bluuebunny/crossref_metadata_2025 huggingface dataset:
Apoprotein B-100 Production Is Decreased in Subjects Heterozygous for Truncations of Apoprotein B
Authors: Aguilar-Salinas Carlos A. , Barrett P. Hugh R. , Parhofer Klaus G. , Young Stephen G. , Tessereau Diana , Bateman Joyce , Quinn Catherine , Schonfeld Gustav
Published: June 2011

AbstractAmong individuals who are heterozygous for familial hypobetalipoproteinemia (FHBL) and who have various truncations of apoprotein (apo) B (ie, FHBL with apoB truncation/apoB-100 genotypes), the plasma concentrations of apoB-100 are typically ≈30% rather than the expected ≈50% of those in unaffected family members. The metabolic basis for the low apoB-100 levels is unknown. Therefore, we compared the metabolism of apoB-100 in 8 subjects with heterozygous FHBL (2 apoB-89/apoB-100, 2 apoB-75/apoB-100, 2 apoB-54.8/apoB-100, 1 apoB-52/apoB-100, and 1 apoB-31/apoB-100) with the metabolism of apoB-100 in 8 apoB-100/apoB-100 control subjects who were paired with the heterozygotes by gender, age, height, weight, and race. Endogenous labeling of apoB-100 with [13C]leucine and a multicompartmental kinetic model were used to obtain kinetic parameters. FHBL heterozygotes had significantly reduced VLDL apoB-100 production rates (7.7±3.7 versus 21.2±6.2 mg · kg−1· d−1,P=.002) and LDL apoB-100 production rates (4.5±3.12 versus 15.3±1 mg · kg−1· d−1,P=.05) compared with control subjects. Fractional conversion rates of VLDL to LDL were not significantly different (0.67±0.36 versus 0.77±0.17 pools/d), and the respective fractional catabolic rates of apoB-100 in VLDL, IDL, and LDL also were similar in both groups. Thus, FHBL heterozygotes produced apoB-100 at about 30% of the rates of control subjects. We believe these reduced production rates largely account for the lower than expected levels of apoB-100 and LDL cholesterol in the plasma of FHBL heterozygotes.
Four Novel Partial Deletions of LDL-Receptor Gene in Italian Patients With Familial Hypercholesterolemia
Authors: Bertolini S. , Garuti R. , Lelli W. , Rolleri M. , Tiozzo R. M. , Ghisellini M. , Simone M. L. , Masturzo P. , Elicio N. C. , Stefanutti C. , Coviello D. , Carabbio C. , Orecchini G. , Calandra S.
Published: June 2011

Abstract
In this study, we report four new partial deletions of the LDL-receptor (LDL-R) gene discovered during a survey of 326 Italian patients with familial hypercholesterolemia (FH). All deletions were found in FH heterozygotes whose LDL-R activity in skin fibroblasts ranged from 52% to 43% of the values found in control cells. The size and boundaries of the deletions were defined by Southern blotting and, in some cases, by polymerase chain reaction (PCR) amplification of genomic DNA. The sequence of the deletion joint was performed after the reverse transcription and PCR amplification of the appropriate regions of LDL-R mRNA. FH
Massa
is a 12-kilobase deletion spanning from intron 2 to intron 10. RT-PCR showed that the mutant allele is transcribed into one major and two minor mRNAs. In the most abundant mRNA species, exon 2 joins exon 11, as expected from DNA analysis. In one minor mRNA, which was sequenced, exon 2 joins exon 13, with exons 11 and 12 skipped as a result of an alternative splicing. FH
Genova
is a 4-kb deletion spanning from intron 10 to intron 12 and eliminating exons 11 and 12. FH
Roma
is a 4.7-kb deletion spanning from the 5′ end of intron 12 to the middle of intron 14 and eliminating exons 13 and 14. This deletion differs in size from the previously described deletion (FH
Chieti/Macerata
), which is located in the same region of the LDL-R gene but is smaller (3.7 kb). In both FH
Roma
and FH
Chieti/Macerata
, the mutant LDL-R mRNA is present in a minute amount, suggesting that the deletion of exons 13 and 14 may increase mRNA degradation. FH
Padova-2
is a 2-kb deletion spanning from intron 15 to intron 16 and eliminating the sole exon 16. All deletions except FH
Padova-2
produce a shift in the reading frame, leading to either a very short peptide or a truncated protein. In FH
Padova-2
, elimination of exon 16 does not change the reading frame but is predicted to produce a receptor protein of 813 amino acids, lacking 18 amino acids of the O-linked sugar and 8 amino acids of the transmembrane domain. Ligand blot experiments with rabbit
125
I-β VLDL indicate that half the amount of LDL-receptor is present in FH
Padova-2
fibroblasts, suggesting that the in-frame deletion of 26 amino acids may disrupt the intracellular transport and/or the insertion of the receptor in the plasma membrane or may increase its degradation.
Estrogen-Induced Alterations in Lipoprotein Metabolism in Autoimmune MRL/lpr Mice
Authors: Zuckerman Steven H. , Bryan-Poole Nancy
Published: June 2011

AbstractEstrogen replacement therapy has been demonstrated to shift the lipoprotein profile toward a less atherogenic one with concomitant increases in HDL and reductions in LDL cholesterol and serum triglycerides. Estrogen, however, has also been implicated in playing a significant role in autoimmune disease and may be involved with disease incidence and progression. The MRL/lpr mouse strain represents an autoimmune disease model with features resembling systemic lupus erythematosus including high-titer autoantibodies, glomerulonephritis, and vasculitis. In the present study, the effects of estrogen treatment on serum lipoprotein profiles were investigated by fast protein liquid chromatography in female MRL/lpr mice, in the MRL/++ strain with a milder form of disease, and in control Balb/c mice. Treatment of MRL/lpr mice for periods of 1 week or longer with pharmacologic doses of estrogen resulted in a significant increase in the amount of cholesterol carried on LDL particles. The up to eightfold increase in LDL cholesterol was less significant in the MRL/++ or Balb/c mice. Maximal increases were observed at 1 to 2 mg/kg of estrogen agonists, and the effect on LDL cholesterol increases was inhibited by tamoxifen. The HDL-to-LDL shift in cholesterol observed in estrogen-treated autoimmune mice correlated with an increase in apolipoprotein E, primarily on larger HDL particles. In addition to the increase in LDL cholesterol, hormonal treatment also resulted in a shift in triglycerides from the VLDL to the LDL fraction in both normal and autoimmune mice. These results suggest that pharmacologic doses of estrogen may contribute to cardiovascular disease progression by shifting the relative distribution of cholesterol from HDL to LDL in this murine model of lupus.
Nitric Oxide Protects Against Leukocyte-Endothelium Interactions in the Early Stages of Hypercholesterolemia
Authors: Gauthier Theresa W. , Scalia Rosario , Murohara Toyoaki , Guo Jin-ping , Lefer Allan M.
Published: June 2011

Abstract
We studied the effects of CAS1609, a nitric oxide donor, on leukocyte-endothelial interactions during the early stages of hypercholesterolemia in rat mesenteric microcirculation. Rats were randomly divided into four groups: (a) rats fed control diet, (b) rats fed control diet while receiving CAS1609, (c) rats fed a high-cholesterol (HC) diet and given C93-4845 (an inactive control compound), and (d) rats fed an HC diet and given CAS1609. Both HC groups developed significantly elevated plasma cholesterol levels compared with rats fed the control diet. Intravital microscopy of mesenteric venules revealed a significant increase in leukocyte rolling and adherence in the untreated HC rats compared with control rats (
P
<.01). This was significantly attenuated in the HC rats given CAS1609. The HC rats given C93-4845 also developed aortic endothelial dysfunction (ie, impaired relaxation to acetylcholine or ADP) that was significantly prevented by CAS1609 infusion (
P
<.02). Immunohistochemical staining of ileum demonstrated significantly enhanced localization of P-selectin and intercellular adhesion molecule–1 (ICAM-1) on venular endothelium in the untreated HC rats compared with control rats (
P
<.01). However, P-selectin and ICAM-1 expression were significantly attenuated in HC rats given CAS1609 (
P
<.05 and
P
<.01, respectively). Thus, hypercholesterolemia induces microvascular dysfunction characterized by loss of endothelium-derived nitric oxide, increased rolling and adherence of leukocytes, and increased expression of P-selectin and ICAM-1. Infusion of CAS1609 significantly attenuated these changes due to hypercholesterolemia. Our data suggest that nitric oxide plays a significant role in the prevention of the early endothelial dysfunction observed in hypercholesterolemia.
Overexpression of Human Lipoprotein Lipase Protects Diabetic Transgenic Mice From Diabetic Hypertriglyceridemia and Hypercholesterolemia
Authors: Shimada Masako , Ishibashi Shun , Gotoda Takanari , Kawamura Masako , Yamamoto Koji , Inaba Toshimori , Harada Kenji , Ohsuga Junichi , Perrey Stephane , Yazaki Yoshio , Yamada Nobuhiro
Published: June 2011

Abstract
We investigated the role of the overexpression of lipoprotein lipase (LPL) in lipoprotein abnormalities in transgenic mice with streptozotocin-induced diabetes mellitus. Before the induction of diabetes, LPL activity was 4.6-fold in skeletal muscle and 2.0-fold higher in the heart in transgenic mice than in their nontransgenic littermates. LPL activity in skeletal muscles in diabetic nontransgenic mice and cardiac LPL activity in diabetic nontransgenic and transgenic mice were decreased. Body weights were similarly reduced, and no appreciable amount of adipose tissue was observed in diabetes in both groups. The plasma triglyceride level was lower in diabetic transgenic mice than in diabetic nontransgenic mice (33.2±22.5 versus 185.3±57.4 mg/dL). Induction of diabetes was associated with a significant increase in the plasma cholesterol level in nontransgenic mice (90.0±11.1 versus 163.9±39.3 mg/dL) but much less in transgenic mice. Our results indicate that overexpression of LPL in transgenic mice inhibited diabetes-associated hypertriglyceridemia and hypercholesterolemia but did not affect the loss of body weight induced by diabetes.
Atherosclerotic Disease in Marked Hyperalphalipoproteinemia
Authors: Hirano Ken-ichi , Yamashita Shizuya , Kuga Yoshio , Sakai Naohiko , Nozaki Shuichi , Kihara Shinji , Arai Takeshi , Yanagi Koji , Takami Shigeki , Menju Masakazu , Ishigami Masato , Yoshida Yu , Kameda-Takemura Kaoru , Hayashi Kozo , Matsuzawa Yuji
Published: June 2011

Abstract
Hyperalphalipoproteinemia (HALP) has been regarded as a beneficial state accompanied by a longevity syndrome. However, we reported the cases of markedly hyperalphalipoproteinemic subjects with juvenile corneal opacification. These patients had reduced postheparin hepatic triglyceride lipase (HTGL) activities, and one of them has recently been identified to be homozygous for a missense mutation in exon 15 (D442: G) in the cholesteryl ester transfer protein (CETP) gene. In the current study, to elucidate the clinical significance of and atherogenicity in marked HALP, we determined the incidence of atherosclerotic cardiovascular disease (ACD) in patients with marked HALP and characterized the lipoprotein abnormalities in those who had ACD, focusing especially on CETP and HTGL. The subjects were 201 patients (111 males and 90 females) with marked HALP (≥2.58 mmol/L [100 mg/dL]), 67% of whom were demonstrated to have the CETP gene mutations in the intron 14 splice donor site or in exon 15. Their mean age was 54±15 years. Plasma levels of total cholesterol, HDL cholesterol, and triglyceride in all subjects were 6.28±1.78, 3.15±0.90, and 1.08±0.53 mmol/L, respectively. Ten of the male patients (9.0%) and two of the female patients (2.2%) had apparent ACD such as myocardial infarction, angina pectoris, and peripheral vascular diseases. Ten patients with HALP who had ACD were identified to be heterozygotes for CETP deficiency. To further clarify the characteristics of marked HALP in patients with ACD, we compared the plasma lipids, lipoproteins, CETP, and HTGL activities between heterozygotes for CETP deficiency who were with and without ACD. There was no significant difference in plasma lipids, lipoproteins, and CETP between the two groups, whereas HTGL activities were significantly lower in the heterozygotes for CETP deficiency with ACD than in the heterozygotes without ACD and in control subjects. These results suggest that marked HALP may not always be a beneficial state and that people who are heterozygotes for CETP deficiency and who have low HTGL may be susceptible to ACD.
A New Case of ApoA-I Deficiency Showing Codon 8 Nonsense Mutation of the ApoA-I Gene Without Evidence of Coronary Heart Disease
Authors: Takata Kouki , Saku Keijiro , Ohta Takao , Takata Mie , Bai Huai , Jimi Shiro , Liu Rui , Sato Hikaru , Kajiyama Goro , Arakawa Kikuo
Published: June 2011

Abstract
We report a 39-year-old Japanese man with HDL and apoA-I deficiency as well as data from members of his family. Corneal opacity and a stomatocyte were found but not tonsillar hypertrophy, xanthomas, or splenomegaly. His serum HDL cholesterol, apoA-I, apoA-II, and LDL cholesterol levels were 6 mg/dL, <3 mg/dL, 6 mg/dL, and 175 mg/dL, respectively. Plasma triglyceride, phospholipid, apoB, apoC-III, and apoE levels were all within normal limits. Lecithin:cholesterol acyltransferase activity was half of normal, while lipoprotein lipase and hepatic triglyceride lipase activities were within normal limits. ApoA-I deficiency was confirmed by combined isoelectric focusing and sodium dodecyl sulfate–polyacrylamide gel electrophoresis and by an immunoblotting method. We surveyed the apoA-I gene of the patient and five of his family members by direct sequencing after amplification by polymerase chain reaction and found a codon 8 nonsense mutation (TGG→TAG, Trp→stop) in exon 3 of the apoA-I gene. The results of a pedigree analysis by DNA sequencing and restricted fragment length polymorphism (
Sty
I) were consistent with an autosomal codominant trait. Coronary angiography was performed to evaluate coronary atherosclerosis, but no significant luminal narrowing was detected. An intracoronary ultrasound study showed mild intimal hyperplasia in segment 6. In summary, this is a case of apoA-I deficiency without evidence of coronary heart disease.
Relative Contributions of Apolipoprotein(a) and Apolipoprotein-B to the Development of Fatty Lesions in the Proximal Aorta of Mice
Authors: Mancini F.P. , Newland D.L. , Mooser V. , Murata J. , Marcovina S. , Young S.G. , Hammer R.E. , Sanan D.A. , Hobbs H.H.
Published: June 2011

Abstract
Transgenic mice expressing transgenes for both human apolipoprotein B-100 (h-apoB) and apolipoprotein(a) [apo(a)] were fed a high-fat, atherogenic diet for 14 weeks to examine the effect of lipoprotein(a) [Lp(a)] on the development of aortic fatty lesions. The extent of lesions in the proximal region of the aorta of Lp(a) mice was measured by use of a computer-assisted image analysis of 20 sections per animal and compared with that of nontransgenic mice as well as mice expressing either the apo(a) or h-apoB transgene. The control (n=23) and apo(a) (n=22) transgenic mice had very small mean lesion areas (607 versus 128 μm
2
per section). The h-apoB–expressing mice (n=20) had significantly higher mean lesion areas (3288 μm
2
per section) than either the control or apo(a) transgenic animals. Coexpression of apo(a) and h-apoB transgenes resulted in only a modest increase in lesion area (4678 μm
2
per section, n=19). Thus, the expression of human apo(a) in C57BL/6/SJL hybrid mice fed an atherogenic diet failed to significantly potentiate the development of aortic fatty lesions in the absence or presence of high levels of h-apoB.
Selective Increase in Cholesterol at Atherosclerosis-Susceptible Aortic Sites After Short-term Cholesterol Feeding
Authors: Schwenke Dawn C.
Published: June 2011

Abstract
In rabbits, the aortic arch and branch sites of the descending thoracic and abdominal aortas are susceptible to atherosclerosis. This study investigated the hypothesis that the reported focal increase in LDL concentration and mean residence time at susceptible aortic sites after feeding cholesterol for 4 to 8 days precede atherosclerotic change as indicated by increased aortic cholesterol concentration. Cholesterol concentrations for all aortic sites of normal rabbits were similar (≈2.8 μmol/g). No change in aortic cholesterol concentration could be detected after feeding cholesterol for 8 days. However, after feeding cholesterol for 12 and 16 days, cholesterol concentrations for abdominal branch sites were increased compared with abdominal branch sites of normal rabbits (4.47±0.50, n=8, and 4.85±0.33, n=11, μmol/g, respectively, versus 2.87±0.27, n=12, μmol/g;
P
<.025 and
P
<.005, respectively). In contrast, the cholesterol concentration of atherosclerosis-resistant nonbranch abdominal aorta was unchanged after feeding cholesterol for 16 days and was much less than that of the branch sites (2.72±0.12 versus 4.85±0.33 μmol/g, n=11;
P
<.001). Cholesterol concentrations for other susceptible sites were also increased after feeding cholesterol for 12 and 16 days. Cholesterol concentrations for susceptible sites were linearly related to a combined measure of duration and extent of hypercholesterolemia (
P
<.001 to
P
<.0001), whereas no such relationship could be detected for resistant sites. Most (59% to 93%) of the cholesterol accumulating in susceptible aortic sites after feeding cholesterol for 12 and 16 days was nonesterified, suggesting that the increased cholesterol concentration did not reflect development of foam cells or the insudation of plasma lipoproteins. This study suggests that the reported focal increases in LDL concentration and mean residence time at susceptible aortic sites during cholesterol feeding precede atherosclerosis.
Reduction of Serum Cholesterol Levels Alters Lesional Composition of Atherosclerotic Plaques
Authors: Shiomi Masashi , Ito Takashi , Tsukada Toyohiro , Yata Tatsuo , Watanabe Yoshio , Tsujita Yoshio , Fukami Masaharu , Fukushige Jun-ichiro , Hosokawa Tsunemichi , Tamura Atsuhiro
Published: June 2011

Abstract
We examined whether serum cholesterol reduction alters the lesional composition of atherosclerotic plaques. To reduce serum cholesterol levels, we gave pravastatin sodium, a 3-hydroxy-3-methylglutaryl Coenzyme A reductase inhibitor, to mature Watanabe heritable hyperlipidemic rabbits, an LDL receptor–deficient animal model, for 48 weeks. Atherosclerotic lesions were immunohistochemically and conventionally stained and each lesional component area was measured by a color image analyzer. Compared with those of a placebo group, serum LDL cholesterol levels were reduced by 22% (
P
<.05). Data for atherosclerosis indicated a significant decrease in percent of surface lesion area (26% reduction) and in intimal thickening (30% reduction) in the abdominal aorta, as well as in coronary stenosis (29% reduction). Data for lesional composition indicated a significant decrease in the percent area of macrophage plus extracellular lipid deposits in aortic lesions (32% reduction) and coronary lesions (45% reduction). A significant increase was observed in the percent area of collagen in aortic lesions and in the percent area of smooth muscle cells in coronary lesions. The plaques seemed to become stable lesions as a result of pravastatin treatment. In conclusion, a long-term reduction of serum LDL cholesterol reduced lipid-related lesional components, in addition to suppressing the progression of established atherosclerosis.
The Role of Lipoprotein A-I and Lipoprotein A-I/A-II in Predicting Coronary Artery Disease
Authors: O’Brien T. , Nguyen T. T. , Hallaway B. J. , Hodge D. , Bailey K. , Holmes D. , Kottke B. A.
Published: June 2011

Abstract
The aim of this study was to examine the role of HDL subparticles with apolipoprotein (apo) A-I alone (LpA-I) and with apoA-I and apoA-II (LpA-I/A-II) in predicting coronary artery disease. Concentrations of these HDL subparticles were compared in 184 subjects with angiographically confirmed significant coronary artery disease (>50% stenosis of at least one vessel) and 191 age- and sex-matched control subjects without clinical coronary artery disease. LpA-I and LpA-I/A-II were measured with magnetic beads coated with anti–apoA-II antibodies to separate particles containing apoA-II from plasma. Total plasma cholesterol and triglyceride levels were similar in both groups. Although subjects with coronary artery disease had lower HDL cholesterol, plasma apoA-I, LpA-I, and LpA-I/A-II than age- and sex-matched control subjects without coronary artery disease, plasma apoA-I was the best predictor of coronary artery disease. In conclusion, LpA-I and LpA-I/A-II are lower in subjects with coronary artery disease but do not add to plasma apoA-I in predicting the presence of coronary artery disease.
Immunohistochemical Demonstration of 15-Lipoxygenase in Transplant Coronary Artery Disease
Authors: Ravalli Stefano , Marboe Charles C. , D’Agati Vivette D. , Michler Robert E. , Sigal Elliott , Cannon Paul J.
Published: June 2011

Abstract
15-Lipoxygenase (15-LO) catalyzes the oxygenation of arachidonic and linoleic acids and has been implicated in the oxidative modification of low-density lipoproteins (LDL). 15-LO mRNA and protein have previously been demonstrated in macrophages of rabbit and human atherosclerotic lesions. The purpose of this study was to investigate whether 15-LO is also present in the accelerated form of coronary artery disease that can complicate cardiac transplantation (TCAD). Immunohistochemical analysis of coronary arteries with TCAD was carried out by using a rabbit polyclonal antibody raised against human recombinant 15-LO and an avidin-biotin-immunoperoxidase system. Normal coronary and pulmonary arteries showed no immunostaining for 15-LO. Two different types of TCAD were observed. One type consisted of concentric intimal proliferation of smooth muscle cells, without lipid or calcium deposits. No immunoreactivity for 15-LO was present in these lesions. The second type of graft arteriosclerosis consisted of complex atheromatous lesions, containing myointimal cells, lipid-laden foam cells, fragmented internal elastic laminae, and calcifications. 15-LO immunostaining of myointimal cells, lipid-laden foam cells, and endothelial cells was consistently present in these atheromatous lesions. The majority of the myointimal and foam cells positive for 15-LO were recognized by antisera to α–smooth muscle actin; the others were identified as macrophages. The results indicate that 15-LO expression is present in endothelial, myointimal, and foam cells in complex atheromatous lesions of TCAD, and suggest that 15-LO may play a role in the pathogenesis of this form of the disease.
Differentiated Macrophages Synthesize a Heparan Sulfate Proteoglycan and an Oversulfated Chondroitin Sulfate Proteoglycan That Bind Lipoprotein Lipase
Authors: Edwards Iris J. , Xu Hongzhi , Obunike Joseph C. , Goldberg Ira J. , Wagner William D.
Published: June 2011

AbstractLipoprotein lipase (LpL), which facilitates lipoprotein uptake by macrophages, associates with the cell surface by binding to proteoglycans (PGs). Studies were designed to identify and characterize specific PGs that serve as receptors for LpL and to examine effects of cell differentiation on LpL binding. PG synthesis was examined by radiolabeling THP-1 monocytes and macrophages (a cell line originally derived from a patient with acute monocytic leukemia) with [35S]sodium sulfate and [3H]serine or [3H]glucosamine. Radiolabeled PGs isolated from the cell surface were purified by chromatography and identified as chondroitin-4–sulfate (CS) PG and heparan sulfate (HS) PG. A sixfold increase in CSPG and an 11-fold increase in HSPG accompanied cell differentiation. Whereas HS glycosaminoglycan chains from both monocytes and macrophages were 7.5 kD in size, CS chains increased in size from 17 kD to 36 kD with cell differentiation, and contained hexuronylN-acetylgalactosamine-4,6-di-Osulfate disaccharides. LpL binding was sevenfold higher to differentiated cells, and affinity chromatography demonstrated that two cell surface PGs bound to LpL: HSPG and the oversulfated CSPG produced only by differentiated cells. We conclude that differentiation-associated changes in cell surface PG of human macrophages have functional consequences that could increase the atherogenic potential of the cells.
Relation of Glycohemoglobin and Adiposity to Atherosclerosis in Youth
Authors: McGill Henry C. , McMahan C. Alex , Malcom Gray T. , Oalmann Margaret C. , Strong Jack P.
Published: June 2011

Abstract
In a cooperative multicenter study (Pathobiological Determinants of Atherosclerosis in Youth, PDAY) of 1532 young persons 15 through 34 years of age who died of external causes and were autopsied in medical examiners’ laboratories, we quantified atherosclerosis of the aorta and the right coronary artery. We analyzed postmortem blood cells for glycohemoglobin and postmortem serum for lipoprotein cholesterol and thiocyanate (as an indicator for smoking). We measured the thickness of the panniculus adiposus and the body mass index (weight per height squared) as indicators of adiposity. Glycohemoglobin levels exceeding 8% were associated with substantially more extensive fatty streaks and raised lesions in the right coronary artery in persons more than 25 years of age and with more extensive raised lesions in the aorta in persons more than 30 years of age. Both thickness of the panniculus adiposus and body mass index were associated with more extensive fatty streaks and raised lesions in the right coronary artery. The associations of atherosclerotic lesions with glycohemoglobin and adiposity were not explained by a less favorable lipoprotein profile or smoking. The results show that atherosclerosis in young adults is associated with the prediabetic or early diabetic state, as indicated by elevated glycohemoglobin levels, and with obesity.
LDL Physical and Chemical Properties in Familial Combined Hyperlipidemia
Authors: Hokanson John E. , Krauss Ronald M. , Albers John J. , Austin Melissa A. , Brunzell John D.
Published: June 2011

Abstract
Familial combined hyperlipidemia (FCHL) is characterized by elevations of triglyceride and/or cholesterol within families and an elevation in apoB. Although small dense LDL has been consistently associated with hypertriglyceridemia, small dense LDL persists despite reductions in triglyceride after treatment with gemfibrozil in FCHL. The current study evaluated potential differences in the distribution and chemical composition of LDL species in patients with FCHL and normolipidemic control subjects. LDL from FCHL patients was characterized by a relative abundance of a discrete LDL species with a mean peak analytic ultracentrifuge flotation rate (S°
f
) of 4.7±0.5 (SEM), a density of 1.041±0.001 g/mL, and a particle diameter of 250±1 Å as assessed by gradient gel electrophoresis. The major LDL species in the control subjects had a higher mean S°
f
rate (6.3±0.4), was more buoyant (density, 1.037±0.001 g/mL), and was larger (diameter, 262±2 Å). In addition, in a series of six LDL fractions separated by equilibrium density gradient ultracentrifugation, particle diameters were significantly smaller in all fractions from FCHL patients compared with those from control subjects. LDL particles from patients contained less free cholesterol, cholesteryl ester, and phospholipid than LDL from control subjects. The amount of triglyceride per LDL particle, however, did not differ between FCHL patients and control subjects. Differences in flotation rate and mass of the major LDL species between patients and control subjects could not be fully accounted for by differences in plasma triglyceride levels. Thus, LDL particles from FCHL patients are smaller and more dense with less cholesterol and phospholipid. Many of these differences appear to be independent of plasma triglyceride. Differences in LDL physical and chemical properties may contribute to the increase in premature coronary disease in FCHL.
Participation of Calpain in Protein-Tyrosine Phosphorylation and Dephosphorylation in Human Blood Platelets
Authors: Ariyoshi Hideo , Oda Atsushi , Salzman Edwin W.
Published: June 2011

Abstract
The possible role of calpains in protein-tyrosine phosphorylation in platelets was examined by the use of the cell-permeant calpain inhibitor calpeptin. In platelets stimulated by 1 U/mL thrombin, protein-tyrosine phosphorylation was maximal after 2 minutes and was followed by protein-tyrosine dephosphorylation. Calpeptin (30 μmol/L) or vanadate (2 mmol/L) enhanced protein-tyrosine phosphorylation and delayed protein-tyrosine dephosphorylation. The effects of these two compounds were not additive. We also observed proteolysis of pp60src and autoproteolysis of μ-calpain. Cleavage of the former was significantly slower than that of the latter and slower than protein-tyrosine dephosphorylation. The activity of protein-tyrosine phosphatase in the platelet lysate was transiently increased to 190% by addition of Ca
2+
. Ca
2+
-dependent activation of protein-tyrosine phosphatase was not observed in the presence of leupeptin. Those observations suggest that platelet calpains may be involved in modulation of protein-tyrosine phosphorylation through activation of protein-tyrosine phosphatase rather than through the inactivation of pp60src, a mechanism that was previously suggested.
Elevated Concentrations of Plasma Lipids and Apolipoproteins B, C-III, and E Are Associated With the Progression of Coronary Artery Disease in Familial Hypercholesterolemic Swine
Authors: Hasler-Rapacz Judith , Prescott Margaret Forney , Von Linden-Reed Jean , Rapacz Jan M. , Hu Zhiliang , Rapacz Jan
Published: June 2011

Abstract
We reported earlier that a complex familial hypercholesterolemia (c-FHC) phenotype characterized by elevated levels of total plasma cholesterol (TC) and apoB and reduced levels of HDL cholesterol (HDL-C) and apoA-I is associated with the development of spontaneous atherosclerotic lesions in swine. In this study, we investigated concentrations of plasma lipids and apolipoproteins B, C-III, and E in six parental animals of two cholesterol concentration phenotypes and their 32 offspring, which segregated into high, intermediate, and normal cholesterol phenotypes. Subsequently, we compared the extent of atherosclerotic lesion development in coronary arteries to the concentrations of plasma lipids and apolipoproteins in the parents and two offspring per family. Mean concentrations for the high (n=23), intermediate (n=13), and normal (n=2) cholesterol level phenotypes at 4 months of age were TC, 316±62.2, 159±17.1, and 105±12 mg/dL; LDL cholesterol, 275±63.1, 113±16.4, and 67±18.4 mg/dL; HDL-C, 35±6.1, 41±5.7, and 33±6.4 mg/dL; triglycerides, 48±10.8, 39±8.0, and 29±5.7 mg/dL; apoB, 152±32.5, 80±7.2, and 48±5.7 mg/dL; apoC-III, 10±4.2, 8±1.7, and 3±0.1 mg/dL; and apoE, 17±3.4, 7±1.7, and 5±0.7 mg/dL, respectively. Histological analysis of the major coronary arteries from members of the three families showed considerable variation in the severity of lesions, ranging from foci of adaptive intimal thickening consisting of two to six layers of smooth muscle cells to advanced lesions containing necrotic cores, cholesterol clefts, calcification, and hemorrhage (type V). The most extensive lesions occurred only in animals of the high cholesterol phenotype (ie, c-FHC), in which the concentration of TC and apoB progressively increased after 4 months of age, apoC-III, apoE, and triglycerides increased or remained elevated, and HDL-C decreased, except for one animal. Data presented here show that the plasma cholesterol phenotypes in FHC animals are associated with levels of apolipoproteins B, C-III, and E and indicate that the increases in the studied parameters after 4 months of age correlate with the progression of coronary artery disease.
Coagulation Factor VII Mass and Activity in Young Men With Myocardial Infarction at a Young Age
Authors: Moor Elisabeth , Silveira Angela , van’t Hooft Ferdinand , Suontaka Anna Maija , Eriksson Per , Blombäck Margareta , Hamsten Anders
Published: June 2011

AbstractFactor VII (FVII) coagulant activity has been proven to be associated with the risk of future fatal coronary heart disease (CHD) in middle-aged men. Recent studies have emphasized the role of triglyceride-rich lipoproteins and FVII genotype in determining plasma levels of FVII protein and activity. The present study was undertaken to examine whether FVII activity state and protein concentration in fasting plasma are altered in young men with proven myocardial infarction (MI) and examined the relations of FVII to subfractions of apo B–containing lipoproteins and the Arg→Gln polymorphism in the FVII gene. Activated FVII (FVIIa) was determined by a clotting assay using soluble, recombinant, truncated tissue factor. A total of 94 men with a first MI before the age of 45 (mean age±SD, 39.6±4.5 years) were included in the study along with 99 population-based, age-matched control subjects. In addition to FVIIa and FVII antigen (FVII:Ag), a panel of FVII activity assays were included for comparison with previous work in this field. The plasma level of FVII:Ag was higher in patients than in control subjects when the entire groups were compared (537±128 versus 479±93 ng/mL,P<.001), the differences being accounted for by patients with hypertriglyceridemic lipoprotein phenotypes. In contrast, FVIIa was similar in patients and control subjects (4.6±1.4 versus 4.3±1.3 ng/mL, NS), which means that the proportion of FVIIa molecules was unaltered or even lower in the patients. As expected, the Arg→Gln polymorphism significantly influenced both FVII mass and activity levels. In addition, presence of the Gln allele appeared to be associated with a lower proportion of fully active FVII molecules. The polymorphism also affected the relation between the plasma concentration of VLDL and FVII:Ag. The triglyceride content and particle number of all VLDL subfractions, irrespective of particle size, correlated fairly strongly with FVII mass determinations but not at all with FVIIa. HDL cholesterol concentration, on the other hand, presumably reflecting the efficiency of lipoprotein lipase–mediated lipolysis of VLDL, related significantly to the FVIIa level. The Arg→Gln polymorphism, independent of lipoprotein effects, explained 5% to 10% of the variation in FVII mass and activity. In conclusion, the present findings speak against a role of FVII as a risk factor for CHD, because a significantly increased potential for activation of coagulation (ie, raised basal concentration of FVIIa) was not observed among young postinfarction patients. Prospective epidemiological studies including specific determination of FVIIa are needed to resolve the issue of whether FVII activity is a risk factor for CHD.
HDL-Mediated Efflux of Intracellular Cholesterol Is Impaired in Fibroblasts From Tangier Disease Patients
Authors: Rogler Gerhard , Trümbach Barbara , Klima Birgit , Lackner Karl J. , Schmitz Gerd
Published: June 2011

Abstract
To further elucidate the cellular mechanisms leading to HDL deficiency in Tangier disease, HDL-mediated cholesterol efflux was studied in cultured skin fibroblasts from Tangier patients. Both Tangier and control fibroblasts show specific saturable binding of HDL
3
to the cell membrane (B
max
= 70 and 52 ng/mg protein, respectively;
K
d
=8.8 and 10.6 μg/mL, respectively). There was no appreciable uptake of HDL
3
by Tangier and control fibroblasts, indicating that cholesterol efflux from fibroblasts occurs at the cell membrane. When cellular cholesterol was labeled to equilibrium by [
14
C]cholesterol incubation for 48 hours at 37°C, HDL
3
-mediated cholesterol efflux from Tangier fibroblasts was only 50% of control fibroblasts. To define this abnormality in HDL
3
-mediated cholesterol efflux more precisely, several additional experiments were performed. First, membrane desorption of cholesterol was determined after cell membranes were labeled with [
14
C]cholesterol for 3 hours at 15°C. With this labeling protocol, there was no difference in HDL
3
-mediated cholesterol efflux between control and Tangier fibroblasts. Second, efflux of newly synthesized sterols was determined after incorporation of the precursor [
14
C]mevalonolactone. Under these conditions, specific HDL
3
-mediated efflux of sterols was almost absent in Tangier fibroblasts. Third, cells were labeled by incubation with reconstituted [
3
H]cholesteryl-linoleate-LDL. Efflux of LDL-derived cholesterol was only slightly reduced for the first 4 hours of incubation. After 12 hours, there was no difference between control and Tangier cells. The combined data indicate that the reduced efflux of cholesterol from Tangier fibroblasts observed after homogeneous labeling is due to severely reduced efflux of newly synthesized sterol. Since it has been shown previously that efflux of newly synthesized cholesterol depends on HDL-mediated activation of protein kinase C (PKC), the effect of pharmacological activation of PKC was analyzed. Incubation of Tangier fibroblasts in the presence of 1,2-dioctanoylglycerol (10
−5
mol/L), a membrane-permeable activator of PKC, led to normalization of HDL
3
-mediated efflux of newly synthesized cholesterol. These data were interpreted to indicate that impaired activation of PKC rather than a defect in the transport mechanism of cellular cholesterol leads to reduced HDL-mediated efflux of cholesterol from Tangier fibroblasts.
Myocardial Infarction and Cardiovascular Risk Factors in Mexico City and San Antonio, Texas
Authors: Mitchell Braxton D. , Villalpando Clicerio González , Pérez Beatriz Arredondo , García Mario Seoane , Valdez Rodolfo , Stern Michael P.
Published: June 2011

Abstract
Because the epidemiology of cardiovascular disease in Mexico is largely unknown, we examined the prevalence of cardiovascular risk factors and myocardial infarction (MI) in adults from low-income colonias in Mexico City. Data were collected as part of the Mexico City Diabetes Study, a population-based survey of diabetes and cardiovascular disease conducted between 1987 and 1992. Results were compared with those obtained from a comparable survey conducted previously among low-income Mexican Americans in San Antonio, Tex. A total of 2271 individuals between the ages of 35 and 64 years from Mexico City and 1143 adults of the same age range from San Antonio were studied. Despite being leaner and having lower levels of total cholesterol, Mexicans in Mexico City had markedly higher levels of triglycerides (
P
<.001) and lower levels of HDL cholesterol (
P
<.001) than Mexican Americans in San Antonio. MI was assessed by Minnesota-coded electrocardiograms and by a self-reported history of physician-diagnosed heart attack. In men, the prevalence of self-reported heart attack was significantly higher in San Antonio than in Mexico City (odds ratio, 5.85;
P
<.001), and in women, the prevalence of electrocardiogram-documented MI was significantly higher in San Antonio than Mexico City (odds ratio, 2.51;
P
<.001). The apparent excess of MI in San Antonio relative to Mexico City could be due to higher case-fatality in Mexico City or to a higher incidence in San Antonio.
A Novel Variant of Lysosomal Acid Lipase (Leu
336
→Pro) Associated With Acid Lipase Deficiency and Cholesterol Ester Storage Disease
Authors: Seedorf Udo , Wiebusch Heiko , Muntoni Sandro , Christensen Niels C. , Skovby Flemming , Nickel Volker , Roskos Martin , Funke Harald , Ose Leiv , Assmann Gerd
Published: June 2011

Abstract
Cholesterol ester storage disease (CESD) is associated with premature atherosclerosis, hepatomegaly, elevated LDL cholesterol levels, and in most cases, low HDL cholesterol levels. Previous studies have shown a G→A mutation at the 3′ splice junction of exon 8 (E8SJM) of the gene encoding lysosomal acid lipase (LAL) in two kindreds with CESD. In a Canadian-Norwegian kindred with this disease, we show this mutation in conjunction with an as yet unknown T→C transition in exon 10 predicting a Leu
336
→Pro (L336P) replacement and an A→C transversion in exon 2 predicting a T-6P replacement in the prepeptide. Identification of the L336P rather than the T-6P replacement as the second defect underlying CESD in our patient is deduced from three lines of evidence. First, the E8SJM allele is located in
cis
with the mutation predicting the T-6P–encoding allele but in
trans
with the L336P-encoding allele; second, the L336P but not the T-6P replacement cosegregates with low LAL activity in the family; third, the T-6P replacement was found in 6 of 28 alleles from subjects with normal lysosomal acid lipase activity, suggesting that this variant represents a frequent nonfunctional polymorphism. Since the residual LAL activity is higher and the clinical phenotype based on plasma lipid values and severity of hepatosplenomegaly is milder in this case than in a previously studied case who was homozygous for the E8SJM allele, we conclude that the L336P variant appears to be associated with a phenotypically mild form of CESD.
Adsorption and Coagulability of Fibrinogen on Atheromatous Lipid Surfaces
Authors: Retzinger Gregory S.
Published: June 2011

AbstractFibrinogen, the precursor of the blood clot matrix and a major constituent of atherosclerotic lesions, is shown to adsorb with high affinity to hydrophobic beads coated with cholesteryl oleate, cholesterol, or loosely packed lecithin. The quantity of fibrinogen that binds to cholesterol- or lecithin-coated beads decreases as the surface concentration of the lipid increases; densely packed films of lecithin bind little, if any, of the protein. In sharp contrast, the appreciable quantity of fibrinogen that binds to cholesteryl oleate–coated beads is indifferent to the surface concentration of that lipid. Not unexpectedly, the quantity of fibrinogen that binds to beads coated with mixtures of cholesteryl oleate and lecithin increases with increasing concentration of the cholesteryl ester. When bound, fibrinogen can be converted by thrombin to fibrin and nucleate clot formation as manifested by the aggregation of stirred beads. These results indicate that hydrophobic, atheromatous lipid surfaces, particularly those rich in cholesteryl esters, may be predisposed to thrombosis by virtue of their inherent capacity to bind functional fibrinogen.
Thrombotic Thrombocytopenia Induced in Dogs and Pigs
Authors: Sanders William E. , Reddick Robert L. , Nichols Timothy C. , Brinkhous Kenneth M. , Read Marjorie S.
Published: June 2011

Abstract
Thrombotic thrombocytopenia with severe depletion of plasma von Willebrand factor (vWF) was induced in normal large animals (5 dogs and 2 pigs) by botrocetin, a
Bothrops
factor requiring vWF for platelet agglutination. Botrocetin (90 to 100 U/kg, 2.14 to 2.38 mg/kg, in a single IV injection) reduced plasma vWF activity to <0.1 U/mL for 24 hours. During this period, multimeric analysis of plasma vWF antigen (Ag) revealed the loss of intermediate- and high-molecular-weight forms with a concomitant increase in lower molecular weight forms. A moderate reduction in factor VIII (FVIII) activity was observed. The vWF reduction was accompanied by transient thrombocytopenia and prolonged bleeding times during the deficiency state. Occlusive platelet thrombi were detected by transmission electron microscopy in the microcirculation of lung and spleen but not kidney or brain 30 minutes after the botrocetin injection. Recovery of plasma vWF and platelet count occurred within 48 hours and was associated with the appearance in the plasma of unusually large forms of vWF:Ag multimers. The vWF:Ag multimer distribution was normal at 72 hours. The ultrastructural distribution of vWF in unstimulated normal porcine and canine platelets was examined by using immunogold staining. VWF was detected in the α-granules of normal pig platelets but was not observed in platelets from normal dogs. However, both animals developed thrombotic thrombocytopenia when injected with botrocetin. A second group of animals (2 dogs and 3 pigs) with von Willebrand disease (vWD) was given a single botrocetin injection (90 to 100 U/kg). No thrombocytopenia occurred. Electron photomicrographs showed no platelet thrombi in any tissues examined. Porcine and canine platelets from vWD animals exhibited no specific labeling of vWF in any α-granule. The vWD animals were entirely protected from the thrombocytopenia and thrombogenic action of botrocetin. These data suggest that plasma vWF but not platelet vWF is required for the intravascular platelet and microthrombotic response and that the thrombotic thrombocytopenic syndrome cannot be induced in the absence of plasma vWF.
Effect of 17α-Dihydroequilin Sulfate, a Conjugated Equine Estrogen, and Ethynylestradiol on Atherosclerosis in Cholesterol-Fed Rabbits
Authors: Sulistiyani  , Adelman S. J. , Chandrasekaran A. , Jayo J. , St. Clair R. W.
Published: June 2011

Abstract
The effect of 17α-dihydroequilin sulfate (DHES), a water-soluble estrogen of conjugated estrogens (Premarin), and ethynylestradiol (EE), a commonly used estrogen found in many oral contraceptives, on the development of atherosclerosis was studied in rabbits fed an atherogenic diet (0.2% cholesterol) for 24 weeks. Ten animals were given 15 μg ·kg
−1
· d
−1
EE, 10 received 3.8 mg · kg
−1
· d
−1
of DHES, and the remaining 10 sham-ovariectomized and 10 ovariectomized animals served as cholesterol-fed controls. These doses were chosen to have similar estrogenic potency. Plasma cholesterol concentrations increased to about 900 mg/dL and did not differ among the experimental groups. After 24 weeks, plasma β-VLDL and HDL cholesterol concentrations were the same for all cholesterol-fed groups, while LDL cholesterol was significantly higher in the two estrogen-treated groups. In spite of this, both EE and DHES significantly reduced atherosclerosis by 35% in the aortic arch and 75% to 80% in the thoracic and abdominal aorta. The reduction in atherosclerosis was seen in animals with a wide range (400 to 1400 mg/dL) of plasma cholesterol concentrations and was independent of lipoprotein profile. β-VLDL isolated from estrogen-treated animals was not significantly different from control β-VLDL in its ability to stimulate cholesterol accumulation in THP-1 macrophages in culture. This suggests that the protective effect of estrogens on the development of atherosclerosis is not mediated by qualitative differences in β-VLDL that affect uptake by macrophages. The results of this study extend our knowledge of the range of estrogens that reduce atherosclerosis. Given the lack of effect on plasma lipid and lipoprotein concentrations, these data are consistent with the conclusion that estrogens exert some of this beneficial effect directly at the level of the arterial wall by influencing certain key components in the pathogenesis of atherosclerosis.
TGF-β and Endothelial Cells Inhibit VCAM-1 Expression on Human Vascular Smooth Muscle Cells
Authors: Gamble Jennifer R. , Bradley Sandy , Noack Leanne , Vadas Mathew A.
Published: June 2011

AbstractVascular smooth muscle cells (VSMCs) are normally devoid of the adhesion protein vascular cell adhesion molecule–1 (VCAM-1), which has, however, been observed on human VSMCs in atheroma. We now show that cultured human saphenous vein VSMCs express small amounts of VCAM-1 and that the cytokine tumor necrosis factor–α (TNF-α) induces, in a time- and dose-dependent fashion, a significant increase in its expression. Interleukin (IL)-4, IL-1, and to a lesser extent interferon gamma have similar effects. TNF-α–stimulated human VSMCs demonstrate increased binding of T lymphocytes that is totally VCAM-1 mediated. The cytokine transforming growth factor–β (TGF-β) at 2.0 ng/mL inhibited basal VCAM-1 expression by 84±8% and the induction by TNF-α by between 56±16% and 77±15% depending on the dose of TNF. Furthermore, coculture on opposing sides of a polycarbonate filter of human VSMCs with human umbilical vein endothelial cells also inhibited the induction of VCAM-1 by 47±6%. As active TGF-β is produced upon the coculture of VSMCs and endothelial cells, we suggest that the close physical proximity of these cells in vivo is responsible for the lack of expression of VCAM-1 on VSMCs and that the interruption of this contact in atheroma is an important pathogenic event. As VCAM-1 not only serves as an adhesion molecule but also as a costimulator of immune cells, its expression may be crucial in the propagation of vascular lesions.