| 1. |
- Karlöf, Eva, et al.
(författare)
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Correlation of computed tomography with carotid plaque transcriptomes associates calcification with lesion-stabilization
- 2019
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Ingår i: Atherosclerosis. - Stockholm : ELSEVIER IRELAND LTD. - 0021-9150 .- 1879-1484. ; 288, s. 175-185
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: Unstable carotid atherosclerosis causes stroke, but methods to identify patients and lesions at risk are lacking. We recently found enrichment of genes associated with calcification in carotid plaques from asymptomatic patients. Here, we hypothesized that calcification represents a stabilising feature of plaques and investigated how macro-calcification, as estimated by computed tomography (CT), correlates with gene expression profiles in lesions. Methods: Plaque calcification was measured in pre-operative CT angiographies. Plaques were sorted into high- and low-calcified, profiled with microarrays, followed by bioinformatic analyses. Immunohistochemistry and qPCR were performed to evaluate the findings in plaques and arteries with medial calcification from chronic kidney disease patients. Results: Smooth muscle cell (SMC) markers were upregulated in high-calcified plaques and calcified plaques from symptomatic patients, whereas macrophage markers were downregulated. The most enriched processes in high-calcified plaques were related to SMCs and extracellular matrix (ECM) organization, while inflammation, lipid transport and chemokine signaling were repressed. These findings were confirmed in arteries with high medial calcification. Proteoglycan 4 (PRG4) was identified as the most upregulated gene in association with plaque calcification and found in the ECM, SMA+ and CD68+/TRAP + cells. Conclusions: Macro-calcification in carotid lesions correlated with a transcriptional profile typical for stable plaques, with altered SMC phenotype and ECM composition and repressed inflammation. PRG4, previously not described in atherosclerosis, was enriched in the calcified ECM and localized to activated macrophages and smooth muscle-like cells. This study strengthens the notion that assessment of calcification may aid evaluation of plaque phenotype and stroke risk.
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| 2. |
- Peacock, Rachel E., et al.
(författare)
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Associations between lipoprotein lipase gene polymorphisms and plasma correlations of lipids, lipoproteins and lipase activities in young myocardial infarction survivors and age-matched healthy individuals from Sweden
- 1992
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 97:2-3, s. 171-185
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Tidskriftsartikel (refereegranskat)abstract
- Association studies were carried out on a sample of 87 patients from Sweden who had survived a myocardial infarction (MI) at a young age and 93 age-matched healthy individuals, to compare the impact of polymorphisms (PvuII, HindIII and Serine447-Stop) at the lipoprotein lipase (LPL) gene locus on among-individual differences in plasma lipid traits and progression of atherosclerosis. Significant linkage disequilibrium was detected between any two of these polymorphisms, with the Stop447 allele being only found on the same chromosome as the rare alleles (no cutting sites) of the PvuII and HindIII polymorphisms. In the healthy individuals, weak associations were found between genotypes of the HindIII polymorphism and triglycerides and the PvuII polymorphism and high density lipoprotein cholesterol explaining 7.4% and 5.6% of sample variance (P = 0.03 and 0.09), respectively. No associations were found between these traits and genotypes of the Serine447-Stop substitution, and thus it is unlikely to be the cause of the associations seen with the PvuII and HindIII polymorphisms even though it truncates the enzyme amino acid sequence. The presence of the rare allele, H-, of the HindIII polymorphism was associated with a smaller variance in triglycerides and both cholesterol and triglycerides in the very low density lipoprotein fraction, and with larger interdependent variation between these lipid traits, and also between LPL activity and these lipid traits. This implies that the H- allele, rather than the Stop447 allele, has the major impact on interdependence between traits which are directly or indirectly influenced by LPL activity. In the healthy individuals who were carriers of the apolipoprotein E2 allele, the inter-dependence between LPL activity and lipid traits was significantly smaller, and that between high density lipoprotein cholesterol and both cholesterol and triglycerides in the very low density lipoprotein fraction was much larger compared with non-carriers (P < 0.05). No significant associations were found between lipid traits or lipase activity and genotypes of the Serine447-Stop substitution. However, in the patients, global severity of coronary atherosclerosis at the first angiography was significantly associated with haplotype combinations of the HindIII and the Serine447-Stop polymorphisms, with the H-Stop haplotype being associated with the highest median score (P = 0.02). The data suggest that variation at the LPL gene locus is associated with a pleiotropic effect, that is not directly mediated by changes in lipids, on severity of coronary atherosclerosis.
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| 3. |
- Quensel, M, et al.
(författare)
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High density lipoprotein concentrations after cessation of smoking: the importance of alterations in diet
- 1989
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 75:2-3, s. 189-193
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Tidskriftsartikel (refereegranskat)abstract
- Cessation of smoking is followed by a rapid rise in plasma HDL concentrations. An earlier study has demonstrated a significant relationship between the increase in HDL concentrations and spontaneous changes in food intake, specifically an increased fat intake. In this investigation we have dissociated the effects of cessation of smoking as such from those of dietary alterations by monitoring plasma lipid and lipoprotein concentrations after cessation of smoking in 12 subjects whose diet was kept constant during an initial 2-week control period and during 2 weeks following cessation of smoking. Under these conditions plasma HDL-cholesterol levels did not increase significantly (1.01 +/- 0.26 mmol/l (mean +/- SD) before and 1.04 +/- 0.27 mmol/l after cessation of smoking). Similarly, no significant alterations were recorded for other plasma lipid or lipoprotein concentrations. Activities of lipoprotein lipase and hepatic lipase were unchanged throughout the study. These results suggest that the marked rise in HDL concentrations after stopping smoking is largely related to spontaneous changes in dietary habits which occur upon cessation of smoking.
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| 4. |
- Tornvall, P, et al.
(författare)
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Autoantibodies against modified low-density lipoproteins in coronary artery disease
- 2003
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Ingår i: Atherosclerosis. - 1879-1484 .- 0021-9150. ; 167:2, s. 347-353
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To evaluate the importance of different autoantibodies against modified low-density lipoprotein (LDL) in patients with coronary artery disease (CAD). Background: Previous studies of autoantibodies against LDL have shown that patients with CAD have increased titers of autoantibodies against LDL modified by copper and malondialdehyde (MDA), whereas there is a lack of information about autoantibody titers against LDL modified by hypochlorite (HOCl). Studies of autoantibodies in relation to severity of atherosclerosis are few and have reached divergent results. Furthermore, no data exist on the relationship between autoantibody titers and prognosis. Methods: Titers of autoantibodies against copper-, MDA- and HOCl-modified LDL were determined in serum by ELISA. Autoantibody titers in young male survivors of a first myocardial infarction were compared with those of healthy controls and related to coronary angiographic findings and to prognosis during I I years of follow-up. Results: Patients had higher titers of autoantibodies against LDL modified by copper and MDA than controls. In contrast, no consistent associations were found between autoantibody titers and global severity of coronary atherosclerosis or number and severity of coronary stenoses and prognosis. Conclusions: The prognostic value of autoantibodies against modified LDL is limited in young postinfarction patients despite the fact that autoantibody titers against copper- and NIDA-modified LDL are raised compared with healthy controls. Furthermore, the results indicate that autoantibodies against modified LDL are not protective in later stages of coronary atherosclerosis. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.
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| 5. |
- Carlson, Lars A., et al.
(författare)
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A case of massive hypertriglyceridemia corrected by nicotinic acid or nicotinamide therapy
- 1972
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 16:3, s. 359-368
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Tidskriftsartikel (refereegranskat)abstract
- A case of massive hypertriglyceridemia with fasting plasma triglycerides around 100 mmoles/l is described. Large amounts of chylomicra were present in fasting plasma and the amounts of low-density and high-density lipoproteins were very low. Postheparin plasma lipolytic activity was normal and intravenous heparin rapidly cleared the patient's abnormally prolonged alimentary lipemia with a concomitant rise in plasma free fatty acid levels.Nicotinic acid or nictotinamide given in doses of 3 g or more daily reduced plasma triglyceride levels to about 2–3 mmoles/1 and raised the reduced levels of low and high-density lipoproteins. The mode of onset of this therapeutic effect was slow and the effect persisted for several weeks after withdrawal of either nicotinic acid or nicotinamide.The pathogenesis of the hypertriglyceridemia as well as the mode of action of nicotinic acid and nicotinamide is discussed.
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| 6. |
- Carlson, Lars A., et al.
(författare)
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Effect of chlorophenoxyisobutyric acid (CPIB) on fat-mobilizing lipolysis and cyclic AMP levels in rat epididymal fat
- 1972
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 16:3, s. 349-357
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Tidskriftsartikel (refereegranskat)abstract
- High concentrations of chlorophenoxyisobutyric acid (CPIB) reduced basal glycerol release from rat epididymal fat pads in vitro and antagonized the lipolytic effects of noradrenaline. Furthermore, very high concentrations of CPIB significantly antagonized the effects or noradrenaline or ACTH on cyclic AMP accumulation by isolated rat adipocytes. These data are not incompatible with the hypothesis that a primary mechanism in the hypolipidemic action of CPIB is to lower the levels of cyclic AMP in adipose tissue, resulting in decreased hormone-sensitive lipase activity and/or increased lipoprotein lipase activity.
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| 7. |
- Eriksson, Jan, et al.
(författare)
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Postprandial regulation of blood lipids and adipose tissue lipoprotein lipase in type 2 diabetes patients and healthy control subjects
- 2003
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Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 166:2, s. 359-367
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Tidskriftsartikel (refereegranskat)abstract
- Background/aim: In type 2 diabetes and other insulin-resistant conditions, postprandial hypertriglyceridaemia is an important metabolic perturbation. To further elucidate alterations in the clearance of triglyceride-rich lipoproteins in type 2 diabetes we focused on the nutritional regulation of adipose tissue lipoprotein lipase (LPL).Subjects and methods: Eight subjects with type 2 diabetes and eight age-, sex- and body mass index (BMI)-matched control subjects underwent subcutaneous abdominal adipose tissue biopsies in the fasting state and 3.5 h following a standardized lipid-enriched meal. LPL activity and mass were measured in adipose tissue and also in plasma after an intravenous injection of heparin.Results: Postprandial, but not fasting, triglycerides were significantly higher in the diabetic subjects than in the control subjects (3.0±0.4 vs 2.0±0.2 mmol/l, P=0.028). Adipose tissue LPL activity was increased following the meal test by ∼35–55% (P=0.021 and 0.004, respectively). There was no significant difference between the groups in this respect. The specific enzyme activity of LPL was not altered in the postprandial state. Fasting and postprandial adipose tissue LPL activity as well as post-heparin plasma LPL activity tended to be lower among the diabetes patients (NS). There was a significant and independent inverse association between insulin resistance (homeostasis model assessment insulin resistance (HOMA-IR) index) vs post-heparin plasma LPL activity and postprandial triglyceride levels, respectively. Adipose tissue LPL activity was related to insulin action in vitro on adipocyte glucose transport, but not to HOMA-IR.Conclusion: Following food intake adipose tissue LPL activity is enhanced to a similar degree in patients with type 2 diabetes and in healthy control subjects matched for BMI, age and gender. If LPL dysregulation is involved in the postprandial hypertriglyceridaemia found in type 2 diabetes, it should occur in tissues other than subcutaneous fat.
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| 8. |
- Holmlund, A., et al.
(författare)
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Soluble intercellular adhesion molecule-1 is related to endothelial vasodilatory function in healthy individuals
- 2002
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 165:2, s. 271-276
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate the associations between markers of systemic and vascular inflammation, and indicators of vascular morphology and function. METHODS: In 59 apparently healthy individuals, we measured serum levels of highly sensitive C-reactive protein (hsCRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Endothelium-dependent (EDV) and -independent (EIDV) vasodilatation was evaluated in the forearm by venous occlusion plethysmography and local infusions of methacholine and sodium nitroprussid. Endothelial function index (EFI) was expressed as the EDV/EIDV ratio. The intima-media thickness (IMT) of the common carotid artery was investigated with ultrasound (far wall). RESULTS: EFI was inversely related only to ICAM-1 (r=-0.31, P<0.02) by univariate analysis. This association remained significant after adjustment for age, sex, blood pressure, smoking and serum cholesterol. EFI did not relate to hsCRP, VCAM-1 or E-selectin. Neither hsCRP, nor the adhesion molecules were significantly related to carotid artery IMT. CONCLUSION: ICAM-1 was related to endothelial vasodilatory function, but not to IMT, suggesting that endothelial inflammatory activation is related to an impaired vascular relaxation in apparently healthy individuals.
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| 9. |
- Krettek, Alexandra, 1968-, et al.
(författare)
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Expression of PDGF receptors and ligand-induced migration of partially differentiated human monocyte-derived macrophages. Influence of IFN-gamma and TGF-beta
- 2001
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Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 156:2, s. 267-275
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Tidskriftsartikel (refereegranskat)abstract
- In the early atherosclerotic lesion, monocytes accumulate at sites of inflammation and endothelial injury. Platelet-derived growth factor (PDGF), produced for example by macrophages, is a chemoattractant for smooth muscle cells and possibly also for macrophages. During early differentiation into macrophages, human monocytes (early hMDM) showed lower expression of PDGF alpha-receptor (PDGF-Ralpha) than beta-receptor (PDGF-Rbeta) mRNA. Early hMDM showed increased random motility (chemokinesis) in the presence of PDGF of the long (BB(L)) but not short (BB(S)) B-chain homodimer. Neither PDGF-AA(S) nor PDGF-AA(L) affected early hMDM motility. Since increased cytokine levels accompany inflammation, the influence of interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta) on PDGF-R expression and migratory response were studied. Only PDGF-Ralpha mRNA was highly upregulated by IFN-gamma. TGF-beta only had minor effects on receptor mRNAs. Upregulation of PDGF-Ralpha levels by IFN-gamma was accompanied by significantly increased migration (chemotaxis) towards PDGF-AA(L) only. Consequently, IFN-gamma modulates PDGF-Rs expression in early hMDM and, subsequently, the chemotactic activity of PDGF-AA(L) on IFN-gamma-stimulated early hMDM. This suggests that PDGF-AA(L) may be involved in attracting activated monocytes to sites of inflammation and injury.
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| 10. |
- Kristenson, Margareta, 1950-, et al.
(författare)
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Ultrasound determined carotid and femoral atherosclerosis in Lithuanian and Swedish men : The LiVicordia study
- 2000
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 151:2, s. 501-508
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Tidskriftsartikel (refereegranskat)abstract
- Coronary heart disease mortality is four times higher in Lithuanian compared to Swedish middle-aged men. Using the same equipment (Acuson XP10 with 5 MHz linear transducer) and staff, we compared the amount of atherosclerosis in carotid and femoral arteries in 100 randomly sampled 50-year-old men in each of the cities Vilnius, Lithuania and Linköping, Sweden. Atherosclerotic plaques were more abundant in Vilnius men compared to Linköping men (53 versus 28% in the common carotid artery, 73 versus 37% in the common femoral artery, P<0.001 for both). Plaques were thicker and more extended in arteries of Vilnius men, and an ultrasound atherosclerosis score was higher in both carotid and femoral arteries (P<0.001 for all). More Vilnius men had a maximal intima-media thickness of the common femoral artery above 1 mm (P<0.005). Stiffness in the common carotid artery was higher in Vilnius men (P<0.001). In a linear regression model of the pooled material, after adjustment for city was made, smoking, systolic blood pressure, low density lipoprotein cholesterol and β-carotene (inversely) significantly contributed to a high total ultrasound score (r2=0.32). These findings show that the higher coronary mortality noted in Lithuanian men goes together with a higher prevalence of early peripheral atherosclerosis.
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| 11. |
- Lindén, Tomas, et al.
(författare)
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Serum lipids, lipoprotein(a) and apo(a) isoforms in patients with established coronary artery disease and their relation to disease and prognosis after coronary by-pass surgery.
- 1998
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Ingår i: Atherosclerosis. - : Elsevier Ireland Ltd. - 0021-9150 .- 1879-1484. ; 137:1, s. 175-86
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Tidskriftsartikel (refereegranskat)abstract
- Consecutive patients (n=964) undergoing coronary angiography were studied and compared with a random population sample regarding serum lipids and lipoproteins with focus on lipoprotein(a) (Lp[a]) levels and apo(a) isoforms. The patients were also followed for 5 years after the angiography, and the prognostic value of serum lipoproteins were analyzed. The patients were divided in two groups: Group 1 (n=814) consisted of patients with angina pectoris and at least one coronary artery with 50% stenosis and group 2 (n=150) patients with none of the coronary arteries significantly obstructed ( < 50%). As controls a random population sample was selected (n=197). Blood samples were collected before coronary angiography for determination of serum lipids, Lp(a) and isoforms of apo(a). When group 1 and group 2 patients were compared, group 1 was found to have higher serum cholesterol, triglycerides, apoB and Lp(a) as well as lower HDL and apoAI. When group 1 was compared with the random sample, after correction for age and sex, similar differences were observed, except that the difference in Lp(a) was not significant. The high Lp(a) levels among patients was found to be primarily due to the female patients, where the difference compared to both group 2 and controls was highly significant (P=0.007 and P=0.001, respectively). There was a significant difference in the apo(a) isoform distribution between group 1 patients and control subjects (P=0.0003), with a higher frequency of low molecular weight isoforms among patients. This was also significant for the male subgroup (P=0.001). Lp(a), LDL, total cholesterol, triglycerides. apoB, HDL and apoAI were significantly related to the number of major coronary arteries with > 50% stenosis. Mortality during follow-up was,in a univariate analysis, significantly correlated to several factors related to the degree of heart disease and to LDL (P=0.02) and apoB (P < 0.01). Increased mortality was, however, related to low levels of apoB and LDL. For cardiac mortality no significant correlation to lipoprotein variables were found. In conclusion established lipoprotein risk factors were more frequent among patient with angina pectoris and verified coronary stenosis. Furthermore high Lp(a) levels and a high frequency of low molecular weight isoforms of apo(a) were found in coronary patients. Higher Lp(a) levels were observed both for female and male patients, the differences were, however, significant only for the female patients. None of the lipoprotein variables could predict coronary death during the follow-up period.
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| 12. |
- Neuger, Lucyna, et al.
(författare)
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Effects of the heparin-mimicking compound RG-13577 on lipoprotein lipase and on lipase mediated binding of LDL to cells
- 2001
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 157:1, s. 13-21
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Tidskriftsartikel (refereegranskat)abstract
- Lipoprotein lipase (LPL) has high affinity for heparin and heparin-like compounds. In vivo the enzyme is attached to heparan sulfate proteoglycans on the endothelium of capillaries and larger blood vessels. The enzyme is released from these sites after intravenous injection of heparin. One has here investigated the effects of RG-13577 on LPL, both after intravenous injection to rats and under cell culture conditions. RG-13577 is a heparin-mimicking compound known to prevent angiogenesis by interference with binding of growth factors to cells. It has therefore been considered for use in cancer therapy as well as for prevention of atherosclerosis and restenosis. It was found that intravenously injected RG-13577 released both LPL and hepatic lipase (HL) to the blood. Binding of LPL in extrahepatic tissues was prevented and clearance of radiolabeled LPL from the circulation was delayed. Furthermore, RG-13577 released LPL from extracellular matrix (ECM) produced by endothelial cells and from THP-1 monocyte-derived macrophages. Lipase-mediated binding and uptake of human LDL in these cells was also prevented by RG-13577. Thus, in the test systems RG-13577 had the same effects as heparin, but on a molar basis RG-13577 was in all cases less effective.
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| 13. |
- Nielsen, Niels Erik, et al.
(författare)
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Plasma total homocysteine levels in postmenopausal women with unstable coronary artery disease
- 2000
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 151:2, s. 423-431
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Tidskriftsartikel (refereegranskat)abstract
- An elevated plasma total homocysteine (tHcy) level is considered a risk factor for coronary artery disease (CAD), but the relationship between plasma tHcy and well-defined CAD in women is still unclear. Plasma tHcy concentrations and the covariates serum folate, vitamin B12, and creatinine were analysed in 157 angiographically examined postmenopausal women with unstable CAD and in 101 healthy controls. At coronary angiography, 16% had normal vessels and 84% had coronary atherosclerosis. Mean plasma tHcy concentration (μmol/l, 95% confidence interval) did not differ in patients compared to controls (13.1 (12.3–13.8) vs. 12.5 (11.6–13.5)) or in patients with or without coronary atherosclerosis (13.3 (12.4–14.1) vs. 12.0 (10.8–13.2)). A trend to an increasing plasma tHcy with increasing degree of coronary atherosclerosis was attenuated after adjustment for age and the previous mentioned covariates. Odds ratio for the risk of coronary artery disease and coronary atherosclerosis in hyperhomocysteinemic patients (≥90th percentile in controls) was approximately 3. However, the confidence interval included unity in half of the groups and the significance was therefore difficult to judge. Receiver operating characteristics showed age to be the only variable with a significant discriminatory ability regarding the presence of coronary atherosclerosis (area 0.77). Mild hyperhomocysteinemia seems not to be related to the risk of unstable CAD in postmenopausal women. The trend towards higher plasma tHcy with increasing degree of coronary atherosclerosis may be a marker of the disease. In future studies adjustment for age and the other three covariates should be considered.
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| 14. |
- Ohrvall, M, et al.
(författare)
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The serum cholesterol ester fatty acid composition but not the serum concentration of alpha tocopherol predicts the development of myocardial infarction in 50-year-old men : 19 years follow-up.
- 1996
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 127:1, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- A low serum tocopherol concentration and a low proportion of linoleic acid in plasma cholesterol esters have been reported to be associated with coronary heart disease. This study was undertaken to evaluate the predictive importance of the serum cholesterol ester fatty acid composition and serum tocopherol concentration in addition to established risk factors for myocardial infarction. The study comprised 2322 fifty-year-old men who participated in a health survey in 1970-1973 regarding risk factors for coronary heart disease. The proportions of myristic, palmitic, palmitoleic, and dihomogammalinolenic acid were significantly higher in 1970-1973 in subjects who suffered myocardial infarction during the following 19 years, while the proportion of linoleic acid was lower, than in those who remained healthy. Serum tocopherol did not differ significantly between the groups. LDL/HDL ratio, systolic blood pressure, and arachidonic acid/dihomogammalinolenic acid ratio were significant independent discriminators between cases and controls in a stepwise logistic regression analysis. This study suggests that middle-aged men who later develop a myocardial infarction are characterized not only by conventional risk factors but also by an altered fatty acid composition of serum cholesterol esters, with a low arachidonic to dihomogammalinolenic acid ratio, indicating reduced delta 5 desaturase activity. This may imply that changes in the quality of dietary fat intake, or an altered capacity to metabolize fatty acids in the body, could precede the development of coronary heart disease.
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| 15. |
- Sarabi, Mahziar, et al.
(författare)
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Endothelium-dependent vasodilation is related to the fatty acid composition of serum lipids in healthy subjects
- 2001
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 156:2, s. 349-355
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The fatty acid (FA) composition of the serum lipids has been associated with cardiovascular disease (CVD). As an attenuated endothelium-dependent vasodilation (EDV) has been suggested as an early marker of atherosclerosis, we investigated the relationships between the proportion of FA in serum lipids (cholesterol esters and phospholipids) together with the levels of serum LDL- and HDL-cholesterol and triglycerides and EDV, as well as endothelium-independent vasodilation (EIDV). Fifty-six healthy subjects (31 men and 25 women), aged between 20 and 69 years, underwent measurements of forearm blood flow (FBF) at rest and during local infusion of 2 and 4 microg/min of metacholine (Mch, evaluating EDV), 5 and 10 microg/min of sodium nitroprusside (SNP, evaluating endothelium-independent vasodilation, EIDV) using venous occlusion plethysmography. An index of endothelial function was calculated as the ratio between EDV and EIDV. The proportion of palmitic (16:0) and palmitoleic (16:1) acids were inversely related (r=-0.35 and -0.35, P<0.01 for both), while linoleic acid (18:2 n6) and the HDL-cholesterol concentration were positively related (r=0.35 and 0.36, P<0.01 for both) to the endothelial function index. In multiple regression analysis also including age and gender, palmitoleic acid and HDL-cholesterol were significant independent predictors of endothelial function. Alfa-linolenic acid (18:3 n3) was positively correlated to both EDV and EIDV (r=0.40 and 0.43, P<0.01 for both), indicating a protective effect of this essential FA on vasodilation in general. It is concluded that the FA composition of serum lipids, partly reflecting the composition of dietary fat and previously associated with the development of CVD, was associated with endothelial function in apparently healthy subjects.
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| 16. |
- Steer, Peter, et al.
(författare)
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Vitamin C, diclophenac and L-arginine protect endothelium-dependent vasodilation against elevated circulating fatty acid levels in humans
- 2003
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 168:1, s. 65-72
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Tidskriftsartikel (refereegranskat)abstract
- An acute elevation of circulating non-esterified fatty acids (NEFAs) has previously been shown to impair endothelium-dependent vasodilation (EDV). In this study, we investigated if local administration of vitamin C (n=8, 18 mg/min), L-arginine (n=8, 12.5 mg/min), or the cyclooxygenase (COX) inhibitor diclophenac (n=8, 0.5 mg/min) can counteract the endothelial dysfunction seen during infusion of Intralipid plus heparin (n=10). EDV and endothelium-independent vasodilation (EIDV) were studied in the forearm after local administration of methacholine chloride (Mch; 2 and 4 microg/min) and sodium nitroprusside (SNP; 5 and 10 microg/min). Forearm blood flow (FBF) was determined with venous occlusion plethysmography. Intralipid and heparin increased circulating NEFA levels sevenfold and impaired EDV (P<0.001 vs baseline). Concomitant administration of L-arginine or diclophenac abolished the NEFA-induced impairment in EDV. Concomitant vitamin C administration actually improved EDV (P<0.05 vs baseline). NEFA elevation increased EIDV (P<0.01), but this effect was not significant after L-arginine or diclophenac infusions. In conclusion, an acute elevation of circulating NEFAs led to impaired EDV. Administration of L-arginine, vitamin C or COX inhibition abolished this effect, suggesting that NEFAs might interact with endothelial vasodilatory function through multiple mechanisms.
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| 17. |
- Yuan, XiMing, et al.
(författare)
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Iron in human atheroma and LDL oxidation by macrophages following erythrophagocytosis
- 1996
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Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 124:1, s. 61-73
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Tidskriftsartikel (refereegranskat)abstract
- The oxidative modification of low density lipoprotein (LDL) has been implicated as an early step in the formation of atheromatous lesions. In vitro studies suggest it to be accelerated, or even initiated, by transition metals such as iron or copper in combination with a reducing agent. Even if such metals have been demonstrated in atheroma gruels, their origin and precise localisation within human atheroma are presently unknown. In the initial part of this study we applied Pearl's method, energy dispersive X-ray microanalysis, and a modified Timm sulphide silver method (SSM) to demonstrate the occurrence of iron in early atherosclerotic lesions from a number of consecutive autopsy cases with evident, general atheromatosis. With the very sensitive SSM, but not with the other techniques, we found foam cells to contain heavy metals with a mainly lysosomal localization. On the basis of the hypothesis that such a lysosomal accumulation of iron might be due to erythrophagocytosis by migrating tissue-bound macrophages that later develop into foam cells, we designed an in vitro model system where human monocyte-derived macrophages were exposed to artificially aged, UV-exposed erythrocytes. The macrophages were then exposed to LDL in serum-and iron-free RPMI medium, occasionally in the presence of the potent iron-chelator desferrioxamine. The capacity of macrophages to oxidise LDL was much enhanced following erythrophagocytosis, and the process was shown to involve secretion of iron. Consequently, LDL oxidation was greatly inhibited by desferrioxamine. We conclude that iron may be exocytosed by macrophages that previously had their lysosomal apparatus enriched with iron, e.g. due to erythrophagocytosis. Oxidation of LDL may result in ensuing foam cell-formation secondary to scavenger-receptor mediated endocytosis by macrophages.
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| 18. |
- Yuan, XiMing, et al.
(författare)
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The toxicity to macrophages of oxidized low-density lipoprotein is mediated through lysosomal damage
- 1997
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Ingår i: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 133:2, s. 153-61
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Tidskriftsartikel (refereegranskat)abstract
- Oxidized low-density lipoprotein (ox-LDL) has been shown to degrade poorly within the secondary lysosomes of macrophages but its possible effect on lysosomal integrity has received less attention. The effect of ultraviolet-C oxidized LDL (UVox-LDL) on cellular viability, and lysosomal membrane stability, was examined on cultured murine J-774 cells and human monocyte-derived macrophages (HMDMs). The acridine orange (AO) relocalization test was applied to study the lysosomal integrity of living cells. UVox-LDL dramatically reduced J-774 cell proliferation at a concentration of 25 microg/ml. Incubation with 5 microM copper alone, normally used to induce LDL oxidation, was also toxic. In contrast to the effects of ox-LDL, in concentrations up to 75 microg/ml, native LDL (nLDL) rather stimulated J-774 cell replication. Incubation with UVox-LDL (25-75 microg/ml) also altered cellular AO uptake, depending on time and dose: its lysosomal accumulation decreased and its cytosolic accumulation increased. This shift indicates damaged lysosomal membranes with decreased intralysosomal, and increased cytosolic, H+ concentration. Many J-774 cells exposed to UVox-LDL initially transformed into foam cells and then assumed an apoptotic-type morphology with TUNEL-positive nuclei. We conclude that ox-LDL is cytotoxic to macrophages due to oxidative damage of lysosomal membranes, with ensuing destabilization and leakage to the cytosol of lysosomal contents, such as hydrolytic enzymes, causing degeneration of apoptotic type.
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| 20. |
- Abedpour Dehkordi, Adel, et al.
(författare)
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Interleukin-6 reduces paraoxonase-1 activity in a dose-dependent manner : evidence for a potential novel lipoprotein-based modulatory mechanism
- 2016
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Ingår i: Atherosclerosis. - : Elsevier. - 0021-9150 .- 1879-1484. ; 252, s. E113-E114
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Objectives: The anti-oxidant/anti-inflammatory nature of HDL is mainly associated with paraoxonase-1 (PON1). Previous studies have revealed an inverse correlation between Interleukin-6 (IL-6) and PON1 expression. The current study investigates the effect of IL-6 on serum PON1 activity in vitro, given the potential structural capability of PON1 to host multiple ligands. Methods: PON1 activity was measured spectrophotometrically (234 nm) using paraoxon substrate in the presence of concentrations of IL-6 than control samples. A sequence alignment using the FASTA sequence was manually conducted to identify possible homologies between PON1 and the IL-6-binding protein. Statistical analysis was conducted using GraphPad Prism v5.0. Results: PON1 enzyme activity decreased by 15%, 26% (P<0.05) and 55% (P<0.001) in the presence of 4, 10 and 20 pg/ml of IL-6, respectively. in comparison with the controls. Student t. test was used as statistical method (p<0.05: statistically significant). There are potential homologies between PON1 active sites and know IL-6-binding residues. Conclusions: This study shows that IL-6 directly reduce the PON1 activity in a dose-dependent manner. This observation supports some studies indicating inverse correlation between PON1 and IL-6. However, as opposed to the gene-mediated approach, this study suggest that IL-6 may act directly through specific binding to PON1 (biochemical modulation). X ray crystallography can further scrutinize the present finding.
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| 21. |
- Adamsson Eryd, Samuel, et al.
(författare)
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Carotid intima-media thickness is associated with incidence of hospitalized atrial fibrillation.
- 2014
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 233:2, s. 673-678
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Tidskriftsartikel (refereegranskat)abstract
- Carotid intima-media thickness (IMT) is a measure of arterial thickening and a risk predictor for myocardial infarction and stroke. It is unclear whether IMT also predicts atrial fibrillation (AF). We explored the association between IMT and incidence of first AF hospitalization in a population-based cohort.
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| 22. |
- Adiels, Martin, 1976, et al.
(författare)
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Postprandial accumulation of chylomicrons and chylomicron remnants is determined by the clearance capacity.
- 2012
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 222:1, s. 222-8
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Tidskriftsartikel (refereegranskat)abstract
- Objective To better understand the postprandial clearance of triglyceride-rich lipoproteins (TRLs) and its relation to the fasting kinetics of TRLs. Methods Two studies were performed on 30 male subjects: a fasting kinetic study to determine the fasting secretion and clearance rates of apolipoprotein B (apoB) 100 and triglycerides in the very low-density lipoprotein 1 and 2 (VLDL1 and VLDL2) fractions; and a postprandial study to determine the postprandial accumulation of apoB48, apoB100 and triglycerides in the chylomicron, VLDL1 and VLDL2 fractions. Results from these two studies were combined to characterize the postprandial clearance of TRLs in a physiologically relevant setting. Results Our results show that postprandial accumulation of the apoB48-carrying chylomicrons can be predicted from the clearance capacity of the lipolytic pathway, determined in the fasting state. Furthermore, we show that chylomicrons and VLDL1 particles are not cleared equally by the lipoprotein lipase pathway, and that chylomicrons seem to be the preferred substrate. Subjects with a rapid fasting lipid metabolism accumulate lower levels of postprandial triglycerides with less accumulation of apoB100 in the VLDL1 fraction and a faster transfer of apoB100 into the VLDL2 fraction. In contrast, fasting VLDL1 secretion does not predict postprandial triglyceride accumulation. Conclusions Non-fasting triglyceride levels have recently been identified as a major predictor of future cardiovascular events. Here we show that the capacity of the lipolytic pathway is a common determinant of both the fasting and non-fasting triglyceride levels and may thus play an important role in the development of dyslipemia and atherosclerosis.
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