RESUMEN
BACKGROUND: Sitosterolemia is a rare inherited lipid metabolic disorder characterized by increased levels of plant sterols and accelerated atherosclerosis. Although early detection is beneficial for the prevention of disease progression, it is largely underdiagnosed by routine screening based on conventional lipid profiles. MATERIALS AND METHODS: A gas chromatography-mass spectrometry (GC-MS)-based profiling has been developed and validated to measure the levels of biologically active free sterols, including five endogenous sterols and three plant sterols (sitosterol, campesterol, and stigmasterol) in dried blood spot (DBS). RESULTS: Within- and between-run precisions were 1.4-11.1 % and 2.2-14.1 %, respectively, while the accuracies were all 86.3 â¼ 121.9 % with the correlation coefficients (r2) > 0.988 for all the sterols. In the patients (four girls and two boys, 6.5 ± 2.8 years), sitosterol levels were significantly increased, with an optimal cut-off value of 2.5 µg/mL distinguishing them from ninety-three age-matched healthy children. A cut-off value of 31.9 µg/mL differentiated the patients from six ABCG5/ABCG8 heterozygous carriers. In addition, the molecular ratios of sitosterol to cholesterol, desmosterol, and 7-dehydrocholesterol provided excellent cut-off values of 26.3, 67.6, and 21.6, respectively, to distinguish patients from both healthy controls and heterozygous carriers. CONCLUSIONS: The novel DBS-based GC-MS profiling of free sterols accurately identified patients with sitosterolemia, with a performance comparable to that of a serum assay. The DBS profiling could be more feasible method in clinical practice as well as population screening programs, and it can provide diagnostic cut-off values for individual plant sterols.
Asunto(s)
Pruebas con Sangre Seca , Cromatografía de Gases y Espectrometría de Masas , Hipercolesterolemia , Enfermedades Intestinales , Errores Innatos del Metabolismo Lipídico , Fitosteroles , Humanos , Errores Innatos del Metabolismo Lipídico/sangre , Errores Innatos del Metabolismo Lipídico/diagnóstico , Femenino , Masculino , Enfermedades Intestinales/sangre , Enfermedades Intestinales/diagnóstico , Niño , Fitosteroles/sangre , Fitosteroles/efectos adversos , Pruebas con Sangre Seca/métodos , Hipercolesterolemia/sangre , Hipercolesterolemia/diagnóstico , Preescolar , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/sangre , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/genética , Esteroles/sangre , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/sangre , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/genética , Lipoproteínas/sangreRESUMEN
Phytosterol serum concentrations are under tight genetic control. The relationship between phytosterols and coronary artery disease (CAD) is controversially discussed. We perform a genome-wide meta-analysis of 32 phytosterol traits reflecting resorption, cholesterol synthesis and esterification in six studies with up to 9758 subjects and detect ten independent genome-wide significant SNPs at seven genomic loci. We confirm previously established associations at ABCG5/8 and ABO and demonstrate an extended locus heterogeneity at ABCG5/8 with different functional mechanisms. New loci comprise HMGCR, NPC1L1, PNLIPRP2, SCARB1 and APOE. Based on these results, we perform Mendelian Randomization analyses (MR) revealing a risk-increasing causal relationship of sitosterol serum concentrations and CAD, which is partly mediated by cholesterol. Here we report that phytosterols are polygenic traits. MR add evidence of both, direct and indirect causal effects of sitosterol on CAD.
Asunto(s)
Colesterol/sangre , Enfermedad de la Arteria Coronaria/genética , Sitios Genéticos , Metabolismo de los Lípidos/genética , Fitosteroles/sangre , Sistema del Grupo Sanguíneo ABO/sangre , Sistema del Grupo Sanguíneo ABO/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/sangre , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/genética , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/sangre , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/genética , Adulto , Apolipoproteínas E/sangre , Apolipoproteínas E/genética , Enfermedad de la Arteria Coronaria/sangre , Enfermedad de la Arteria Coronaria/patología , Femenino , Regulación de la Expresión Génica , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Hidroximetilglutaril-CoA Reductasas/sangre , Hidroximetilglutaril-CoA Reductasas/genética , Lipasa/sangre , Lipasa/genética , Lipoproteínas/sangre , Lipoproteínas/genética , Masculino , Proteínas de Transporte de Membrana/sangre , Proteínas de Transporte de Membrana/genética , Análisis de la Aleatorización Mendeliana , Herencia Multifactorial , Polimorfismo de Nucleótido Simple , Receptores Depuradores de Clase B/sangre , Receptores Depuradores de Clase B/genéticaAsunto(s)
Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/genética , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/genética , Trastornos de las Plaquetas Sanguíneas/genética , Hipercolesterolemia/genética , Enfermedades Intestinales/genética , Errores Innatos del Metabolismo Lipídico/genética , Lipoproteínas/genética , Fitosteroles/efectos adversos , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/sangre , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/sangre , Animales , Trastornos de las Plaquetas Sanguíneas/sangre , Femenino , Humanos , Lipoproteínas/sangre , Masculino , Ratones , Fitosteroles/genéticaRESUMEN
Classical lipid transporters are suggested to modulate cellular vitamin D uptake. This study investigated the vitamin D levels in serum and tissues of mice deficient in SR-B1 (Srb1-/-), CD36 (Cd36-/-) and ABC-G5/G8 (Abcg5/g8-/-) and compared them with corresponding wild-type (WT) mice. All mice received triple-deuterated vitamin D3 (vitamin D3-d3) for six weeks. All knockout mice vs. WT mice showed specific alterations in their vitamin D concentrations. Srb1-/- mice had higher levels of vitamin D3-d3 in the serum, adipose tissue, kidney and heart, whereas liver levels of vitamin D3-d3 remained unaffected. Additionally, Srb1-/- mice had lower levels of deuterated 25-hydroxyvitamin D3 (25(OH)D3-d3) in the serum, liver and kidney compared to WT mice. In contrast, Cd36-/- and WT mice did not differ in the serum and tissue levels of vitamin D3-d3, but Cd36-/- vs. WT mice were characterized by lower levels of 25(OH)D3-d3 in the serum, liver and kidney. Finally, Abcg5/g8-/- mice tended to have higher levels of vitamin D3-d3 in the serum and liver. Major alterations in Abcg5/g8-/- mice were notably higher levels of 25(OH)D3-d3 in the serum and kidney, accompanied by a higher hepatic mRNA abundance of Cyp27a1 hydroxylase. To conclude, the current data emphasize the significant role of lipid transporters in the uptake, tissue distribution and activation of vitamin D.
Asunto(s)
Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/sangre , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/sangre , Lipoproteínas/sangre , Receptores Depuradores de Clase B/sangre , Receptores Depuradores de Clase B/deficiencia , Vitamina D/sangre , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/deficiencia , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/deficiencia , Animales , Transporte Biológico , Peso Corporal , Antígenos CD36/sangre , Antígenos CD36/deficiencia , Calcifediol/sangre , Colesterol/sangre , Deshidrocolesteroles/sangre , Femenino , Riñón/metabolismo , Lipoproteínas/deficiencia , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transaminasas/sangre , Triglicéridos/sangre , Vitamina D/farmacocinéticaRESUMEN
BACKGROUND: Familial hypercholesterolaemia (FH) is the most common inherited metabolic disease with an autosomal dominant mode of inheritance. It is characterised by raised serum levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c), leading to premature coronary artery disease. Children with FH are subjected to early and enhanced atherosclerosis, leading to greater risk of coronary events, including premature coronary artery disease. To the best of our knowledge, this is the first report of a pair of monochorionic diamniotic identical twins with a diagnosis of heterozygous FH, resulting from mutations in both LDLR and ABCG8 genes. CASE PRESENTATION: This is a rare case of a pair of 8-year-old monochorionic diamniotic identical twin, who on family cascade screening were diagnosed as definite FH, according to the Dutch Lipid Clinic Criteria (DLCC) with a score of 10. There were no lipid stigmata noted. Baseline lipid profiles revealed severe hypercholesterolaemia, (TC = 10.5 mmol/L, 10.6 mmol/L; LDL-c = 8.8 mmol/L, 8.6 mmol/L respectively). Their father is the index case who initially presented with premature CAD, and subsequently diagnosed as FH. Family cascade screening identified clinical FH in other family members including their paternal grandfather who also had premature CAD, and another elder brother, aged 10 years. Genetic analysis by targeted next-generation sequencing using MiSeq platform (Illumina) was performed to detect mutations in LDLR, APOB100, PCSK9, ABCG5, ABCG8, APOE and LDLRAP1 genes. Results revealed that the twin, their elder brother, father and grandfather are heterozygous for a missense mutation (c.530C > T) in LDLR that was previously reported as a pathogenic mutation. In addition, the twin has heterozygous ABCG8 gene mutation (c.55G > C). Their eldest brother aged 12 years and their mother both had normal lipid profiles with absence of LDLR gene mutation. CONCLUSION: A rare case of Asian monochorionic diamniotic identical twin, with clinically diagnosed and molecularly confirmed heterozygous FH, due to LDLR and ABCG8 gene mutations have been reported. Childhood FH may not present with the classical physical manifestations including the pathognomonic lipid stigmata as in adults. Therefore, childhood FH can be diagnosed early using a combination of clinical criteria and molecular analyses.
Asunto(s)
Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/genética , ADN/genética , Enfermedades en Gemelos/genética , Hiperlipoproteinemia Tipo II/genética , Mutación Missense , Receptores de LDL/genética , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/sangre , Adulto , Niño , Análisis Mutacional de ADN , Enfermedades en Gemelos/sangre , Femenino , Pruebas Genéticas/métodos , Humanos , Hiperlipoproteinemia Tipo II/sangre , Masculino , Persona de Mediana Edad , Linaje , Fenotipo , Receptores de LDL/metabolismo , Gemelos MonocigóticosAsunto(s)
Apolipoproteína B-100/genética , Hiperlipoproteinemia Tipo II/genética , Mutación , Proproteína Convertasa 9/genética , Receptores de LDL/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/sangre , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/genética , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/sangre , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/genética , Proteínas Adaptadoras Transductoras de Señales/sangre , Proteínas Adaptadoras Transductoras de Señales/genética , Apolipoproteína B-100/sangre , Apolipoproteínas E/sangre , Apolipoproteínas E/genética , LDL-Colesterol/sangre , Bases de Datos Genéticas , Expresión Génica , Genómica/métodos , Humanos , Hiperlipoproteinemia Tipo II/sangre , Hiperlipoproteinemia Tipo II/patología , Metabolismo de los Lípidos/genética , Lipoproteínas/sangre , Lipoproteínas/genética , Proproteína Convertasa 9/sangre , Receptores de LDL/sangre , Esterol Esterasa/sangre , Esterol Esterasa/genéticaRESUMEN
Low-density lipoprotein cholesterol (LDL-C) plays a causal role in atherosclerosis. One way to reduce LDL-C levels is to inhibit cholesterol absorption. Plant sterols and stanols compete with cholesterol for absorption in the intestine and induce an average decrease in LDL-C by 5% to 15% in a dose-dependent manner, but not in all individuals. This review focuses on the interindividual variability in response to dietary supplementation with plant sterols and stanols. Dietary plant sterols and stanols have no significant effects on LDL-C in substantial numbers of individuals. Higher responses, in absolute value and percentage of LDL-C, are observed in individuals with higher cholesterol absorption and a lower rate of cholesterol synthesis. Some data provide evidence of the influence of genetics on the response to plant sterols and stanols. Further studies in large populations are required to extend these conclusions about genetic influences.
Asunto(s)
Anticolesterolemiantes/administración & dosificación , Colesterol/sangre , Fitosteroles/administración & dosificación , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/sangre , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 5/genética , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/sangre , Transportador de Casete de Unión a ATP, Subfamilia G, Miembro 8/genética , Apolipoproteínas E/sangre , Apolipoproteínas E/genética , Dieta , Suplementos Dietéticos , Grano Comestible/química , Frutas/química , Humanos , Lipoproteínas/sangre , Lipoproteínas/genética , Proteínas de la Membrana/sangre , Proteínas de la Membrana/genética , Proteínas de Transporte de Membrana , Metaanálisis como Asunto , Nueces/química , Aceites de Plantas/química , Polimorfismo Genético , Ensayos Clínicos Controlados Aleatorios como Asunto , Sitoesteroles/administración & dosificación , Verduras/químicaRESUMEN
PURPOSE: The sun mushroom (Agaricus brasiliensis) is considered a major source of bioactive compounds with potential health benefits. Mushrooms typically act as lipid-lowering agents; however, little is known about the mechanisms of action of A. brasiliensis in biological systems. This study aimed to determine the underlying mechanism involved in the cholesterol-lowering effect of A. brasiliensis through the assessment of fecal and serum lipid profiles in addition to gene expression analysis of specific transcription factors, enzymes, and transporters involved in cholesterol homeostasis. METHODS: Twenty-four albino Fischer rats approximately 90 days old, with an average weight of 205 g, were divided into four groups of 6 each and fed a standard AIN-93 M diet (C), hypercholesterolemic diet (H), hypercholesterolemic diet +1 % A. brasiliensis (HAb), or hypercholesterolemic diet +0.008 % simvastatin (HS) for 6 weeks. Simvastatin was used as a positive control, as it is a typical drug prescribed for lipid disorders. Subsequently, blood, liver, and feces samples were collected for lipid profile and quantitative real-time polymerase chain reaction gene expression analyses. RESULTS: Diet supplementation with A. brasiliensis significantly improved serum lipid profiles, comparable to the effect observed for simvastatin. In addition, A. brasiliensis dietary supplementation markedly promoted fecal cholesterol excretion. Increased expression of 7α-hydroxylase (CYP7A1), ATP-binding cassette subfamily G-transporters (ABCG5/G8), and low-density lipoprotein receptor (LDLR) was observed following A. brasiliensis administration. CONCLUSIONS: Our results suggest that consumption of A. brasiliensis improves the serum lipid profile in hypercholesterolemic rats by modulating the expression of key genes involved in hepatic cholesterol metabolism.