bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Mutant, ApoA-I Nichinan (Glu235→0), Is Associated With Low HDL Cholesterol Levels and Decreased Cholesterol Efflux From Cells
Authors: Han Hua , Sasaki Jun , Matsunaga Akira , Hakamata Hideki , Huang Wei , Ageta Masato , Taguchi Toshifumi , Koga Takafumi , Kugi Mari , Horiuchi Seikoh , Arakawa Kikuo
Published: June 2011

Abstract—A novel variant of apolipoprotein (apo) A-I associated with low high density lipoprotein (HDL) cholesterolemia has been identified in a Japanese family during screening for apoA-I variants by isoelectric focusing (IEF) gel analysis. ApoA-I (Glu235→0) Nichinan was caused by a 3-bp deletion of nucleotides 1998 through 2000 in exon 4 of the apoA-I gene. Four subjects in the family were heterozygous carriers for this mutation; the mean plasma concentrations of apoA-I and HDL cholesterol of affected family members were 30% and 32% lower, respectively, than those of unaffected family members. There were no differences in the levels of very low density lipoprotein and low density lipoprotein cholesterol, triglycerides, and other apolipoproteins between the carriers and the noncarrier family members. In the proband, plasma lecithin:cholesterol acyltransferase activity was normal. Functional consequences of the mutation were examined by expressing the mutated and wild-type proapoA-I cDNAs inEscherichiacoli. Cholesterol efflux to recombinant proapoA-I Nichinan from mouse peritoneal macrophages loaded with [3H]cholesterol-labeled acetylated low density lipoprotein was decreased by 54% when compared that of normal recombinant proapoA-I. In vivo turnover studies in normal rabbits demonstrated that the recombinant proapoA-I Nichinan was rapidly cleared (22% faster) compared with normal recombinant proapoA-I. We conclude that apoA-I (Glu235→0) Nichinan induced a critical structural change in the carboxyl-terminal domain of apoA-I for cellular cholesterol efflux and increased the catabolism of apoA-I, resulting in low HDL cholesterol levels.
The Natural Course of Atherosclerosis
Authors: Kiechl Stefan , Willeit Johann
Published: June 2011

Abstract—The natural course of early atherogenesis is not well established. The current prospective survey was designed to monitor 5-year changes in carotid atherosclerosis in a large, stratified random sample of the general population using high-resolution duplex ultrasound (Bruneck Study). Incidence rates of carotid atherosclerosis ranged from near zero to 184 per 1000 person-years. Most atherosclerotic lesions developed at sites with enhanced wall thickness. Incidence of atherosclerosis in premenopausal women was less than half of that observed in men of equal age. The sex difference disappeared within 5 years after menopause and may possibly be attributed to sex variations in body iron stores. Preexisting atherosclerotic lesions may experience 1 of 2 different types of disease progression. 1) The first main type of plaque growth causing nonstenotic or diffuse dilative atherosclerosis was characterized by slow and continuous plaque extension, which usually affected several lesions simultaneously and did not primarily focus on the carotid bifurcation. This step-by-step process relied on a cumulative exposure to well-known risk factors such as hyper-lipidemia. Compensatory enlargement of the artery at the site of active atherosclerosis effectively preserved a (near) normal lumen. 2) The second main type of plaque growth was characterized by occasional prominent increases in lesion size. This process primarily occurred in the internal carotid artery and was mediated by procoagulant risk factors in a way that peak levels were relevant rather than cumulative exposure. As the main underlying pathomechanism, atherothrombosis may be hypothesized. Marked increases in plaque size and insufficient vascular remodeling acted synergistically in producing a significant compromise of the lumen. The current study provides novel insights into the natural course of early carotid atherosclerosis, thereby focusing on disease incidence and various types of spontaneous disease progression. Nonstenotic or diffuse dilating atherosclerosis and focal stenotic disease were found to constitute epidemiologically and etiologically distinct disease entities that develop and proceed independently of each other.
Monocyte Chemoattractant Protein-1 Accelerates Atherosclerosis in Apolipoprotein E-Deficient Mice
Authors: Aiello Robert J. , Bourassa Patricia-Ann K. , Lindsey Saralyn , Weng Weifan , Natoli Edward , Rollins Barrett J. , Milos Patrice M.
Published: June 2011

Abstract—The pro-inflammatory chemokine, monocyte chemoattractant protein-1 (MCP-1), plays a fundamental role in monocyte recruitment and has been implicated as a contributing factor to atherosclerosis. The predominant cell types within the vessel wall—endothelial cells, smooth muscle cells, and macrophages—all contribute to overexpression of MCP-1 in atherosclerotic tissue. In this report we assess the role of MCP-1 expression by leukocytes on lesion progression in a murine model susceptible to atherosclerosis. Bone marrow cells from mice overexpressing a murine MCP-1 transgene on a background of apoE-deficiency or from control mice were transplanted into irradiated apoE-knockout mice. After repopulation of apoE-knockout mice with bone marrow containing the MCP-1 transgene, macrophages expressing the MCP-1 transgene were found in several tissues, including the aorta. Qualitative assessment of atherosclerosis in these mice revealed increased lipid staining, a 3-fold (P<0.001) increase in the amount of oxidized lipid, and increased immunostaining for macrophage cell surface markers with anti-F4/80 and anti-CD11b antibodies. There were no differences in plasma lipids, plasma lipoprotein profiles, or body weight between the 2 groups. These results provide the first direct evidence that MCP-1 expression by leukocytes, predominately macrophages, increases the progression of atherosclerosis by increasing both macrophage numbers and oxidized lipid accumulation.
Effects of Fibrate Compounds on Expression of Plasminogen Activator Inhibitor-1 by Cultured Endothelial Cells
Authors: Nilsson Lennart , Takemura Toshiya , Eriksson Per , Hamsten Anders
Published: June 2011

Abstract
—The consistent positive correlation between triglyceride and plasminogen activator inhibitor-1 (PAI-1) levels in plasma and the fact that very low density lipoprotein (VLDL) induces secretion of PAI-1 from cultured human umbilical vein endothelial cells (HUVECs) and human hepatoblastoma cells have raised the question of whether fibrate treatment, the main effect of which is a profound lowering of plasma concentrations of VLDL, might improve fibrinolytic function by reducing the plasma levels of PAI-1. However, the findings of controlled clinical trials using various fibrate compounds have been discrepant. ECs express PAI-1 under normal conditions in humans. We therefore examined the effects of several fibrate compounds on PAI-1 expression and secretion by cultured HUVECs and the HUVEC-derived cell line EA.hy926. All fibrate compounds examined had significant effects on PAI-1 gene transcription in the EA.hy926 cells. Low concentrations of clofibric acid and bezafibrate increased PAI-1 transcription and secretion, whereas Wy-14643 increased PAI-1 synthesis in a dose-dependent way. In contrast, both fenofibric acid and gemfibrozil markedly decreased PAI-1 transcription and secretion from HUVECs and EA.hy926 cells. Thus, stimulation of the transcriptional activity of the PAI-1 gene by some fibrates is linked to increased secretion of PAI-1 protein by the cells, whereas the opposite effects occur with other fibrate compounds. Whether the different effects on PAI-1 transcription and secretion by ECs in vitro also reflect differences in treatment effects on the regulation of plasma PAI-1 activity in vivo will have to be determined in larger-scale, controlled clinical trials.
Cross-Sectional Study of Soluble Intercellular Adhesion Molecule-1 and Cardiovascular Risk Factors in Apparently Healthy Men
Authors: Rohde Luis E. P. , Hennekens Charles H. , Ridker Paul M.
Published: June 2011

Abstract
—An elevated plasma concentration of the soluble intercellular adhesion molecule-1 (sICAM-1) is associated with increased risk for future coronary events. However, data exploring the interrelations of sICAM-1 with known cardiovascular risk factors are sparse. We determined sICAM-1 levels in 948 middle-aged men with no prior history of cardiovascular disease. sICAM-1 levels increased with age (
P
<0.001) and were significantly associated with smoking (
P
<0.001), hypertension (
P
<0.05), and frequent alcohol consumption (
P
=0.006). Positive correlations were observed between sICAM-1 and triglycerides (
r
=0.15;
P
<0.001), fibrinogen (
r
=0.21;
P
<0.001), tissue-type plasminogen activator antigen (
r
=0.17;
P
<0.001), and total homocysteine (
r
=0.09;
P
=0.02); whereas a negative correlation was observed for high density lipoprotein cholesterol (
r
=−0.15;
P
<0.001). Overall, plasma concentrations of sICAM-1 increased with increasing prevalence of usual cardiovascular risk factors; mean plasma concentrations were 231, 236, 245, 257, and 312 ng/mL for those subjects with 0, 1, 2, 3, and >4 risk factors, respectively (
P
<0.01 for trend). In multivariate analysis, age, smoking status, diabetes, systolic blood pressure, positive family history of coronary disease, and serum levels of total homocysteine and fibrinogen were all independently associated with sICAM-1 levels (all
P
≤0.05). sICAM-1 levels are associated with several established cardiovascular risk factors. Further studies will be needed to evaluate whether these associations reflect the role of sICAM-1 as a marker of preclinical atherosclerosis, and whether such interrelations might have a causal basis.
Aortic Connexin43 Is Decreased During Hypertension Induced by Inhibition of Nitric Oxide Synthase
Authors: Haefliger Jacques-Antoine , Meda Paolo , Formenton Andrea , Wiesel Philippe , Zanchi Anne , Brunner Hans R. , Nicod Pascal , Hayoz Daniel
Published: June 2011

Abstract
—Connexin43 (Cx43), the predominant gap junction protein in vessels and heart, is involved in the control of cell-to-cell communication and is thought to modulate the contractility of the vascular wall and the electrical coupling of cardiac myocytes. We have investigated the effects of arterial hypertension induced by inhibition of nitric oxide synthase on the expression of Cx43 in aorta and heart as well as on the distensibility of the carotid artery. Administration of 0.4 g/L
N
G
-nitro-
l
-arginine methyl ester (L-NAME) to rats in their drinking water for 4 weeks increased intra-arterial mean blood pressure, wall thickness of aorta and carotid artery (25%), and heart weight (17%). Analysis of heart mRNA demonstrated increased expression of the fetal skeletal α-actin and of atrial natriuretic peptide but not of Cx43. In contrast, Cx43 mRNA and protein were decreased by 50% in the aortas of L-NAME–treated rats that did not show increased carotid distensibility. Because these data contrasted with those obtained in the 2-kidney, 1 clip model of rat hypertension, which is characterized by increased arterial distensibility and Cx43 expression in aorta, we investigated by Western blot analysis the posttranslational modifications of Cx43. We found that Cx43 was more phosphorylated in the aorta of 2-kidney, 1 clip rats than in that of L-NAME or control rats, which indicated a differential regulation of Cx43 in different models of hypertension. The data suggest that the cell-to-cell communication mediated by Cx43 channels may help regulate the elasticity of the vascular wall.
Increased Secretion of Basement Membrane–Degrading Metalloproteinases in Pig Saphenous Vein Into Carotid Artery Interposition Grafts
Authors: Southgate Kay M. , Mehta Dheeraj , Izzat Mohammed B. , Newby Andrew C. , Angelini Gianni D.
Published: June 2011

Abstract—Late saphenous vein bypass graft failure in humans involves medial and neointimal thickening as the result of migration and proliferation of vascular smooth muscle cells (SMCs). Recent work on angioplasty indicates that basement membrane–degrading metalloproteinases (MMPs) cooperate with growth factors to mediate SMC migration and proliferation. We sought evidence here for a similar role in experimental vein grafts in pigs. Tissue levels and secretion of MMP-2 and MMP-9 were compared by quantitative zymography in veins and grafts removed 2 to 168 days after implantation. Pro and active forms of MMP-2 were present in veins, but levels were increased in vein grafts after 7 days (4- and 6-fold, respectively) and 28 days (3-fold for both), returning to values in veins after 168 days. MMP-9 was not detected in veins, was increased in grafts after 2 days, further increased after 7 days (6-fold) and 28 days (15-fold), and declined to undetectable levels by 168 days. Immunocytochemistry detected increased expression of MMP-2 and MMP-9 with the same time course. MMP-2 was widely distributed, whereas MMP-9 was concentrated in highly proliferative SMCs at the superficial layers of the thickened neointima. We conclude that increased production of the basement membrane–degrading MMP-2 and MMP-9 spanned the period of neointima formation and SMC proliferation in experimental vein grafts. MMPs therefore constitute new therapeutic targets for reducing late vein graft failure.
Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) Modulates the Expression of Type VIII Collagen mRNA in Vascular Smooth Muscle Cells and Both Are Codistributed During Atherogenesis
Authors: Plenz Gabriele , Reichenberg Stefan , Koenig Carsten , Rauterberg Jürgen , Deng Mario C. , Baba Hideo A. , Robenek Horst
Published: June 2011

Abstract
—The expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) and type VIII collagen was studied in human arteries. GM-CSF and type VIII collagen were codistributed in all layers of the walls of nondiseased arteries and during early atherogenesis with up to type V lesions. The number of cells expressing both mRNAs increased during the development of advanced atherosclerotic lesions. Whereas type VIII collagen expression increased further in complicated lesions, GM-CSF was downregulated. During early atherogenesis smooth muscle cells (SMC) and endothelial cells were the principal GM-CSF and type VIII collagen mRNA-expressing cell types. In advanced lesions monocytes/macrophages also expressed the mRNAs. In complicated lesions the number of GM-CSF mRNA-expressing SMC was markedly reduced. In in vitro experiments transforming growth factor-β1, platelet-derived growth factor, and GM-CSF, but not basic fibroblast growth factor, stimulated the expression of type VIII collagen mRNA by SMC. GM-CSF transiently stimulated type VIII collagen transcription. Thus GM-CSF is a prominent component of the regulatory network influencing collagen metabolism during atherogenesis. By modulating the synthesis of type VIII collagen in SMC, GM-CSF may influence the course of plaque development and may govern processes such as cell movement, plaque stability, and thrombus organization.
A Transcriptional Repressor of the Tissue Factor Gene in Endothelial Cells
Authors: Holzmüller Harry , Moll Thomas , Hofer-Warbinek Renate , Mechtcheriakova Diana , Binder Bernd R. , Hofer Erhard
Published: June 2011

Abstract
—Tissue factor, the high-affinity receptor and cofactor for the plasma serine protease VII/VIIa, is the primary cellular initiator of the blood coagulation cascade. Inside the vasculature, expression of the tissue factor gene must be tightly controlled. Whereas the endothelium normally does not express tissue factor, on stimulation with inflammatory cytokines or endotoxin the gene is transcriptionally upregulated leading to a procoagulant state. We have now detected a repressive cis-acting element in the tissue factor promoter that downmodulates tissue factor transcription in endothelial cells. In reporter gene assays, deletion of this element leads to an increase of tissue factor transcription and insertion of a trimerized site reduces transcription. Specific protein/DNA complexes are formed on the element with nuclear extracts in electrophoretic mobility shift assays and cross-linking of the proteins followed by SDS-PAGE detects the presence of at least 2 subunits of ≈40 and 60 kDa, respectively. After transfection of different cell types with the reporter genes, the suppressive effect of the element can only be revealed in endothelial cells. These data suggest that this element represents a novel transcription factor target sequence that functions to suppress expression of the tissue factor gene, preferentially in endothelial cells thereby supporting a noncoagulant state.
Angiotensin II Stimulates Collagen Synthesis in Human Vascular Smooth Muscle Cells
Authors: Ford Carol M. , Li Shaohua , Pickering J. Geoffrey
Published: June 2011

Abstract—Angiotensin II is an established regulator of vascular tone and smooth muscle cell (SMC) growth. However, there are little data about its effect on collagen synthesis by SMCs and none regarding the mechanism of such an effect. We studied the effect of angiotensin II on collagen production by human arterial SMCs, using uptake of [3H]proline into collagenase-digestible proteins, and by ribonuclease protection assay for mRNA encoding the proα1 chain of type I collagen, the major collagen in arteries. This revealed a dose-dependent increase in relative collagen synthesis rate and a dose-dependent increase in proα1(I) collagen mRNA abundance, with the half-maximal effect at 1.7 nmol/L. Angiotensin II–stimulated collagen expression was associated with a 6-fold increase in transforming growth factor-β (TGF-β) production and was inhibited by a neutralizing antibody to TGF-β. Both collagen production and TGF-β release were inhibited by the AT1-specific antagonist, losartan, but not by the AT2receptor antagonist, PD123319. To determined if tyrosine phosphorylation was functionally linked to collagen synthesis, we studied the effect of 2 mechanistically distinct inhibitors of tyrosine kinase, genistein, and tyrphostin A25. These inhibitors abrogated angiotensin II–mediated procollagen mRNA expression and angiotensin II–mediated TGF-β production, whereas the inactive homolog tyrphostin A1 had no effect. We conclude that angiotensin II stimulates collagen production in human arterial SMCs via the AT1receptor and an autocrine loop of TGF-β, induction of which requires tyrosine phosphorylation.
Noncollagenous Bone Matrix Proteins, Calcification, and Thrombosis in Carotid Artery Atherosclerosis
Authors: Bini Alessandra , Mann Kenneth G. , Kudryk Bohdan J. , Schoen Frederick J.
Published: June 2011

Abstract—Advanced atherosclerosis is often associated with dystrophic calcification, which may contribute to plaque rupture and thrombosis. In this work, the localization and association of the noncollagenous bone matrix proteins osteonectin, osteopontin, and osteocalcin with calcification, lipoproteins, thrombus/hemorrhage (T/H), and matrix metalloproteinases (MMPs) in human carotid arteries from endarterectomy samples have been determined. According to the recent American Heart Association classification, 6 of the advanced lesions studied were type V (fibroatheroma) and 16 type VI (complicated). Osteonectin, osteocalcin, and osteopontin were identified by monoclonal antibodies IIIA3A8, G12, and MPIIIB101and antiserum LF-123. Apolipoprotein (apo) AI, B, and E; lipoprotein(a); fibrinogen; fibrin; fragment D/D-dimer; MMP-2 (gelatinase A); and MMP-3 (stromelysin-1) were identified with previously characterized antibodies. Calcium phosphate deposits (von Kossa’s stain) were present in 82% of samples (3 type V and 15 type VI). Osteonectin was localized in endothelial cells, SMCs, and macrophages and was associated with calcium deposits in 33% of type V and 88% of type VI lesions. Osteopontin was distributed similarly to osteonectin and was associated with calcium deposits in 50% of type V and 94% of type VI lesions. Osteocalcin was localized in large calcified areas only (in 17% of type V and 38% of type VI lesions). ApoB colocalized with cholesterol crystals and calcium deposits. Lipoprotein(a) was localized in the intima, subintima, and plaque shoulder. Fibrin (T/H) colocalized with bone matrix proteins in 33% of type V and 69% of type VI lesions. MMP-3 was cytoplasmic in most cells and colocalized with calcium and fibrin deposits. MMP-2 was less often associated with calcification. The results of this study show that osteonectin, osteopontin, and osteocalcin colocalized with calcium deposits with apoB, fibrin, and MMP-3 in advanced, symptomatic carotid lesions. These data suggest that the occurrence of T/H might contribute to dystrophic arterial calcification in the progression and complications of atherosclerosis.
Dysfunction of Nitric Oxide Mediation in Isolated Rat Arterioles With Methionine Diet–Induced Hyperhomocysteinemia
Authors: Ungvari Zoltan , Pacher Pal , Rischák Katalin , Szollár Lajos , Koller Akos
Published: June 2011

Abstract
—In humans, increased plasma homocysteine (Hcy) has been shown to be correlated with occlusive arterial diseases and atherosclerosis. Studies of isolated conductance vessels of experimental animals suggest that Hcy may interfere with local vasoregulatory mechanisms, yet the effect of hyperhomocysteinemia (HHcy) on the function of microvessels, such as skeletal muscle arterioles, has not been investigated. Male Wistar rats were divided into 2 groups: control rats (C; plasma Hcy, 7.1±0.3 μmol/L; n=25), and rats made HHcy by 1 g/kg body weight daily intake of methionine in the drinking water for 4 weeks (plasma Hcy, 23.6±2.9 μmol/L;
P
<0.01 versus C; n=25). First-order arterioles (≈130 μm in diameter) were isolated from gracilis muscle, cannulated, and pressurized (80 mm Hg, no-flow conditions). Changes in diameter were observed by videomicroscopy. Arteriolar constrictions to norepinephrine (NE; 3×10
−7
mol/L) were significantly (
P
<0.01) greater in HHcy compared with C rats (C, 37.7±4.9%; HHcy, 59.5±5.2%). Removal of the endothelium (-E) augmented NE-induced constrictions only in arterioles from C rats, whereas it had no effect on responses of arterioles from HHcy rats (C-E, 55.9±6.9%; HHcy-E, 56.5±7.0%). Dilations to cumulative doses of acetylcholine (ACh; 10
−8
mol/L) were significantly reduced in arterioles from HHcy rats (C, 64.0±5.2%; HHcy, 24.1±6.8%). Inhibition of nitric oxide (NO) synthesis with N
ω
-nitro-
l
-arginine (L-NNA; 10
−4
mol/L) significantly decreased ACh-induced dilations of C arterioles, whereas it did not affect HHcy arterioles. Similar alterations were found in arteriolar dilations to histamine, another known NO-dependent agonist. Endothelium-independent dilations to the NO donor sodium nitroprusside were not different in arterioles from C and HHcy rats, either in the presence or absence of L-NNA. Presence of superoxide dismutase and catalase (scavenger of reactive oxygen metabolites) did not affect HHcy-induced alterations in the ACh response. We conclude that hyperhomocysteinemia reduces rat skeletal muscle arteriolar dilations in response to ACh and histamine, and enhances constrictions to NE, alterations that are likely to be caused by the reduced mediation of these responses by NO. The reduced activity of NO in arterioles may contribute to the microvascular impairment described in HHcy.
MRI of Rabbit Atherosclerosis in Response to Dietary Cholesterol Lowering
Authors: McConnell Michael V. , Aikawa Masanori , Maier Stephan E. , Ganz Peter , Libby Peter , Lee Richard T.
Published: June 2011

Abstract
—Direct imaging of the atherosclerotic plaque, rather than the angiographic lumen, may provide greater insight into the response of atherosclerosis to cholesterol-lowering therapy. Aortic plaque was studied in vivo by MRI in rabbits undergoing dietary cholesterol intervention. Thirty-one rabbits underwent aortic balloon injury and high-cholesterol diet for 4 months and then were assigned to low-cholesterol versus continued high-cholesterol diet for up to an additional 16 months. High-resolution (310 μm) fast spin-echo MRI of the abdominal aorta was performed at 4, 12, and 20 months and compared with histology. MRI demonstrated a significant reduction in % area stenosis in rabbits placed on low-cholesterol diet (44.6±2.1% at 20 months versus 55.8±1.5% at 4 months,
P
=0.0002). In contrast, % area stenosis increased in rabbits maintained on high-cholesterol diet (69.8±3.8% at 20 months versus 55.8±1.5% at 4 months,
P
=0.001). Similarly, plaque thickness decreased significantly in the low-cholesterol group (0.60±0.05 mm at 20 months versus 0.85±0.06 mm at 4 months,
P
=0.006), with a trend toward increase in the high-cholesterol group (1.02±0.08 mm at 20 months versus 0.85±0.06 mm at 4 months,
P
=0.1). Thus, in rabbits undergoing dietary cholesterol lowering, MRI detected regression of aortic atherosclerotic plaque in vivo. Plaque progression was seen with maintenance of high-cholesterol diet. MRI is a promising noninvasive technology for directly imaging atherosclerosis and its response to therapeutic interventions.
Identifying Cloninger’s Temperament Profiles as Related to the Early Development of the Metabolic Cardiovascular Syndrome in Young Men
Authors: Keltikangas-Järvinen Liisa , Ravaja Niklas , Viikari Jorma
Published: June 2011

Abstract—Our aim in this study was to (1) identify naturally occurring temperament profiles in young adulthood by using Cloninger’s temperament dimensions and (2) examine the relationship of these profiles with the coronary heart disease (CHD) risk factors of the metabolic cardiovascular syndrome (insulin resistance syndrome, IRS) measured during adolescence and young adulthood. A randomly selected sample of 190 healthy, young adult men was divided into 4 temperament groups by cluster analysis. Physiological parameters studied were serum insulin, high density lipoprotein cholesterol, triglycerides, systolic blood pressure, body-mass index, subscapular skinfold thickness, and the IRS factor. The results showed that a temperament profile characterized by a high level of persistence and reward dependence, an average level of novelty seeking, and a low level of harm avoidance was related to a high level of physiological CHD risk factors; in 3 study phases over a 6-year period, the subjects belonging to that cluster in adulthood were shown to have always belonged to the highest risk group in terms of the physiological risk factors in adolescence and young adulthood. The findings suggest that the temperament profile in question may predispose an individual to the development of the IRS and CHD.
Estrogen Mediates the Protective Effects of Pregnancy and Chorionic Gonadotropin in a Mouse Model of Vascular Injury
Authors: Zhang Lin , Fishman Mark C. , Huang Paul L.
Published: June 2011

Abstract
—To determine why pregnancy protects against intimal proliferation in a mouse model of vessel injury, we administered chorionic gonadotropin to intact and ovariectomized female mice. Chorionic gonadotropin markedly suppressed intimal proliferation in intact but not in ovariectomized female mice, indicating that the protective effects of chorionic gonadotropin require ovarian function. To test whether estrogen or progesterone might mediate the protective effects of pregnancy and chorionic gonadotropin, we administered estrogen and progesterone to ovariectomized mice. Estrogen administration to ovariectomized mice to achieve the elevated levels seen in pregnancy was sufficient to reproduce the marked suppression of intimal proliferation in response to vessel injury. Progesterone administration reduced intimal proliferation to a lesser degree and was correlated with increases in estrogen to levels seen in nonpregnant female mice. Staining for proliferating cell nuclear antigen suggested that estrogen reduced medial and intimal cell proliferation. Both the classic estrogen receptor-α and the recently discovered estrogen receptor-β are present in vascular tissue as assessed by immunohistochemistry, providing a possible mechanism for the effects of estrogen. These results suggest that the protective effects of estrogen do not plateau at levels seen in normal females but increase further with estrogen levels up through levels seen during pregnancy.
Expression of CCR2 by Endothelial Cells
Authors: Weber Kim S. C. , Nelson Peter J. , Gröne Hermann-Joseph , Weber Christian
Published: June 2011

Abstract—Endothelial cell proliferation and migration may play a central role in angiogenesis, wound healing, and atherosclerosis. Although CXC chemokines can act on endothelial cells by influencing proliferation, an involvement of CC chemokines and endothelial expression of chemokine receptors remains to be elucidated. Reverse transcription-polymerase chain reaction, RNase protection, Western blot, and flow cytometric analysis showed that human umbilical vein endothelial cells express mRNA and surface protein of the monocyte chemotactic protein-1 (MCP-1) receptor CCR2, which was upregulated by inflammatory cytokines. MCP-1 induced migration of endothelial cells in a transwell assay, which was inhibited by the 9-76 MCP-1 receptor antagonist. Increased secretion of MCP-1 or interleukin-8, but not RANTES, on endothelial injury suggested a functional role of CCR2 in wound repair as measured by ELISA. After mechanical injury to endothelial monolayers, which spontaneously closed within 24 hours, wound repair was delayed by the 9-76 antagonist and by a blocking monoclonal antibody to MCP-1, but not to interleukin-8, and was improved by exogenous MCP-1. This was confirmed by quantification of cell migration into the wound area, whereas proliferation and viability were unaltered by MCP-1 or its analogue. Notably, immunohistochemistry of inflamed tissue revealed CCR2 staining on arterial, venous, and venular endothelium affected by cellular infiltration. This is the first demonstration of endothelial CCR2 expression ex vivo, inferring its involvement in inflammatory conditions. Thus endothelial cells express functional CCR2 that may have important implications for endothelial wound repair and inflammatory reactions.
Angiotensin II Activation of Insulin-Like Growth Factor 1 Receptor Transcription Is Mediated by a Tyrosine Kinase–Dependent Redox-Sensitive Mechanism
Authors: Du Jie , Peng Tao , Scheidegger Kathrin J. , Delafontaine Patrick
Published: June 2011

Abstract
—We have recently shown that angiotensin II activation of insulin-like growth factor 1 receptor (IGF-1R) transcription is a critical requirement for angiotensin-stimulated vascular smooth muscle cell growth; therefore, we examined the signaling pathway involved. In rat aortic smooth muscle cells, the antioxidants
N
-acetyl-
l
-cysteine (5 mmol/L) and pyrrolidine dithiocarbamate (100 μmol/L) completely inhibited angiotensin II–stimulated increases in IGF-1R mRNA and protein levels, suggesting the involvement of reactive oxygen species. Indeed, catalase abolished the Ang II–stimulated increase of IGF-1R protein expression, and accordingly, H
2
O
2
(0.2 mmol/L) or the oxidized products of linoleic acid, hydroperoxyoctadecadienoic acids (10 μmol/L), increased IGF-1R mRNA levels at 3 hours by 74±20% and 107±22% and increased receptor number at 24 hours by 51±6.7% and 55±7.4%, respectively. The protein tyrosine kinase inhibitors genistein and tyrphostin A25 also blocked angiotensin II increases in IGF-1R mRNA and protein levels and blocked the ability of hydroperoxyoctadecadienoic acids and H
2
O
2
to increase IGF-1R expression, suggesting that oxidative stress may be an early event in the angiotensin II signaling cascade. Furthermore, calcium chelation inhibited the angiotensin II effect. Transient transfection assays revealed that a −2350/+640 IGF-1R promoter/luciferase construct was fully responsive to angiotensin II stimulation (127±20% increase). Ten millimoles per liter hydroperoxyoctadecadienoic acids and 0.2 mmol/L H
2
O
2
increased luciferase activity by 79±8.5% and 63±12%, respectively, and 5 mmol/L
N
-acetyl-
l
-cysteine blocked the angiotensin II–induced upregulation of luciferase activity by 70%. These data suggest that angiotensin II stimulates IGF-1R gene transcription via calcium-dependent activation of protein tyrosine kinase activity that lies downstream from an oxidant stimulus. These findings provide key insights into the signaling mechanisms whereby angiotensin II exerts its growth-promoting effects on the vasculature.
Efficient Nuclear Delivery of Antisense Oligodeoxynucleotides and Selective Inhibition of CETP Expression by Apo E Peptide in a Human CETP–Stably Transfected CHO Cell Line
Authors: Liu Kan , Ou Jiafu , Saku Keijiro , Jimi Shiro , Via David P. , Sparrow James T. , Zhang Bo , Pownall Henry J. , Smith Louis C. , Arakawa Kikuo
Published: June 2011

Abstract
—
N,N
-Dipalmitylglycyl–apolipoprotein E (129–169) peptide (dpGapoE) is an efficient gene delivery system for both plasmids and antisense oligodeoxynucleotides (ODNs). To develop a new and efficient approach to the regulation of cholesteryl ester transfer protein (CETP) expression, we used dpGapoE to transfect phosphorothioate antisense ODNs against nucleotides 329 to 349 of human CETP cDNA into a human CETP–stably transfected Chinese hamster ovary (CHO) cell line (hCETP-CHO). After transfection, translocation to the nuclei and concentration in nuclear structures were observed in >95% of the cells at 6 and 12 hours by fluorescence microscopy. No membrane disruption was observed after transfection of ODNs by dpGapoE. Although the translocation stability of phosphorothioate ODNs in the nuclei continued for >48 hours, it had weakened after 24 hours. Cellular CETP mRNA levels gradually declined, and the maximum reduction in the mRNA level (>50%) was observed at 36 hours, after which the mRNA level started to recover. CETP activity in the culture medium declined over 72 hours. The maximum reduction in CETP activity was observed at 36 hours (53.8% of control). Neither CETP mRNA nor CETP activities changed throughout the experiment after the transfection of sense phosphorothioate ODNs delivered by dpGapoE complex or naked antisense ODNs. We conclude that (1) the novel synthetic dpGapoE was a highly effective and nontoxic vehicle for the nuclear delivery of antisense ODNs into hCETP-CHO cells and (2) antisense ODNs selectively inhibited both CETP expression and activity in an hCETP-CHO cell line. This approach may enable gene regulation in vivo and could possibly be used as an antiatherosclerotic agent to alter high density lipoprotein metabolism.
Decreased Protection by HDL From Poorly Controlled Type 2 Diabetic Subjects Against LDL Oxidation May Be Due to the Abnormal Composition of HDL
Authors: Gowri Maya S. , Van der Westhuyzen Deneys R. , Bridges Susan R. , Anderson James W.
Published: June 2011

Abstract—High plasma triglyceride concentrations in diabetic subjects increase their risk for developing coronary heart disease. Numerous studies have shown that the high density lipoprotein (HDL) composition is abnormal in type 2 diabetic subjects. One study has shown that HDL (lipoprotein A-I) isolated from subjects with non–insulin-dependent diabetes mellitus exhibits a decreased capacity to induce cholesterol efflux. The current study examined the effect of HDL2and HDL3subfractions from poorly controlled type 2 diabetic and control subjects on THP-1 macrophage–mediated low density lipoprotein (LDL) oxidation. The composition and protective effects of HDL2, but not of HDL3, differed significantly between control and diabetic subjects. HDL2from diabetics were triglyceride enriched and cholesterol depleted compared with those from controls. Control HDL2inhibited LDL oxidation, as assessed by lipid peroxides and electrophoretic mobility, significantly (P<0.05) more than did diabetic HDL2in both the fasting and postprandial state. In addition, HDL2from diabetics did not protect against apolipoprotein B-100 fragmentation in LDL. Cross-linking in apolipoprotein A-I, oxidized in the presence of LDL, was extensive in HDL2from diabetics compared with that from controls. Serum triglyceride concentrations were negatively correlated with protection by HDL2(r=−0.673,P<0.05) in diabetic but not in control subjects. HDL2-associated platelet-activating factor acetylhydrolase activity was positively correlated with protection by HDL2in control (r=0.872,P<0.002) but not in diabetic subjects. In conclusion, compositional alterations in HDL2from poorly controlled type 2 diabetic subjects may reduce its antiatherogenic properties.
Endothelial cells from umbilical vein and a hemangioendothelioma secrete basement membrane largely to the exclusion of interstitial procollagens.
Authors: Sage H , Bornstein P
Published: June 2011

The biosynthesis of extracellular matrix proteins by primary cultures of endothelial cells from human umbilical vein, and by clones from a murine hemangioendothelioma, was studied and compared to that reported for endothelium cultured from other sources. Umbilical vein endothelial cells secreted two glycoproteins-fibronectin and thrombospondin-which comprise the major proportion of the protein in the culture media of bovine aortic, venous, and corneal endothelial cells. These biosynthetic products were absent from hemangioendothelioma cultures. However, in contrast to bovine endothelium from large vessels and cornea, which secrete primarily Type III procollagen into the culture medium, both the umbilical vein and hemangioendothelioma cultures secrete Type IV (basement membrane) procollagen. In addition, EC, a novel endothelial collagen type that has been characterized in bovine endothelial cell supernates, was not present in the umbilical vein or tumor-derived endothelium. The production of basement membrane procollagen as the major collagen type in the medium of these cultures probably reflects the nature of the vascular bed from which the endothelial cells originated, rather than differences in species of in cellular isolation and subculture. We suggest that endothelial cells from different vascular environments could display variations in growth, migration, morphology, and response to exogenous blood-borne factors as a result of their relationship to an extracellular matrix/subendothelium composed of diverse structural glycoproteins.
Triglyceride and cholesterol metabolism in primary hypertriglyceridemia.
Authors: Beil U , Grundy S M , Crouse J R , Zech L
Published: June 2011

To determine mechanisms of elevated plasma triglycerides (TG) in patients with primary hypertriglyceridemias, simultaneous studies were carried out on kinetics of very low density lipoprotein-triglycerides (VLDL-TG) and synthesis of cholesterol and bile acids. Sixteen hypertriglyceridemic patients with familial combined hyperlipidemia (FCHL) and 12 patients with poorly classified, primary hypertriglyceridemia were studied, and their results were compared to a series of normal and obese subjects previously studied in our laboratory. The mean value for transport (synthesis) of VLDL-TG in patients with FCHL was about twice normal. Although the upper normal synthesis rates overlapped with transport rates of some patients with FCHL, it appeared that the major cause of hypertriglyceridemia in FCHL was an elevated production of VLDL-TG. However, the height of the plasma TG in FCHL patients also was influenced by individual clearance capacities for VLDL-TG, and fractional clearance rates in several seemed particularly low. Synthesis rates for cholesterol and/or bile acids were high in several patients with FCHL, suggesting simultaneous overproduction of VLDL-TG and sterols; however, increased synthesis of both was not observed in all the patients. Most patients with poorly classified hypertriglyceridemia had over-production of VLDL-TG, but an apparent reduction in clearance was common. In these patients, increased synthesis of cholesterol and bile acids was infrequent. Our results indicate that abnormally high production of VLDL-TG seemed to be the major factor in causing primary hypertriglyceridemia, but that clearance capacity can play an important role in determining the the severity of the TG elevation.
Abnormal hormone levels in men with coronary artery disease.
Authors: Zumoff B , Troxler R G , O'Connor J , Rosenfeld R S , Kream J , Levin J , Hickman J R , Sloan A M , Walker W , Cook R L , Fukushima D K
Published: June 2011

Plasma concentrations and urinary excretions of various hormones and hormone metabolites were measured in four groups. Group 1 was composed of 13 men with prior myocardial infarction; Group 2 contained 35 clinically normal men; Group 3 consisted of 44 men with normal coronary arteriograms; and Group 4 was composed of 25 men with severe coronary artery disease shown on arteriogram but no infarction. There were four major findings: Group 1 had significantly higher 24-hour mean plasma concentrations of estrone (E1), dehydroisoandrosterone (DHA), and dehydroisoandrosterone sulfate (DHAS) than Group 2, while Group 3 had the same levels as Group 4; Group 4 had significantly lower urinary excretion of androsterone glucuronide (AG) than Group 3, while Group 1 excreted normal amounts. There are three possible explanations for these findings: 1) myocardial infarction occurring in men with coronary artery disease may elevate the plasma levels of E1, DHA, and DHAS and eliminate the preinfarction depression of urinary AG levels; 2) higher than average levels of E1, DHA, DHAS, and AG may favor the development of infarction in men with coronary artery disease; 3) higher than average levels of E1, DHA, DHAS, and AG may favor survival from any infarction that occurs in men with coronary artery disease. Experimental and epidemiological evidence seems to favor the third possibility.
Increased apoprotein B in very low density lipoproteins of patients with peripheral vascular disease.
Authors: Franceschini G , Bondioli A , Mantero M , Sirtori M , Tattoni G , Biasi G , Sirtori C R
Published: June 2011

Lipoprotein compositional studies were carried out in 20 patients with atherosclerotic peripheral vascular disease. Twelve of these patients were normolipidemic, the other eight, hypertriglyceridemic. Ten normolipidemic and 10 hypertriglyceridemic age-matched subjects were used as controls. High density lipoprotein cholesterol levels were markedly reduced in the hypertriglyceridemic subjects, both with (35.1 +/- 5.0 mg/dl) and without (36.2 +/- 11.7 mg/dl) peripheral vascular disease, as compared to the normolipidemic patients (47.0 +/- 6.3 mg/dl) and controls (48.1 +/- 10.0 mg/dl). A decreased relative content of apo C-11 in very low density lipoproteins in the hypertriglyceridemic subjects, as compared to the normolipidemics, was detected by isoelectric focusing. Hypertriglyceridemia in patients with peripheral vascular disease shows a typical Type IV lipoprotein and apoprotein profile. Apoprotein B levels in very and low density lipoproteins were determined by electroimmunodiffusion and selective precipitation with tetramethylurea (r = 0.981 between the two methods). All the patients with peripheral vascular disease showed an increased apo B content in very low density lipoproteins vascular disease showed an increased apo B content in very low density lipoproteins (VLDL) as compared to controls (apo B cholesterol in VLDL = 0.341 +/- 0.124 for peripheral vascular disease patients and 0.236 +/- 0.086 for controls, p less than 0.001). A significant correlation between VLDL cholesterol and apo b levels was detected both in peripheral vascular disease patients and in controls; however, two distinct populations could be clearly separated (slopes of the regression lines: peripheral vascular disease patients = 0.350; controls = 0.215, p less than 0.001). The data suggest a possible discriminatory power of VLDL-apo B levels in patients with peripheral vascular disease independent from other lipoprotein and lipid parameters.
A secretory product of human monocyte-derived macrophages stimulates low density lipoprotein receptor activity in arterial smooth muscle cells and skin fibroblasts.
Authors: Chait A , Mazzone T
Published: June 2011

The ability of macrophages to influence the metabolism of native low density lipoprotein by arterial smooth muscle cells was evaluated using cultured human monocyte-derived macrophages. Macrophage-conditioned medium stimulated the binding and degradation of low density lipoprotein by cultured arterial smooth muscle cells and skin fibroblasts. Sterol synthesis also was stimulated by macrophage-conditioned medium as was cholesterol esterification in the presence of high concentrations of low density lipoprotein. These findings suggest that macrophages secrete a factor that enhances the activity of the low density lipoprotein receptor. Low density lipoprotein degradation by arterial smooth muscle cells also was enhanced by macrophage-conditioned medium in the presence of high concentrations of low density lipoproteins in the medium. The macrophage factor that stimulates low density lipoprotein metabolism is stable to freezing, is inactivated by acid hydrolysis, tryptic digestion, and boiling, and is of large molecular weight (greater than 12,000 to 14,000 daltons). Modulation of arterial smooth muscle cell metabolism of low density lipoprotein by a macrophage secretory product may be of importance in the pathogenesis of atherosclerosis.
Decreased plasma phosphatidylcholine/free cholesterol ratio as an indicator of risk for ischemic vascular disease.
Authors: Kuksis A , Myher J J , Geher K , Jones G J , Breckenridge W C , Feather T , Hewitt D , Little J A
Published: June 2011

As part of a population survey and a follow-up study of plasma lipid profiles by high temperature gas-liquid chromatography, we have determined the quantities and relative proportions of all major chemical classes and molecular species of lipids of plasma from 1200 subjects at Visit 2 of the Toronto-McMaster Lipid Research Clinic Prevalence Study. We have compared these values between our 24 subjects with ischemic vascular disease and 73 control subjects matched for age, sex, and plasma total cholesterol and triacylglycerols. The phosphatidylcholine/free cholesterol ratio showed the highest association with ischemic vascular disease of any of over 10 other lipid parameters and all the common risk indicators except high density lipoprotein cholesterol. The phosphatidylcholine/free cholesterol ratio had a relative risk ratio of 20/4 (95% confidence limits, 15/9, 23/1) and high density lipoprotein cholesterol, a risk ratio of 23/1 (95% confidence limits, 24/0, 19/5) for ischemic vascular disease. The average ratio of phosphatidylcholine/free cholesterol for the ischemic vascular disease group was 1.36 and for the controls 1.51, the population average being 1.50. Plasma high density lipoprotein cholesterol had a significant correlation (R = 0.15) with the phosphatidylcholine/free cholesterol ratio in the total population sample. The increased risk for ischemic vascular disease from a lower phosphatidylcholine/free cholesterol ratio may possibly be explained on the basis of decreased fluidity and stability of the lipoproteins due to a relative oversaturation with free cholesterol.