358 research outputs found
Increased cholesterol efflux capacity in metabolic syndrome: Relation with qualitative alterations in HDL and LCAT
No full textBackground: Metabolic syndrome (MetS) is associated with changes in HDL levels, composition and sub-fraction profile. Whether these alterations affect HDL anti-atherogenic function, specifically measured as its capacity to perform cholesterol efflux, is not yet clearly known. Objective: To evaluate the relation between serum cholesterol efflux capacity and the changes in HDL composition and sub-fraction profile in MetS. Methods: In 35 non-treated MetS patients and 15 healthy controls, HDL mediated cholesterol efflux was measured as the ability of apoB-depleted serum to accept cholesterol from cholesterol-loaded BHK cells expressing either ABCA1 or ABCG1. Additionally we determined: lipid profile, HDL sub-fractions (NMR) and LCAT mass (ELISA). Isolated HDL (δ:1.063-1.210 g/mL) was chemically characterized. Pre-β1-HDL was determined by 2D-electrophoresis in a sub-group of MetS and controls (n = 6 each). Results: Surprisingly, MetS patients presented higher ABCA1 mediated cholesterol efflux (10.4 ± 1.8 vs. 8.7 ± 0.3%; p = 0.0001), without differences in ABCG1 efflux. In MetS, HDL showed reduction in particle size and number (p < 0.02) and lower large/small HDL ratio (p = 0.05), as well as triglyceride enrichment (p = 0.0001). Pre-β1-HDL was increased in MetS (p = 0.048) and correlated with ABCA1-cholesterol efflux (r = 0.64; p = 0.042). LCAT mass showed a tendency to reduction in MetS (p = 0.08), and inversely correlated with ABCA1-cholesterol efflux (r = -0.51; p = 0.001), independently of obesity and insulin-resistance (β = -0.40, p = 0.034). Conclusion: This is the first description of ABCA1 mediated cholesterol efflux in MetS. Regardless the reduced HDL-cholesterol, in vitro cholesterol efflux capacity by ABCA1 was enhanced, linked to increased pre-β1-HDL and slightly reduced in LCAT mass that would probably reflect a delay in reverse cholesterol transport occurring in MetS.Fil: Lucero, Diego Martín. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Svidirov, Denis. National Institutes of Health; Estados UnidosFil: Freeman, Lita. National Institutes of Health; Estados UnidosFil: López, Graciela I.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; ArgentinaFil: Fassio, Eduardo. Hospital Nacional Profesor Alejandro Posadas; ArgentinaFil: Remaley, Alan T.. National Institutes of Health; Estados UnidosFil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; Argentin
Determinants of HDL Cholesterol Efflux Capacity after Virgin Olive Oil Ingestion: Interrelationships with Fluidity of HDL Monolayer
No full textScope: Cholesterol efflux capacity of HDL (CEC) is inversely associated with cardiovascular risk. HDL composition, fluidity, oxidation, and size are related with CEC. We aimed to assess which HDL parameters were CEC determinants after virgin olive oil (VOO) ingestion. Methods and results: Post‐hoc analyses from the VOHF study, a crossover intervention with three types of VOO. We assessed the relationship of 3‐week changes in HDL‐related variables after intervention periods with independence of the type of VOO. After univariate analyses, mixed linear models were fitted with variables related with CEC and fluidity. Fluidity and Apolipoprotein (Apo)A‐I content in HDL was directly associated, and HDL oxidative status inversely, with CEC. A reduction in free cholesterol, an increase in triglycerides in HDL, and a decrease in small HDL particle number or an increase in HDL mean size, were associated to HDL fluidity. Conclusions: HDL fluidity, ApoA‐I concentration, and oxidative status are major determinants for CEC after VOO. The impact on CEC of changes in free cholesterol and triglycerides in HDL, and those of small HDL or HDL mean size, could be mechanistically linked through HDL fluidity. Our work points out novel therapeutic targets to improve HDL functionality in humans through nutritional or pharmacological interventions.Fil: Fernández Castillejo, Sara. Universitat Rovira I Virgili; EspañaFil: Rubió, Laura. Universitat Rovira I Virgili; España. Universidad de Lleida; EspañaFil: Hernáez, Álvaro. Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición; EspañaFil: Catalán, Úrsula. Universitat Rovira I Virgili; EspañaFil: Pedret, Anna. Universitat Rovira I Virgili; EspañaFil: Valls, Rosa M.. Universitat Rovira I Virgili; EspañaFil: Mosse, Juana Inés. Universidad de Lleida; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Covas, Maria Isabel. Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición; EspañaFil: Remaley, Alan T.. National Institutes of Health; Estados UnidosFil: Castañer, Olga. Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición; EspañaFil: Motilva, Maria José. Universidad de Lleida; EspañaFil: Solá, Rosa. Universitat Rovira I Virgili; Españ
Lipoprotein(a) and the Vascular Redox Interface: Linking Arteriosclerosis, Thrombosis and Vascular Biology
No full text
Interferences from blood collection tube components on clinical chemistry assays
No full textImproper design or use of blood collection devices can adversely affect the accuracy of laboratory test results. Vascular access devices, such as catheters and needles, exert shear forces during blood flow, which creates a predisposition to cell lysis. Components from blood collection tubes, such as stoppers, lubricants, surfactants, and separator gels, can leach into specimens and/or adsorb analytes from a specimen; special tube additives may also alter analyte stability. Because of these interactions with blood specimens, blood collection devices are a potential source of pre-analytical error in laboratory testing. Accurate laboratory testing requires an understanding of the complex interactions between collection devices and blood specimens. Manufacturers, vendors, and clinical laboratorians must consider the pre-analytical challenges in laboratory testing. Although other authors have described the effects of endogenous substances on clinical assay results, the effects/impact of blood collection tube additives and components have not been well systematically described or explained. This review aims to identify and describe blood collection tube additives and their components and the strategies used to minimize their effects on clinical chemistry assays
The ApoA-I mimetic peptide 5A enhances remyelination by promoting clearance and degradation of myelin debris
No full textThe progressive nature of demyelinating diseases lies in the inability of the central nervous system (CNS) to induce proper remyelination. Recently, we and others demonstrated that a dysregulated innate immune response partially underlies failure of CNS remyelination. Extensive accumulation of myelin-derived lipids and an inability to process these lipids was found to induce a disease-promoting phagocyte phenotype. Hence, restoring the ability of these phagocytes to metabolize and efflux myelin-derived lipids represents a promising strategy to promote remyelination. Here, we show that ApoA-I mimetic peptide 5A, a molecule well known to promote activity of the lipid efflux transporter ABCA1, markedly enhances remyelination. Mechanistically, we find that the repair-inducing properties of 5A are attributable to increased clearance and metabolism of remyelination-inhibiting myelin debris via the fatty acid translocase protein CD36, which is transcriptionally controlled by the ABCA1-JAK2-STAT3 signaling pathway. Altogether, our findings indi-cate that 5A promotes remyelination by stimulating clearance and degradation of myelin debris.We thank M.P. Tulleners for excellent technical assistance. The work was financially supported by the Research Foundation of Flanders (FWO Vlaanderen; 1S15519N, G099618FWO, and 12J9119N) and the Interreg V-A EMR program (EURLIPIDS, EMR23). The funding agencies had no role in the design, analysis, or writing of the article
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