. However, the significance of genetic variations of the ER in vascular diseases has not been reported. We have examined the association between coronary artery disease (CAD) and the three polymorphisms in ER. Genotypes (P1/P2, X1/X2, and B-wild type/B-variant type) were determined in 87 men and postmenopausal women with myocardial infarction or angina pectoris whose lesions were confirmed by coronary angiography, as well as from 94 control individuals from the general population with no coronary heart disease and normal resting ECG. For B-variant polymorphism, all individuals examined had B-wild type, which contrasts with the reported allele frequency for B-variant type (0.1) in the white population. Genotype distributions and allele frequencies ofPvuII orXbaI polymorphisms were not significantly different between control subjects and patients (P>.05 forPvuII orXbaI genotypes;P>.05 forPvuII orXbaI allele frequencies). When the allele frequencies were analyzed separately by sex, there was still no statistically significant difference for both polymorphisms (P>.05 for men;P>.05 for women). No association was found between the polymorphisms and the angiographic severity of CAD. Total cholesterol, triglyceride, or HDL-cholesterol levels were not significantly different among ER genotypes. These findings suggest that the three polymorphisms in ER are not associated with the prevalence and severity of CAD and that the polymorphisms are unrelated to the serum lipid levels in control subjects and patients.
Upregulation of Connexin43 Gap Junctions Between Smooth Muscle Cells After Balloon Catheter Injury in the Rat Carotid Artery
Authors: Yeh Hung-I , Lupu Florea , Dupont Emmanuel , Severs Nicholas J.
Published: June 2011

Abstract
Phenotypic transformation of smooth muscle cells (SMCs) to the synthetic state in vitro and in human coronary atherosclerosis is reported to be associated with upregulation of connexin43 gap junctions. To determine whether cellular interactions mediated by gap junctions participate in the phenotypic transformation of SMCs in arterial injury and disease in general and to establish the spatial and temporal pattern of any such change in relation to neointimal development, we investigated SMC connexin43 gap junction expression during vascular healing in the rat carotid artery after balloon catheter injury. Quantitative immunoconfocal microscopy was applied to localize and to quantify connexin43 gap junctions 1, 3, 9, and 14 days after injury. Parallel studies were conducted by electron microscopy (direct morphological demonstration of SMC gap junctions) and immunoconfocal microscopy (localization of altered actin expression). Synthetic-state SMCs in the neointima (first apparent from 9 days postinjury) revealed abundant expression of gap junctions, with levels of immunodetectable connexin43 threefold greater than those of medial cells. However, the first detectable changes were found in the media, before neointimal formation; at 1 to 3 days postinjury, an increase in SMC gap junction expression was apparent in the innermost (subluminal) zone, the major site from which the cells subsequently found in the neointima are recruited. We conclude that upregulation of connexin43 gap junctions is intimately linked to SMC phenotypic transition and that interactions mediated by gap junctions may be a hitherto unrecognized contributor to the cellular mechanisms underlying the vascular response to injury.
Role of Hemostatic Risk Factors for Restenosis in Peripheral Arterial Occlusive Disease After Transluminal Angioplasty
Authors: Tschöpl Martin , Tsakiris Dimitrios A. , Marbet German A. , Labs Karl-Heinz , Jäger Kurt
Published: June 2011

Abstract
In a prospective study, the role of various hemostatic factors known to be associated with thrombotic risk was investigated in 71 patients with peripheral arterial occlusive disease (PAOD, stages II through IV, Fontaine; aged 68±13 years). Laboratory investigations were done before; 1, 24, and 48 hours after; and 3 and 6 months after percutaneous transluminal angioplasty (PTA). Thirty of 71 (42.3%) patients developed restenosis (>50% reduction of the lumen diameter) at the site of PTA within 6 months, verified by color-coded duplex sonography. Significantly increased levels of thrombin–antithrombin III complexes (
P
<.01), prothrombin fragments 1+2 (
P
<.01), and
d
-dimers (
P
<.01) were found 1 hour, as well as 24 to 48 hours, after PTA. Fibrinogen (
P
<.01) and von Willebrand factor (
P
<.01) were significantly higher 48 hours after PTA. Restenotic patients as a whole had higher plasma fibrinogen (3.46±1.12 versus 2.95±0.62 g/L,
P
<.01) and C-reactive protein (25.4±46.7 versus 7.9±6.9 mg/L,
P
<.05) at baseline, as well as higher fibrinogen (
P
<.05) and prothrombin fragments 1+2 (
P
<.01) during months 3 to 6 after PTA. There was a nonsignificant tendency for higher values of von Willebrand factor (206±98% versus 184±100%,
P
=.2) at baseline in patients with restenosis, whereas tissue plasminogen activator, plasminogen activator inhibitor, coagulation screening tests, blood cell counts, and serum lipids showed no significant difference between the two groups. The relative risk for developing restenosis within 6 months while having high fibrinogen (>2.8 g/L) or C-reactive protein at baseline was 2.80 (95% CI: 1.30–6.02,
P
<.01) and 1.96 (95% CI: 1.07–3.58,
P
<.05), respectively. Patients with critical limb ischemia (stage III/IV, Fontaine) had significantly higher fibrinogen and von Willebrand factor at repeated points of time, as well as significantly higher C-reactive protein and lower creatinine clearance at entry. In the logistic regression risk factor analysis, baseline plasma fibrinogen, C-reactive protein concentration, and the severity of the arterial disease were significantly predictive of restenosis. Our results indicate that high procoagulant factors and persistent thrombin generation of the hemostatic system might promote restenosis, particularly in patients with extended atherosclerosis. This finding suggests that new treatment strategies should be taken under consideration for patients with PAOD and PTA.
In Vivo Formation of 8-Epi-Prostaglandin F
2α
Is Increased in Hypercholesterolemia
Authors: Davi Giovanni , Alessandrini Paola , Mezzetti Andrea , Minotti Giorgio , Bucciarelli Tonino , Costantini Fabrizio , Cipollone Francesco , Bon Gabriele Bittolo , Ciabattoni Giovanni , Patrono Carlo
Published: June 2011

Abstract
F
2
-isoprostanes are bioactive prostaglandin (PG) -like compounds that are produced from arachidonic acid through a nonenzymatic process of lipid peroxidation catalyzed by oxygen free-radicals. 8-Epi-PGF
2α
may amplify the platelet response to agonists, circulates in plasma, and is excreted in urine. We examined the hypothesis that the formation of 8-epi-PGF
2α
is altered in patients with hypercholesterolemia and contributes to platelet activation in this setting. Urine samples were obtained from 40 hypercholesterolemic patients and 40 age- and sex-matched control subjects for measurement of immunoreactive 8-epi-PGF
2α
. Urinary excretion of 11-dehydro-thromboxane (TX) B
2
, a major metabolite of TXA
2
, was measured as an in vivo index of platelet activation. Low-dose aspirin, indobufen, and vitamin E were used to investigate the mechanism of formation and effects of 8-epi-PGF
2α
on platelet activation. Urinary 8-epi-PGF
2α
was significantly (
P
=.0001) higher in hypercholesterolemic patients than in control subjects: 473±305 versus 205±95 pg/mg creatinine. Its rate of excretion was inversely related to the vitamin E content of LDL and showed a positive correlation with urinary 11-dehydro-TXB
2
. Urinary 8-epi-PGF
2α
was unchanged after 2-week dosing with aspirin and indobufen despite complete suppression of TX metabolite excretion. Vitamin E supplementation was associated with dose-dependent reductions in both urinary 8-epi-PGF
2α
and 11-dehydro-TXB
2
by 34% to 36% and 47% to 58% at 100 and 600 mg daily, respectively. We conclude that the in vivo formation of the F
2
-isoprostane 8-epi-PGF
2α
is enhanced in the vast majority of patients with hypercholesterolemia. This provides an aspirin-insensitive mechanism possibly linking lipid peroxidation to amplification of platelet activation in the setting of hypercholesterolemia. Dose-dependent suppression of enhanced 8-epi-PGF
2α
formation by vitamin E supplementation may contribute to the beneficial effects of antioxidant treatment.
Familial Resemblance of Plasma Lipids, Lipoproteins and Postheparin Lipoprotein and Hepatic Lipases in the HERITAGE Family Study
Authors: Pérusse Louis , Rice Treva , Després J. P. , Bergeron Jean , Province Michael A. , Gagnon Jacques , Leon Arthur S. , Rao D. C. , Skinner James S. , Wilmore Jack H. , Bouchard Claude
Published: June 2011

AbstractThe familial aggregation of lipids and lipoproteins and plasma postheparin triglyceride lipases was investigated in 86 Caucasian families participating in the HERITAGE Family study, a study investigating the role of genetic factors in the adaptation to exercise training and its relationships with cardiovascular disease risk factors. Accordingly, sedentary subjects were recruited, tested for a battery of measurements, exercise trained for 20 weeks, and were re-measured. The present report includes plasma levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides, and postheparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activities measured in 437 sedentary individuals (171 parents and 266 adult offspring) before training. Significant familial resemblance was observed for all the age-adjusted phenotypes. The pattern of familial correlations reveals no spouse correlations but significant parent-offspring and sibling correlations for total cholesterol, HDL-cholesterol and LDL-cholesterol with heritability (h2) estimates of 62%, 83%, and 50%, respectively. For plasma triglyceride concentrations (h2=55%) and HL activity (h2=40%), significant spouse correlations were found in addition to parent-offspring and sibling correlations, suggesting that common familial environment in addition to genetic factors contribute to the familial resemblance. For plasma LPL activity, there was no spouse correlation, but sex differences were found in the familial correlations with higher heritabilities in female pairs (h2=76%) compared to male pairs (h2=30%) and opposite-sex pairs (h2=44%). These results confirm the findings of previous family studies showing that genetic factors are major determinants of the familial resemblance in plasma lipids and lipoproteins and suggest the presence of sex differences in the heritability of postheparin LPL activity.
Endothelium-Dependent Vasodilation and Tissue-Type Plasminogen Activator Release in Borderline Hypertension
Authors: Jern Sverker , Wall Ulrika , Bergbrant Anders , Selin-Sjögren Lena , Jern Christina
Published: June 2011

Abstract
We recently showed that muscarinic receptor stimulation causes a marked increase in the net release of tissue-type plasminogen activator (TPA) antigen and activity across the human forearm in vivo, in conjunction with endothelium-dependent vasodilation. Because hypertension has been associated with endothelial dysfunction, the aim of the study was to compare forearm TPA release and vasodilation in response to muscarinic stimulation in normotensive (NC) and borderline hypertensive (BH) subjects. The study was performed in 10 apparently healthy young men with BH and 10 male NC subjects. Methacholine (MCh: 0.1, 0.8, and 4.0 μg/min) and sodium nitroprusside (SNP: 0.5, 2.5, and 10 μg/min) were administered in randomized order as double-blind, stepwise, intrabrachial artery infusions. Forearm blood flow was assessed by plethysmography. Net release/uptake was calculated as the product of the arteriovenous concentration gradient and forearm plasma flow. Vasodilator responses to MCh were similar in both groups (
P
=NS), whereas the decrease in forearm vascular resistance in response to SNP was somewhat less in BH subjects (
P
=.005). At rest, both groups showed a significant arteriovenous gradient and net release of TPA antigen across the forearm (
P
<.05 throughout). However, in contrast to the significant net increment in TPA activity across the forearm in the NC group (
P
<.018), BH subjects had no basal forearm increment in TPA activity (NC vs BH,
P
=.006). Arterial and venous plasma levels of plasminogen activator inhibitor 1 (PAI-1) antigen and activity were higher in BH subjects (
P
≤.05 throughout), who in contrast to NC subjects, also had a significant forearm net release of PAI-1 antigen (
P
=.006). Across the whole group, there was a significant inverse relation between arterial PAI-1 antigen levels and increment in TPA activity across the forearm (
r
=−.57,
P
=.008) but no relation to TPA antigen release. In response to MCh infusion, both the net release of TPA antigen and increment in TPA activity increased markedly and to similar extents in both groups (
P
<.01 throughout). SNP infusion had no effect on either TPA antigen release or increment in TPA activity in the NC group but elicited a significant net release of TPA antigen and increase in TPA activity in the BH group (
P
<.05). Both circulating levels and local release of PAI-1 antigen were significantly correlated to fasting plasma insulin. Endothelium-dependent vasodilation and endothelial TPA release in response to muscarinic receptor stimulation were preserved in BH subjects. At rest, BH subjects had higher circulating PAI-1 antigen levels and a corresponding decrease in circulating levels and local increment of TPA activity. In contrast to NC subjects, BH subjects responded with a TPA release also in response to increased flow, which may indicate an enhanced endothelial cell responsiveness to fluid shear stress.
Effect of Human Recombinant Interleukin-6 and Interleukin-8 on Monocyte Procoagulant Activity
Authors: Neumann Franz-Josef , Ott Ilka , Marx Nikolaus , Luther Thomas , Kenngott Silke , Gawaz Meinrad , Kotzsch Mathias , Schömig Albert
Published: June 2011

AbstractInterleukin (IL)-6 and IL-8 are important regulators of inflammatory responses in myocardial infarction. Induction of monocyte procoagulant activity (PCA) by these cytokines could present a mechanism that links inflammatory responses to thrombotic events. We therefore investigated the effect of IL-6 and IL-8 on monocyte tissue factor (TF) expression. Recombinant human IL-6 and IL-8 caused a time- and dose-dependent increase in PCA (recalcification time) of monocytic U937 cells and of mononuclear leukocytes. Using blocking anti-TF monoclonal antibodies and factor VII–deficient control plasma, this PCA was shown to be TF dependent. Compared with unstimulated cells, mononuclear cell PCA increased by 4.5-fold to 17±2 mU/5×105cells after exposure to 100 ng/L IL-6 for 4 hours and by 6.6-fold to 27±4 mU/5×105cells after exposure to IL-8 under the same conditions. Northern blot analysis showed an increase in TF mRNA after stimulation with IL-6 or IL-8 for 2 hours, and after 4 hours an increase in cellular TF protein content was found by immunoassay. Flow cytometry demonstrated that IL-6 and IL-8 induced an increase in TF surface expression on monocytes. Thus, IL-6 and IL-8 induce monocyte PCA by increasing mRNA, protein content, and surface expression of TF.