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1.
J Alzheimers Dis ; 97(4): 1629-1639, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38306049

RESUMEN

APOE2 lowers Alzheimer's disease (AD) risk; unfortunately, the mechanism remains poorly understood and the use of mice models is problematic as APOE2 homozygosity is associated with hyperlipidemia. In this study, we developed mice that are heterozygous for APOE2 and APOE3 or APOE4 and overexpress amyloid-ß peptide (Aß) (EFAD) to evaluate the effect of APOE2 dosage on Aß pathology. We found that heterozygous mice do not exhibit hyperlipidemia. Hippocampal but not cortical levels of soluble Aß42 followed the order E2/2FAD > E2/3FAD≤E3/3FAD and E2/2FAD > E2/4FAD < E4/4FAD without an effect on insoluble Aß42. These findings offer initial insights on the impact of APOE2 on Aß pathology.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Apolipoproteína E2 , Hipocampo , Animales , Ratones , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Apolipoproteína E2/genética , Apolipoproteína E3 , Apolipoproteína E4/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Hipocampo/patología , Hiperlipidemias/genética , Ratones Endogámicos , Ratones Transgénicos
2.
Lipids ; 58(1): 3-17, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36114729

RESUMEN

It is widely accepted that unesterified polyunsaturated ω-6 and ω-3 fatty acids (PUFA) are converted through various lipoxygenases, cyclooxygenases, and cytochrome P450 enzymes to a range of oxygenated derivatives (oxylipins), among which the polyhydroxides of unesterified PUFA have recently been recognized as cell signaling molecules with anti-inflammatory and pro-resolving properties, known as specialized pro-resolving mediators (SPMs). This study investigates the mono-, di-, and trihydroxy 16:0/PUFA-GPCs, and the corresponding 16:0/SPM-GPC, in plasma lipoproteins. We describe the isolation and identification of mono-, di-, and trihydroxy AA, EPA, and DHA-GPC in plasma LDL, HDL, HDL3, and acute phase HDL using normal phase LC/ESI-MS, as previously reported. The lipoproteins contained variable amounts of the polyhydroxy-PUFA-GPC (0-10 nmol/mg protein), likely the product of lipid peroxidation and the action of various lipoxygenases and cytochrome P450 enzymes on both free fatty acids and the parent GPCs. Polyhydroxy-PUFA-GPC was hydrolyzed to variable extent (20%-80%) by the different secretory phospholipases A2 (sPLA2 s), with Group IIA sPLA2 showing the lowest and Group X sPLA2 the highest activity. Surprisingly, the trihydroxy-16:0/PUFA-GPC of APHDL was largely absent, while large amounts of unidentified material had migrated in the free fatty acid elution area. The free fatty acid mass spectra were consistent with that anticipated for branched chain polyhydroxy fatty acids. There was general agreement between the masses determined by LC/ESI-MS for the polyhydroxy PUFA-GPC and the masses calculated for the GPC equivalents of resolvins, protectins, and maresins using the fatty acid structures reported in the literature.


Asunto(s)
Ácidos Grasos Omega-3 , Fosfolipasas A2 Secretoras , Hidrólisis , Ácidos Grasos no Esterificados , Lipoproteínas/metabolismo , Ácidos Grasos , Oxilipinas
3.
Lipids ; 57(2): 91-104, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34904243

RESUMEN

Plasma lipoproteins are carriers of various glycerophospholipids including diacyl, alkenyl/acyl, and alkyl/acyl glycerophosphocholines (GPCs), which become distributed among cells and tissues during metabolism. For metabolic function, these phospholipids require hydrolysis by phospholipases, but the responsible enzymes have not been identified. We had previously shown that after complete digestion of lipoprotein diacyl- and oxo-diacyl-GPCs, degradation of residual alkyl/acyl and alkenyl/acyl GPCs continues, despite the fact that ether lipids are resistant to hydrolysis by Ca2+ -activated secretory PLA2 s and require the presence of the Ca2+ -independent PLA2 . In the course of further investigation, we came across a report by Khaselev and Murphy in which the autoxidative degradation of plasmalogens in the presence of 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) proceeded beyond the formation of dihydroperoxides, hydroxides and epoxides, and led to an attack on the enyl bond of the plasmalogen, resulting in formation of 1-OH/2-20:4-GPC and 1-formyl/2-20:4-GPC. Our preliminary investigation indicated that lipoprotein 16:0p/20:4ω6-GPC yielded the same autoxidation products as those reported for synthetic 16:0p/20:4ω6-GPC in the presence of AAPH. Such autoxidative degradation of lipoprotein plasmalogens had not been previously reported with or without AAPH. Subsequent study led to the conclusion that this reaction was not limited to arachidonates, but extended to other polyunsaturated eicosanoids, docosanoids, and tetracosanoids, as well as oligounsaturated octadecanoids. These observations led to a hypothesis that the autoxidative cleavage of the lipoprotein plasmalogens proceeded under the influence of apo-protein-derived free radicals as intermediates of oxidative processes.


Asunto(s)
Fosfolipasas , Plasmalógenos , Hidrólisis , Lipoproteínas , Fosfolipasas A2
4.
Lipids ; 56(5): 521-535, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34278577

RESUMEN

This study was prompted by recent reports that epoxyeicosatrienoic (EET) and epoxyeicosatetraenoic (EEQ) acids accelerate tumor growth and metastasis by stimulation of angiogenesis, while eicosapentaenoic (EPA) and epoxydocosapentaenoic (EDP) acids inhibit angiogenesis, tumor growth, and metastasis. Cytochrome P450 epoxygenases convert arachidonic to EET, eicosapentaenoic acid to EEQ, and docosahexaenoic acid to EDP, which are found both in free form and esterified to glycerophosphocholine (GPC). Both free and esterified epoxy (EP) acids are also formed during lipid autoxidation. For biological activity, the GPC-EP requires hydrolysis, which we presumed could occur by sPLA2 s located in proximity of lipoproteins carrying the lipid epoxides. The plasma lipoproteins were isolated by ultracentrifugation and analyzed by LC/ESI-MS. The GPC-EPs were identified by reference to standards and to retention times of phospholipid masses. The GPC-EP monoepoxides (corrected for isobaric ether overlaps) in stored human LDL, HDL, HDL3 , or APHDL ranged from 0 to 1 nmol/mg protein, but during 4-h incubation at 37°C increased to 1-5 nmol/mg protein. An incubation of autoxidized LDL, HDL, or HDL3 with 1 µg/ml of group V or X sPLA2 resulted in complete hydrolysis of diacyl GPC epoxide esters. Group IIA sPLA2 at 1 µg/ml failed to produce significant hydrolysis in 4 h, but at 2.5 µg/ml in 8 h yielded almost 80% hydrolysis, which represented complete diacyl GPC-EP hydrolysis. The present study shows that group IIA, V, and X sPLA2 s are capable of extensive hydrolysis of PtdCho epoxides of autoxidized plasma lipoproteins. Therefore, all three human sPLA2 s were potentially capable of inducing epoxide biological activity in vivo.


Asunto(s)
Compuestos Epoxi , Fosfolipasas A2 Secretoras , Eicosanoides , Fosfolipasas A2 Grupo II , Humanos , Hidrólisis , Lipoproteínas
5.
Proteomics ; 21(6): e2000224, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33471423

RESUMEN

We described a targeted mass spectrometry assay based on selected reaction monitoring (SRM) for five apolipoproteins (apoA1, apoB, apoJ, apoD, and apoE) in plasma lipoproteins isolated by anion exchange fast protein liquid chromatography using only 100 µL of plasma. We performed analytical characterization of the SRM assay and evaluated reproducibility of the entire workflow. The limit of detections for apoA1, apoB, apoD, apoJ, and apoE were 0.6, 4.6, 0.8, 1.2, and 0.7 nM, respectively; the limit of quantifications was 8.3 nM for all peptides except apoD (4.2 nM). The SRM assay was linear from 0.4 to 1667 nM. The intra-day and inter-day and total repeatability (CV%) of the assay ranged from 2.2% to 21.7% for all five peptides. The intra-day and inter-day and total reproducibility of the entire workflow ranged from 12.2% to 43.9% for all five peptides in fractionated high-density lipoprotein, low-density lipoprotein, and IDL. In the future, we will apply this workflow to investigate the association of fractionated plasma lipoproteins with amyloid deposition and cognitive changes in the context of Alzheimer's disease.


Asunto(s)
Apolipoproteínas E , Aniones , Cromatografía Líquida de Alta Presión , Humanos , Espectrometría de Masas , Reproducibilidad de los Resultados
6.
Clin Proteomics ; 15: 31, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30250409

RESUMEN

BACKGROUND: Although total plasma lipoproteome consists of proteins that have shown promises as biomarkers that can identify Alzheimer's disease (AD), effect sizes are modest. The objective of this study is to provide initial proof-of-concept that the plasma lipoproteome more likely differ between AD cases and controls when measured in individual plasma lipoprotein fractions than when measured as total in immunodepleted plasma. METHODS: We first developed a targeted proteomics method based on selected reaction monitoring (SRM) and liquid chromatography and tandem mass spectrometry for measurement of 120 tryptic peptides from 79 proteins that are commonly present in plasma lipoproteins. Then in a proof-of concept case-control study of 5 AD cases and 5 sex- and age-matched controls, we applied the targeted proteomic method and performed relatively quantification of 120 tryptic peptides in plasma lipoprotein fractions (fractionated by sequential gradient ultracentrifugation) and in immunodepleted plasma (of albumin and IgG). Unadjusted p values from two-sample t-tests and overall fold change was used to evaluate a peptide relative difference between AD cases and controls, with lower p values (< 0.05) or greater fold differences (> 1.05 or < 0.95) suggestive of greater peptide/protein differences. RESULTS: Within-day and between-days technical precisions (mean %CV [SD] of all SRM transitions) of the targeted proteomic method were 3.95% (2.65) and 9.31% (5.59), respectively. Between-days technical precisions (mean % CV [SD]) of the entire plasma lipoproteomic workflow including plasma lipoprotein fractionation was 27.90% (14.61). Ten tryptic peptides that belonged to 5 proteins in plasma lipoproteins had unadjusted p values < 0.05, compared to no peptides in immunodepleted plasma. Furthermore, 27, 32, 17, and 20 tryptic peptides in VLDL, IDL, LDL and HDL, demonstrated overall peptide fold differences > 1.05 or < 0.95, compared to only 6 tryptic peptides in immunodepleted plasma. The overall comparisons, therefore, suggested greater peptide/protein differences in plasma lipoproteome when measured in individual plasma lipoproteins than as total in immunodepleted plasma. Specifically, protein complement C3's peptide IHWESASLLR, had unadjusted p values of 0.00007, 0.00012, and 0.0006 and overall 1.25, 1.17, 1.14-fold changes in VLDL, IDL, and LDL, respectively. After positive False Discovery Rate (pFDR) adjustment, the complement C3 peptide IHWESASLLR in VLDL remained statistically different (adjusted p value < 0.05). DISCUSSION: The findings may warrant future studies to investigate plasma lipoproteome when measured in individual plasma lipoprotein fractions for AD diagnosis.

7.
Clin Sci (Lond) ; 132(10): 1075-1083, 2018 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-29724769

RESUMEN

Therapeutic antibodies targeting proprotein convertase subtilisin kexin type 9 (PCSK9) (e.g. alirocumab) lower low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] levels in clinical trials. We recently showed that PCSK9 enhances apolipoprotein(a) [apo(a)] secretion from primary human hepatocytes but does not affect Lp(a) cellular uptake. Here, we aimed to determine how PCSK9 neutralization modulates Lp(a) levels in vivoSix nonhuman primates (NHP) were treated with alirocumab or a control antibody (IgG1) in a crossover protocol. After the lowering of lipids reached steady state, NHP received an intravenous injection of [2H3]-leucine, and blood samples were collected sequentially over 48 h. Enrichment of apolipoproteins in [2H3]-leucine was assessed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Kinetic parameters were calculated using numerical models with the SAAMII software. Compared with IgG1, alirocumab significantly reduced total cholesterol (TC) (-28%), LDL-C (-67%), Lp(a) (-56%), apolipoprotein B100 (apoB100) (-53%), and apo(a) (-53%). Alirocumab significantly increased the fractional catabolic rate of apoB100 (+29%) but not that of apo(a). Conversely, alirocumab sharply and significantly reduced the production rate (PR) of apo(a) (-42%), but not significantly that of apoB100, compared with IgG1, respectively.In line with the observations made in human hepatocytes, the present kinetic study establishes that PCSK9 neutralization with alirocumab efficiently reduces circulating apoB100 and apo(a) levels by distinct mechanisms: apoB primarily by enhancing its catabolism and apo(a) primarily by lowering its production.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Anticolesterolemiantes/farmacología , Lipoproteína(a)/sangre , Inhibidores de PCSK9 , Animales , Anticuerpos Monoclonales Humanizados , Apoproteína(a)/biosíntesis , Colesterol/sangre , Estudios Cruzados , Femenino , Lípidos/sangre , Macaca fascicularis , Masculino
8.
Bull Exp Biol Med ; 164(3): 308-311, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29313227

RESUMEN

Culturing of bone marrow cells in serum-free RPMI-1640 medium led to a decrease in the rate of DNA biosynthesis. Addition of HDL or their main protein component apolipoprotein A-I to the culture medium dose-dependently increased the rate of [3H]-thymidine incorporation into DNA. The maximum stimulation was achieved at HDL concentration of 80 µg/ml and apolipoprotein A-I concentration of 20 µg/ml. To identify the target-cells of apolipoprotein A-I, we used thymidine analogue 5-ethynyl-2'-deoxyuridine (EdU) that incorporates into cell DNA at the stage of replicative DNA synthesis (S phase) and can be detected by fluorescence microscopy. In bone marrow cell culture, apolipoprotein A-I stimulates the proliferation of monocyte (monoblasts, promonocytes) and granulocyte (myeloblasts, promyelocytes) progenitor cells, as well as bone marrow stromal cells.


Asunto(s)
Apolipoproteína A-I/farmacología , Células de la Médula Ósea/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Granulocitos/efectos de los fármacos , Células Madre Mesenquimatosas/efectos de los fármacos , Monocitos/efectos de los fármacos , Animales , Apolipoproteína A-I/aislamiento & purificación , Células de la Médula Ósea/citología , Células de la Médula Ósea/inmunología , Medio de Cultivo Libre de Suero/química , ADN/biosíntesis , Desoxiuridina/análogos & derivados , Desoxiuridina/metabolismo , Desoxiuridina/farmacología , Relación Dosis-Respuesta a Droga , Granulocitos/citología , Granulocitos/inmunología , Humanos , Lipoproteínas HDL/química , Lipoproteínas HDL/farmacología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/inmunología , Monocitos/citología , Monocitos/inmunología , Cultivo Primario de Células , Ratas , Ratas Wistar , Timidina/metabolismo , Timidina/farmacología , Tritio
9.
Curr Drug Deliv ; 15(6): 850-859, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-28925873

RESUMEN

The purpose of this study was to evaluate the most appropriate conditions to generate silver nanoparticles (AgNPs) loaded with a potent antimycotic drug like amphotericin B (AmB), characterize the physicochemical properties, and to evaluate the cytotoxic effect and biological activity of these new nanostructures as a potential nanocarrier for hydrophobic drugs. It was determined that the optimal molar ratio between Ag and AmB is 1/1 given the uniformity of size around 170 nm of the nanoparticles generated as well as their strongly negative ζ potential of -35 mV, a condition that favors repulsions between AgNPs and inhibiting their aggregation. In this condition, only 0.8 mg.mL-1 of Ag is needed to solubilize 5 mg.mL-1 of AmB, a concentration currently used in commercial formulations. It is important to emphasize that the loading capacity (w/w) of this nanostructure is much higher than that of micellar and liposomal formulations. These AgNP-AmB nanoparticles retain both the bactericidal effect of silver and the cytotoxic and antifungal effect of AmB. However, it was shown that these nanoparticles are spontaneously associated with plasma lipoproteins (LDL and HDL), inhibiting their cytotoxic effects on red blood cells and on at least two cell lines, Vero and H1299 and slightly reducing its bactericidal effect on P. aeruginosa. In contrast, the antifungal effect of the formulation is maintained and is even higher than that when the nanoparticle is not associated with lipoproteins, indicating that this association is of the reversible type. The characterization of these nanoparticles is discussed as a potential new model formulation able to improve the antifungal therapeutic efficiency of AmB.


Asunto(s)
Anfotericina B/farmacología , Antibacterianos/farmacología , Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Nanopartículas del Metal/química , Pseudomonas aeruginosa/efectos de los fármacos , Plata/farmacología , Anfotericina B/química , Animales , Antibacterianos/química , Antifúngicos/química , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Chlorocebus aethiops , Eritrocitos/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Tamaño de la Partícula , Plata/química , Solubilidad , Propiedades de Superficie , Células Vero
10.
Clin Sci (Lond) ; 131(21): 2561-2573, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-28923880

RESUMEN

Dietary sugars are linked to the development of non-alcoholic fatty liver disease (NAFLD) and dyslipidaemia, but it is unknown if NAFLD itself influences the effects of sugars on plasma lipoproteins. To study this further, men with NAFLD (n = 11) and low liver fat 'controls' (n = 14) were fed two iso-energetic diets, high or low in sugars (26% or 6% total energy) for 12 weeks, in a randomised, cross-over design. Fasting plasma lipid and lipoprotein kinetics were measured after each diet by stable isotope trace-labelling.There were significant differences in the production and catabolic rates of VLDL subclasses between men with NAFLD and controls, in response to the high and low sugar diets. Men with NAFLD had higher plasma concentrations of VLDL1-triacylglycerol (TAG) after the high (P<0.02) and low sugar (P<0.0002) diets, a lower VLDL1-TAG fractional catabolic rate after the high sugar diet (P<0.01), and a higher VLDL1-TAG production rate after the low sugar diet (P<0.01), relative to controls. An effect of the high sugar diet, was to channel hepatic TAG into a higher production of VLDL1-TAG (P<0.02) in the controls, but in contrast, a higher production of VLDL2-TAG (P<0.05) in NAFLD. These dietary effects on VLDL subclass kinetics could be explained, in part, by differences in the contribution of fatty acids from intra-hepatic stores, and de novo lipogenesis. The present study provides new evidence that liver fat accumulation leads to a differential partitioning of hepatic TAG into large and small VLDL subclasses, in response to high and low intakes of sugars.


Asunto(s)
Carbohidratos de la Dieta/administración & dosificación , Grasas/metabolismo , Lipoproteínas VLDL/metabolismo , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Triglicéridos/metabolismo , Adulto , Anciano , Estudios Cruzados , Carbohidratos de la Dieta/farmacología , Ensayo de Inmunoadsorción Enzimática , Ayuno/sangre , Humanos , Lípidos/sangre , Lipoproteínas VLDL/sangre , Hígado/efectos de los fármacos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/sangre , Evaluación de Resultado en la Atención de Salud , Factores de Tiempo , Triglicéridos/sangre
11.
J Proteome Res ; 16(8): 2947-2953, 2017 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-28650171

RESUMEN

Lipoproteins are responsible for the transport of lipids and other nutrients in the circulation and therefore play an important role in lipid metabolism and dyslipidemia. They have also been linked to multiple metabolic disorders including cardiovascular disease, and thus understanding their lipid composition is of crucial importance. Characterization of lipoproteins is a challenging task due to their heterogeneity. In particular, their fractionation is often laborious and time-consuming, making large sets of clinical samples difficult to analyze. We developed and validated lipidomics analysis of lipoproteins including chylomicrons, very low-density, low-density, and high-density lipoproteins. Lipoproteins were first fractionated by polyacrylamide tube gel electrophoresis, and, after liquid-liquid extraction, lipids were analyzed by direct-infusion mass spectrometry. About 100 unique lipid species were detected with good reproducibility and reliability. In addition to their lipid composition, valuable information on the fatty acid composition of lipoproteins and lipids was obtained. The presented method offers in-depth analysis of the lipid as well as fatty acid composition of lipoproteins while allowing a good sample throughput. It is thus especially suited for studying lipid associated diseases in clinical cohorts.


Asunto(s)
Lípidos/sangre , Lipoproteínas/análisis , Electroforesis de las Proteínas Sanguíneas , Humanos , Lipoproteínas HDL/sangre , Lipoproteínas LDL/sangre , Lipoproteínas VLDL/sangre , Extracción Líquido-Líquido , Espectrometría de Masas , Métodos
12.
Lipids ; 52(6): 477-488, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28528433

RESUMEN

Biologically active F- and E/D-type-prostane ring isomers (F2-IP and E2/D2-IP, respectively) are produced in situ by non-enzymatic peroxidation of arachidonic acid esterified to GroPCho (PtdCho-IP) and are universally distributed in tissue lipoproteins and cell membranes. Previous work has shown that platelet-activating factor acetylhydrolases (PAF-AH) are the main endogenous PLA2 involved in degradation of PtdCho-IP. The present study shows that the PtdCho-IP are also subject to hydrolysis by group IIA, V and X secretory PLA2, which also have a wide peripheral tissue distribution. For this demonstration, we compared the LC/MS profiles of PtdCho-IP of auto-oxidized plasma lipoproteins after incubation for 1-4 h (37 °C) in the absence or presence of recombinant human sPLA2 (1-2.5 µg/ml). In the absence of exogenously added sPLA2 the total PtdCho-IP level after 4 h incubation reached 15.9, 21.6 and 8.7 nmol/mg protein of LDL, HDL and HDL3, respectively. In the presence of group V or group X sPLA2 (2.5 µg/ml), the PtdCho-IP was completely hydrolyzed in 1 h, while in the presence of group IIA sPLA2 (2.5 µg/ml) the hydrolysis was less than 25% in 4 h, although it was complete after 8-24 h incubation. This report provides the first demonstration that PtdCho-IP are readily hydrolyzed by group IIA, V and X sPLA2. A co-location of sPLA2 and the substrates in various tissues has been recorded. Thus, the initiation of interaction and production of isoprostanes in situ are highly probable.


Asunto(s)
Fosfolipasas A2 Grupo II/metabolismo , Fosfolipasas A2 Grupo V/metabolismo , Fosfolipasas A2 Grupo X/metabolismo , Isoprostanos/metabolismo , Fosfatidilcolinas/metabolismo , Humanos , Hidrólisis , Isoprostanos/química , Fosfatidilcolinas/química , Proteínas Recombinantes/metabolismo
13.
Atherosclerosis ; 259: 5-11, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28279834

RESUMEN

BACKGROUND AND AIMS: The major apolipoproteins of plasma lipoproteins play vital roles in the structural integrity and physiological functions of lipoproteins. More than ten structural models of apolipoprotein A-I (apoA-I), the major apolipoprotein of high-density lipoprotein (HDL), have been developed successively. In these models, apoA-I was supposed to organize in a ring-shaped form. To date, however, there is no direct evidence under physiological condition. METHODS: Here, atomic force microscopy (AFM) was used to in situ visualize the organization of apoA-I, which was exposed via depletion of the lipid component of plasma HDL pre-immobilized on functionalized mica sheets. RESULTS: For the first time, the ring-shaped coarse structure and three detailed structures (crescent-shaped, gapped "O"-shaped, and parentheses-shaped structures, respectively) of apoA-I in plasma HDL, which have the ability of binding scavenger receptors, were directly observed and quantitatively measured by AFM. The three detailed structures probably represent the different extents to which the lipid component of HDL was depleted. Data on lipid depletion of HDL may provide clues to understand lipid insertion of HDL. CONCLUSIONS: These data provide important information for the understanding of the structure/maturation of plasma HDL. Moreover, they suggest a powerful method for directly visualizing the major apolipoproteins of plasma lipoproteins or the protein component of lipoprotein-like lipid-protein complexes.


Asunto(s)
Apolipoproteína A-I/sangre , Apolipoproteína A-I/química , Lipoproteínas HDL/sangre , Lipoproteínas HDL/química , Microscopía de Fuerza Atómica , Silicatos de Aluminio/química , Detergentes/química , Humanos , Octoxinol , Polietilenglicoles/química , Unión Proteica , Conformación Proteica , Relación Estructura-Actividad
14.
Br J Nutr ; 117(1): 56-66, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28112077

RESUMEN

Dietary cholesterol and plant sterols differentially modulate cholesterol kinetics and circulating cholesterol. Understanding how healthy individuals with their inherent variabilities in cholesterol trafficking respond to such dietary sterols will aid in improving strategies for effective cholesterol lowering and alleviation of CVD risk. The objectives of this study were to assess plasma lipid responsiveness to dietary cholesterol v. plant sterol consumption, and to determine the response in rates of cholesterol absorption and synthesis to each sterol using stable isotope approaches in healthy individuals. A randomised, double-blinded, crossover, placebo-controlled clinical trial (n 49) with three treatment phases of 4-week duration were conducted in a Manitoba Hutterite population. During each phase, participants consumed one of the three treatments as a milkshake containing 600 mg/d dietary cholesterol, 2 g/d plant sterols or a control after breakfast meal. Plasma lipid profile was determined and cholesterol absorption and synthesis were measured by oral administration of [3, 4-13C] cholesterol and 2H-labelled water, respectively. Dietary cholesterol consumption increased total (0·16 (sem 0·06) mmol/l, P=0·0179) and HDL-cholesterol (0·08 (sem 0·03) mmol/l, P=0·0216) concentrations with no changes in cholesterol absorption or synthesis. Plant sterol consumption failed to reduce LDL-cholesterol concentrations despite showing a reduction (6 %, P=0·0004) in cholesterol absorption. An over-compensatory reciprocal increase in cholesterol synthesis (36 %, P=0·0026) corresponding to a small reduction in absorption was observed with plant sterol consumption, possibly resulting in reduced LDL-cholesterol lowering efficacy of plant sterols. These data suggest that inter-individual variability in cholesterol trafficking mechanisms may profoundly impact plasma lipid responses to dietary sterols in healthy individuals.


Asunto(s)
Colesterol en la Dieta/farmacología , Dieta , Metabolismo de los Lípidos/efectos de los fármacos , Lípidos/sangre , Fitosteroles/farmacología , Adolescente , Adulto , Transporte Biológico , Colesterol en la Dieta/administración & dosificación , Estudios Cruzados , Método Doble Ciego , Análisis de los Alimentos , Humanos , Persona de Mediana Edad , Fitosteroles/administración & dosificación , Adulto Joven
15.
Biology (Basel) ; 4(3): 494-511, 2015 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-26226008

RESUMEN

MicroRNAs (miRNAs) are small, non-coding RNAs that have the ability to post-transcriptionally regulate gene expression. Hundreds of miRNAs have been identified in humans and they are involved in the regulation of almost every process, including cholesterol transport, metabolism, and maintenance of cholesterol homeostasis. Because of their small size and their ability to very specifically regulate gene expression, miRNAs are attractive targets for the regulation of dyslipidemias and other lipid-related disorders. However, the complex interactions between miRNAs, transcription factors, and gene expression raise great potential for side effects as a result of miRNA overexpression or inhibition. Many dietary components can also target specific miRNAs, altering the expression of downstream genes. Therefore, much more research is necessary to fully understand the role(s) of each miRNA in the body and how they may be impacted by diet and health. The present review aims to summarize the known roles of miRNAs in the regulation of reverse cholesterol transport and the maintenance of cholesterol homeostasis, as well as the potential clinical consequences of their manipulation.

16.
Nutrition ; 31(6): 807-12, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25933487

RESUMEN

OBJECTIVES: Omega-3 polyunsaturated fatty acid (ω-3 PUFA) metabolism seems to be disrupted in carriers of the epsilon 4 allele of apolipoprotein E (E4+). The objective of this study was to investigate whether the ω-3 PUFA distribution in the high and low density lipoproteins is APOE-genotype dependant before and after supplementation with ω-3 PUFAs. METHODS: Eighty participants, aged between 20 and 35 y old were recruited and supplemented with 900 mg of eicosapentaenoic acid plus 680 mg of docosahexaenoic acid for 4 wk. Over the 4-wk intervention, blood samples were collected and HDL and LDL particles were obtained using sucrose gradient ultracentifugation. Fatty acid profiles of the HDL and LDL fractions were performed by gas chromatography. RESULTS: Baseline anthropometric characteristics of participants were not significantly different between the two APOE-groups (E4+, N = 10; E4-, N = 70). At baseline, in the LDL of E4+ subjects, the ω-6/ω-3 PUFA ratio was 17% higher than E4- subjects. At week 4, the ω-6/ω-3 PUFA ratio was significantly higher in the LDL of E4+ than E4- subjects. There was a significant genotype × time interaction for 16:0 in HDL and LDL and for 18:2 ω-6 in HDL. DHA in the HDL was positively correlated to HDL-C levels pre- and postsupplementation in E4- only. CONCLUSIONS: Contrary to what we anticipated, ω-3 PUFAs content? in HDL and LDL were not APOE isoform-dependant in young participants. However, young E4+ participants already had a tendency toward lower baseline-DHA levels in LDL particles as well as a more atherogenic ω-6/ω-3 PUFA ratio in LDL pre- and post-supplementation.


Asunto(s)
Alelos , Apolipoproteínas E/genética , Ácidos Grasos Omega-3/sangre , Genotipo , Lipoproteínas HDL/sangre , Lipoproteínas LDL/sangre , Adulto , Aterosclerosis/genética , Suplementos Dietéticos , Ácidos Docosahexaenoicos/sangre , Ácidos Grasos Omega-6/sangre , Femenino , Humanos , Masculino , Adulto Joven
17.
Adv Biomed Res ; 4: 68, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25878993

RESUMEN

BACKGROUND: Polycystic ovary syndrome (PCOS) is one of the most frequent endocrine disorders. The PCOS manifest by hyperandrogenism, hypertension and cholesterol and lipoprotein improper profiles. Changing the life style, e.g. increasing physical activities is the first approach in controlling PCOS. MATERIALS AND METHODS: Twenty-four women affected by polycystic ovary syndrome (PCOS) after medical screening were divided in to two groups: Experimental group (n = 12) and control group (n = 12), with the average age, weight, height, BMI and WHR of 26.87 ± 4.43 years, 75.71 ± 10.65 kg. 159.29 ± 6.44 cm, 29.86 ± 3.22 kg/m(2) and 91.75 ± 5.86 respectively. First the body composition such as BMI, WHR, percent body fat, weight and body fat mass were measured. In fasting blood samples the level of HDL, LDL, VLDL, triglyceride and cholesterol were measured. Then the experiment group underwent the effect of an aerobic exercise program. After 12 weeks, all the measured variables before intervention the test were re-measured. Correlated t-test was used for comparing the two groups before and after intervention the test and independent t-test was used for comparing the two groups (P < 0.05). RESULTS: The results showed that after 12 weeks of exercise, BMI, WHR, fat rate, weight and fat mass and triglyceride had significant reduction and HDL had significant increase. But no significant changes happened in LDL, VLDL, and cholesterol levels. CONCLUSION: Reducing the weight by aerobic exercise in obese women and affected by PCOS can correct lipoprotein profile and improving health.

18.
J Ethnopharmacol ; 150(1): 32-50, 2013 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-24012528

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Calotropis gigantiea (L.) R. Br (Apocynaceae) commonly called as "crown flower" or "giant milk weed" is a well-known weed to many cultures for treating various disorders related to central nervous system, skin diseases, digestive system, respiratory system, reproductive system etc. Indigenous groups made the plant as a part of their lives since they use the fruit fibre to make ropes, household items, for weaving clothes and flowers for garlands apart from usage for various indications. The study aims at far-reaching review on phytochemistry, pharmacological activities, ethnopharmacology, intellectual property transfer on pharmacological therapies, toxicity which aids to provide scientific evidence for the ethnobotanical claims and to identify gaps required to be conducted as a future research prerequisite. MATERIALS AND METHODS: A systematic literature search was performed using different databases such as Scopus, Science direct, PubMed and Sciverse with no timeline limit set during the search. All the available abstracts and full text articles were included in the systematic review. RESULTS: Most of the folkloric uses were validated by the scientific studies such as analgesic, anti-arthritic, anti-asthmatic, anti-bacterial, anti-convulsant, anti-pyretic, central nervous system disorders, contraceptive, anti-ulcer and wound healing. In addition other studies such as anti-diabetic, anti-diarrhoeal, anti-helminthic, anti-histamine, anti-inflammatory, anti-microbial, anti-oxidant, cardio-protective studies, cytotoxicity, hepatoprotectivity, fibrinolytic, mosquitocidal, nerve muscle activity, vasodilation and skeletal muscle activities were also reported for the plant. Isolated compounds such as calotropin, frugoside and 4'-O-ß-D-glucopyranosyl frugoside were tested for the cytotoxicity efficacy against both human and rat cell lines out of which calotropin showed potent activity (IC50-15 ng/ml). However there were no clinical trials reported on the plant which is one of the major lacunas. CONCLUSIONS: This review article explores the ethnopharmacological, pharmacological activities phytochemistry and intellectual rights of Cg which gives the evidence of a potent and commercial drug which up on further research leads to the most viable drug for variety of treatments. However there is further need for in-vivo studies and clinical trials on isolated phytoconstituents which will help to commercialise.


Asunto(s)
Calotropis , Preparaciones de Plantas/farmacología , Animales , Calotropis/química , Humanos , Propiedad Intelectual , Medicina Tradicional , Preparaciones de Plantas/química
19.
J Lipid Res ; 54(8): 2273-2281, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23690506

RESUMEN

HDL subclasses detection, in cardiovascular risk, has been limited due to the time-consuming nature of current techniques. We have developed a time-saving and reliable separation of the principal HDL subclasses employing iodixanol density gradient ultracentrifugation (IxDGUC) combined with digital photography. HDL subclasses were separated in 2.5 h from prestained plasma on a three-step iodixanol gradient. HDL subclass profiles were generated by digital photography and gel scan software. Plasma samples (n = 46) were used to optimize the gradient for the resolution of HDL heterogeneity and to compare profiles generated by IxDGUC with gradient gel electrophoresis (GGE); further characterization from participants (n = 548) with a range of lipid profiles was also performed. HDL subclass profiles generated by IxDGUC were comparable to those separated by GGE as indicated by a significant association between areas under the curve for both HDL2 and HDL3 (HDL2, r = 0.896, P < 0.01; HDL3, r = 0.894, P < 0.01). The method was highly reproducible, with intra- and interassay coefficient of variation percentage < 5 for percentage area under the curve HDL2 and HDL3, and < 1% for peak Rf and peak density. The method provides time-saving and cost-effective detection and preparation of the principal HDL subclasses.


Asunto(s)
Lipoproteínas HDL/clasificación , Lipoproteínas HDL/aislamiento & purificación , Ácidos Triyodobenzoicos/química , Ultracentrifugación
20.
Artículo en Portugués | LILACS | ID: lil-609289

RESUMEN

Fundamento: Nenhum estudo foi encontrado em relação aos efeitos da combinação de ácido linoleico conjugado (CLA) e exercício físico na progressão de aterosclerose de camundongos APO E (-/-). Objetivo: Avaliar os efeitos da combinação de exercício físico e ácido linoleico conjugado (CLA) na progressão de aterosclerose de camundongos knockout para o gene da Apo E alimentados com dietas normo e hiperlipídica. Métodos: Camundongos knockout para Apo E foram alocados em quatro grupos/dieta: NS - dieta normolipídica e sedentário (n=5), HS - dieta hiperlipídica e sedentário (n=5), NECLA - dieta normolipídica com CLA e exercitado (n=8) e HECLA - dieta hiperlipídica com CLA e exercitado (n=8). O colesterol total e o HDL-C foram determinados através do método enzimático-colorimétrico. O LDL-C foi calculado pela fórmula de Friedewald. O fígado foi pesado e as lesões ateroscleróticas foram analisadas por fotomicrografia representativa da aorta. Utilizou-se ANOVA e Tukey ao nível de significância de 5%. Resultados: O grupo HECLA apresentou maiores valores de colesterol total e LDL-c que os grupos NECLA e NS (p<0,05). Em relação ao HDL-c, o grupo HS apresentou maior concentração que o grupo HECLA (p=0,019). O peso do fígado foi maior no grupo HECLA comparado com o NECLA (p=0,003). Em relação à progressão da aterosclerose, não foi encontrado diferenças significativas entre os grupos (p>0,05). Conclusões: A combinação exercício físico e CLA, independente do tipo de dieta, não foi eficiente na redução da progressão de aterosclerose de camundongos Knockout para o gene que expressa a apolipoproteina E.


Background: No studies were found regarding the effects of the combination of conjugated linoleic acid (CLA) and physical exercise in the progression of atherosclerosis in mice APO E (-/-). Objective: To evaluate the effects of the combination of exercise and conjugated linoleic acid (CLA) on the progression of atherosclerosis in mice knockout for the gene Apo E fed diets with normal and hyperlipidemic. Methods: Apo E knockout mice were divided into four groups / diet: NS - normolipídica diet and sedentary (n = 5), HS - high fat diet and sedentary (n = 5), NECLA - normolipídica diet with CLA and exercised (n = 8) and HECLA - High fat diet with CLA and exercised (n = 8). Total cholesterol and HDL-C were determined by enzymatic-colorimetric method. LDL-C was calculated using the Friedewald formula. The liver was weighed and atherosclerotic lesions were analyzed by representative photomicrographs of aorta. We used ANOVA and Tukey tests at a significance level of 5%. Results: The HECLA group had higher total cholesterol and LDL-C than groups NECLA and NS (p <0,05). In relation to HDL-C, the HS group had a higher concentration than the group HECLA (p = 0,019). Liver weight was higher in the group HECLA compared with NECLA (p = 0,003). Regarding the progression of atherosclerosis, was not found significant differences between groups (p> 0.05). Conclusions: The combination of exercise and CLA, regardless of the diet was not effective in reducing the progression of atherosclerosis Knockout mice for the gene that expresses the apolipoprotein E.


Asunto(s)
Animales , Composición Corporal , Ratones/metabolismo , Grasas de la Dieta/análisis , Grasas de la Dieta/efectos adversos , Lipoproteínas/análisis , Lipoproteínas/metabolismo
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