| 1. |
|
|
| 2. |
- Wiegman, Albert, et al.
(författare)
-
Familial hypercholesterolaemia in children and adolescents: gaining decades of life by optimizing detection and treatment.
- 2015
-
Ingår i: European heart journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 36, s. 2425-2437
-
Tidskriftsartikel (refereegranskat)abstract
- Familial hypercholesterolaemia (FH) is a common genetic cause of premature coronary heart disease (CHD). Globally, one baby is born with FH every minute. If diagnosed and treated early in childhood, individuals with FH can have normal life expectancy. This consensus paper aims to improve awareness of the need for early detection and management of FH children. Familial hypercholesterolaemia is diagnosed either on phenotypic criteria, i.e. an elevated low-density lipoprotein cholesterol (LDL-C) level plus a family history of elevated LDL-C, premature coronary artery disease and/or genetic diagnosis, or positive genetic testing. Childhood is the optimal period for discrimination between FH and non-FH using LDL-C screening. An LDL-C ≥5 mmol/L (190 mg/dL), or an LDL-C ≥4 mmol/L (160 mg/dL) with family history of premature CHD and/or high baseline cholesterol in one parent, make the phenotypic diagnosis. If a parent has a genetic defect, the LDL-C cut-off for the child is ≥3.5 mmol/L (130 mg/dL). We recommend cascade screening of families using a combined phenotypic and genotypic strategy. In children, testing is recommended from age 5 years, or earlier if homozygous FH is suspected. A healthy lifestyle and statin treatment (from age 8 to 10 years) are the cornerstones of management of heterozygous FH. Target LDL-C is <3.5 mmol/L (130 mg/dL) if >10 years, or ideally 50% reduction from baseline if 8-10 years, especially with very high LDL-C, elevated lipoprotein(a), a family history of premature CHD or other cardiovascular risk factors, balanced against the long-term risk of treatment side effects. Identifying FH early and optimally lowering LDL-C over the lifespan reduces cumulative LDL-C burden and offers health and socioeconomic benefits. To drive policy change for timely detection and management, we call for further studies in the young. Increased awareness, early identification, and optimal treatment from childhood are critical to adding decades of healthy life for children and adolescents with FH.
|
|
| 3. |
- Gomaraschi, Monica, et al.
(författare)
-
eNOS Activation by HDL Is Impaired in Genetic CETP Deficiency.
- 2014
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:5
-
Tidskriftsartikel (refereegranskat)abstract
- Mutations in the CETP gene resulting in defective CETP activity have been shown to cause remarkable elevations of plasma HDL-C levels, with the accumulation in plasma of large, buoyant HDL particles enriched in apolipoprotein E. Genetic CETP deficiency thus represents a unique tool to evaluate how structural alterations of HDL impact on HDL atheroprotective functions. Aim of the present study was to assess the ability of HDL obtained from CETP-deficient subjects to protect endothelial cells from the development of endothelial dysfunction. HDL isolated from one homozygous and seven heterozygous carriers of CETP null mutations were evaluated for their ability to down-regulate cytokine-induced cell adhesion molecule expression and to promote NO production in cultured endothelial cells. When compared at the same protein concentration, HDL and HDL3 from carriers proved to be as effective as control HDL and HDL3 in down-regulating cytokine-induced VCAM-1, while carrier HDL2 were more effective than control HDL2 in inhibiting VCAM-1 expression. On the other hand, HDL and HDL fractions from carriers of CETP deficiency were significantly less effective than control HDL and HDL fractions in stimulating NO production, due to a reduced eNOS activating capacity, likely because of a reduced S1P content. In conclusion, the present findings support the notion that genetic CETP deficiency, by affecting HDL particle structure, impacts on HDL vasculoprotective functions. Understanding of these effects might be important for predicting the outcomes of pharmacological CETP inhibition.
|
|
| 4. |
- Holleboom, Adriaan G, et al.
(författare)
-
Heterozygosity for a Loss-of-Function Mutation in GALNT2 Improves Plasma Triglyceride Clearance in Man
- 2011
-
Ingår i: Cell Metabolism. - : Elsevier. - 1550-4131 .- 1932-7420. ; 14:6, s. 811-8
-
Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies have identified GALNT2 as a candidate gene in lipid metabolism, but it is not known how the encoded enzyme ppGalNAc-T2, which contributes to the initiation of mucin-type O-linked glycosylation, mediates this effect. In two probands with elevated plasma high-density lipoprotein cholesterol and reduced triglycerides, we identified a mutation in GALNT2. It is shown that carriers have improved postprandial triglyceride clearance, which is likely attributable to attenuated glycosylation of apolipoprotein (apo) C-III, as observed in their plasma. This protein inhibits lipoprotein lipase (LPL), which hydrolyses plasma triglycerides. We show that an apoC-III-based peptide is a substrate for ppGalNAc-T2 while its glycosylation by the mutant enzyme is impaired. In addition, neuraminidase treatment of apoC-III which removes the sialic acids from its glycan chain decreases its potential to inhibit LPL. Combined, these data suggest that ppGalNAc-T2 can affect lipid metabolism through apoC-III glycosylation, thereby establishing GALNT2 as a lipid-modifying gene.
|
|
| 5. |
- Ljunggren, Stefan A, et al.
(författare)
-
Lipoprotein profiles in human heterozygote carriers of a functional mutation P297S in scavenger receptor class B1.
- 2015
-
Ingår i: Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. - : Elsevier. - 1388-1981 .- 1879-2618. ; 1851:12, s. 1587-1595
-
Tidskriftsartikel (refereegranskat)abstract
- The scavenger receptor class B type 1 (SR-B1) is an important HDL receptor involved in cholesterol uptake and efflux, but its physiological role in human lipoprotein metabolism is not fully understood. Heterozygous carriers of the SR-B1P297S mutation are characterized by increased HDL cholesterol levels, impaired cholesterol efflux from macrophages and attenuated adrenal function. Here, the composition and function of lipoproteins were studied in SR-B1P297S heterozygotes.Lipoproteins from six SR-B1P297S carriers and six family controls were investigated. HDL and LDL/VLDL were isolated by ultracentrifugation and proteins were separated by two-dimensional gel electrophoresis and identified by mass spectrometry. HDL antioxidant properties, paraoxonase 1 activities, apoA-I methionine oxidations and HDL cholesterol efflux capacity were assessed.Multivariate modeling separated carriers from controls based on lipoprotein composition. Protein analyses showed a significant enrichment of apoE in LDL/VLDL and of apoL-1 in HDL from heterozygotes compared to controls. The relative distribution of plasma apoE was increased in LDL and in lipid-free form. There were no significant differences in paraoxonase 1 activities, HDL antioxidant properties or HDL cholesterol efflux capacity but heterozygotes showed a significant increase of oxidized methionines in apoA-I.The SR-B1P297S mutation affects both HDL and LDL/VLDL protein compositions. The increase of apoE in carriers suggests a compensatory mechanism for attenuated SR-B1 mediated cholesterol uptake by HDL. Increased methionine oxidation may affect HDL function by reducing apoA-I binding to its targets. The results illustrate the complexity of lipoprotein metabolism that has to be taken into account in future therapeutic strategies aiming at targeting SR-B1.
|
|
| 6. |
- Ljunggren, Stefan, et al.
(författare)
-
ApoA-I mutations, L202P and K131del, in HDL from heterozygotes with low HDL-C
- 2014
-
Ingår i: PROTEOMICS - Clinical Applications. - : Wiley-Blackwell. - 1862-8346 .- 1862-8354. ; 8:3-4, s. 241-250
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Mutations in apolipoprotein A-I (apoA-I) may affect plasma high-density lipoprotein (HDL) cholesterol levels and the risk for cardiovascular disease but little is known about the presence and effects of circulating apoA-I variants. This study investigates whether the apoA-I mutations, apoA-I(L202P) and apoA-I(K131del) , are present on plasma HDL particles derived from heterozygote carriers and whether this is associated to changes in HDL protein composition.EXPERIMENTAL DESIGN: Plasma HDL of heterozygotes for either apoA-I(L202P) or apoA-I(K131del) and family controls was isolated using ultracentrifugation. HDL proteins were separated by 2DE and analyzed by MS.RESULTS: ApoA-I peptides containing apoA-I(L202P) or apoA-I(K131del) were identified in HDL from heterozygotes. The apoA-I(L202P) mutant peptide was less abundant than wild-type peptide while the apoA-I(K131del) mutant peptide was more abundant than wild-type peptide in the heterozygotes. Two-dimensional gel electrophoresis analyses indicated that, compared to controls, HDL in apoA-I(L202P) carriers contained less apoE and more zinc-α-2-glycoprotein while HDL from the apoA-I(K131del) heterozygotes contained more alpha-1-antitrypsin and transthyretin.CONCLUSIONS AND CLINICAL RELEVANCE: Both apoA-I(L202P) and apoA-I(K131del) were identified in HDL. In heterozygotes, these mutations have markedly differential effects on the concentration of wild-type apoA-I in the circulation, as well as the HDL proteome, both of which might affect the clinical phenotype encountered in the heterozygous carriers.
|
|
| 7. |
- Ljunggren, Stefan, 1988-
(författare)
-
Lipoproteomics : Environmental and Genetic Factors Affecting High-Density Lipoprotein (HDL)
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lipoprotein particles act as lipid transporters in the blood stream, and measuring cholesterol content in specific subclasses of lipoprotein particles has long been, and still is, a frequently used tool to estimate the risk of cardiovascular disease (CVD). High-density lipoprotein (HDL) is a subclass of lipoproteins often regarded as providing protection against CVD via several functions including reverse cholesterol transport and anti-inflammatory capacities. However, the precise relationship between HDL cholesterol levels and health outcome is still unclear. Lately, new approaches to study HDL composition and function have therefore become more important.HDL function is to a large extent dependent on its proteome, containing more than 100 proteins. Investigating the proteome in individuals with altered gene expression for HDL-associated proteins or with known exposure to environmental contaminants may reveal new insights into how HDL metabolism is affected by various factors. This is of interest in order to better understand the role of HDL in CVD.Papers I and II focus on two different mutations in a structural HDL protein, apolipoprotein A-I (L202P and K131del), and one mutation in the scavenger receptor class B-1 (P297S), which is involved in selective lipid uptake of cholesterol mainly into hepatocytes and adrenal cells. The HDL proteome was analyzed using two-dimensional gel electrophoresis and mass spectrometry. The L202P mutation was identified in HDL of the heterozygote carriers together with a significant decrease of apolipoprotein E and increased zinc-alpha-2-glycoprotein. By contrast, the second apolipoprotein AI mutation (K131del) was associated with significantly elevated alpha-1-antitrypsin and transthyretin levels. Protein analyses of the scavenger receptor class B1 P297S heterozygotes showed a significant increase in HDL apoL-1 along with increased free apoE. The carriers showed no difference in antioxidative capability but a significant increase in apoA-I methionine oxidation.Papers III and IV focus on persistent organic pollutants that may influence HDL composition and function. These compounds accumulate in humans, and exposure has been linked to an increased risk of CVD. To provide a better understanding of the HDL system in relation to pollutants, a population living in a contaminated area was studied. Persistent organic pollutants in isolated HDL were quantified using high-resolution gas chromatography mass spectrometry and significantly increased levels were found in individuals with CVD as compared to healthy controls. Furthermore, there was a significant negative association between the pollutants and paraoxonase-1 anti-oxidant activity. Studying the proteome with nano-liquid chromatography tandem mass spectrometry led to the identification of 118 proteins in HDL, of which ten were significantly associated with the persistent organic pollutants.In summary, the present studies demonstrate protein pattern alterations in HDL associated with inherited genetic variants or pollutant exposure. The studies also provide a set of methods that are useful tools to further comprehend the complexity of lipoprotein metabolism and function. The results are important in order to improve our understanding of HDL in CVD and to explain an increased risk of CVD associated with exposure to organic pollutants.
|
|
