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Recent genome- and exome-wide association studies suggest that the human APOE ε4 allele protects against non-alcoholic fatty liver disease (NAFLD), while ε3 promotes hepatic steatosis and steatohepatitis. The present study aimed at examining the APOE genotype-dependent development of fatty liver disease and its underlying mechanisms in a targeted replacement mouse model. Male mice expressing the human APOE3 or APOE4 protein isoforms on a C57BL/6J background and unmodified C57BL/6J mice were chronically fed a high-fat and high-sucrose diet to induce obesity. After 7 months, body weight gain was more pronounced in human APOE than endogenous APOE expressing mice with elevated plasma biomarkers suggesting aggravated metabolic dysfunction. APOE3 mice exhibited the highest liver weights and, compared to APOE4, massive hepatic steatosis. An untargeted quantitative proteome analysis of the liver identified a high number of proteins differentially abundant in APOE3 versus APOE4 mice. The majority of the higher abundant proteins in APOE3 mice could be grouped to inflammation and damage-associated response, and lipid storage, amongst others. Results of the targeted qRT-PCR and Western blot analyses contribute to the overall finding that APOE3 as opposed to APOE4 promotes hepatic steatosis, inflammatory- and damage-associated response signaling and fibrosis in the liver of obese mice. Our experimental data substantiate the observation of an increased NAFLD-risk associated with the human APOEε3 allele, while APOEε4 appears protective. The underlying mechanisms of the protection possibly involve a higher capacity of nonectopic lipid deposition in subcutaneous adipose tissue and lower hepatic pathogen recognition in the APOE4 mice.
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Apolipoproteína E4 , Enfermedad del Hígado Graso no Alcohólico , Humanos , Ratones , Masculino , Animales , Apolipoproteína E4/genética , Apolipoproteína E3/genética , Enfermedad del Hígado Graso no Alcohólico/etiología , Ratones Transgénicos , Ratones Endogámicos C57BL , Apolipoproteínas E/genética , DietaRESUMEN
INTRODUCTION: In chronic kidney disease, proteinuria increases urinary copper excretion, inducing oxidative tubular damage and worsening kidney function. We investigated whether this phenomenon occurred in kidney transplant recipients (KTRs). In addition, we studied the associations of urinary copper excretion with the biomarker of oxidative tubular damage urinary liver-type fatty-acid binding protein (u-LFABP) and death-censored graft failure. METHODS: This prospective cohort study was performed in the Netherlands between 2008 and 2017, including outpatient KTR with a functioning graft for longer than 1 year, who were extensively phenotyped at baseline. Twenty-four-hour urinary copper excretion was measured by inductively coupled plasma mass spectrometry. Multivariable linear and Cox regression analyses were performed. RESULTS: In 693 KTR (57% men, 53 ± 13 years, estimated glomerular filtration rate [eGFR] 52 ± 20 mL/min/1.73 m2), baseline median urinary copper excretion was 23.6 (interquartile range 11.3-15.9) µg/24 h. Urinary protein excretion was positively associated with urinary copper excretion (standardized ß = 0.39, p < 0.001), and urinary copper excretion was positively associated with u-LFABP (standardized ß = 0.29, p < 0.001). During a median follow-up of 8 years, 109 (16%) KTR developed graft failure. KTR with relatively high copper excretion were at higher risk of long-term graft failure (hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.32-1.86 per log2, p < 0.001), independent of multiple potential confounders like eGFR, urinary protein excretion, and time after transplantation. A dose-response relationship was observed over increasing tertiles of copper excretion (HR: 5.03, 95% CI: 2.75-9.19, tertile 3 vs. 1, p < 0.001). u-LFABP was a significant mediator of this association (74% of indirect effect, p < 0.001). CONCLUSION: In KTR, urinary protein excretion is positively correlated with urinary copper excretion. In turn, higher urinary copper excretion is associated with an independent increased risk of kidney graft failure, with a substantial mediating effect through oxidative tubular damage. Further studies are warranted to investigate whether copper excretion-targeted interventions could improve kidney graft survival.
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Trasplante de Riñón , Masculino , Humanos , Femenino , Trasplante de Riñón/efectos adversos , Cobre , Estudios Prospectivos , Riñón , Proteinuria/etiología , Receptores de Trasplantes , Factores de Riesgo , Supervivencia de InjertoAsunto(s)
Encéfalo , Metilación de ADN , Humanos , Ratones , Animales , Islas de CpG/genética , Alelos , Apolipoproteínas E/genéticaRESUMEN
BACKGROUND: Deficiency of the essential trace element selenium is common in kidney transplant recipients (KTR), potentially hampering antioxidant and anti-inflammatory defence. Whether this impacts the long-term outcomes of KTR remains unknown. We investigated the association of urinary selenium excretion, a biomarker of selenium intake, with all-cause mortality; and its dietary determinants. METHODS: In this cohort study, outpatient KTR with a functioning graft for longer than 1 year were recruited (2008-11). Baseline 24-h urinary selenium excretion was measured by mass spectrometry. Diet was assessed by a 177-item food frequency questionnaire, and protein intake was calculated by the Maroni equation. Multivariable linear and Cox regression analyses were performed. RESULTS: In 693 KTR (43% men, 52 ± 12 years), baseline urinary selenium excretion was 18.8 (interquartile range 15.1-23.4) µg/24-h. During a median follow-up of 8 years, 229 (33%) KTR died. KTR in the first tertile of urinary selenium excretion, compared with those in the third, had over a 2-fold risk of all-cause mortality [hazard ratio 2.36 (95% confidence interval 1.70-3.28); P < .001], independent of multiple potential confounders including time since transplantation and plasma albumin concentration. The most important dietary determinant of urinary selenium excretion was protein intake (Standardized ß 0.49, P < .001). CONCLUSIONS: Relatively low selenium intake is associated with a higher risk of all-cause mortality in KTR. Dietary protein intake is its most important determinant. Further research is required to evaluate the potential benefit of accounting for selenium intake in the care of KTR, particularly among those with low protein intake.
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Trasplante de Riñón , Selenio , Masculino , Humanos , Femenino , Trasplante de Riñón/efectos adversos , Estudios de Cohortes , Proteínas en la Dieta , Dieta , Receptores de Trasplantes , Factores de RiesgoRESUMEN
In the context of the growing prevalence of type 2 diabetes (T2DM), control of postprandial hyperglycemia is crucial for its prevention. Blood glucose levels are determined by various factors including carbohydrate hydrolyzing enzymes, the incretin system and glucose transporters. Furthermore, inflammatory markers are recognized predictors of diabetes outcome. Although there is some evidence that isoflavones may exhibit anti-diabetic properties, little is known about to what extent their corresponding hydroxylated metabolites may affect glucose metabolism. We evaluated the ability of a soy extract before (pre-) and after (post-) fermentation to counteract hyperglycemia in vitro and in Drosophila melanogaster in vivo. Fermentation with Aspergillus sp. JCM22299 led to an enrichment of hydroxy-isoflavones (HI), including 8-hydroxygenistein, 8-hydroxyglycitein and 8-hydroxydaidzein, accompanied by an enhanced free radical scavenging activity. This HI-rich extract demonstrated inhibitory activity towards α-glucosidase and a reduction of dipeptidyl peptidase-4 enzyme activity. Both the pre- and post-fermented extracts significantly inhibited the glucose transport via sodium-dependent glucose transporter 1. Furthermore, the soy extracts reduced c-reactive protein mRNA and secreted protein levels in interleukin-stimulated Hep B3 cells. Finally, supplementation of a high-starch D. melanogaster diet with post-fermented HI-rich extract decreased the triacylglyceride content of female fruit flies, confirming its anti-diabetic properties in an in vivo model.
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Diabetes Mellitus Tipo 2 , Hiperglucemia , Isoflavonas , Animales , Femenino , Drosophila melanogaster/metabolismo , Hipoglucemiantes/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/prevención & control , Isoflavonas/farmacología , Isoflavonas/metabolismo , Extractos Vegetales/farmacología , GlucosaRESUMEN
Kidney transplant recipients (KTR) are at increased risk of cardiovascular mortality. We investigated whether, in KTR, post-transplantation copper status is associated with the risk of cardiovascular mortality and potential effect modification by sex. In this cohort study, plasma copper was measured using mass spectrometry in extensively-phenotyped KTR with a functioning allograft >1-year. Cox regression analyses with the inclusion of multiplicative interaction terms were performed. In 660 KTR (53 ± 13 years old, 56% male), the median baseline plasma copper was 15.42 (IQR 13.53-17.63) µmol/L. During a median follow-up of 5 years, 141 KTR died, 53 (38%) due to cardiovascular causes. Higher plasma copper was associated with an increased risk of cardiovascular mortality in the overall KTR population (HR 1.37; 95% CI, 1.07-1.77 per 1-SD, p = 0.01). Sex was a significant effect modifier of this association (Pinteraction = 0.01). Among male KTR, higher plasma copper concentration was independently associated with a two-fold higher risk of cardiovascular mortality (HR 2.09; 95% CI, 1.42-3.07 per 1-SD, p < 0.001). Among female KTR, this association was absent. This evidence offers a rationale for considering a sex-specific assessment of copper's role in cardiovascular risk evaluation. Further studies are warranted to elucidate whether copper-targeted interventions may decrease cardiovascular mortality in male KTR.
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BACKGROUND AND AIMS: Apolipoprotein E (APOE) is known for its role in lipid metabolism and its association with age-related disease pathology. The aim of the present work was to identify previously unknown functions of APOE based on the detection of novel APOE protein-protein interaction candidates. APPROACH AND RESULTS: APOE targeted replacement mice and transfected cultured hepatocytes expressing the human isoforms APOE3 and APOE4 were used. For 7 months, APOE3 and APOE4 mice were fed a high-fat and high-sugar diet to induce obesity, while a subgroup was subjected to 30% dietary restriction. Proteomic analysis of coimmunoprecipitation products from APOE mouse liver extracts revealed 28 APOE-interacting candidate proteins, including branched-chain alpha-keto acid dehydrogenase (BCKD) complex subunit alpha (BCKDHA) and voltage-dependent anion-selective channel 1 (VDAC1). The binding of APOE and BCKDHA was verified in situ by proximity ligation assay in cultured cells. The activity of the BCKD enzyme complex was significantly higher in obese APOE4 mice than in APOE3 mice, while the plasma levels of branched-chain amino acids and mTOR signalling proteins were not different. However, the protein-protein interaction with VDAC1 was strongly induced in APOE3 and APOE4 mice upon dietary restriction, suggesting a prominent role of APOE in mitochondrial function. CONCLUSIONS: The protein-protein interactions of APOE with BCKDHA and VDAC1 appear to be of physiological relevance and are modulated upon dietary restriction. Because these are mitochondrial proteins, it may be suggested that APOE is involved in mitochondria-related processes and adaptation to hepatic energy demands.
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Apolipoproteína E4 , Proteómica , Ratones , Humanos , Animales , Apolipoproteína E4/metabolismo , Apolipoproteína E3/metabolismo , Apolipoproteínas E/metabolismo , Hígado/metabolismo , Células Cultivadas , Mitocondrias/metabolismo , Proteínas Portadoras/metabolismo , Ratones TransgénicosRESUMEN
BACKGROUND: Long-term high-dose lithium therapy in bipolar disorder is known to adversely affect kidney function. However, recent animal studies have revealed that low amounts of lithium are beneficial for the kidney when it is damaged by exposure to nephrotoxic compounds, inflammation or oxidative stress. This study aimed to investigate whether urinary lithium excretion, reflecting dietary lithium intake, is associated with adverse long-term kidney graft outcomes and patient survival. METHODS: Urinary lithium concentration was measured using inductively coupled plasma mass spectrometry in 642 stable kidney transplant recipients (KTRs). Graft failure was defined as the start of dialysis or retransplantation and kidney function decline was defined as a doubling of serum creatinine. RESULTS: The median urinary lithium excretion was 3.03 µmol/24 h [interquartile range (IQR) 2.31-4.01]. Urinary lithium excretion was associated with energy, plant protein and water intake. During a median follow-up of 5.3 years (IQR 4.5-6.0), 79 (12%) KTRs developed graft failure and 127 (20%) KTRs developed kidney function decline. Higher urinary lithium excretion was associated with a lower risk of graft failure {hazard ratio [HR] per doubling 0.54 [95% confidence interval (CI) 0.38-0.79]} and kidney function decline [HR per doubling 0.73 (95% CI 0.54-0.99)]. These associations remained independent of adjustment for potential confounders and in sensitivity analyses. There was a significant effect modification with the use of proliferation inhibitors (P = .05) and baseline estimated glomerular filtration rate (eGFR; P < .001), with higher urinary lithium excretion being more protective in KTRs not using proliferation inhibitors and in KTRs with lower baseline eGFR. Furthermore, higher urinary lithium excretion was associated with a reduced risk of all-cause mortality [HR 0.64 (95% CI 0.49-0.83); P = .001]. CONCLUSION: Dietary lithium intake may be a potentially modifiable, yet rather overlooked, risk factor for adverse long-term kidney graft outcomes and patient survival. TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02811835.
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Trasplante de Riñón , Trasplante de Riñón/efectos adversos , Litio/uso terapéutico , Diálisis Renal , Riñón , Factores de Riesgo , Receptores de TrasplantesRESUMEN
Human apolipoprotein E (APOE), originally known for its role in lipid metabolism, is polymorphic with three major allele forms, namely, APOEε2, APOEε3, and APOEε4, leading to three different human APOE isoforms. The ε4 allele is a genetic risk factor for Alzheimer's disease (AD); therefore, the vast majority of APOE research focuses on its role in AD pathology. However, there is increasing evidence for other functions of APOE through the involvement in other biological processes such as transcriptional regulation, mitochondrial metabolism, immune response, and responsiveness to dietary factors. Therefore, the aim of this review is to provide an overview of the potential novel functions of APOE and their characterization. The detection of APOE in various cell organelles points to previously unrecognized roles in mitochondria and others, although it is actually considered a secretory protein. Furthermore, numerous interactions of APOE with other proteins have been detected, providing indications for new metabolic pathways involving APOE. The present review summarizes the current evidence on APOE beyond its original role in lipid metabolism, to change the perspective and encourage novel approaches to future research on APOE and its isoform-dependent role in the cellular metabolism.
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Enfermedad de Alzheimer , Fenómenos Biológicos , Apolipoproteínas E , Humanos , Mitocondrias , Isoformas de ProteínasRESUMEN
PURPOSE: In a search for potentially modifiable factors to improve long-term outcome among kidney transplant recipients (KTR), we hypothesized that boron exposure is associated with improved long-term outcome in KTR. METHODS: We determined 24 h urinary boron excretion using inductively coupled plasma mass spectrometry as a measure of boron exposure in 693 stable KTR (57% male, mean age 53y), enrolled in the TransplantLines Food and Nutrition Biobank and Cohort Study. Dietary intake was assessed using validated food-frequency questionnaires. RESULTS: Linear regression analyses showed that dietary intake of fruit, wine and nuts were key determinants of boron excretion. In addition, boron excretion was negatively correlated with homocysteine and inflammatory parameters. In total, 73 (32%), 47 (20%) and 30 (13%) KTR died among the lowest, middle and highest tertiles of 24 h urinary boron excretion, respectively (Plog-rank < 0.001). Cox regression analyses showed that high boron excretion was strongly associated with lower risk of mortality, independent of age, sex, estimated glomerular filtration rate and history of cardiovascular disease (HR per doubling: 0.51, 95% CI: 0.40 to 0.66, P < 0.001). CONCLUSION: Boron may be an overlooked target to improve long-term survival among KTR and potentially other patients, likely through pathways other than inflammation or the methionine-homocysteine cycle that were previously suggested. Interventional trials are warranted to confirm the potential of dietary boron supplementation in KTR and other patient populations.
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Boro , Trasplante de Riñón , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Receptores de TrasplantesRESUMEN
Taurine is a nonproteinogenic amino sulfonic acid in mammals. Interestingly, skeletal muscle is unable to synthesize taurine endogenously, and the processing of muscular taurine changes throughout ageing and under specific pathophysiological conditions, such as muscular dystrophy. Ageing and disease are also associated with altered iron metabolism, especially when there is an excess of labile iron. The present study addresses the question of whether taurine connects cytoprotective effects and redox homeostasis in a previously unknown iron-dependent manner. Using cultured differentiated C2C12 myotubes, the impact of taurine on markers of lipid peroxidation, redox-sensitive enzymes and iron-related proteins was studied. Significant increases in the heme protein myoglobin and the iron storage protein ferritin were observed in response to taurine treatment. Taurine supplementation reduced lipid peroxidation and BODIPY oxidation by ~60 and 25%, respectively. Furthermore, the mRNA levels of redox-sensitive heme oxygenase (Hmox1), catalase (Cat) and glutamate-cysteine ligase (Gclc) and the total cellular glutathione content were lower in taurine-supplemented cells than they were in the control cells. We suggest that taurine may inhibit the initiation and propagation of lipid peroxidation by lowering basal levels of cellular stress, perhaps through reduction of the cellular labile iron pool.
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The purpose of food processing has changed over time. High-intensity industrially processed food often exhibits higher concentrations of added sugar, salt, higher energy, and lower micronutrient density than does similar food or meals prepared at home from raw or minimally processed food. Viewing the evolution of food processing from history, one could make out three major transitions related to human socioeconomic changes. The first transition was marked by the change from hunting and gathering to settled societies with agriculture and livestock farming. The second and third transitions were associated with the Industrial Revolution and with market liberalization, global trade and automation, respectively. The next major transition that will influence food processing and shape human nutrition may include the exploitation of sustainable and efficient protein and food sources that will ensure high-quality food production for the growing world population. Apart from novel food sources, traditional food such as legumes and pulses likewise exhibit great potential to contribute to a healthy balanced diet. The promotion of legumes should be intensified in public dietary guidelines because their consumption is rather low in high-income countries and increasingly displaced as a traditional staple by industrially processed food in low- to middle-income countries.
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Algal products are well known for their health promoting effects. Nonetheless, an in depth understanding of the underlying molecular mechanisms is still only fragmentary. Here, we show that aqueous furbelow extracts (brown algae, Saccorhiza polyschides) lengthen the life of both sexes of the fruit fly Drosophila melanogaster substantially, if used as nutritional additives to conventional food. This life prolonging effect became even more pronounced in the presence of stressors, such as high-fat dieting of living under drought conditions. Application of the extracts did not change food intake, excretion, or other major physiological parameters. Nevertheless, effects on the intestinal microbiota were observed, leading to an increased species richness, which is usually associated with healthy conditions. Lifespan extension was not observed in target of rapamycin (TOR)-deficient animals, implying that functional TOR signaling is necessary to unfold the positive effects of brown algae extract (BAE) on this important trait. The lack of life lengthening in animals with deregulated TOR signaling exclusively targeted to body fat showed that this major energy storage organ is instrumental for transmitting these effects. In addition, expression of Imaginal morphogenesis protein-Late 2 (Imp-L2), an effective inhibitor of insulin signaling implies that BAE exerts their positive effects through interaction with the tightly interwoven TOR- and insulin-signaling systems, although insulin levels were not directly affected by this intervention.
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Suplementos Dietéticos , Drosophila melanogaster/genética , Drosophila melanogaster/fisiología , Longevidad/efectos de los fármacos , Fenómenos Fisiológicos de la Nutrición/efectos de los fármacos , Fenómenos Fisiológicos de la Nutrición/fisiología , Phaeophyceae/química , Extractos Vegetales/farmacología , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Animales , Distribución de la Grasa Corporal , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Insulina/metabolismo , MasculinoRESUMEN
In this study, we provide experimental evidence that a maternally inherited polymorphism in the mitochondrial cytochrome b gene (mt-Cytb; m.15124A>G, Ile-Val) in mitochondrial complex III resulted in middle-aged obesity and higher susceptibility to diet-induced obesity, as well as age-related inflammatory disease, e.g., ulcerative dermatitis, in mice. As a consequence of the gene variation, we observed alterations in body composition, metabolism and mitochondrial functions, i.e., increased mitochondrial oxygen consumption rate and higher levels of reactive oxygen species, as well as in the commensal bacterial composition in the gut, with higher abundance of Proteobacteria in mice carrying the variant. These observations are in line with the previously described links of the mitochondrial complex III gene with obesity and metabolic diseases in humans. Given that these functional changes by the G variant at m.15124 in the mt-Cytb are already present in young mice that were kept under normal condition, it is plausible that the m.15124A>G variant is a disease susceptibility modifier to the diseases induced by additional stressors, i.e., dietary and/or aging stress, and that the variant results in the higher incidence of clinical diseases presentation in C57BL/6J-mt129S1/SvlmJ than C57BL/6J mice. Thus, mtDNA variants could be potential biomarkers to evaluate the healthspan.
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ADN Mitocondrial/genética , Genes Mitocondriales/genética , Animales , Bacteroidetes/genética , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Membranas Mitocondriales/metabolismo , Mutación/genética , Estrés Oxidativo/genética , Estrés Oxidativo/fisiología , Polimorfismo de Nucleótido Simple/genética , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Taurine is a nonproteinogenic ß-aminosulfonic acid. Important dietary sources of taurine are fish and seafood. Taurine interacts with ion channels, stabilizes membranes, and regulates the cell volume. These actions confirm its high concentrations in excitable tissues like retina, neurons, and muscles. Retinal degeneration, cardiomyopathy, as well as skeletal muscle malfunction are evident in taurine-deficient phenotypes. There is evidence that taurine counteracts lipid peroxidation and increases cellular antioxidant defense in response to inflammation. In activated neutrophils, taurine reacts with hypochloric acid to form taurine chloramine, which triggers the Kelch-like ECH-associated protein 1-nuclear factor E2-related factor 1 (Keap1-Nrf2) pathway. Consequently, Nrf2 target genes, such as heme oxygenase-1 and catalase, are induced. Furthermore, taurine may prevent an overload of reactive oxygen species (ROS) directly by an inhibition of ROS generation within the respiratory chain. Taurine affects mitochondrial bioenergetics and taurine-deficient mice exhibit an impaired exercise performance. Moreover, some studies demonstrate that taurine enhances the glycogen repletion in the postexercise recovery phase. In the case of taurine deficiency, many studies observed a phenotype known in muscle senescence and skeletal muscle disorders. Overall, taurine plays an important role in cellular redox homeostasis and skeletal muscle function.
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Homeostasis , Músculo Esquelético/fisiología , Taurina/fisiología , Animales , Dieta , Ejercicio Físico , Glutatión/metabolismo , Humanos , Peroxidación de Lípido , Mitocondrias/metabolismo , Factor 2 Relacionado con NF-E2/fisiología , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Taurina/administración & dosificación , Taurina/deficienciaAsunto(s)
Apolipoproteína E3/genética , Apolipoproteína E4/genética , Dieta Occidental , Inmunidad Innata , Receptores Toll-Like/sangre , Proteínas de Fase Aguda/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Proteínas Portadoras/metabolismo , Heces/química , Femenino , Genotipo , Humanos , Receptores de Lipopolisacáridos/metabolismo , Hígado/enzimología , Masculino , Glicoproteínas de Membrana/metabolismo , RatonesRESUMEN
The mitochondrial proteome comprises 1000 to 1500 proteins, in addition to proteins for which the mitochondrial localization is uncertain. About 800 diseases have been linked with mutations in mitochondrial proteins. We devised a cell survival assay for assessing the mitochondrial localization in a high-throughput format. This protocol allows us to assess the mitochondrial localization of proteins and their mutants, and to identify drugs and nutrients that modulate the mitochondrial targeting of proteins. The assay works equally well for proteins directed to the outer mitochondrial membrane, inner mitochondrial membrane mitochondrial and mitochondrial matrix, as demonstrated by assessing the mitochondrial targeting of the following proteins: carnitine palmitoyl transferase 1 (consensus sequence and R123C mutant), acetyl-CoA carboxylase 2, uncoupling protein 1 and holocarboxylase synthetase. Our screen may be useful for linking the mitochondrial proteome with rare diseases and for devising drug- and nutrition-based strategies for altering the mitochondrial targeting of proteins.
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Muerte Celular , Técnicas Citológicas , Mitocondrias/metabolismo , Proteínas Mitocondriales/metabolismo , Proteoma , Supervivencia Celular , Células HEK293 , Humanos , Microscopía Confocal , Mutación , Proteómica , Xenobióticos/químicaRESUMEN
In this study we addressed the questions whether an Atlantic brown algae extract (BAE) affects diet induced obesity in mice and which would be the primary targets and underlying key mechanisms. Male C57 BL/6 mice were fed a hypercaloric diet, referred to as high fat diet (HFD), supplemented with a freeze-dried aqueous BAE from Saccorhiza polyschides (5 %) for 8 months. Compared to the control group, dietary BAE supplementation significantly attenuated increase in body weight and fat mass. We observed apparent metabolic improvement including normalization of blood glucose, reduced plasma leptin, reduced fecal bile salt hydrolase activity with lower microbial production of toxic bile acid metabolites in the gut and increased systemic bile acid circulation in BAE-fed mice counteracting adverse effects of long term HFD feeding. Survival of mice receiving dietary BAE supplementation appeared slightly enhanced; however, median and maximal life spans as well as hepatic mTOR activation were not significantly different between BAE and control mice. We suggest that the beneficial metabolic effects of our BAE are at least partly mediated by alterations in gut microbiota associated with fermentation of indigestible polysaccharides that are major components of brown algae such as alginates and fucoidans. We moreover propose a multi-factorial mechanism that involves profound alterations in bile acid homeostasis, changes in intestinal and systemic glucose metabolism likely including increased intestinal gluconeogenesis, increased activity of the intestinally derived hormone GLP-1 contributing to promote systemic insulin sensitivity, and inhibition of α-amylase activity, which expectably limits dietary carbohydrate digestion and glucose release.
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Cocoa polyphenols are thought to reduce the risk of cardiovascular diseases. Thus, cocoa-containing foods may have significant health benefits. Here, we studied the impact of chocolate liquor on vascular lesion development and plaque composition in a mouse model of atherosclerosis. Apolipoprotein E (apoE)-knockout mice were assigned to two groups and fed a Western diet that contained 250 g/kg of either chocolate liquor or a polyphenol-free isoenergetic control paste for 16 weeks. In addition to fat, protein, and fibers, the chocolate liquor contained 2 g/kg of polyphenols. Compared with the control group, mice fed the chocolate liquor had larger plaque areas in the descending aorta and aortic root, which were attributed to a higher mass of vascular smooth muscle cells (VSMCs) and collagen. Vascular lipid deposits and calcification areas did not differ between the two groups. The aortic tissue level of interleukin-6 (IL-6) mRNA was 5-fold higher in the mice fed chocolate liquor than in the control mice. Chocolate-fed mice exhibited an increased hepatic saturated to polyunsaturated fatty acid ratio than the controls. Although the chocolate liquor contained 14 µg/kg of vitamin D2, the chocolate liquor-fed mice did not have measurable 25-hydroxyvitamin D2 in the serum. These mice even showed a 25% reduction in the level of 25-hydroxyvitamin D3 compared with the control mice. Overall, present data may contribute to our understanding how chocolate constituents can impact vascular lesion development.
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Aterosclerosis/terapia , Chocolate , Dieta Alta en Grasa , Placa Aterosclerótica/patología , Animales , Apolipoproteínas E/deficiencia , Apolipoproteínas E/metabolismo , Aterosclerosis/genética , Ergocalciferoles/administración & dosificación , Ergocalciferoles/farmacología , Masculino , Ratones NoqueadosRESUMEN
Apolipoprotein E (APOE) is a member of the vertebrate protein family of exchangeable apolipoproteins that is characterized by amphipathic α-helices encoded by multiple nucleotide tandem repeats. Its equivalent in flying insects - apolipophorin-III - shares structural and functional commonalities with APOE, suggesting the possibility of an evolutionary relationship between the proteins. In contrast to all other known species, human APOE is functionally polymorphic and possesses three major allelic variants (ε4, ε3 and ε2). The present review examines the current knowledge on APOE gene structure, phylogeny and APOE protein topology as well as its human isoforms. The ε4 allele is associated with an increased age-related disease risk but is also the ancestral form. Despite increased mortality in the elderly, ε4 has not become extinct and is the second-most common allele worldwide after ε3. APOE ε4, moreover, shows a non-random geographical distribution, and similarly, the ε2 allele is not homogenously distributed among ethnic populations. This likely suggests the existence of selective forces that are driving the evolution of human APOE isoforms, which may include differential interactions with dietary factors. To that effect, micronutrients such as vitamin D and carotenoids or dietary macronutrient composition are elucidated with respect to APOE evolution.