| 1. |
- Li, Wei, et al.
(author)
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NK cell apoptosis in coronary artery disease. Relation to oxidative stress
- 2008
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In: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 199:1, s. 65-72
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Journal article (peer-reviewed)abstract
- Objective: Natural killer (NK) cells, key elements in initiation and modulation of immune responses, were recently found to be reduced in coronary artery disease (CAD). To clarify mechanisms behind this reduction, we here investigated NK cell apoptosis in CAD patients. Since oxidative stress has been linked to NK cell apoptosis, we related the findings to oxidative stress in vivo and evaluated the ex vivo susceptibility of NK cells to oxidized lipids. Methods and results: The number of apoptotic NK cells in peripheral blood was significantly increased in CAD patients compared to controls. Purified NK cells from CAD patients also showed a higher rate of spontaneous apoptosis ex vivo. Dose- and time-dependent effects of oxidized LDL and 7β-hydroxycholesterol (7βOH) on apoptosis and ROS production were determined in NK cells from blood donors. Thereafter, purified NK cells from CAD patients and healthy controls were exposed to the oxidized lipids in a paired design. NK cells from patients were more susceptible to apoptosis induced by oxidized LDL, in particular 7βOH, compared to cells from controls. Plasma measurements of LDL protein oxidation and lipid peroxidation did not show any differences between patients and controls. On the other hand, plasma carotenoids were significantly decreased in patients and inversely correlated to NK cell apoptosis rate. Conclusion: The rate of spontaneous NK cell apoptosis was increased in CAD patients. Although NK cells in CAD patients were more sensitive to oxidized lipids ex vivo, indicating a mechanism contributing to the reduced NK cell activity in CAD, the data could not verify an obvious link between NK cell apoptosis and increased oxidative stress in vivo. © 2007 Elsevier Ireland Ltd. All rights reserved.
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| 2. |
- Lidebjer, Caroline, 1979-, et al.
(author)
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Low plasma levels of oxygenated carotenoids in patients with coronary artery disease
- 2007
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In: NMCD. Nutrition Metabolism and Cardiovascular Diseases. - : Elsevier BV. - 0939-4753 .- 1590-3729. ; 17:6, s. 448-456
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Journal article (peer-reviewed)abstract
- Background and aims: Low circulating levels of carotenoids have been associated with cardiovascular disease. The distribution of different carotenoids in blood may have an impact on the cardioprotective capacity. The aim of the present study was to determine the plasma levels of 6 major carotenoids in patients with coronary artery disease (CAD) and relate the findings to clinical, metabolic and immune parameters. Methods and results: Plasma levels of oxygenated carotenoids (lutein, zeaxanthin, β-cryptoxanthin) and hydrocarbon carotenoids (α-carotene, β-carotene, lycopene) were determined in 39 patients with acute coronary syndrome, 50 patients with stable CAD and 50 controls. Serological assays for inflammatory activity and flow cytometrical analysis of lymphocyte subsets were performed. Both patient groups had significantly lower plasma levels of oxygenated carotenoids, in particular lutein + zeaxanthin, compared to controls. Low levels of oxygenated carotenoids were associated with smoking, high body mass index (BMI), low high density lipoprotein (HDL) cholesterol and, to a minor degree, inflammatory activity. Plasma levels of lutein + zeaxanthin were independently associated with the proportions of natural killer (NK) cells, but not with other lymphocytes, in blood. Conclusion: Among carotenoids, lutein + zeaxanthin and β-cryptoxanthin were significantly reduced in CAD patients independent of clinical setting. The levels were correlated to a number of established cardiovascular risk factors. In addition, the relationship between NK cells and lutein + zeaxanthin may indicate a particular role for certain carotenoids in the immunological scenario of CAD. © 2006 Elsevier B.V. All rights reserved.
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