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1.
J Lipid Res ; 60(11): 1905-1911, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31455614

RESUMEN

Dietary plant sterols, such as campesterol and sitosterol, reduce plasma cholesterol concentrations, but any relationship to plaque development and CVD remains unclear. Some epidemiologic studies have suggested that elevated plasma plant sterol concentrations are atherogenic, including the Framingham Offspring Study that identified a positive association between plant sterol concentrations and CVD status. We hypothesized that this suggested atherogenicity relates to the oxidation status of plant sterols (i.e., concentrations of plasma oxyphytosterols). Therefore, in the Framingham Offspring Study cohort, we measured plasma oxyphytosterol concentrations in 144 patients with documented CVD and/or more than 50% carotid stenosis and 383 matched controls. We analyzed plasma oxyphytosterol concentrations by GC/MS/MS and performed conditional logistic regression analysis to determine associations between plasma plant sterol or oxyphytosterol concentrations and CVD status. We found that higher total cholesterol (TC)-standardized campesterol concentrations [odds ratio (OR): 2.36; 95% CI: 1.60, 3.50] and higher sitosterol concentrations (OR: 1.47; 95% CI: 1.09, 1.97) were significantly associated with increased CVD risk, as in the earlier study. However, the sum of absolute oxyphytosterol concentrations (OR: 0.99; 95% CI: 0.81, 1.21) and the sum of TC-standardized oxyphytosterol concentrations (OR: 0.98; 95% CI: 0.80, 1.19) were not associated with an increased CVD risk. Results were comparable for individual absolute and TC-standardized oxycampesterol and oxysitosterol concentrations. Plasma nonoxidized TC-standardized sitosterol and campesterol concentrations showed weak or no correlations with oxyphytosterol concentrations, while all individual plasma concentrations of oxyphytosterol correlated with each other. In conclusion, circulating plasma oxyphytosterols are not associated with CVD risk in the Framingham Offspring Study.


Asunto(s)
Enfermedades Cardiovasculares/sangre , Fitosteroles/sangre , Anciano , Estudios de Cohortes , Femenino , Humanos , Masculino , Factores de Riesgo
2.
Anal Bioanal Chem ; 411(9): 1905-1913, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30397760

RESUMEN

In this study, we report the simultaneous use of gold and silver nanoparticles to set a multicolor multiplex lateral flow immunoassay (xLFIA). Silver nanoparticles (AgNPs), spherical in shape and characterized by a brilliant yellow color, were obtained by a new viable one-step synthetic protocol. AgNPs were stable over time and acceptably robust to conditions used for fabricating LFIA devices. These AgNPs were employed as a colorimetric probe in combination with two different kinds of gold nanoparticles (AuNPs) to set a visual xLFIA for detecting allergens. Surface plasmon resonance peaks of probes (AgNPs, spherical and desert rose-like AuNPs) were centered at 420, 525, and 620 nm, respectively. Therefore, the xLFIA output was easily interpreted through a "yellow magenta cyan (YMC)" color code. The prospect of the YMC xLFIA was demonstrated by simultaneously detecting three major allergens in bakery products. Antibodies directed towards casein, ovalbumin, and hazelnut allergenic proteins were individually adsorbed onto metal nanoparticles to produce three differently colored specific probes. These were inserted in a LFIA comprising three lines, each responsive for one allergen. The trichromatic xLFIA was able to detect allergenic proteins at levels as low as 0.1 mg/l and enabled the easy identification of the allergens in commercial biscuits based on the color of the probes. Graphical Abstract.


Asunto(s)
Alérgenos/análisis , Colorimetría/métodos , Hipersensibilidad a los Alimentos/diagnóstico , Oro/química , Nanopartículas del Metal/química , Sondas Moleculares/química , Plata/química
3.
Eur J Nutr ; 56(3): 909-923, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27591863

RESUMEN

PURPOSE: Plant sterols and stanols interfere with intestinal cholesterol absorption, and it has been questioned whether absorption and plasma concentrations of fat-soluble vitamins and carotenoids are also affected. We conducted a meta-analysis to assess the effects of plant sterol and stanol consumption on plasma fat-soluble vitamin and carotenoid concentrations. METHODS: Forty-one randomized controlled trials involving 3306 subjects were included. Weighted absolute and relative changes of non-standardized and total cholesterol (TC)-standardized values (expressed as summary estimates and 95 % CIs) were calculated for three fat-soluble vitamins (α- and γ-tocopherol, retinol and vitamin D) and six carotenoids (ß-carotene, α-carotene, lycopene, lutein, zeaxanthin and ß-cryptoxanthin) using a random effects model. Heterogeneity was assessed using predefined subject and treatment characteristics. RESULTS: Average plant sterol or stanol intake was 2.5 g/d. Relative non-standardized and TC-standardized concentrations of ß-carotene decreased by, respectively, -16.3 % (95 % CI -18.3; -14.3) and -10.1 % (-12.3; -8.0), α-carotene by -14.4 % (-17.5; 11.3) and -7.8 % (-11.3; -4.3), and lycopene by -12.3 % (-14.6; -10.1) and -6.3 % (-8.6; -4.0). Lutein concentrations decreased by -7.4 % (-10.1; -4.8), while TC-standardized concentrations were not changed. For zeaxanthin, these values were -12.9 % (-18.9; -6.8) and -7.7 % (-13.8; -1.7) and for ß-cryptoxanthin -10.6 % (-14.3; -6.9) and -4.8 % (-8.7; -0.9). Non-standardized α-tocopherol concentrations decreased by -7.1 % (-8.0; -6.2) and γ-tocopherol by -6.9 % (-9.8; -3.9), while TC-standardized tocopherol concentrations were not changed. Non-standardized retinol and vitamin D concentrations were not affected. Results were not affected by baseline concentrations, dose, duration and type of plant sterols/stanols, except for significant effects of duration (≤4 vs. >4 weeks) on TC-standardized lutein concentrations (1.0 vs. -5.6 %) and type of plant sterol/stanol on TC-standardized ß-carotene concentrations (-8.9 vs. -14.2 %). CONCLUSIONS: Plant sterol and stanol intake lowers TC-standardized hydrocarbon carotenoid concentrations, differently affects TC-standardized oxygenated carotenoid concentrations, but does not affect TC-standardized tocopherol concentrations or absolute retinol and vitamin D concentrations. Observed concentrations remained within normal ranges.


Asunto(s)
Carotenoides/sangre , Fitosteroles/administración & dosificación , Vitaminas/sangre , Colesterol/sangre , Bases de Datos Factuales , Dieta , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Tocoferoles/sangre , Vitamina A/sangre , Vitamina D/sangre
4.
J Sci Food Agric ; 97(3): 1010-1017, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27247268

RESUMEN

BACKGROUND: In soybean, at least 16 seed proteins have been identified as causing allergenic reactions in sensitive individuals. As a soybean genebank accession low in the immunodominant protein P34 (Gly m Bd 30K) has recently been found, introgression of the low-P34 trait into adapted soybean germplasm has been attempted in order to improve the safety of food products containing soybean protein. Therefore, marker-assisted selection and proteomics were applied to identify and characterize low-P34 soybeans. RESULTS: In low-P34 lines selected from a cross-population, concentrations of the P34 protein as identified with a polyclonal antibody were reduced by 50-70% as compared to P34-containing controls. Using 2D electrophoresis and immunoblotting, the reduction of P34 protein was verified in low-P34 lines. This result was confirmed by liquid chromatographic-tandem mass spectrometric analysis, which revealed either a reduction or complete absence of the authentic P34 protein as suggested from presence or absence of a unique peptide useful for discriminating between conventional and low-P34 lines. CONCLUSION: Marker-assisted selection proved useful for identifying low-P34 soybean lines for the development of hypoallergenic soy foods. The status of the P34 protein in low-P34 lines needs further characterization. In addition, the food safety relevance of low-P34 soybeans should be tested in clinical studies. © 2016 Society of Chemical Industry.


Asunto(s)
Antígenos de Plantas/efectos adversos , Cruzamientos Genéticos , Regulación hacia Abajo , Glycine max/química , Fitomejoramiento , Semillas/química , Alimentos de Soja/análisis , Proteínas de Soja/efectos adversos , Antígenos de Plantas/genética , Antígenos de Plantas/metabolismo , Ensayo de Inmunoadsorción Enzimática , Sistemas Especialistas , Hipersensibilidad a los Alimentos/dietoterapia , Hipersensibilidad a los Alimentos/prevención & control , Inocuidad de los Alimentos , Alimentos Funcionales/efectos adversos , Alimentos Funcionales/análisis , Regulación de la Expresión Génica de las Plantas , Ligamiento Genético , Marcadores Genéticos , Humanos , Repeticiones de Microsatélite , Proteómica/métodos , Semillas/efectos adversos , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Selección Genética , Alimentos de Soja/efectos adversos , Proteínas de Soja/genética , Proteínas de Soja/metabolismo , Glycine max/efectos adversos , Glycine max/crecimiento & desarrollo , Glycine max/metabolismo
5.
J AOAC Int ; 98(3): 697-700, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25942754

RESUMEN

The recent IMPROVE-IT trial clearly showed that lowering serum low-density lipoprotein cholesterol (LDL-C) concentrations via inhibiting intestinal cholesterol absorption through ezetimibe effectively lowered the number of new cardiovascular disease (CVD) events. This supports the use of other (dietary) interventions that lower serum LDL-C concentrations via comparable mechanisms such as described for plant sterol and stanol ester enriched functional foods. Therefore it is tempting to suggest that these compounds may have the same effects on CVD outcome, as described for ezetimibe in the IMPROVE-IT trial. This has however not been proven so far. A possible advantage of plant sterol and stanol ester enriched foods over ezetimibe-a typical single-target drug-is that these dietary compounds act on multiple targets, since they not only lower serum LDL-C concentrations, but also lower serum triacylglycerol (TAG) concentrations in subjects with elevated serum TAG concentrations. In addition, they might influence the functioning of our immune system via a changed activity of the regulatory T-cells. This combination of effects makes these compounds highly attractive to decrease CVD risk.


Asunto(s)
Salud , Fitosteroles/farmacología , Plantas/química , Animales , Anticolesterolemiantes/farmacología , Colesterol en la Dieta/metabolismo , Humanos , Sistema Inmunológico/efectos de los fármacos , Triglicéridos/sangre
6.
Anal Bioanal Chem ; 406(11): 2581-90, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24577577

RESUMEN

Hazelnut (Corylus avellana L.) is responsible for a significant part of the allergies related to nuts. Still, it is a very much appreciated nut and as consequence is widely used in all types of processed foods, such as chocolates. Correct food labelling is currently the most effective means of preventing the consumption of allergenic ingredients, namely hazelnut, by the sensitised/allergic individuals. Thus, to verify labelling compliance and to ensure allergic patient protection, the development of highly sensitive methodologies is of extreme importance. In this study, three major methodologies, namely enzyme-linked immunosorbent assays (ELISA), liquid chromatography coupled with mass spectrometry and real-time polymerase chain reaction, were evaluated for their performance regarding the detection of hazelnut allergens in model chocolates. The sandwich ELISA and respective antibodies were in-house developed and produced. With sensitivity levels of approximately 1 mg kg(-1) and limits of quantification of 50-100 mg kg(-1), all the performed methods were considered appropriate for the identification of hazelnut in complex foods such as chocolates. To our knowledge, this was the first successful attempt to develop and compare three independent approaches for the detection of allergens in foods.


Asunto(s)
Alérgenos/análisis , Corylus/química , Ensayo de Inmunoadsorción Enzimática/métodos , Nueces/química , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Espectrometría de Masas en Tándem/métodos , Alérgenos/genética , Alérgenos/inmunología , Cacao/química , Corylus/genética , Corylus/inmunología , ADN de Plantas/química , ADN de Plantas/genética , Análisis de los Alimentos , Nueces/genética , Nueces/inmunología , Proteínas de Plantas/química , Proteínas de Plantas/genética
7.
Biomedicines ; 11(1)2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36672634

RESUMEN

Inflammation is associated with changes in plasma lipids, lipoproteins, and cholesterol efflux capacity (CEC). It is unknown if the changes in lipids and lipoproteins during inflammation are related to changes in cholesterol absorption, synthesis, and bile acid synthesis. We, therefore, examined the effects of acute lipopolysaccharide (LPS)-induced transient systemic inflammation on lipids, lipoproteins, CEC, and markers of cholesterol metabolism. We also evaluated whether markers for cholesterol metabolism at baseline predict the intensity of the inflammatory response. Eight healthy young subjects received LPS infusion, and blood was sampled for the following 24 h. In addition to lipids, lipoproteins, and CEC, we also measured markers for cholesterol absorption and synthesis, bile acid synthesis, and inflammation. Compared with baseline, plasma total cholesterol, low-density lipoprotein cholesterol, and CEC decreased, while triglycerides increased in the 24 h following LPS infusion. TC-standardized levels of cholesterol synthesis markers (lathosterol, lanosterol, and desmosterol) and a bile acid synthesis marker (7α-OH-cholesterol) also decreased, with no changes in cholesterol absorption markers (campesterol, sitosterol, and cholestanol). Baseline TC-standardized levels of desmosterol and 7α-OH-cholesterol were positively correlated with concentrations of various inflammatory markers. Changes in TC-standardized desmosterol and 7α-OH-cholesterol were negatively correlated with concentrations of inflammatory markers. LPS infusion reduced endogenous cholesterol synthesis and bile acid synthesis in healthy young men.

8.
Anal Bioanal Chem ; 402(8): 2607-15, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21735061

RESUMEN

The aim of this work was identifying and selecting hazelnut marker peptides and subsequently developing a complementary method of common immunoassay for the detection of hazelnut. For this purpose, at first, an in silico digestion of three major hazelnut allergens (Cor a 8, Cor a 9 and Cor a 11) was performed to get information about expected peptides. After extraction and trypsin digestion of hazelnut proteins, the samples were measured with tandem mass spectrometry (MS/MS) by direct infusion, which led to identification of 14 peptides. Eight of them with the highest MS signal were synthesized and used as standards for developing a liquid chromatography (LC)-MS/MS method in selected reaction monitoring (SRM) mode. Since almost all food allergens derived from nuts belong to the seed storage protein family and have homologue structure, a Basic Local Alignment Search Tool (BLAST) search was performed to identify the hazelnut specificity of the developed method. According to BLAST, only one peptide occurs in three other nuts, and the remaining seven selected peptides are hazelnut specific. Additionally to hazelnut, the eight other listed nuts in Directive 2003/89/EC as allergen were extracted, digested and measured with the developed method to prove the BLAST results. The analytical data confirmed that six peptides are hazelnut specific, on the contrary to anti-hazelnut antibodies, which showed cross-reactivities to all other nut extracts. Comparing these results, it could be shown that with this LC-MS/MS method in SRM mode, the specific detection of hazelnut is possible.


Asunto(s)
Corylus/química , Nueces/química , Péptidos/análisis , Western Blotting , Cromatografía Líquida de Alta Presión , Electroforesis , Espectrometría de Masas en Tándem
9.
Nutrients ; 14(23)2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36500981

RESUMEN

Non-Alcoholic Fatty Liver Disease (NAFLD) is characterized by hepatic free cholesterol accumulation. In addition, microRNAs (miRNAs) might be involved in NAFLD development. Therefore, we systematically reviewed the literature to examine the link between miRNAs and cholesterol metabolism in NAFLD. Nineteen studies were retrieved by a systematic search in September 2022. From these papers, we evaluated associations between 13 miRNAs with NAFLD and cholesterol metabolism. Additionally, their diagnostic potential was examined. Four miRNAs (miR122, 34a, 132 and 21) were associated with cholesterol metabolism and markers for NAFLD. MiR122 was upregulated in serum of NAFLD patients, increased with disease severity and correlated with HDL-C, TAG, VLDL-C, AST, ALT, ALP, lobular inflammation, hepatocellular ballooning and NAFLD score. Serum and hepatic levels also correlated. Serum and hepatic miR34a levels were increased in NAFLD, and correlated with VLDL-C and TAG. Serum miR379 was also higher in NAFLD, especially in early stages, while miR21 gave ambiguous results. The diagnostic properties of these miRNAs were comparable to those of existing biomarkers. However, serum miR122 levels appeared to be elevated before increases in ALT and AST were evident. In conclusion, miR122, miR34a, miR21 and miR132 may play a role in the development of NAFLD via effects on cholesterol metabolism. Furthermore, it needs to be explored if miRNAs 122, 34a and 379 could be used as part of a panel in addition to established biomarkers in early detection of NAFLD.


Asunto(s)
MicroARNs , Enfermedad del Hígado Graso no Alcohólico , Humanos , MicroARNs/metabolismo , Metabolismo de los Lípidos , Hígado/metabolismo , Biomarcadores , Colesterol
10.
Nutrients ; 14(24)2022 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-36558527

RESUMEN

Introduction. Pharmacological reduction of cholesterol (C) synthesis and C absorption lowers serum low-density lipoprotein C (LDL-C) concentrations. We questioned whether high baseline C synthesis or C absorption translates into high serum LDL-C concentrations or if there was no connection. Therefore, we studied the association between serum LDL-C and C synthesis or C absorption in healthy subjects. Methods. Three published data sets of young subjects on different diets (study 1), mildly hypercholesterolemic subjects without cardiovascular disease (study 2) and healthy controls of the Framingham study (study 3) were used. The three study populations varied in sex, age, and weight. C synthesis and C fractional absorption rate (FAR) were measured with fecal sterol balance and stable isotope techniques (studies 1 and 2). Additionally, serum lathosterol and campesterol concentrations corrected for the serum total C concentration (R_lathosterol and R_campesterol) were used as markers for hepatic C synthesis and C FAR, respectively (studies 1−3). Linear regression analysis was applied to evaluate associations between LDL-C, C synthesis, and C absorption. Results. Seventy-three, 37, and 175 subjects were included in studies 1, 2, and 3, respectively. No statistically significant associations were found between LDL-C and the measured C synthesis and C FAR, nor for R_lathosterol and R_campesterol in any of the study groups. This lack of associations was confirmed by comparing the male subjects of studies 1 and 2. Study 1 subjects had a 50% lower serum LDL-C than the study 2 subjects (p < 0.01), but not a lower C synthesis, C FAR, R-lathosterol, or R_campesterol. Conclusions. Under physiological conditions, C synthesis and C FAR are not major determinants of circulating serum LDL-C concentrations in healthy subjects. The results need to be confirmed in large-scale studies in healthy subjects and patients at risk for cardiovascular disease.


Asunto(s)
Enfermedades Cardiovasculares , Fitosteroles , Humanos , Masculino , LDL-Colesterol , Biomarcadores , Colesterol
11.
Biomedicines ; 10(10)2022 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-36289617

RESUMEN

Cathepsins are lysosomal proteases that are essential to maintain cellular physiological homeostasis and are involved in multiple processes, such as immune and energy regulation. Predominantly, cathepsins reside in the lysosomal compartment; however, they can also be secreted by cells and enter the extracellular space. Extracellular cathepsins have been linked to several pathologies, including non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). NASH is an increasingly important risk factor for the development of HCC, which is the third leading cause of cancer-related deaths and poses a great medical and economic burden. While information regarding the involvement of cathepsins in NASH-induced HCC (NASH-HCC) is limited, data to support the role of cathepsins in either NASH or HCC is accumulating. Since cathepsins play a role in both NASH and HCC, it is likely that the role of cathepsins is more significant in NASH-HCC compared to HCC derived from other etiologies. In the current review, we provide an overview on the available data regarding cathepsins in NASH and HCC, argue that cathepsins play a key role in the transition from NASH to HCC, and shed light on therapeutic options in this context.

12.
Nutrients ; 14(8)2022 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-35458107

RESUMEN

Cross-sectional studies have shown that obesity is associated with lower intestinal cholesterol absorption and higher endogenous cholesterol synthesis. These metabolic characteristics have also been observed in patients with type 2 diabetes, metabolic syndrome, steatosis or cholestasis. The number of intervention studies evaluating the effect of weight loss on these metabolic characteristics is, however, limited, while the role of the different fat compartments has not been studied into detail. In a randomized trial, abdominally obese men (N = 54) followed a 6-week very low caloric (VLCD) diet, followed by a 2 week weight-maintenance period. Non-cholesterol sterols were measured at baseline and after 8 weeks, and compared to levels in lean participants (N = 25). After weight loss, total cholesterol (TC)-standardized cholestanol levels increased by 0.18 µmol/mmol (p < 0.001), while those of campesterol and lathosterol decreased by 0.25 µmol/mmol (p < 0.05) and 0.39 µmol/mmol (p < 0.001), respectively. Moreover, after weight loss, TC-standardized lathosterol and cholestanol levels were comparable to those of lean men. Increases in TC-standardized cholestanol after weight loss were significantly associated with changes in waist circumference (p < 0.01), weight (p < 0.001), BMI (p < 0.001) and visceral fat (p < 0.01), but not with subcutaneous and intrahepatic lipids. In addition, cross-sectional analysis showed that visceral fat fully mediated the association between BMI and TC-standardized cholestanol levels. Intrahepatic lipid content was a partial mediator for the association between BMI and TC-standardized lathosterol levels. In conclusion, diet-induced weight loss decreased cholesterol synthesis and increased cholesterol absorption. The increase in TC-standardized cholestanol levels was not only related to weight loss, but also to a decrease in visceral fat volume. Whether these metabolic changes ameliorate other metabolic risk factors needs further study.


Asunto(s)
Diabetes Mellitus Tipo 2 , Fitosteroles , Biomarcadores , Colestanol , Colesterol , Estudios Transversales , Dieta Reductora , Humanos , Masculino , Obesidad , Fitosteroles/metabolismo , Pérdida de Peso
13.
Biology (Basel) ; 11(12)2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36552209

RESUMEN

BACKGROUND: the effect on liver function markers and inflammation of the different content of phytosterols in lipid emulsions (LEs) used in the parenteral nutrition (PN) regimen of adult home PN (HPN) patients is not clear. METHODS: plasma phytosterol and cytokine concentrations, fatty acid composition, liver function markers, and triglycerides were measured in 58 adult HPN patients receiving one of three different LEs (soybean oil-based: Intralipid; olive oil-based: ClinOleic; containing fish oil: SMOFLipid). RESULTS: patients receiving Intralipid had higher plasma campesterol and stigmasterol concentrations than those receiving ClinOleic or SMOFLipid. Plasma sterol concentrations were not different between patients receiving ClinOleic and SMOFLipid. Differences in plasma fatty acids reflected the fatty acid composition of the LEs. Markers of liver function did not differ among the three groups. Blood triglycerides were higher with ClinOleic than with Intralipid or SMOFLipid. Total bilirubin correlated positively with the plasma concentrations of two of the phytosterols, ALT correlated positively with one, AST with one, and GGT with three. CONCLUSIONS: liver function markers correlate with plasma plant sterol concentrations in adult HPN patients. Adult HPN patients receiving SMOFLipid are more likely to have liver function markers and triglycerides within the normal range than those receiving ClinOleic or Intralipid. The omega-3 fatty acids in SMOFLipid may act to mitigate the adverse effects of plant sterols on liver function.

14.
J Biol Chem ; 285(8): 5776-91, 2010 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-19996312

RESUMEN

Auxiliary beta subunits modulate current properties and mediate the functional membrane expression of voltage-gated Ca(2+) channels in heterologous cells. In brain, all four beta isoforms are widely expressed, yet little is known about their specific roles in neuronal functions. Here, we investigated the expression and targeting properties of beta subunits and their role in membrane expression of Ca(V)1.2 alpha(1) subunits in cultured hippocampal neurons. Quantitative reverse transcription-PCR showed equal expression, and immunofluorescence showed a similar distribution of all endogenous beta subunits throughout dendrites and axons. High resolution microscopy of hippocampal neurons transfected with six different V5 epitope-tagged beta subunits demonstrated that all beta subunits were able to accumulate in synaptic terminals and to colocalize with postsynaptic Ca(V)1.2, thus indicating a great promiscuity in alpha(1)-beta interactions. In contrast, restricted axonal targeting of beta(1) and weak colocalization of beta(4b) with Ca(V)1.2 indicated isoform-specific differences in local channel complex formation. Membrane expression of external hemagglutinin epitope-tagged Ca(V)1.2 was strongly enhanced by all beta subunits in an isoform-specific manner. Conversely, mutating the alpha-interaction domain of Ca(V)1.2 (W440A) abolished membrane expression and targeting into dendritic spines. This demonstrates that in neurons the interaction of a beta subunit with the alpha-interaction domain is absolutely essential for membrane expression of alpha(1) subunits, as well as for the subcellular localization of beta subunits, which by themselves possess little or no targeting properties.


Asunto(s)
Canales de Calcio Tipo L/metabolismo , Hipocampo/metabolismo , Terminales Presinápticos/metabolismo , Subunidades de Proteína/metabolismo , Sustitución de Aminoácidos , Animales , Canales de Calcio Tipo L/genética , Membrana Celular/genética , Membrana Celular/metabolismo , Ratones , Ratones Endogámicos BALB C , Mutación Missense , Estructura Terciaria de Proteína/fisiología , Subunidades de Proteína/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
15.
Anal Bioanal Chem ; 399(3): 1105-15, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21107975

RESUMEN

The aim of this work was the determination of peptides, which can function as markers for identification of milk allergens in food samples. Emphasis was placed on two casein proteins (α- and ß-casein) and two whey proteins (α-lactalbumin and ß-lactoglobulin). In silico tryptic digestion provided preliminary information about the expected peptides. After tryptic digestion of four milk allergens, the analytical data obtained by combination of reversed-phase high performance liquid chromatography and quadrupole tandem mass spectrometry (LC-MS/MS) led to the identification of 26 peptides. Seven of these peptides were synthesized and used for calibration of the LC-MS/MS system. Species specificity of the selected peptides was sought by BLAST search. Among the selected peptides, only LIVTQTMK from ß-lactoglobulin (m/z 467.6, charge 2+) was found to be cow milk specific and could function as a marker. Two other peptides, FFVAPFPEVFGK from α-casein (m/z 693.3, charge 2+) and GPFPIIV from ß-casein (m/z 742.5, charge 1+), occur in water buffalo milk too. The other four peptides appear in the milk of other species also and can be used as markers for ruminant species milk. Using these seven peptides, a multianalyte MS-based method was developed. For the establishment of the method, it was applied at first to different dairy samples, and then to chocolate and blank samples, and the peptides could be determined down to 1 ng/mL in food samples. At the end, spiked samples were measured, where the target peptides could be detected with a high recovery (over 50%).


Asunto(s)
Caseínas/análisis , Productos Lácteos/análisis , Lactalbúmina/análisis , Lactoglobulinas/análisis , Leche/química , Péptidos/química , Animales , Biomarcadores/química , Cromatografía Líquida de Alta Presión , Análisis de los Alimentos , Espectrometría de Masas en Tándem
16.
Anal Bioanal Chem ; 401(8): 2561-71, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21901458

RESUMEN

A rapid fluorescence polarization (FP) immunoassay has been developed for the simultaneous determination of T-2 and HT-2 toxins in naturally contaminated wheat samples. Syntheses of four fluorescein-labelled T-2 or HT-2 toxin tracers were carried out and their binding response with seven monoclonal antibodies was evaluated. The most sensitive antibody-tracer combination was obtained by using an HT-2-specific antibody and a fluorescein-HT-2 tracer. The developed competitive FP immunoassay in solution showed high cross-reactivity for T-2 toxin (CR% = 100%) while a very low CR% for neosolaniol (0.12%) and no cross-reactivity with other mycotoxins frequently occurring in wheat. A rapid extraction procedure using 90% methanol was applied to wheat samples prior to FP immunoassay. The average recovery from spiked wheat samples (50 to 200 µg kg(-1)) was 96% with relative standard deviation generally lower than 8%. A limit of detection of 8 µg kg(-1) for the combined toxins was determined. Comparative analyses of 45 naturally contaminated and spiked wheat samples by both the FP immunoassay and high-performance liquid chromatography/immunoaffinity clean-up showed a good correlation (r = 0.964). These results, combined with the rapidity (10 min) and simplicity of the assay, show that this method is suitable for high throughput screening as well as for quantitative determination of T-2 and HT-2 toxins in wheat.


Asunto(s)
Inmunoensayo de Polarización Fluorescente/métodos , Fusarium/química , Toxina T-2/análogos & derivados , Toxina T-2/análisis , Triticum/microbiología , Inmunoensayo de Polarización Fluorescente/economía , Límite de Detección , Toxina T-2/aislamiento & purificación , Factores de Tiempo
17.
J AOAC Int ; 94(4): 1026-33, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21919335

RESUMEN

Allergen detection and quantification is an essential part of allergen management as practiced by food manufacturers. Recently, protein MS methods (in particular, multiple reaction monitoring experiments) have begun to be adopted by the allergen detection community to provide an alternative technique to ELISA and PCR methods. MS analysis of proteins in foods provides additional challenges to the analyst, both in terms of experimental design and methodology: (1) choice of analyte, including multiplexing to simultaneously detect several biologically relevant molecules able to trigger allergic reactions; (2) choice of processing stable peptide markers for different target analytes that should be placed in publicly available databases; (3) markers allowing quantification (e.g., through standard addition or isotopically labeled peptide standards); (4) optimization of protease digestion protocols to ensure reproducible and robust method development; and (5) effective validation of methods and harmonization of results through the use of naturally incurred reference materials spanning several types of food matrix.


Asunto(s)
Alérgenos/análisis , Análisis de los Alimentos/métodos , Espectrometría de Masas/métodos , Cromatografía Líquida de Alta Presión/métodos , Humanos , Reproducibilidad de los Resultados
18.
Biomedicines ; 9(12)2021 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-34944726

RESUMEN

Nonalcoholic fatty liver disease (NAFLD) is known as the hepatic manifestation of the metabolic syndrome, and while most patients develop simple steatosis, up to one-third can develop nonalcoholic steatohepatitis (NASH) [...].

19.
Atherosclerosis ; 311: 116-123, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32861515

RESUMEN

A wealth of data demonstrates a causal link between serum low-density lipoprotein cholesterol (LDL-C) concentrations and cardiovascular disease (CVD). Any decrease in serum LDL-C concentrations is associated with a decreased CVD risk, and this benefit is similar to a comparable LDL-C reduction after drug treatment and dietary intervention. Moreover, life-long reductions in serum LDL-C levels have a large impact on CVD risk and a long-term dietary enrichment with functional foods or supplements with a proven LDL lowering efficacy is therefore a feasible and efficient approach to decrease future CVD risk. Functional foods with an LDL-C lowering effect can improve health and/or a reduce the risk of disease. However, it has not been mentioned specifically whether this concerns mainly universal prevention or whether this can also be applied to the hierarchy towards care related prevention. Therefore, we here describe the effects of a list of interesting functional food ingredients with proven benefit in LDL-C lowering. In addition, we pay particular attention to the emerging evidence that the addition of these functional ingredients and supplements is advisable as universal and selective prevention in the general population. Moreover, functional ingredients and supplements are also helpful in care related prevention, i.e. in patients with elevated LDL-C concentrations who are statin-intolerant or are not able to achieve their LDL-C target levels. Furthermore, we will highlight practical aspects regarding the use of functional foods with an LDL-C lowering effect, such as the increasing importance of shared decision making of medical doctors and dieticians with patients to ensure proper empowerment and better adherence to dietary approaches. In addition, we will address costs issues related to the use of these functional foods, which might be a barrier in some populations.


Asunto(s)
Anticolesterolemiantes , Enfermedades Cardiovasculares , Enfermedades Cardiovasculares/prevención & control , LDL-Colesterol , Alimentos Funcionales , Humanos , Gestión de Riesgos
20.
Anal Bioanal Chem ; 394(2): 539-48, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19247640

RESUMEN

Blocking is an important step before an enzyme-linked immunosorbent assay (ELISA) can be performed. It reduces non-specific binding to the microtiter plate to a minimum. For detecting food allergens by means of ELISA, the problem with protein blocking solutions is obvious. The blocker might interfere with the antibodies of the assay and leads to false positive results. Therefore, other blocking solutions are greatly needed. There are some alternatives like synthetic blockers or carbohydrates. Comparisons of these different blocking agents, namely proteins, carbohydrates, and synthetic blockers, were made at different reaction conditions. The incubation periods and temperatures were varied, as well as the pH. The best combinations were evaluated and compared, in respect of their blocking efficiency. The two best non-proteinaceous blockers, i.e. polyvinylalcohol and Ficoll, were subsequently applied to ELISA tests for the determination of alpha-casein and peanut. The study showed that Ficoll and PVA did as well as BSA in buffer solution. Therefore, they can be considered as alternative blocking reagents for ELISA, especially for the detection of food allergens.


Asunto(s)
Alérgenos/análisis , Alérgenos/inmunología , Productos Biológicos/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Hipersensibilidad a los Alimentos/inmunología
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