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März W, Scharnagl H, Kleber M, Silbernagel G, Nauck M, Müller-Wieland D, von Eckardstein A. [Laboratory diagnostics of lipid metabolism disorders]. Dtsch Med Wochenschr 2023; 148:e120-e146. [PMID: 37949074 PMCID: PMC10637831 DOI: 10.1055/a-1516-2511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Clinically, disorders of lipid metabolism often remain without symptoms. Typical skin lesions, however, can be indicative. Secondary hyperlipoproteinemias (HLP) are more common than primary hyperlipoproteinemias; they can (partially) be improved by treating the underlying disease. Basic diagnostics consist of the determination of cholesterol, triglycerides, LDL cholesterol and HDL cholesterol. To exclude secondary HLP, glucose, HbA1C, TSH, transaminases, creatinine, urea, protein and protein in the urine are useful. Since virtually all routine methods for LDL-C are biased by high triglycerides, lipoprotein electrophoresis is indicated for triglycerides above 400 mg/dl (4.7 mmol/l). Primary HLPs have known or yet unknown genetic causes. Primary hyperlipidemias should be taken into consideration especially in young patients with an LDL cholesterol concentration are above 190 mg/dl (4.9 mmol/l) and/or triglycerides above 400 mg/dl (10 mmol/l) and secondary HLP (obesity, alcohol, diabetes mellitus, kidney disease) is excluded. The basic diagnostics is meaningfully extended by the measurement of lipoprotein (a) (Lp(a)). It is indicated in moderate and high risk of vascular disease, progression of atherosclerosis in "well-controlled" LDL cholesterol, familial clustering of atherosclerosis or high Lp(a), evidence for elevated Lp(a) coming from lipoprotein electrophoresis, aortic stenosis and in patients in whom statins have a poor effect. Genetic diagnostics needs to be considered if primary HLP is suspected. It is most frequently conducted for suspected familial hypercholesterolemia and has already been recommended in guidelines.
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Affiliation(s)
- Winfried März
- Korrespondenzadresse Univ. Prof. Dr. med. Winfried März SYNLAB AkademieP5,7D-68167 Mannheim+49/6 21/43 17 94 32+49/6 21/4 31 94 33
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Alterations of NMR-Based Lipoprotein Profile Distinguish Unstable Angina Patients with Different Severity of Coronary Lesions. Metabolites 2023; 13:metabo13020273. [PMID: 36837892 PMCID: PMC9958945 DOI: 10.3390/metabo13020273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/09/2022] [Accepted: 11/08/2022] [Indexed: 02/17/2023] Open
Abstract
Non-invasive detection of unstable angina (UA) patients with different severity of coronary lesions remains challenging. This study aimed to identify plasma lipoproteins (LPs) that can be used as potential biomarkers for assessing the severity of coronary lesions, determined by the Gensini score (GS), in UA patients. We collected blood plasma from 67 inpatients with angiographically normal coronary arteries (NCA) and 230 UA patients, 155 of them with lowGS (GS ≤ 25.4) and 75 with highGS (GS > 25.4), and analyzed it using proton nuclear magnetic resonance spectroscopy to quantify 112 lipoprotein variables. In a logistic regression model adjusted for four well-known risk factors (age, sex, body mass index and use of lipid-lowering drugs), we tested the association between each lipoprotein and the risk of UA. Combined with the result of LASSO and PLS-DA models, ten of them were identified as important LPs. The discrimination with the addition of selected LPs was evaluated. Compared with the basic logistic model that includes four risk factors, the addition of these ten LPs concentrations did not significantly improve UA versus NCA discrimination. However, thirty-two selected LPs showed notable discrimination power in logistic regression modeling distinguishing highGS UA patients from NCA with a 14.9% increase of the area under the receiver operating characteristics curve. Among these LPs, plasma from highGS patients was enriched with LDL and VLDL subfractions, but lacked HDL subfractions. In summary, we conclude that blood plasma lipoproteins can be used as biomarkers to distinguish UA patients with severe coronary lesions from NCA patients.
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Quantitative NMR-Based Lipoprotein Analysis Identifies Elevated HDL-4 and Triglycerides in the Serum of Alzheimer’s Disease Patients. Int J Mol Sci 2022; 23:ijms232012472. [PMID: 36293327 PMCID: PMC9604278 DOI: 10.3390/ijms232012472] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/30/2022] [Accepted: 10/08/2022] [Indexed: 11/17/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia in the elderly and has been associated with changes in lipoprotein metabolism. We performed quantitative lipoprotein analysis in a local cohort of cognitively impaired elderly and control subjects using standardized nuclear magnetic resonance (NMR) spectroscopy. A commercially available quantitative NMR-based assay covering 112 lipoprotein main and subtype variables was used to investigate blood serum samples from a moderate cohort size of 161 persons (71 female, 90 male), including measures of quality control. Additionally, clinical metadata and cerebrospinal fluid AD biomarkers were collected and used for analysis. High-density lipoprotein (HDL) HDL-4 subfraction levels were mostly high in female individuals with mild cognitive impairment (MCI), followed by AD. Low-density lipoprotein (LDL) LDL-2 cholesterol was slightly elevated in male AD patients. HDL-2 apolipoprotein Apo-A1, HDL-2 phospholipids, and HDL-3 triglycerides were highly abundant in AD and MCI women compared to men. When considering clinical biomarkers (Aβ, tau), very low-density lipoprotein (VLDL) VLDL-1 and intermediate-density lipoprotein (IDL) triglycerides were substantially higher in AD compared to MCI. In addition, triglyceride levels correlated positively with dementia. Different lipoprotein serum patterns were identified for AD, MCI, and control subjects. Interestingly, HDL-4 and LDL-2 cholesterol parameters revealed strong gender-specific changes in the context of AD-driven dementia. As gender-based comparisons were based on smaller sub-groups with a low n-number, several statistical findings did not meet the significance threshold for multiple comparisons testing. Still, our finding suggests that serum HDL-4 parameters and various triglycerides correlate positively with AD pathology which could be a read-out of extended lipids traveling through the blood-brain barrier, supporting amyloid plaque formation processes. Thereof, we see herein a proof of concept that this quantitative NMR-based lipoprotein assay can generate important and highly interesting data for refined AD diagnosis and patient stratification, especially when larger cohorts are available.
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Jansen M, Contini C. LDL retention time in plasma can be -based on causation- estimated by the lipid composition of LDL and other lipoproteins. PLoS One 2022; 17:e0272050. [PMID: 35901111 PMCID: PMC9333322 DOI: 10.1371/journal.pone.0272050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 07/12/2022] [Indexed: 11/21/2022] Open
Abstract
Introduction Information on LDL’s dynamic behaviour of LDL (i.e. production rate and fractional catabolic rate) are of interest if pathologies, lipid-lowering strategies or LDL-metabolism itself are investigated. Determination of these rates is costly and elaborate. Here we studied the interrelationship of LDL mass, its composition and other lipoproteins. Based on this data, we deducted information about LDL’s dynamic behaviour. Methods Lipoprotein profiles of n = 236 participants are evaluated. Plasma was separated by sequential ultracentrifugation into VLDL, IDL, LDL and HDL. Additionally, LDL and HDL were separated into subfractions. Stepwise multiple linear regressions were used to study LDL’s ApoB mass and lipid composition. Relying on these results and on causation, we constructed a mathematical model to estimate LDL’s retention time. Results The ApoB mass in LDL correlated best among all measured parameters (including corresponding lipid compositions but using no LDL-associated parameters) with the cholesterol ester content in IDL. TG/CE ratios in LDL’s subfractions were strongly correlated with the corresponding ratios in IDL and HDL. The constructed mathematical model links the TG/CE ratio of LDL and HDL to LDL’s ApoB concentration and enables a good estimate of LDL’s retention time in plasma. Discussion Relying on our statistic evaluations, we assume that i) the production of nascent LDL via IDL as well as ii) LDL’s prolonged retention are mapped by the TG/CE ratio in LDL subfractions. HDL’s TG/CE ratio is associated with the change in LDL’s TG/CE ratio during its retention in plasma. Our mathematical model uses this information and enables–by relying on causation- a good estimation of LDL’s retention time.
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Affiliation(s)
- Martin Jansen
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre -University of Freiburg, Freiburg im Breisgau, Germany
- Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- * E-mail:
| | - Christine Contini
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre -University of Freiburg, Freiburg im Breisgau, Germany
- Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
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The LDL Apolipoprotein B-to-LDL Cholesterol Ratio: Association with Cardiovascular Mortality and a Biomarker of Small, Dense LDLs. Biomedicines 2022; 10:biomedicines10061302. [PMID: 35740324 PMCID: PMC9220033 DOI: 10.3390/biomedicines10061302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 05/20/2022] [Indexed: 12/10/2022] Open
Abstract
Background and Objective: Small, dense low-density lipoproteins (LDLs) are considered more atherogenic than normal size LDLs. However, the measurement of small, dense LDLs requires sophisticated laboratory methods, such as ultracentrifugation, gradient gel electrophoresis, or nuclear magnetic resonance. We aimed to analyze whether the LDL apolipoprotein B (LDLapoB)-to-LDL cholesterol (LDLC) ratio is associated with cardiovascular mortality and whether this ratio represents a biomarker for small, dense LDLs. Methods: LDLC and LDLapoB were measured (beta-quantification) and calculated (according to Friedewald and Baca, respectively) for 3291 participants of the LURIC Study, with a median (inter-quartile range) follow-up for cardiovascular mortality of 9.9 (8.7−10.7) years. An independent replication cohort included 1660 participants. Associations of the LDLapoB/LDLC ratio with LDL subclass particle concentrations (ultracentrifugation) were tested for 282 participants. Results: In the LURIC Study, the mean (standard deviation) LDLC and LDLapoB concentrations were 117 (34) and 85 (22) mg/dL, respectively; 621 cardiovascular deaths occurred. Elevated LDLapoB/LDLC (calculated and measured) ratios were significantly and independently associated with increased cardiovascular mortality in the entire cohort (fourth vs. first quartile: hazard ratio (95% confidence interval) = 2.07 (1.53−2.79)) and in statin-naïve patients. The association between calculated LDLapoB/LDLC ratio and cardiovascular mortality was replicated in an independent cohort. High LDLapoB/LDLC ratios were associated with higher LDL5 and LDL6 concentrations (both p < 0.001), but not with concentrations of larger LDLs. Conclusions: Elevated measured and calculated LDLapoB/LDLC ratios are associated with increased cardiovascular mortality. Use of LDLapoB/LDLC ratios allows estimation of the atherogenic risk conferred by small, dense LDLs.
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Jakubauskas D, Jansen M, Lyngsø J, Cheng Y, Pedersen JS, Cárdenas M. Toward reliable low-density lipoprotein ultrastructure prediction in clinical conditions: A small-angle X-ray scattering study on individuals with normal and high triglyceride serum levels. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 31:102318. [PMID: 33091569 DOI: 10.1016/j.nano.2020.102318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/23/2020] [Accepted: 10/05/2020] [Indexed: 10/23/2022]
Abstract
Atherosclerosis is the main killer in the west and therefore a major health challenge today. Total serum cholesterol and lipoprotein concentrations, used as clinical markers, fail to predict the majority of cases, especially between the risk scale extremes, due to the high complexity in lipoprotein structure and composition. In particular, low-density lipoprotein (LDL) plays a key role in atherosclerosis development, with LDL size being a parameter considered for determining the risk for cardiovascular diseases. Determining LDL size and structural parameters is challenging to address experimentally under physiological-like conditions. This article describes the biochemistry and ultrastructure of normolipidemic and hypertriglyceridemic LDL fractions and subfractions using small-angle X-ray scattering. Our results conclude that LDL particles of hypertriglyceridemic compared to healthy individuals 1) have lower LDL core melting temperature, 2) have lower cholesteryl ester ordering in their core, 3) are smaller, rounder and more spherical below melting temperature, and 4) their protein-containing shell is thinner above melting temperature.
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Affiliation(s)
- Dainius Jakubauskas
- Biofilms - Research center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmo University, Malmo, Sweden.
| | - Martin Jansen
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre, University of Freiburg, Freiburg im Breisgau, Germany.
| | - Jeppe Lyngsø
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark.
| | - Yuanji Cheng
- Department of Materials Science and Applied Mathematics, Faculty of Technology and Society, Malmo University, Malmo, Sweden.
| | - Jan Skov Pedersen
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark.
| | - Marité Cárdenas
- Biofilms - Research center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmo University, Malmo, Sweden.
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Monsonis-Centelles S, Hoefsloot HC, Engelsen SB, Smilde AK, Lind MV. Repeatability and reproducibility of lipoprotein particle profile measurements in plasma samples by ultracentrifugation. ACTA ACUST UNITED AC 2019; 58:103-115. [DOI: 10.1515/cclm-2019-0729] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 09/05/2019] [Indexed: 01/31/2023]
Abstract
Abstract
Background
Characterization of lipoprotein particle profiles (LPPs) (including main classes and subclasses) by means of ultracentrifugation (UC) is highly requested given its clinical potential. However, rapid methods are required to replace the very labor-intensive UC method and one solution is to calibrate rapid nuclear magnetic resonance (NMR)-based prediction models, but the reliability of the UC-response method required for the NMR calibration has been largely overlooked.
Methods
This study provides a comprehensive repeatability and reproducibility study of various UC-based lipid measurements (cholesterol, triglycerides [TGs], free cholesterol, phospholipids, apolipoprotein [apo]A1 and apoB) in different main classes and subclasses of 25 duplicated fresh plasma samples and of 42 quality control (QC) frozen pooled plasma samples of healthy individuals.
Results
Cholesterol, apoA1 and apoB measurements were very repeatable in all classes (intraclass correlation coefficient [ICC]: 92.93%–99.54%). Free cholesterol and phospholipid concentrations in main classes and subclasses and TG concentrations in high-density lipoproteins (HDL), HDL subclasses and low-density lipoproteins (LDL) subclasses, showed worse repeatability (ICC: 19.21%–99.08%) attributable to low concentrations, variability introduced during UC and assay limitations. On frozen QC samples, the reproducibility of cholesterol, apoA1 and apoB concentrations was found to be better than for the free cholesterol, phospholipids and TGs concentrations.
Conclusions
This study shows that for LPPs measurements near or below the limit of detection (LOD) in some of the subclasses, as well as the use of frozen samples, results in worsened repeatability and reproducibility. Furthermore, we show that the analytical assay coupled to UC for free cholesterol and phospholipids have different repeatability and reproducibility. All of this needs to be taken into account when calibrating future NMR-based models.
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Affiliation(s)
- Sandra Monsonis-Centelles
- Biosystems Data Analysis, Swammerdam Institute for Life Sciences , Universiteit van Amsterdam , Amsterdam , The Netherlands
- Department of Food Science, Chemometrics and Analytical Technology, Faculty of Science , University of Copenhagen , Frederiksberg C , Denmark
| | - Huub C.J. Hoefsloot
- Biosystems Data Analysis, Swammerdam Institute for Life Sciences , Universiteit van Amsterdam , Amsterdam , The Netherlands
| | - Søren B. Engelsen
- Department of Food Science, Chemometrics and Analytical Technology, Faculty of Science , University of Copenhagen , Frederiksberg C , Denmark
| | - Age K. Smilde
- Biosystems Data Analysis, Swammerdam Institute for Life Sciences , Universiteit van Amsterdam , Amsterdam , The Netherlands
- Department of Food Science, Chemometrics and Analytical Technology, Faculty of Science , University of Copenhagen , Frederiksberg C , Denmark
| | - Mads V. Lind
- Department of Nutrition, Exercise and Sports , University of Copenhagen , Rolighedsvej 26 , DK-1958 Frederiksberg C , Denmark
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Jansen M, Puetz G, Hoffmann MM, Winkler K. A mathematical model to estimate cholesterylester transfer protein (CETP) triglycerides flux in human plasma. BMC SYSTEMS BIOLOGY 2019; 13:12. [PMID: 30670016 PMCID: PMC6341636 DOI: 10.1186/s12918-019-0679-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 01/04/2019] [Indexed: 12/31/2022]
Abstract
Background Cholesterylester transfer protein (CETP) modulates the composition of various lipoproteins associated with cardiovascular disease. Despite its central role in lipoprotein metabolism, its mode of action is still not fully understood. Here we present a simple way to estimate CETP-mediated lipid fluxes between different lipoprotein fractions. Results The model derived adequately describes the observed findings, especially regarding low- and high dense lipoproteins (LDL and HDL), delivering correlation coefficients of R2 = 0.567 (p < 0.001) and R2 = 0.466 (p < 0.001), respectively. These estimated fluxes correlate best among all other measured concentrations and ‘lipid per lipoprotein’ ratios to the observed fluxes. Conclusion Our model approach is independent of CETP-action’s exact mechanistic mode. It is simple and easy to apply, and may be a useful tool in revealing CETP’s ambiguous role in lipid metabolism. The model mirrors a diffusion-like exchange of triglycerides between lipoproteins. Cholesteryl ester and triglyceride concentrations measured in HDL, LDL and VLDL are sufficient to apply the model on a plasma sample. Electronic supplementary material The online version of this article (10.1186/s12918-019-0679-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martin Jansen
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre - University of Freiburg, Freiburg im Breisgau, Germany. .,Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany.
| | - Gerhard Puetz
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre - University of Freiburg, Freiburg im Breisgau, Germany.,Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Michael M Hoffmann
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre - University of Freiburg, Freiburg im Breisgau, Germany.,Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Karl Winkler
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre - University of Freiburg, Freiburg im Breisgau, Germany.,Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
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Contini C, Winkler BS, Maass N, Alkatout I, Winkler K, Pecks U. Concomitant intrauterine growth restriction alters the lipoprotein profile in preeclampsia. Pregnancy Hypertens 2018; 15:154-160. [PMID: 30825913 DOI: 10.1016/j.preghy.2018.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/03/2018] [Accepted: 12/29/2018] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Preeclampsia and intrauterine growth restriction (IUGR) are related conditions. We aimed to characterise common lipid changes. METHODS Triglyceride and cholesterol levels of patients 24-42 weeks of gestation with IUGR (n = 52), hypertensive IUGR (HIUGR, n = 28), and preeclampsia without IUGR (PE, n = 56) were compared to a control group (CTRL, n = 167). In addition, 60 sera (n = 10 of each pathology IUGR, HIUGR, PE (without IUGR) compared to n = 30 matched CTRL) of severe early onset cases <34 weeks of gestation were chosen and further analysed by ultracentrifugation lipid subfractionation including VLDL, IDL, LDL, and HDL composition. RESULTS In the full cohort we found low cholesterol in IUGR (p = 0.0405), while triglyceride levels were high in PE (p < 0.0001). Lipid concentrations in HIUGR did not differ significantly from CTRL. In the 60 patients analysed by lipid subfractionation, triglyceride levels were increased in the VLDL subfraction in PE (p < 0.01), however, LDL-bound ApoB and cholesterol levels were lower in IUGR and HIUGR (p < 0.0001 for total cholesterol and p < 0.001 for ApoB in both groups), but not in PE when compared to CTRL. CONCLUSION Low cholesterol, especially LDL cholesterol levels are a feature of IUGR while high triglyceride levels are a feature of preeclampsia. Increased VLDL-triglycerides suggest a disturbed conversion to LDL in preeclampsia. Of note, the presence of IUGR in hypertensive disorders further alters lipid profiles, which may explain heterogeneous data on lipid values for preeclampsia in the literature. Study groups have to be selected carefully to avoid misinterpretation.
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Affiliation(s)
- Christine Contini
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106 Freiburg, Germany.
| | - B Sophia Winkler
- Department of Obstetrics and Gynecology, University Hospital of the RWTH, Pauwelsstraße 30, 52074 Aachen, Germany.
| | - Nicolai Maass
- Department of Obstetrics and Gynecology, University Hospital Schleswig-Holstein, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
| | - Ibrahim Alkatout
- Department of Obstetrics and Gynecology, University Hospital Schleswig-Holstein, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
| | - Karl Winkler
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106 Freiburg, Germany.
| | - Ulrich Pecks
- Department of Obstetrics and Gynecology, University Hospital of the RWTH, Pauwelsstraße 30, 52074 Aachen, Germany; Department of Obstetrics and Gynecology, University Hospital Schleswig-Holstein, Arnold-Heller-Straße 3, 24105 Kiel, Germany.
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Vitamin D supplementation and lipoprotein metabolism: A randomized controlled trial. J Clin Lipidol 2018; 12:588-596.e4. [PMID: 29653812 DOI: 10.1016/j.jacl.2018.03.079] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 03/01/2018] [Accepted: 03/12/2018] [Indexed: 01/15/2023]
Abstract
BACKGROUND Vitamin D deficiency is associated with an unfavorable lipid profile, but whether and how vitamin D supplementation affects lipid metabolism is unclear. OBJECTIVE To examine the effects of vitamin D supplementation on lipid and lipoprotein parameters. METHODS This is a post hoc analysis of the single-center, double-blind, randomized, placebo-controlled Styrian Vitamin D Hypertension Trial (2011-2014). Two hundred individuals with arterial hypertension and 25-hydroxyvitamin D concentrations of <75 nmol/L were randomized to 2800 IU of vitamin D daily or placebo for 8 weeks. RESULTS One hundred sixty-three participants (62.2 [53.1-68.4] years of age; 46% women) had available lipid data and were included in this analysis. Vitamin D supplementation significantly increased total cholesterol, triglycerides, very-low-density lipoprotein (VLDL) triglycerides, low-density lipoprotein (LDL) triglycerides, high-density lipoprotein (HDL) triglycerides, apolipoprotein B (ApoB), LDL-ApoB, ApoCII, ApoCIII, phospholipids, and ApoE (P < .05 for all). Except for ApoCII and ApoCIII and HDL-triglycerides, all other treatment effects remained statistically significant after adjustment for multiple testing with the Benjamini and Hochberg false discovery rate method. There was a nonsignificant increase in LDL cholesterol. Furthermore, no significant effects were seen on free fatty acids, lipoprotein (a), ApoAI, ApoAII, VLDL cholesterol, VLDL-ApoB, HDL cholesterol, LDL diameter, and VLDL diameter. CONCLUSIONS The effects of vitamin D on lipid metabolism are potentially unfavorable. They require further investigation in view of the wide use of vitamin D testing and treatment.
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Contini C, Jansen M, König B, Markfeld-Erol F, Kunze M, Zschiedrich S, Massing U, Merfort I, Prömpeler H, Pecks U, Winkler K, Pütz G. Lipoprotein turnover and possible remnant accumulation in preeclampsia: insights from the Freiburg Preeclampsia H.E.L.P.-apheresis study. Lipids Health Dis 2018. [PMID: 29540222 PMCID: PMC5853053 DOI: 10.1186/s12944-018-0698-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background Preeclampsia is a life-threatening disease in pregnancy, and its complex pathomechanisms are poorly understood. In preeclampsia, lipid metabolism is substantially altered. In late onset preeclampsia, remnant removal disease like lipoprotein profiles have been observed. Lipid apheresis is currently being explored as a possible therapeutic approach to prolong preeclamptic pregnancies. Here, apheresis-induced changes in serum lipid parameters are analyzed in detail and their implications for preeclamptic lipid metabolism are discussed. Methods In the Freiburg H.E.L.P.-Apheresis Study, 6 early onset preeclamptic patients underwent repeated apheresis treatments. Serum lipids pre- and post-apheresis and during lipid rebound were analyzed in depth via ultracentrifugation to yield lipoprotein subclasses. Results The net elimination of Apolipoprotein B and plasma lipids was lower than theoretically expected. Lipids returned to previous pre-apheresis levels before the next apheresis even though apheresis was repeated within 2.9 ± 1.2 days. Apparent fractional catabolic rates and synthetic rates were substantially elevated, with fractional catabolic rates for Apolipoprotein B / LDL-cholesterol being 0.7 ± 0.3 / 0.4 ± 0.2 [day− 1] and synthetic rates being 26 ± 8 / 17 ± 8 [mg*kg− 1*day− 1]. The distribution of LDL-subclasses after apheresis shifted to larger buoyant LDL, while intermediate-density lipoprotein-levels remained unaffected, supporting the notion of an underlying remnant removal disorder in preeclampsia. Conclusion Lipid metabolism seems to be highly accelerated in preeclampsia, likely outbalancing remnant removal mechanisms. Since cholesterol-rich lipoprotein remnants are able to accumulate in the vessel wall, remnant lipoproteins may contribute to the severe endothelial dysfunction observed in preeclampsia. Trial registration ClinicalTrails.gov, NCT01967355.
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Affiliation(s)
- Christine Contini
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Martin Jansen
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Brigitte König
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Filiz Markfeld-Erol
- Department of Obstetrics and Gynecology, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Mirjam Kunze
- Department of Obstetrics and Gynecology, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Stefan Zschiedrich
- Department of Medicine IV (Nephrology and Primary Care), Medical Center, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Ulrich Massing
- Andreas Hettich GmbH & Co KG, Engesser Straße 4a, 79108, Freiburg, Germany
| | - Irmgard Merfort
- Department of Pharmaceutical Biology and Biotechnology, Albert-Ludwigs-University of Freiburg, Stefan-Meier-Straße 19, 79104, Freiburg, Germany
| | - Heinrich Prömpeler
- Department of Obstetrics and Gynecology, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Ulrich Pecks
- Department of Gynecology and Obstetrics, University Hospital Schleswig-Holstein Campus, Kiel, Germany
| | - Karl Winkler
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany
| | - Gerhard Pütz
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Center - University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany.
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Monsonis Centelles S, Hoefsloot HCJ, Khakimov B, Ebrahimi P, Lind MV, Kristensen M, de Roo N, Jacobs DM, van Duynhoven J, Cannet C, Fang F, Humpfer E, Schäfer H, Spraul M, Engelsen SB, Smilde AK. Toward Reliable Lipoprotein Particle Predictions from NMR Spectra of Human Blood: An Interlaboratory Ring Test. Anal Chem 2017; 89:8004-8012. [PMID: 28692288 PMCID: PMC5541326 DOI: 10.1021/acs.analchem.7b01329] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
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Lipoprotein
profiling of human blood by 1H nuclear magnetic
resonance (NMR) spectroscopy is a rapid and promising approach to
monitor health and disease states in medicine and nutrition. However,
lack of standardization of measurement protocols has prevented the
use of NMR-based lipoprotein profiling in metastudies. In this study,
a standardized NMR measurement protocol was applied in a ring test
performed across three different laboratories in Europe on plasma
and serum samples from 28 individuals. Data was evaluated in terms
of (i) spectral differences, (ii) differences in LPD predictions obtained
using an existing prediction model, and (iii) agreement of predictions
with cholesterol concentrations in high- and low-density lipoproteins
(HDL and LDL) particles measured by standardized clinical assays.
ANOVA-simultaneous component analysis (ASCA) of the ring test spectral
ensemble that contains methylene and methyl peaks (1.4–0.6
ppm) showed that 97.99% of the variance in the data is related to
subject, 1.62% to sample type (serum or plasma), and 0.39% to laboratory.
This interlaboratory variation is in fact smaller than the maximum
acceptable intralaboratory variation on quality control samples. It
is also shown that the reproducibility between laboratories is good
enough for the LPD predictions to be exchangeable when the standardized
NMR measurement protocol is followed. With the successful implementation
of this protocol, which results in reproducible prediction of lipoprotein
distributions across laboratories, a step is taken toward bringing
NMR more into scope of prognostic and diagnostic biomarkers, reducing
the need for less efficient methods such as ultracentrifugation or
high-performance liquid chromatography (HPLC).
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Affiliation(s)
- Sandra Monsonis Centelles
- Biosystems Data Analysis, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam , Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Huub C J Hoefsloot
- Biosystems Data Analysis, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam , Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | | | | | | | | | - Niels de Roo
- Unilever R&D , Olivier van Noortlaan 120, 3133 AT, Vlaardingen, The Netherlands
| | - Doris M Jacobs
- Unilever R&D , Olivier van Noortlaan 120, 3133 AT, Vlaardingen, The Netherlands
| | - John van Duynhoven
- Unilever R&D , Olivier van Noortlaan 120, 3133 AT, Vlaardingen, The Netherlands.,Laboratory of Biophysics, Wageningen University , Stippeneng 4, 6708WE, Wageningen, The Netherlands
| | | | - Fang Fang
- Bruker BioSpin GmbH , 76287 Rheinstetten, Germany
| | | | | | | | | | - Age K Smilde
- Biosystems Data Analysis, Swammerdam Institute for Life Sciences, Universiteit van Amsterdam , Science Park 904, 1098 XH, Amsterdam, The Netherlands
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Maric S, Lind TK, Lyngsø J, Cárdenas M, Pedersen JS. Modeling Small-Angle X-ray Scattering Data for Low-Density Lipoproteins: Insights into the Fatty Core Packing and Phase Transition. ACS NANO 2017; 11:1080-1090. [PMID: 28048943 DOI: 10.1021/acsnano.6b08089] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Atherosclerosis and its clinical consequences are the leading cause of death in the western hemisphere. While many studies throughout the last decades have aimed at understanding the disease, the clinical markers in use today still fail to accurately predict the risks. The role of the current main clinical indicator, low density lipoprotein (LDL), in depositing fat to the vessel wall is believed to be the onset of the process. However, many subfractions of the LDL, which differ both in structure and composition, are present in the blood and among different individuals. Understanding the relationship between LDL structure and composition is key to unravel the specific role of various LDL components in the development and/or prevention of atherosclerosis. Here, we describe a model for analyzing small-angle X-ray scattering data for rapid and robust structure determination for the LDL. The model not only gives the overall structure but also the particular internal layering of the fats inside the LDL core. Thus, the melting of the LDL can be followed in situ as a function of temperature for samples extracted from healthy human patients and purified using a double protocol based on ultracentrifugation and size-exclusion chromatography. The model provides information on: (i) the particle-specific melting temperature of the core lipids, (ii) the structural organization of the core fats inside the LDL, (iii) the overall shape of the particle, and (iv) the flexibility and overall conformation of the outer protein/hydrophilic layer at a given temperature as governed by the organization of the core. The advantage of this method over other techniques such as cryo-TEM is the possibility of in situ experiments under near-physiological conditions which can be performed relatively fast (minutes at home source, seconds at synchrotron). This approach now allows the monitoring of structural changes in the LDL upon different stresses from the environment, such as changes in temperature, oxidation, or external agents used or currently in development against atherosclerotic plaque build-up and which are targeting the LDL.
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Affiliation(s)
- Selma Maric
- Biofilms- Research Center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmö University , Malmö 20506, Sweden
| | - Tania Kjellerup Lind
- Biofilms- Research Center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmö University , Malmö 20506, Sweden
| | - Jeppe Lyngsø
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , 8000 Aarhus, Denmark
| | - Marité Cárdenas
- Biofilms- Research Center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmö University , Malmö 20506, Sweden
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , 8000 Aarhus, Denmark
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Winkler K, Friedrich I, Baumstark MW, Wieland H, März W. Pioglitazone reduces atherogenic dense low density lipoprotein (LDL) particles in patients with type 2 diabetes mellitus. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/14746514020020021301] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Aim The new oral antidiabetic agent pioglitazone improves insulin sensitivity and glycaemic control, lowers triglycerides and increases high density lipoprotein (HDL) cholesterol in type 2 diabetes. The effect of pioglitazone on low density lipoprotein (LDL) subfractions is investigated, herein. Methods The effect of pioglitazone monotherapy (45 mg o.d. for six months) on LDL subfractions was observed in 30 patients with poorly controlled type 2 diabetes (HbA1C ≥ 7.5% and < 11.5% and triglycerides ≥ 150 mg/dL). The distribution of LDL subfractions was determined by equilibrium density gradient ultracentrifugation before and during treatment. Results HbA1C (9.5% before and 7.4% on treatment, p<0.001), triglycerides (-135 mg/dL [-32.2%], p=0.002) and apo B in LDL-6 (the most dense LDL subfraction) decreased significantly. The mean diameter of LDL particles increased (19.5 nm before and 19.8 nm on treatment, p=0.005), while the mean LDL density decreased significantly (from 1.0394 kg/L to 1.0381 kg/L on treatment; p=0.033). HDL increased from 36.3 mg/dL to 44.2 mg/dL (+ 21.6%, p<0.001). Total cholesterol and LDL-cholesterol did not change significantly. Conclusions The results confirm that pioglitazone improves glycaemic control in patients with type 2 diabetes. In addition, pioglitazone reduced the proportion of atherogenic dense LDL. The effects of pioglitazone on lipoprotein metabolism may translate into a reduced risk for atherosclerotic complications in type 2 diabetes.
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Affiliation(s)
- Karl Winkler
- Department of Clinical Chemistry, University of Freiburg, Germany, -freiburg.de
| | - Isolde Friedrich
- Department of Clinical Chemistry, University of Freiburg, Germany
| | | | - Heinrich Wieland
- Department of Clinical Chemistry, University of Freiburg, Germany
| | - Winfried März
- Department of Clinical Chemistry, University of Freiburg, Germany
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Hörl G, Froehlich H, Ferstl U, Ledinski G, Binder J, Cvirn G, Stojakovic T, Trauner M, Koidl C, Tafeit E, Amrein K, Scharnagl H, Jürgens G, Hallström S. Simvastatin Efficiently Lowers Small LDL-IgG Immune Complex Levels: A Therapeutic Quality beyond the Lipid-Lowering Effect. PLoS One 2016; 11:e0148210. [PMID: 26840480 PMCID: PMC4739583 DOI: 10.1371/journal.pone.0148210] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 01/14/2016] [Indexed: 01/28/2023] Open
Abstract
We investigated a polyethylene glycol non-precipitable low-density lipoprotein (LDL) subfraction targeted by IgG and the influence of statin therapy on plasma levels of these small LDL-IgG-immune complexes (LDL-IgG-IC). LDL-subfractions were isolated from 6 atherosclerotic subjects and 3 healthy individuals utilizing iodixanol density gradient ultracentrifugation. Cholesterol, apoB and malondialdehyde (MDA) levels were determined in each fraction by enzymatic testing, dissociation-enhanced lanthanide fluorescence immunoassay and high-performance liquid chromatography, respectively. The levels of LDL-IgG-IC were quantified densitometrically following lipid electrophoresis, particle size distribution was assessed with dynamic light scattering and size exclusion chromatography. The influence of simvastatin (40 mg/day for three months) on small LDL-IgG-IC levels and their distribution among LDL-subfractions (salt gradient separation) were investigated in 11 patients with confirmed coronary artery disease (CAD). We demonstrate that the investigated LDL-IgG-IC are small particles present in atherosclerotic patients and healthy subjects. In vitro assembly of LDL-IgG-IC resulted in particle density shifts indicating a composition of one single molecule of IgG per LDL particle. Normalization on cholesterol levels revealed MDA values twice as high for LDL-subfractions rich in small LDL-IgG-IC if compared to dominant LDL-subfractions. Reactivity of affinity purified small LDL-IgG-IC to monoclonal antibody OB/04 indicates a high degree of modified apoB and oxidative modification. Simvastatin therapy studied in the CAD patients significantly lowered LDL levels and to an even higher extent, small LDL-IgG-IC levels without affecting their distribution. In conclusion simvastatin lowers levels of small LDL-IgG-IC more effectively than LDL-cholesterol and LDL-apoB levels in atherosclerotic patients. This antiatherogenic effect may additionally contribute to the known beneficial effects of this drug in the treatment of atherosclerosis.
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Affiliation(s)
- Gerd Hörl
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Graz, Austria
- * E-mail:
| | - Harald Froehlich
- Division of Angiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Ulrika Ferstl
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Graz, Austria
| | - Gerhard Ledinski
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Graz, Austria
| | - Josepha Binder
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Gerhard Cvirn
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Graz, Austria
| | - Tatjana Stojakovic
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Christoph Koidl
- Institute of Hygiene, Medical University of Graz, Graz, Austria
| | - Erwin Tafeit
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Graz, Austria
| | - Karin Amrein
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Hubert Scharnagl
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Günther Jürgens
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Graz, Austria
| | - Seth Hallström
- Institute of Physiological Chemistry, Center of Physiological Medicine, Medical University of Graz, Graz, Austria
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Okazaki M, Yamashita S. Recent Advances in Analytical Methods on Lipoprotein Subclasses: Calculation of Particle Numbers from Lipid Levels by Gel Permeation HPLC Using “Spherical Particle Model”. J Oleo Sci 2016; 65:265-82. [DOI: 10.5650/jos.ess16020] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Shizuya Yamashita
- Rinku General Medical Center
- Department of Community Medicine & Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine
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Rasmiena AA, Barlow CK, Ng TW, Tull D, Meikle PJ. High density lipoprotein efficiently accepts surface but not internal oxidised lipids from oxidised low density lipoprotein. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1861:69-77. [PMID: 26569052 DOI: 10.1016/j.bbalip.2015.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/17/2015] [Accepted: 11/08/2015] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Oxidised low density lipoprotein (oxLDL) contributes to atherosclerosis, whereas high density lipoprotein (HDL) is known to be atheroprotective due, at least in part, to its ability to remove oxidised lipids from oxLDL. The molecular details of the lipid transfer process are not fully understood. We aimed to identify major oxidised lipid species of oxLDL and investigate their transfer upon co-incubation with HDL with varying levels of oxidation. APPROACH AND RESULTS A total of 14 major species of oxidised phosphatidylcholine and oxidised cholesteryl ester from oxLDL were identified using an untargeted mass spectrometry approach. HDL obtained from pooled plasma of normolipidemic subjects (N=5) was oxidised under mild and heavy oxidative conditions. Non-oxidised (native) HDL and oxidised HDL were co-incubated with oxLDL, re-isolated and lipidomic analysis was performed. Lipoprotein surface lipids, oxidised phosphatidylcholines and oxidised cholesterols (7-ketocholesterol and 7β-hydroxycholesterol), but not internal oxidised cholesteryl esters, were effectively transferred to native HDL. Saturated and monounsaturated lyso-phosphatidylcholines were also transferred from the oxLDL to native HDL. These processes were attenuated when HDL was oxidised under mild and heavy oxidative conditions. The impaired capacities were accompanied by an increase in a ratio of sphingomyelin to phosphatidylcholine and a reduction in phosphatidylserine content in oxidised HDL, both of which are potentially important regulators of the oxidised lipid transfer capacity of HDL. CONCLUSIONS Our study has revealed the differential transfer efficiency of surface and internal oxidised lipids from oxLDL and their acceptance onto HDL. These capacities were modulated when HDL was itself oxidised.
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Affiliation(s)
- Aliki A Rasmiena
- Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dentistry, and Health Sciences, The University of Melbourne, Victoria, Australia
| | - Christopher K Barlow
- Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Theodore W Ng
- Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Metabolic Research Centre, School of Medicine and Pharmacology, The University of Western Australia, Western Australia, Australia
| | - Dedreia Tull
- Metabolomics Australia, Bio21 Institute, Parkville, Victoria, Australia
| | - Peter J Meikle
- Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dentistry, and Health Sciences, The University of Melbourne, Victoria, Australia.
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Grammer TB, Kleber ME, März W, Silbernagel G, Siekmeier R, Wieland H, Pilz S, Tomaschitz A, Koenig W, Scharnagl H. Low-density lipoprotein particle diameter and mortality: the Ludwigshafen Risk and Cardiovascular Health Study. Eur Heart J 2014; 36:31-8. [DOI: 10.1093/eurheartj/ehu055] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tanja B. Grammer
- Mannheim Institute of Public Health, Social and Preventive Medicine, Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany
| | - Marcus E. Kleber
- Mannheim Institute of Public Health, Social and Preventive Medicine, Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany
| | - Winfried März
- Mannheim Institute of Public Health, Social and Preventive Medicine, Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Auenbruggerplatz 15, Graz A-8036, Austria
- Synlab Academy, Mannheim, Germany
| | - Günther Silbernagel
- Department of Angiology, Swiss Cardiovascular Center, Inselspital, University of Bern, Bern, Switzerland
| | | | - Heinrich Wieland
- Division of Clinical Chemistry, University Medical Center Freiburg, Freiburg, Germany
| | - Stefan Pilz
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Medical University of Graz, Graz, Austria
| | - Andreas Tomaschitz
- Department of Cardiology, Medical University of Graz, Graz, Austria
- Specialist Clinic for Rehabilitation PVA Bad Aussee, Bad Aussee, Austria
| | - Wolfgang Koenig
- Department of Internal Medicine II – Cardiology, University of Ulm Medical Centre, Ulm, Germany
| | - Hubert Scharnagl
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Auenbruggerplatz 15, Graz A-8036, Austria
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Simultaneous binding of the anti-cancer IgM monoclonal antibody PAT-SM6 to low density lipoproteins and GRP78. PLoS One 2013; 8:e61239. [PMID: 23620733 PMCID: PMC3631193 DOI: 10.1371/journal.pone.0061239] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 03/06/2013] [Indexed: 11/30/2022] Open
Abstract
The tumour-derived monoclonal IgM antibody PAT-SM6 specifically kills malignant cells by an apoptotic mechanism linked to the excessive uptake of plasma lipids. The mechanism is postulated to occur via the multi-point attachment of PAT-SM6 to the unfolded protein response regulator GRP78, located on the surface of tumour cells, coupled to the simultaneous binding of plasma low density lipoprotein (LDL). We prepared and characterised LDL and oxidized LDL using sedimentation velocity and small-angle X-ray scattering (SAXS) analysis. Enzyme-linked immunosorbent (ELISA) techniques indicated apparent dissociation constants of approximately 20 nM for the binding of LDL or oxidized LDL to PAT-SM6. ELISA experiments showed cross competition with LDL inhibiting PAT-SM6 binding to immobilised GRP78, while, in the reverse experiment, GRP78 inhibited PAT-SM6 binding to immobilized LDL. In contrast to the results of the ELISA experiments, sedimentation velocity experiments indicated relatively weak interactions between LDL and PAT-SM6, suggesting immunoabsorbance to the microtiter plate is driven by an avidity-based binding mechanism. The importance of avidity and the multipoint attachment of antigens to PAT-SM6 was further investigated using antigen-coated polystyrene beads. Absorption of GRP78 or LDL to polystyrene microspheres led to an increase in the inhibition of PAT-SM6 binding to microtiter plates coated with GRP78 or LDL, respectively. These results support the hypothesis that the biological action of PAT-SM6 in tumour cell apoptosis depends on the multivalent nature of PAT-SM6 and the ability to interact simultaneously with LDL and multiple GRP78 molecules clustered on the tumour cell surface.
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Grammer TB, Hoffmann MM, Scharnagl H, Kleber ME, Silbernagel G, Pilz S, Tomaschitz A, Lerchbaum E, Siekmeier R, März W. Smoking, apolipoprotein E genotypes, and mortality (the Ludwigshafen RIsk and Cardiovascular Health study). Eur Heart J 2013; 34:1298-305. [DOI: 10.1093/eurheartj/eht001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Winkler K, Jacob S, Müller-Schewe T, Hoffmann MM, Konrad T. Ezetimibe alone and in combination lowers the concentration of small, dense low-density lipoproteins in type 2 diabetes mellitus. Atherosclerosis 2011; 220:189-93. [PMID: 22115011 DOI: 10.1016/j.atherosclerosis.2011.10.043] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 10/27/2011] [Accepted: 10/30/2011] [Indexed: 10/15/2022]
Abstract
OBJECTIVE The effectiveness of the cholesterol absorption inhibitor ezetimibe on LDL subfractions and ultimately on the atherosclerotic risk profile remains controversial. We thus determined the concentration of atherogenic small, dense LDL (sdLDL) in patients with type 2 diabetes and an elevated cardiovascular risk profile. RESEARCH DESIGN AND METHODS Multicenter, randomized, open-label 6-week study investigating the effect of ezetimibe 10mg (E), simvastatin 20mg (S) and the combination of ezetimibe-/simvastatin 10/20mg (C) on the concentration of sdLDL separated from fresh plasma by gradient ultracentrifugation in patients with type 2 diabetes (NCT01384058). RESULTS Fifty-six patients were screened for sdLDL, 41 were randomized, and 40 patients (12 E, 14 S and 14 C) completed the study. Total and LDL cholesterol fell by 14% (p=0.004) and 15% (p=0.006) with E, 22% (p<0.001) and 32% (p<0.001) with S, and 32% (p<0.001) and 44% (p<0.001) with C, respectively. E reduced the concentration of sdLDL by 20% (p=0.043) whereas S and C reduced sdLDL by 24% (p=0.020) and 33% (p=0.003), respectively, and non-sdLDL by 28% (p=0.004) and 42% (p<0.001), respectively. However, the further drop in sdLDL by adding E to S was not significant. CONCLUSION Ezetimibe alone and in combination with simvastatin reduced the concentration of atherogenic sdLDL in patients with type 2 diabetes.
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Affiliation(s)
- Karl Winkler
- Department of Clinical Chemistry, University Medical Center Freiburg, Hugstetter Straße 55, D-79106 Freiburg, Germany.
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Wehr E, Pilz S, Boehm BO, März W, Obermayer-Pietsch B. The lipid accumulation product is associated with increased mortality in normal weight postmenopausal women. Obesity (Silver Spring) 2011; 19:1873-80. [PMID: 21394091 DOI: 10.1038/oby.2011.42] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Lipid accumulation product (LAP) is an emerging cardiovascular risk factor, which is calculated from waist circumference (WC) and triglyceride (TG) levels. The aim of this study was to elucidate the relationship between LAP and cardiovascular mortality as well as the presence of type 2 diabetes with respect to gender-specific differences. We determined WC and fasting TG levels and the cardiovascular and metabolic phenotypes coronary artery disease (CAD), hypertension, metabolic syndrome, and diabetes mellitus in 2,279 men and 875 postmenopausal women who were routinely referred to coronary angiography. The LAP was calculated as (WC (cm)--65) × (TG (mmol/l)) for men and as (WC (cm)--58) × (TG (mmol/l)) for women. LAP levels were independently associated with congestive heart failure mortality in all postmenopausal women and with all-cause mortality in diabetic postmenopausal women but not in men. Multivariable-adjusted hazard ratios (with 95% confidence intervals) for all-cause, cardiovascular, and congestive heart failure mortality in the third compared to the first LAP tertile were 4.28 (1.94-9.44; P < 0.001), 3.47 (1.28-9.40; P = 0.015), and 10.77 (1.21-95.88; P = 0.033), respectively, in normal weight postmenopausal women, whereas no significant associations were found in men. LAP levels were highly associated with type 2 diabetes in all subjects, postmenopausal women, and men. High LAP values are predictive of mortality independently of other cardiovascular risk factors in normal weight and diabetic postmenopausal women but not in men. Type 2 diabetes (T2DM) was highly associated with LAP in women and men. Our study validates an inexpensive and simple risk profiling that may allow identifying postmenopausal women at high cardiovascular risk.
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Affiliation(s)
- Elisabeth Wehr
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Medical University Graz, Graz, Austria.
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Kumar V, Butcher SJ, Öörni K, Engelhardt P, Heikkonen J, Kaski K, Ala-Korpela M, Kovanen PT. Three-dimensional cryoEM reconstruction of native LDL particles to 16Å resolution at physiological body temperature. PLoS One 2011; 6:e18841. [PMID: 21573056 PMCID: PMC3090388 DOI: 10.1371/journal.pone.0018841] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 03/21/2011] [Indexed: 11/20/2022] Open
Abstract
Background Low-density lipoprotein (LDL) particles, the major carriers of cholesterol in the human circulation, have a key role in cholesterol physiology and in the development of atherosclerosis. The most prominent structural components in LDL are the core-forming cholesteryl esters (CE) and the particle-encircling single copy of a huge, non-exchangeable protein, the apolipoprotein B-100 (apoB-100). The shape of native LDL particles and the conformation of native apoB-100 on the particles remain incompletely characterized at the physiological human body temperature (37°C). Methodology/Principal Findings To study native LDL particles, we applied cryo-electron microscopy to calculate 3D reconstructions of LDL particles in their hydrated state. Images of the particles vitrified at 6°C and 37°C resulted in reconstructions at ∼16 Å resolution at both temperatures. 3D variance map analysis revealed rigid and flexible domains of lipids and apoB-100 at both temperatures. The reconstructions showed less variability at 6°C than at 37°C, which reflected increased order of the core CE molecules, rather than decreased mobility of the apoB-100. Compact molecular packing of the core and order in a lipid-binding domain of apoB-100 were observed at 6°C, but not at 37°C. At 37°C we were able to highlight features in the LDL particles that are not clearly separable in 3D maps at 6°C. Segmentation of apoB-100 density, fitting of lipovitellin X-ray structure, and antibody mapping, jointly revealed the approximate locations of the individual domains of apoB-100 on the surface of native LDL particles. Conclusions/Significance Our study provides molecular background for further understanding of the link between structure and function of native LDL particles at physiological body temperature.
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Affiliation(s)
- Vibhor Kumar
- Department of Biomedical Engineering and Computational Science, School of Science and Technology, Centre of Excellence in Computational Complex Systems Research, Aalto University Aalto, Finland
- Computational and Mathematical Biology, Genome Institute of Singapore, A*STAR, Singapore
| | - Sarah J. Butcher
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Katariina Öörni
- Wihuri Research Institute, Kalliolinnantie 4, Helsinki, Finland
| | - Peter Engelhardt
- Department of Biomedical Engineering and Computational Science, School of Science and Technology, Centre of Excellence in Computational Complex Systems Research, Aalto University Aalto, Finland
- Department of Pathology, Haartman Institute, Haartmaninkatu 3, University of Helsinki, Helsinki, Finland
- Department of Applied Physics, Nanomicroscopy Center, School of Science and Technology, Puumiehenkuja 2, Aalto University, Espoo, Finland
| | - Jukka Heikkonen
- Department of Biomedical Engineering and Computational Science, School of Science and Technology, Centre of Excellence in Computational Complex Systems Research, Aalto University Aalto, Finland
- Department of Information Technology, University of Turku, Turku, Finland
| | - Kimmo Kaski
- Department of Biomedical Engineering and Computational Science, School of Science and Technology, Centre of Excellence in Computational Complex Systems Research, Aalto University Aalto, Finland
| | - Mika Ala-Korpela
- Computational Medicine Research Group, Institute of Clinical Medicine, Faculty of Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
- Department of Internal Medicine and Biocenter Oulu, Clinical Research Center, University of Oulu, Oulu, Finland
| | - Petri T. Kovanen
- Wihuri Research Institute, Kalliolinnantie 4, Helsinki, Finland
- * E-mail:
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Kleber ME, Renner W, Grammer TB, Linsel-Nitschke P, Boehm BO, Winkelmann BR, Bugert P, Hoffmann MM, März W. Association of the single nucleotide polymorphism rs599839 in the vicinity of the sortilin 1 gene with LDL and triglyceride metabolism, coronary heart disease and myocardial infarction. Atherosclerosis 2010; 209:492-7. [DOI: 10.1016/j.atherosclerosis.2009.09.068] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 09/18/2009] [Accepted: 09/23/2009] [Indexed: 10/20/2022]
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Stojakovic T, de Campo A, Scharnagl H, Sourij H, Schmölzer I, Wascher TC, März W. Differential effects of fluvastatin alone or in combination with ezetimibe on lipoprotein subfractions in patients at high risk of coronary events. Eur J Clin Invest 2010; 40:187-94. [PMID: 20067513 DOI: 10.1111/j.1365-2362.2009.02249.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Ezetimibe, a cholesterol-absorption inhibitor, significantly lowers low-density lipoprotein cholesterol (LDL-C) when administered in addition to statin treatment. The effect of ezetimibe on the incidence and progression of vascular disease is elusive. The objective of the study was to examine the effects of fluvastatin plus ezetimibe on lipoprotein subfractions in patients with type 2 diabetes and/or coronary heart disease. MATERIALS AND METHODS Ninety patients with LDL-C between 100 and 160 mg dL(-1) were enrolled in this prospective, randomized, single-blind, single-centre study. A total of 84 patients were treated with either fluvastatin 80 mg (n = 28) alone or in combination with ezetimibe 10 mg (n = 56) for 12 weeks to determine the effects on lipids, apolipoproteins and LDL subfractions by equilibrium density gradient ultracentrifugation. This study is registered with ClinicalTrials.gov, number NCT00814723. RESULTS Total cholesterol, LDL-C and apolipoprotein B were significantly more reduced in the combined therapy group. High density lipoproteins increased in the fluvastatin-only group and decreased in the combined therapy group. There was a significant difference between the two groups in buoyant and intermediate, but not in dense LDL particles. CONCLUSIONS Addition of ezetimibe to fluvastatin resulted in a further reduction of buoyant and intermediate, but not of dense LDL compared with fluvastatin alone.
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Affiliation(s)
- T Stojakovic
- Medical University of Graz, A-8036 Graz, Austria.
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26
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Atomistic simulations of phosphatidylcholines and cholesteryl esters in high-density lipoprotein-sized lipid droplet and trilayer: clues to cholesteryl ester transport and storage. Biophys J 2009; 96:4099-108. [PMID: 19450481 DOI: 10.1016/j.bpj.2009.01.058] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 01/14/2009] [Accepted: 01/14/2009] [Indexed: 12/15/2022] Open
Abstract
Cholesteryl esters (CEs) are the water-insoluble transport and storage form of cholesterol. For both transport and storage, phospholipids and proteins embrace the CEs to form an amphipathic monolayer that surrounds the CEs. CEs are transported extracellularly in lipoproteins and are stored intracellularly as cytoplasmic lipid droplets. To clarify the molecular phenomena related to the above structures, we conducted atomistic molecular-dynamics simulations for a spherical, approximately high density lipoprotein sized lipid droplet comprised of palmitoyl-oleoyl-phosphatidylcholine (POPC) and cholesteryl oleate (CO) molecules. An additional simulation was conducted for a lamellar lipid trilayer consisting of the same lipid constituents. The density profiles showed that COs were located in the core of the spherical droplet. In trilayer simulations, CO molecules were also in the core and formed two denser strata. This is remarkable because the intra- and intermolecular behaviors of the COs were similar to previous findings from bulk COs in the fluid phase. In accordance with previous experimental studies, the solubility of COs in the POPC monolayers was found to be low. The orientation distribution of the sterol moiety with respect to the normal of the system was found to be broad, with mainly isotropic or slightly parallel orientations observed deep in the core of the lipid droplet or the trilayer, respectively. In both systems, the orientation of the sterol moiety changed to perpendicular with respect to the normal close to the phopsholipid monolayers. Of interest, within the POPC monolayers, the intramolecular conformation of the COs varied from the previously proposed horseshoe-like conformation to a more extended one. From a metabolic point of view, the observed solubilization of CEs into the phospholipid monolayers, and the conformation of CEs in the phospholipid monolayers are likely to be important regulatory factors of CE transport and hydrolysis.
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Winkler K, Schewe T, Pütz G, Odünc N, Schäfer G, Siegel E, Geisen U, Abletshauser C, Hoffmann MM. Fluvastatin/fenofibrate vs. simvastatin/ezetimibe in patients with metabolic syndrome: different effects on LDL-profiles. Eur J Clin Invest 2009; 39:463-70. [PMID: 19397693 DOI: 10.1111/j.1365-2362.2009.02126.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Patients with metabolic syndrome (MS) and type 2 diabetes (T2DM) show increased risk for coronary artery disease. Lipoprotein metabolism is characterized by elevated triglycerides (TG), low high-density lipoprotein cholesterol (HDL-C) and predominance of atherogenic small, dense low-density lipoprotein (sdLDL), while low-density lipoprotein (LDL) cholesterol is only slightly elevated. METHODS Multicentre, randomized, open-label cross-over study investigating the effect of combination of fluvastatin/fenofibrate (80/200 mg) (F&F) on LDL-subfractions compared with combination of simvastatin/ezetimibe (20/10 mg) (S&E) in patients with MS/T2DM. RESULTS Seventy-five patients were randomized, 69 completed the study and LDL-subfractions of 56 patients were analysed. Thirty-eight out of 56 patients (68%) showed a profile dominated by sdLDL. In these, TG and total cholesterol (TC) were elevated compared with non-sdLDL patients. In all patients, reduction of TC and LDL cholesterol (LDL-C) by S&E was stronger than by F&F. The increase of HDL-C was stronger with S&E in the non-sdLDL group, whereas in the sdLDL group, there was no difference between treatments. In non-sdLDL patients, there was no effect on TG or LDL-radius. However, in the sdLDL group, F&F was more effective in reducing TG and increased LDL radius, whereas S&E reduced LDL radius even further. CONCLUSIONS S&E is more efficient in reducing TC and LDL-C. This is also true for HDL-C increase in non-sdLDL patients. However, in patients with sdLDL, F&F was more efficient in reducing TG and increasing LDL radius.
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Affiliation(s)
- K Winkler
- University Medical Center Freiburg, Freiburg, Germany.
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28
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Prassl R, Pregetter M, Amenitsch H, Kriechbaum M, Schwarzenbacher R, Chapman JM, Laggner P. Low density lipoproteins as circulating fast temperature sensors. PLoS One 2008; 3:e4079. [PMID: 19114995 PMCID: PMC2603587 DOI: 10.1371/journal.pone.0004079] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Accepted: 11/28/2008] [Indexed: 11/18/2022] Open
Abstract
Background The potential physiological significance of the nanophase transition of neutral lipids in the core of low density lipoprotein (LDL) particles is dependent on whether the rate is fast enough to integrate small (±2°C) temperature changes in the blood circulation. Methodology/Principal Findings Using sub-second, time-resolved small-angle X-ray scattering technology with synchrotron radiation, we have monitored the dynamics of structural changes within LDL, which were triggered by temperature-jumps and -drops, respectively. Our findings reveal that the melting transition is complete within less than 10 milliseconds. The freezing transition proceeds slowly with a half-time of approximately two seconds. Thus, the time period over which LDL particles reside in cooler regions of the body readily facilitates structural reorientation of the apolar core lipids. Conclusions/Significance Low density lipoproteins, the biological nanoparticles responsible for the transport of cholesterol in blood, are shown to act as intrinsic nano-thermometers, which can follow the periodic temperature changes during blood circulation. Our results demonstrate that the lipid core in LDL changes from a liquid crystalline to an oily state within fractions of seconds. This may, through the coupling to the protein structure of LDL, have important repercussions on current theories of the role of LDL in the pathogenesis of atherosclerosis.
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Affiliation(s)
- Ruth Prassl
- Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Graz, Austria.
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29
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Molecular structure of low density lipoprotein: current status and future challenges. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2008; 38:145-58. [DOI: 10.1007/s00249-008-0368-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 08/28/2008] [Indexed: 01/01/2023]
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30
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Kumpula LS, Kumpula JM, Taskinen MR, Jauhiainen M, Kaski K, Ala-Korpela M. Reconsideration of hydrophobic lipid distributions in lipoprotein particles. Chem Phys Lipids 2008; 155:57-62. [PMID: 18611396 DOI: 10.1016/j.chemphyslip.2008.06.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2008] [Revised: 05/25/2008] [Accepted: 06/03/2008] [Indexed: 11/29/2022]
Abstract
Lipoprotein particles are commonly known as micellar aggregates with hydrophobic lipids located within the core and amphipathic molecules in the surface. Using a new structural model for optimizing the distribution of hydrophobic lipids, namely triglyceride (TG) and cholesterol ester (CE) molecules, we reveal that particle size-dependent proportion of these 'core lipids' may locate in the surface of lipoprotein particles. The composition of the particles also strongly influences the actual molecular content of the surface. For example, in high-density lipoprotein (HDL) particles the percentage of CEs of all surface lipids is between 13% and 27% due to the high tendency of CEs to locate in the surface and the high concentration of CEs in the particles. Conversely, although the percentage of TG molecules in the surface of HDL particles is also high, approximately 60% as for CE, the percentage of TGs of all surface lipids is low, only up to 5%, because HDL particles have a low-TG concentration. These structural models provide an intuitive and coherent structural rationale for various metabolic cascades in lipoprotein metabolism with the catalytic enzyme action and molecular binding for transport proteins taking place at the surface of the particles.
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Affiliation(s)
- Linda S Kumpula
- Computational Medicine Research Group, Department of Biomedical Engineering and Computational Science, Helsinki University of Technology, P.O. Box 9203, FI-02015 HUT, Finland
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31
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Computational lipidology: predicting lipoprotein density profiles in human blood plasma. PLoS Comput Biol 2008; 4:e1000079. [PMID: 18497853 PMCID: PMC2361219 DOI: 10.1371/journal.pcbi.1000079] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 04/04/2008] [Indexed: 01/14/2023] Open
Abstract
Monitoring cholesterol levels is strongly recommended to identify patients at risk for myocardial infarction. However, clinical markers beyond "bad" and "good" cholesterol are needed to precisely predict individual lipid disorders. Our work contributes to this aim by bringing together experiment and theory. We developed a novel computer-based model of the human plasma lipoprotein metabolism in order to simulate the blood lipid levels in high resolution. Instead of focusing on a few conventionally used predefined lipoprotein density classes (LDL, HDL), we consider the entire protein and lipid composition spectrum of individual lipoprotein complexes. Subsequently, their distribution over density (which equals the lipoprotein profile) is calculated. As our main results, we (i) successfully reproduced clinically measured lipoprotein profiles of healthy subjects; (ii) assigned lipoproteins to narrow density classes, named high-resolution density sub-fractions (hrDS), revealing heterogeneous lipoprotein distributions within the major lipoprotein classes; and (iii) present model-based predictions of changes in the lipoprotein distribution elicited by disorders in underlying molecular processes. In its present state, the model offers a platform for many future applications aimed at understanding the reasons for inter-individual variability, identifying new sub-fractions of potential clinical relevance and a patient-oriented diagnosis of the potential molecular causes for individual dyslipidemia.
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32
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Banaszak LJ, Ranatunga WK. The assembly of apoB-containing lipoproteins: a structural biology point of view. Ann Med 2008; 40:253-67. [PMID: 18428019 DOI: 10.1080/07853890701813070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Atherosclerosis is a widespread disease caused by the deposition of lipids on arterial walls. Such lipid plaques in coronary arteries can be fatal. Although many factors related to diet, life-style, etc. contribute to the worsening of the ailment, the primary cause, the lipids in the circulatory system, come from a series of low-density lipoproteins. These lipoproteins are necessary for the transport of lipids to and from different organs. It would be valuable to medicine and the field of drug design if a more detailed understanding of the organization of lipid and protein in these molecules were available. Unfortunately because of heterogeneity in their size and lipid composition, all classes of the low-density serum lipoproteins appear to be not amenable to the most widely used method for obtaining detailed atomic data - X-ray crystallography. However there appears to be a recently identified homolog that is relatively homogeneous, and crystal structures have been obtained. Used as a molecular model, the homolog serves as a source of conformational information that might help to unravel the processes involved in the lipid loading of the low-density lipoproteins. The review attempts to give a brief summary of the structural biology of the serum low-density lipoproteins relative to the molecular model of lipovitellin.
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Affiliation(s)
- Leonard J Banaszak
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
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Petersen M, Dyrby M, Toubro S, Engelsen SB, Nørgaard L, Pedersen HT, Dyerberg J. Quantification of lipoprotein subclasses by proton nuclear magnetic resonance-based partial least-squares regression models. Clin Chem 2005; 51:1457-61. [PMID: 15961551 DOI: 10.1373/clinchem.2004.046748] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Cardiovascular disease risk can be estimated in part on the basis of the plasma lipoprotein profile. Analysis of lipoprotein subclasses improves the risk evaluation, but the traditional methods are very time-consuming. Novel, rapid, and productive methods are therefore needed. METHODS We obtained plasma samples from 103 fasting people and determined the plasma lipoprotein subclass profiles by an established ultracentrifugation-based method. Proton nuclear magnetic resonance (NMR) spectra were obtained from replicate samples on a 600 MHz NMR spectrometer. From the ultracentrifugation-based reference data and the NMR spectra, we developed partial least-squares (PLS) regression models to predict cholesterol and triglyceride (TG) concentrations in plasma as well as in VLDL, intermediate-density lipoprotein (IDL), LDL, 3 LDL fractions, HDL, and 3 HDL subclasses. RESULTS The correlation coefficients (r) between the plasma TG and cholesterol concentrations measured by the 2 methods were 0.98 and 0.91, respectively. For LDL- and HDL-cholesterol concentrations, r = 0.90 and 0.94, respectively. For cholesterol concentrations in the LDL-1, LDL-2, and LDL-3 fractions, r = 0.74, 0.78, and 0.69, respectively, and for HDL subclasses HDL(2b), HDL(2a), and HDL(3), cholesterol concentrations were predicted with r = 0.92, 0.94, and 0.75, respectively. TG concentrations in VLDL, IDL, LDL, and HDL were predicted with correlations of 0.98, 0.85, 0.77, and 0.74, respectively. The cholesterol and TG concentrations in the main lipoprotein fractions and in LDL fractions and HDL subclasses predicted by the PLS models were 94%-100% of the concentrations obtained by ultracentrifugation. CONCLUSION NMR-based PLS regression models are appropriate for use in research in which analyses of the plasma lipoprotein profile, including LDL and HDL subclasses, are required in large numbers of samples.
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Affiliation(s)
- Martin Petersen
- Institute of Human Nutrition, Department of Food Science, Quality and Technology, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
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34
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Winkler K, Winkelmann BR, Scharnagl H, Hoffmann MM, Grawitz AB, Nauck M, Böhm BO, März W. Platelet-activating factor acetylhydrolase activity indicates angiographic coronary artery disease independently of systemic inflammation and other risk factors: the Ludwigshafen Risk and Cardiovascular Health Study. Circulation 2005; 111:980-7. [PMID: 15710755 DOI: 10.1161/01.cir.0000156457.35971.c8] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Platelet-activating factor acetylhydrolase (PAF-AH), also denoted as lipoprotein-associated phospholipase A2, is a lipoprotein-bound enzyme that is possibly involved in inflammation and atherosclerosis. This study investigates the relationship of PAF-AH activity to angiographic coronary artery disease (CAD), the use of cardiovascular drugs, and other established risk factors. METHODS AND RESULTS PAF-AH activity, lipoproteins, sensitive C-reactive protein (sCRP), fibrinogen, serum amyloid A, and white blood cell count were determined in 2454 subjects with angiographically confirmed CAD and in 694 control subjects. PAF-AH activity was highly correlated with LDL cholesterol (r=0.517), apolipoprotein B (r=0.644), and non-HDL cholesterol (r=0.648) but not with sCRP or fibrinogen. PAF-AH activity was lower in women than in men and was affected by the intake of lipid-lowering drugs (-12%; P<0.001), aspirin (-6%; P<0.001), beta-blockers (-6%; P<0.001), and digitalis (+7%; P<0.001). Unlike sCRP, fibrinogen, and serum amyloid A, PAF-AH activity was not elevated in unstable angina, non-ST-elevation myocardial infarction, or ST-elevation myocardial infarction. When nonusers of lipid-lowering drugs were examined, PAF-AH activity was associated with the severity of CAD and the number of coronary vessels with significant stenoses. In individuals not taking lipid-lowering drugs and after adjustment for use of aspirin, beta-blocker, and digitalis, the odds ratio for CAD associated with increasing PAF-AH activity was 1.39 (95% CI 1.26 to 1.54, P<0.001), a finding that was robust against further adjustments. CONCLUSIONS PAF-AH activity is not an indicator of the systemic inflammation that accompanies acute coronary syndromes. PAF-AH activity is affected by a number of cardiovascular drugs; however, after such medication use was accounted for, PAF-AH activity was associated with angiographic CAD, complementary to sCRP and independently of established risk factors such as LDL cholesterol.
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Affiliation(s)
- Karl Winkler
- Department of Medicine, University of Freiburg, Freiburg, Germany.
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März W, Scharnagl H, Winkler K, Tiran A, Nauck M, Boehm BO, Winkelmann BR. Low-Density Lipoprotein Triglycerides Associated With Low-Grade Systemic Inflammation, Adhesion Molecules, and Angiographic Coronary Artery Disease. Circulation 2004; 110:3068-74. [PMID: 15505088 DOI: 10.1161/01.cir.0000146898.06923.80] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Markers of systemic inflammation and LDL cholesterol (LDL-C) have been considered independent risk factors of coronary artery disease (CAD). We examined whether alterations of LDL metabolism not reflected by LDL-C were associated with low-grade inflammation, vascular injury, and CAD.
Methods and Results—
We studied 739 subjects with stable angiographic CAD and 570 matched control subjects in which CAD had been ruled out by angiography. The association of LDL triglycerides (LDL-TGs) (odds ratio [OR], 1.30; 95% CI, 1.19 to 1.43;
P
<0.001) with CAD was stronger than that of LDL-C (OR, 1.10; 95% CI, 1.00 to 1.21;
P
=0.047). The predictive value of LDL-TG for CAD was independent of LDL-C. “Sensitive” C-reactive protein (CRP), serum amyloid A, fibrinogen, interleukin 6, intercellular adhesion molecule-1 (ICAM-1), and vascular adhesion molecule-1 (VCAM-1) increased in parallel to LDL-TG. CRP, ICAM-1, and VCAM-1 were inversely related to LDL-C. To examine whether LDL-TGs were associated with the distribution of LDL subfractions, we studied 114 individuals with impaired fasting glucose, impaired glucose tolerance, or type 2 diabetes mellitus. In subjects with high LDL-TG, LDLs were depleted of cholesteryl esters (CEs), and VLDLs, IDLs, and dense LDLs were significantly elevated.
Conclusions—
Alterations of LDL metabolism characterized by high LDL-TG are related to CAD, systemic low-grade inflammation, and vascular damage. High LDL-TGs are indicative of CE-depleted LDL, elevated IDL, and dense LDL. LDL-TG may better reflect the atherogenic potential of LDL than LDL-C.
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Affiliation(s)
- Winfried März
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria.
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36
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Torzewski M, Suriyaphol P, Paprotka K, Spath L, Ochsenhirt V, Schmitt A, Han SR, Husmann M, Gerl VB, Bhakdi S, Lackner KJ. Enzymatic Modification of Low-Density Lipoprotein in the Arterial Wall. Arterioscler Thromb Vasc Biol 2004; 24:2130-6. [PMID: 15345515 DOI: 10.1161/01.atv.0000144016.85221.66] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Functionally interactive proteases of the plasminogen/plasmin and the matrix metalloproteinase (MMP) system degrade and reorganize the extracellular matrix of the vessel wall in atherosclerosis. Here we investigated whether such proteases are able to confer atherogenic properties onto low density lipoprotein by nonoxidative modification. METHODS AND RESULTS Similar to the recently described enzymatically-modified low-density lipoprotein (E-LDL), native LDL exposed to plasmin or matrix MMP-2 or MMP-9 and cholesterylester-hydrolase (CEH) showed extensive deesterification, with ratios of free cholesterol to total cholesterol rising to 0.8 compared with 0.2 in native LDL. When the ratio exceeded 0.6, both plasmin/CEH-LDL and MMP/CEH-LDL fused into larger particles. In parallel, they gained C-reactive protein-dependent complement-activating capacity. E-LDL produced with any protease/CEH combination was efficiently taken up by human macrophages, whereby marked induction of MMP-2 expression by E-LDL was observed. These in vitro findings had their in vivo correlates: urokinase-type plasminogen activator, MMP-2, and MMP-9 were detectable in both early and advanced human atherosclerotic lesions in colocalization with E-LDL. CONCLUSIONS Plasmin and MMP-2/MMP-9 may not only be involved in remodeling of the extracellular matrix in progressing plaques, but they may also be involved in lipoprotein modification during genesis and progression of atherosclerotic lesions.
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Affiliation(s)
- Michael Torzewski
- Institute for Clinical Chemistry and Laboratory Medicine, University of Mainz, Mainz, Germany
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Teerlink T, Scheffer PG, Bakker SJL, Heine RJ. Combined data from LDL composition and size measurement are compatible with a discoid particle shape. J Lipid Res 2004; 45:954-66. [PMID: 14967822 DOI: 10.1194/jlr.m300521-jlr200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The size of LDL is usually reported as particle diameter, with the implicit assumption that it is a spherical particle. On the other hand, data obtained by cryoelectron microscopy and crystallographic analysis suggest that LDL shape may be discoid. We have investigated LDL particle geometry by combining data on LDL lipid composition with size measurement. The mean LDL diameter of 160 samples was measured by high-performance gel-filtration chromatography (HPGC), and particle volume was calculated from its lipid composition. Assuming a spherical shape, diameters calculated from volume correlated poorly with values obtained by HPGC (R(2) = 0.36). Assuming a discoid shape, particle height was calculated from volume and HPGC diameter. Diameter (20.9 +/- 0.5 nm) and height (12.1 +/- 0.8 nm) were not significantly related to each other (r = 0.14, P = 0.09) and accounted for 23% and 77%, respectively, of the variation in particle volume. In multivariate regression models, LDL core lipids were the main determinants of height (R(2) = 0.83), whereas free cholesterol in the shell, which contributes only 5-9% to LDL mass, was the main determinant of diameter (R(2) = 0.54). We conclude that combined data from composition and size measurements are compatible with a discoid particle shape and propose a structural model for LDL in which free cholesterol plays a major role in determining particle shape and diameter.
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Affiliation(s)
- Tom Teerlink
- Departments of Clinical Chemistry, Institute for Cardiovascular Research, VU University Medical Center, 1007 MB Amsterdam, The Netherlands.
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38
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Schmidt-Trucksäss A, Baumstark MW, Daub C, Espenschied S, Grathwohl D, Berg A. Lipoprotein phenotype and adhesion molecules correlate with diurnal triglyceride profiles in patients with coronary artery disease. Nutr Metab Cardiovasc Dis 2004; 14:20-25. [PMID: 15053160 DOI: 10.1016/s0939-4753(04)80043-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND AND AIM To assess the relationships between different diurnal triglyceride (TG) profiles (p) and the atherogenicity of the lipoprotein phenotype and adhesion molecule concentrations in patients with coronary artery disease (CAD). METHODS AND RESULTS Repeated measurements of fasting TG and TGp were made in 29 CAD patients; fasting cholesterol levels (total-C, VLDL, LDL, HDL and small dense LDL) and soluble cell adhesion molecules (sCAM) (ICAM-1 and E-selectin) were measured once. Three different TGps were defined: fasting (137.0 +/- 60.7 mg/dL) and all other TG levels <200 mg/dL (LL; n=7); a fasting TG level <200 mg/dL (147.0 +/- 49.9 mg/dL) and maximum TG levels >200 mg/dL (LH; n=13); and both fasting (225.1+/-76.2 mg/dL) and maximum TG levels >200 mg/dL (HH; n=9). We then analysed the associations between the TGp types and the lipoprotein phenotype and CAMs. LL had significantly lower values than LH (p<0.05 for all parameters except sE-selectin) and HH (p<0.05 for all parameters) of VLDL (11.2 +/- 5.8, 18.8 +/- 9.4, 28.1 +/- 8.8 mg/dL), LDL-5 (11.6 +/- 3.3, 16.4 +/- 4.5, 22.1 +/-7.9 mg/dl) and LDL-6 (12.0 +/- 3.2, 17.0 +/- 5.7, 25.7 +/- 9.6 mg/dL), sICAM-1 (209.4 +/- 30.3, 267.5 +/- 60.6, 273.4 +/- 59.1 ng/dL) and sE-selectin (25.1 +/- 17.6, 35.5 +/- 11.5, 48.5 +/- 20.2 ng/dL). CONCLUSION Although the differences in fasting TG levels between the LL and LH groups were not significantly different, LH had a more atherogenic lipoprotein phenotype and higher concentrations of adhesion molecules. TGp measurements seem to be suitable for identifying CAD patients with an unfavourable diurnal TG and atherosclerosis-prone lipoprotein metabolism.
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Affiliation(s)
- A Schmidt-Trucksäss
- Freiburg University Hospital, Center for Internal Medicine, Department of Rehabilitative and Preventive Sports Medicine, Freiburg, Germany.
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Winkler K, Konrad T, Füllert S, Friedrich I, Destani R, Baumstark MW, Krebs K, Wieland H, März W. Pioglitazone reduces atherogenic dense LDL particles in nondiabetic patients with arterial hypertension: a double-blind, placebo-controlled study. Diabetes Care 2003; 26:2588-94. [PMID: 12941723 DOI: 10.2337/diacare.26.9.2588] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The oral antidiabetic agent pioglitazone improves insulin sensitivity and glycemic control and appears to lower atherogenic dense LDL in type 2 diabetes. Insulin resistance may occur frequently in nondiabetic patients with hypertension. This study is the first to report the effect of pioglitazone on LDL subfractions in normolipidemic, nondiabetic patients with arterial hypertension. RESEARCH DESIGN AND METHODS We performed a monocentric, double-blind, randomized, parallel-group comparison of 45 mg pioglitazone (n = 26) and a placebo (n = 28), each given once daily for 16 weeks. Fifty-four moderately hypertensive patients (LDL cholesterol, 2.8 +/- 0.8 mmol/l; HDL cholesterol, 1.1 +/- 0.3 mmol/l; triglycerides, 1.4 mmol/l (median; range 0.5-7.1) were studied at baseline and on treatment. RESULTS At baseline, dense LDLs were elevated (apolipoprotein [apo]B in LDL-5 plus LDL-6 >250 mg/l) in 63% of all patients. Sixteen weeks of treatment with pioglitazone did not significantly change triglycerides, total, LDL, and HDL cholesterol. However, pioglitazone reduced dense LDLs by 22% (P = 0.024). The mean diameter of LDL particles increased from 19.83 +/- 0.30 to 20.13 +/- 0.33 nm (P < 0.001 vs. placebo), whereas the mean LDL density decreased from 1.0384 +/- 0.0024 to 1.0371 +/- 0.0024 kg/l (P = 0.005 vs. placebo). The effect of pioglitazone on LDL size and density was independent of fasting triglycerides and HDL cholesterol at baseline and of changes in fasting triglycerides and HDL cholesterol. CONCLUSIONS The prevalence of atherogenic dense LDL in nondiabetic, hypertensive patients is similar to patients with type 2 diabetes. Pioglitazone significantly reduces dense LDL independent from fasting triglycerides and HDL cholesterol. The antiatherogenic potential of pioglitazone may thus be greater than that expected from its effects on triglycerides, LDL, and HDL cholesterol alone.
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Affiliation(s)
- Karl Winkler
- Department of Clinical Chemistry, University of Freiburg, Germany.
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40
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Hammel M, Laggner P, Prassl R. Structural characterisation of nucleoside loaded low density lipoprotein as a main criterion for the applicability as drug delivery system. Chem Phys Lipids 2003; 123:193-207. [PMID: 12691852 DOI: 10.1016/s0009-3084(03)00002-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The potential role of human low density lipoprotein (LDL) particles as delivery system for lipophilic, cytotoxic drugs critically depends on their structural integrity. In the present study, LDL particles were loaded with antineoplastic prodrugs, i.e. monooleoyl (MOT)- and dioleoyl (DOT)- thymidine esters by different techniques. Using the reconstitution method MOT shows the highest incorporation efficiency with over 80% of the initial drug associated with LDL. In contrast, for the more lipophilic DOT the incorporation efficiency for reconstitution, dry film as well as dimethylsulfoxide method was extremely low. Structural changes upon drug loading were monitored by differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS). The results show that the influence of MOT and DOT is predominantly confined to the surface monolayer of LDL seen as a destabilisation of the protein moiety and a small increase in particle diameter. The core lipid region of the LDL-drug complexes remains essentially unaffected, as verified by undisturbed core lipid arrangement and core lipid melting behaviour.
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Affiliation(s)
- Michal Hammel
- Institute of Biophysics and X-Ray Structure Research, Austrian Academy of Sciences, Schmiedlstrasse 6, A-8042, Graz, Austria
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Winkler K, Wetzka B, Hoffmann MM, Friedrich I, Kinner M, Baumstark MW, Zahradnik HP, Wieland H, März W. Triglyceride-rich lipoproteins are associated with hypertension in preeclampsia. J Clin Endocrinol Metab 2003; 88:1162-6. [PMID: 12629100 DOI: 10.1210/jc.2002-021160] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Disorders of the lipoprotein metabolism are a major cause of endothelial dysfunction that may result in hypertension and proteinuria, clinical hallmarks of preeclampsia (PE). Lipoproteins and low-density lipoprotein (LDL) subfractions were investigated in 15 women with severe PE and compared with 23 women with a normal course of pregnancy. Compared with normal pregnancy, in PE apolipoprotein (apo)B in very low-density lipoprotein was increased by 76% (P = 0.008), and the triglyceride content of intermediate dense lipoproteins (IDL) was increased by 51% (P < 0.001); cholesterol and apoB in LDL were decreased by 26% (P = 0.005) and 23% (P = 0.016), respectively. Although not significant, the LDL profile was dominated by the most buoyant LDL-1. ApoB in the most dense LDL (dLDL), namely LDL-5 and LDL-6, was significantly decreased by 49% (P < 0.001) and 55% (P < 0.001), respectively. Diastolic blood pressure was positively correlated with the triglyceride content of IDL (r = 6.31; P < 0.001 and r = 0.352; P = 0.033 by partial correlation controlling for the presence or absence of PE) and negatively correlated with the concentration of apoB in dLDL (r = -0.500; P = 0.002). In addition, IDL triglycerides correlated negatively with infant birth weight percentile (r = -0.373; P = 0.027) and positively with proteinuria (r = 0.430; P = 0.014). Low birth weight was associated with high IDL triglycerides and low rather than high concentrations of dLDL. Triglyceride-rich remnants are known to cause endothelial dysfunction. Because the triglyceride content of IDL was positively correlated with elevated blood pressure and proteinuria, triglyceride-rich remnant lipoproteins might contribute to the pathophysiology of PE.
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Affiliation(s)
- Karl Winkler
- Department of Clinical Chemistry, University of Freiburg, Germany.
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Segrest JP, Jones MK, De Loof H, Dashti N. Structure of apolipoprotein B-100 in low density lipoproteins. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)30267-4] [Citation(s) in RCA: 359] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Rühlmann C, Thieme M, Helmstedt M. Interaction between dextran and human low density lipoproteins (LDL) observed using laser light scattering. Chem Phys Lipids 2001; 110:173-81. [PMID: 11369326 DOI: 10.1016/s0009-3084(00)00202-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Dextran infusions in humans lead to a reduction of low density lipoproteins (LDL) in the plasma compartment. The interaction of dextran with human LDL was investigated in vitro by static and dynamic light scattering. The experiments were performed with human LDL (apoB concentration 0.75 g l(-1)) and dextran (Mw = 40,000 and 70,000 g mol(-1)) at 25 degrees C. The dextran concentrations after mixing were 10 and 50 g l(-1). The hydrodynamic radius for native LDL was found to be RH = 12.9 nm. The addition of dextran induces the formation of LDL associates with a mean radius of RH approximately 200 nm. These findings show that even non-sulphated polysaccharides interact with LDL. The dextran-dependent formation of LDL associates detected in vitro could be the reason for the in vivo effect of dextran on the lipid metabolism.
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Affiliation(s)
- C Rühlmann
- Centre of Internal Medicine, Fakultät für Physik und Geowissenschaften, Universität Leipzig, Linnéstrasse 5, D-04103, Leipzig, Germany
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März W, Scharnagl H, Abletshauser C, Hoffmann MM, Berg A, Keul J, Wieland H, Baumstark MW. Fluvastatin lowers atherogenic dense low-density lipoproteins in postmenopausal women with the atherogenic lipoprotein phenotype. Circulation 2001; 103:1942-8. [PMID: 11306521 DOI: 10.1161/01.cir.103.15.1942] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although HMG-CoA reductase inhibitors (HMGRIs) are effective lipid-lowering agents, it remains controversial whether these agents also lower dense LDL (dLDL), a predominance of which is considered to contribute to the atherogenicity of the metabolic syndrome. METHODS AND RESULTS In a multicenter, double-blind, randomized, placebo-controlled study, we determined the effect of the HMGRI fluvastatin on lipids, apolipoproteins, and LDL subfractions (by equilibrium density gradient ultracentrifugation). A total of 52 postmenopausal women with combined hyperlipidemia and increased dLDL were treated with either fluvastatin 40 mg/d (n=35) or placebo (n=17). After 12 weeks' treatment, significant reductions (P<0.001) in total cholesterol (-19%), IDL cholesterol (-35%), LDL cholesterol (-23%), apolipoprotein B (-21%), and apolipoprotein B in dLDL (-42%) were apparent among fluvastatin recipients. No significant changes in triglycerides or HDL cholesterol were observed. The effect of fluvastatin on dLDL was correlated with baseline values. There was no consistent relationship, however, between the effect of fluvastatin on triglycerides and the decrease in dLDL. CONCLUSIONS Fluvastatin lowers total and LDL cholesterol and the concentration of dLDL. This profile may contribute to an antiatherogenic effect for fluvastatin that is greater than expected on the basis of changes in lipids and apolipoproteins.
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Affiliation(s)
- W März
- Division of Clinical Chemistry, Division of Sports Medicine, Department of Medicine, Albert Ludwigs-University, Freiburg, Germany.
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Pedersen A, Baumstark MW, Marckmann P, Gylling H, Sandström B. An olive oil-rich diet results in higher concentrations of LDL cholesterol and a higher number of LDL subfraction particles than rapeseed oil and sunflower oil diets. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)32351-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Hevonoja T, Pentikäinen MO, Hyvönen MT, Kovanen PT, Ala-Korpela M. Structure of low density lipoprotein (LDL) particles: basis for understanding molecular changes in modified LDL. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1488:189-210. [PMID: 11082530 DOI: 10.1016/s1388-1981(00)00123-2] [Citation(s) in RCA: 271] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Low density lipoprotein (LDL) particles are the major cholesterol carriers in circulation and their physiological function is to carry cholesterol to the cells. In the process of atherogenesis these particles are modified and they accumulate in the arterial wall. Although the composition and overall structure of the LDL particles is well known, the fundamental molecular interactions and their impact on the structure of LDL particles are not well understood. Here, the existing pieces of structural information on LDL particles are combined with computer models of the individual molecular components to give a detailed structural model and visualization of the particles. Strong evidence is presented in favor of interactions between LDL lipid constituents that lead to specific domain formation in the particles. A new three-layer model, which divides the LDL particle into outer surface, interfacial layer, and core, and which is capable of explaining some seemingly contradictory interpretations of molecular interactions in LDL particles, is also presented. A new molecular interaction model for the beta-sheet structure and phosphatidylcholine headgroups is introduced and an overall view of the tertiary structure of apolipoprotein B-100 in the LDL particles is presented. This structural information is also utilized to understand and explain the molecular characteristics and interactions of modified, atherogenic LDL particles.
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Affiliation(s)
- T Hevonoja
- Wihuri Research Institute, Kalliolinnantie 4, FIN-00140 Helsinki, Finland
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Aggregation, fusion, and vesicle formation of modified low density lipoprotein particles: molecular mechanisms and effects on matrix interactions. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)31964-7] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Halle M, Berg A, Garwers U, Grathwohl D, Knisel W, Keul J. Concurrent reductions of serum leptin and lipids during weight loss in obese men with type II diabetes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:E277-82. [PMID: 10444423 DOI: 10.1152/ajpendo.1999.277.2.e277] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The aim of the study was to examine the effects of weight reduction by exercise and diet on metabolic control in obese subjects with insulin resistance, particularly investigating if changes in serum leptin concentrations were directly associated with improvements in metabolic control. Twenty obese men (48 +/- 8 yr; body mass index 32. 1 +/- 3.9 kg/m(2)) with previously diagnosed type II diabetes mellitus were assigned to a 4-wk intervention program of exercise (2, 200 kcal/wk) and diet (1,000 kcal/day; 50% carbohydrates, 25% protein, 25% fat; polyunsaturated-to-saturated fatty acid ratio 1.0). Intervention induced significant reductions in body weight and serum leptin levels, and improvements in lipoprotein profile and glucose control. Reductions in leptin levels were directly associated with reductions in serum triglycerides and cholesterol, a finding that was independent of improvements in glucose control. These data show that serum leptin concentrations can be reduced with caloric restriction and exercise in male patients with type II diabetes, and they suggest a direct relationship between leptin and lipoprotein metabolism that is not solely due to weight reduction.
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Affiliation(s)
- M Halle
- Department of Prevention, Rehabilitation, and Sports Medicine, Center for Internal Medicine, Freiburg University Hospital, D-79106 Freiburg, Germany.
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Affiliation(s)
- I Rajman
- Clinical Pharmacology, Eli Lilly and Company, Lilly Research Centre, Erl Wood Manor, Windlesham, UK
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50
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Königer M, Quaschning T, Wanner C, Schollmeyer P, Krämer-Guth A. Abnormalities in lipoprotein metabolism in hemodialysis patients. KIDNEY INTERNATIONAL. SUPPLEMENT 1999; 71:S248-50. [PMID: 10412790 DOI: 10.1046/j.1523-1755.1999.07166.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Patients on chronic hemodialysis treatment are at elevated atherogenic risk, and dyslipidemia appears to be one of the major risk factors. However, most of these patients exhibit elevated serum triglycerides, whereas serum cholesterol and low-density lipoprotein (LDL) cholesterol levels are in the normal range. This study was therefore designed to examine the influence of hypertriglyceridemia under the condition of hemodialysis and diabetes mellitus on LDL metabolism. METHODS LDL was isolated from healthy controls, hypertriglyceridemic diabetic patients, and nondiabetic hemodialysis patients (N = 30, 10 in each group), which were separated into six subfractions by density gradient ultracentrifugation and were characterized concerning lipid/protein composition, degree of glycation, and oxidation. Uptake of 125I-labeled LDL was examined via LDL receptors of HepG2 cells and scavenger receptors of mouse peritoneal macrophages. RESULTS In hemodialysis patients, serum triglycerides were significantly elevated, whereas cholesterol levels were within the normal range. Triglyceride enrichment occurred in the very low-density lipoprotein (VLDL) class and LDL class, and an accumulation of a highly atherogenic small dense LDL subfraction could be detected predominantly in patients with non-insulin-dependent diabetes mellitus. LDL of hemodialysis patients also contained elevated levels of lipid peroxidation products, which were even higher in diabetic patients. Alterations in composition, size, and configuration of LDL from diabetic and nondiabetic patients on hemodialysis impaired LDL receptor-mediated degradation and enhanced the uptake of these modified LDL particles via nonsaturable scavenger receptors. CONCLUSION Diminished LDL receptor-mediated uptake of modified, triglyceride-rich, small dense LDL most likely leads to accumulation of these lipoproteins in vivo, favoring the development of atherosclerotic lesions. Future clinical studies must demonstrate whether patients will benefit from reducing these atherogenic particles by lipid-lowering intervention.
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Affiliation(s)
- M Königer
- Department of Medicine, University of Freiburg, Germany.
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