Iron incorporation in red blood cells of pediatric sickle cell anemia: a stable isotope pilot investigation.

BACKGROUND/OBJECTIVES: Sickle cell anemia (SCA) is marked by hypoxia, inflammation, and secondary iron overload (IO), which potentially modulate hepcidin, the pivotal hormone governing iron homeostasis. The aim was to evaluate the iron incorporation in red blood cells (RBC) in SCA pediatric patients, considering the presence or absence of IO. SUBJECTS/METHODS: SCA children (n = 12; SCAtotal) ingested an oral stable iron isotope (57Fe) and iron incorporation in RBC was measured after 14 days. Patients with ≥1000 ng/mL serum ferritin were considered to present IO (SCAio+; n = 4) while the others were classified as being without IO (SCAio-; n = 8). Liver iron concentration (LIC) was determined by Magnetic Resonance Imaging (MRI) T2* method. RESULTS: The SCAio+ group had lower iron incorporation (mean ± SD: 0.166 ± 0.04 mg; 3.33 ± 0.757%) than SCAio- patients (0.746 ± 0.303 mg; 14.9 ± 6.05%) (p = 0.024). Hepcidin was not different between groups. Iron incorporation was inversely associated with serum ferritin level (SCAtotal group: r = -0.775, p = 0.041; SCAio- group: r = -0.982; p = 0.018) and sickle hemoglobin (HbS) presented positive correlation with iron incorporation (r = 0.991; p = 0.009) in SCAio- group. LIC was positively associated with ferritin (SCAtotal: r = 0.921; p = 0.026) and C reactive protein (SCAio+: r = 0.999; p = 0.020). CONCLUSION: SCAio+ group had lower iron incorporation in RBC than SCAio- group, suggesting that they may not need to reduce their intake of iron-rich food, as usually recommended. Conversely, a high percentage of HbS may indirectly exacerbate hypoxia and seems to increase iron incorporation in RBC. TRIAL REGISTRATION: This trial was registered at www.ensaiosclinicos.gov.br . Identifier RBR-4b7v8pt.

Iron absorption in adults with sickle cell anemia: a stable-isotope approach.

PURPOSE: Iron absorption in sickle cell anemia (SCA) remains unclear and studies in adults with SCA are scarce. The aim of this study was to evaluate the iron absorption SCA adults and its association with iron status and hepcidin concentration. METHODS: SCA patients (n = 13; SCAtotal) and control participants (n = 10) ingested an oral stable iron isotope (57Fe). Iron absorption was measured by inductively coupled plasma mass spectrometry (ICP-MS) 14 days after isotope administration. Patients with ≥ 1000 ng/mL serum ferritin were considered to present iron overload (IO) (SCAio+; n = 3) and others classified without IO (SCAio-; n = 10). RESULTS: Iron absorption in the control group ranged from 0.3 to 26.5% (median = 0.9%), while it varied from 0.3 to 5.4% in SCAio+ (median = 0.5%) and from 0.3 to 64.2% in the SCAio- (median = 6.9%). Hepcidin median values were 14.1 ng/mL (3.0-31.9 ng/mL) in SCAio-, 6.2 ng/mL (3.3-7.8 ng/mL) in SCAio + and 6.2 ng/mL (0.6-9.3 ng/mL) in control. Iron absorption was associated with ferritin level (r = - 0.641; p = 0.018) and liver iron concentration (LIC; r = - 0.786; p = 0.036) in the SCAtotal group. CONCLUSION: Our data suggest that SCAio- individuals may be at risk of developing primary IO. Simultaneously, secondary IO may induce physiological adaptation, resulting in reduced iron absorption. Further studies evaluating intestinal iron absorption using larger sample sizes should be conducted to help establish a safe nutrition approach to be adopted and to ensure the security of food-fortifying public policies for these patients. TRIAL REGISTRATION: This trial was registered at www.ensaiosclinicos.gov.br (Identifier RBR-4b7v8pt).

Novel bioanalytical strategy using isotope pattern deconvolution and ICP-QMS for the study of iron incorporation in erythrocytes: An insight to better assessment.

Iron is an essential element for human life and its nutritional status in the human body is directly linked to human health. More than 1015 atoms of iron per second are necessary for the maintenance of haemoglobin formation. To predict iron bioavailability three approaches are normally employed: (a) faecal recovery; (b) plasma appearance; and (c) erythrocyte incorporation (the most used). Isotope Pattern Deconvolution (IPD) is a mathematical tool that allows the isolation of distinct isotope signatures from mixtures of natural abundance and enriched tracers. In this work we propose a novel strategy to assess erythrocyte iron incorporation, based on the use of an iron stable isotope (57Fe) and the IPD concept. This strategy allows direct calculation of the exogenous concentration of 57Fe incorporated into RBCs after supplementation. In this way, to determine the mass of iron incorporated into erythrocytes, the unique prediction that must be made is the blood volume, estimate to reproduce the natural dilution of the tracer (57Fe) in the blood. This novel bioanalytical approach was applied for the measurements of iron incorporation and further iron absorption studies in humans, using a group of twelve healthy participants, that should be further evaluated for the assessment of other chemical elements that could be of health concerns and directly impact society.

Chemical Composition, Fatty Acid Profile, Phenolic Compounds, and Antioxidant Activity of Raw and Germinated Chia (Salvia hispanica L.) Seeds.

The consumption of chia seeds has become popular due to their beneficial health properties and the germination of chia seeds seems to further enhance these properties. This study aimed to evaluate the changes in the nutritional composition of chia seeds after germination for 3 and 6 days. Chemical composition, fatty acid profile, phenolic content and antioxidant capacity were determined. The indices of lipid quality, atherogenicity, thrombogenicity, and the n-6/n-3 ratio were calculated. Chia sprouts presented a significant increase in minerals, proteins, and a reduction in total lipid content with maintenance of lipid quality. Total phenolic content decreased significantly as germination time increased, but there was a significant increase in the amount of rosmarinic acid. Chia sprouts showed a significant increase in antioxidant potential when compared to raw chia seeds. As a conclusion, the results of this study demonstrated that chia seed germination is a simple, economical, and short-term process capable of improving the nutritional composition of the seeds.

Can Iron and Polyunsaturated Fatty Acid Supplementation Induce Ferroptosis?

Ferroptosis is a regulated non-apoptotic cell death process triggered by excessive iron-induced lipid peroxidation. Excess intracellular iron promotes lipid peroxidation by increasing reactive oxygen species formation through the Fenton reaction. Thus, iron and polyunsaturated fatty acid intake may trigger ferroptosis under certain conditions. The aims of this review were to compile and examine evidence in the literature for the effects of iron and polyunsaturated fatty acid supplementation on ferroptosis. Omega-6 polyunsaturated fatty acids have relatively greater susceptibility to lipid peroxidation and could, therefore, participate in ferroptosis. By contrast, omega-3 polyunsaturated fatty acids promote intracellular antioxidants synthesis and reduce the formation of hydroperoxides that induce ferroptosis. As intestinal iron absorption is regulated by iron nutritional status, individuals with normal functioning of the hepcidin-ferroportin axis are at low risk of developing iron overload in response to ingestion of iron-rich foods. Therefore, iron supplementation is potentially toxic mainly for the intestinal epithelium and the microbiota. In animal models, iron-rich diets increased oxidative damage, lowered the glutathione concentration within hepatocytes, and downregulated desaturases that synthesize long-chain polyunsaturated fatty acids. These adverse effects of iron supplementation were prevented by omega-3 fatty acid co-supplementation. The impact of food and supplement intake on ferroptosis has seldom been investigated. Scientific evidence still does not allow us to know for sure whether iron and PUFA supplementation are capable of inducing ferroptosis. As the mechanisms that control ferroptosis can determine whether cells proliferate or die, future studies should directly investigate the effects of nutrient supplementation and food intake on the ferroptosis process in different types of cells and tissues.

Nutrients with Antioxidant Properties and Their Effects on Lower-Limb Ulcers: A Systematic Review.

Chronic lower-limb ulcers (LLUs) are ulcers that fail to proceed through an orderly and timely process to produce anatomic and functional integrity. LLUs reduce the quality of life of affected individuals and are a public health problem. The treatment options include medications or surgery. Nutrition therapy is an important adjunct to improve the clinical picture and healing of LLUs. Considering that nutrients with antioxidant properties can improve the process of tissue healing, this systematic review aimed to evaluate the efficacy of antioxidant nutrient supplementation in the treatment of LLUs through randomized clinical trials. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses and the Cochrane Handbook for Systematic Reviews of Interventions. The guiding question was-can antioxidant nutrients help in the treatment of chronic LLUs? In total, 1184 articles were found when searching for antioxidant nutrients associated with the most common causes of LLUs. Fourteen articles were included in this review after removing duplicates, studies with topical and/or venous use of antioxidants, and articles published in other languages, except English. Omega-3 fatty acids, magnesium, zinc, vitamins A, C, D, and resveratrol along with probiotics positively improved the ulcer healing. These effects were more significant when there was initially a deficiency of the respective supplemented nutrients. Therefore, correcting and maintaining an adequate nutritional status can improve ulcer healing and contribute to the clinical treatment of patients with LLUs.

The effect of food and nutrients on iron overload: what do we know so far?

There has been no established food and nutrition guidance for diseases characterized by the presence of iron overload (IOL) yet. Hepcidin is a hormone that diminishes iron bioavailability. Its levels increase in response to increased iron stores. Hence, IOL conditions could hypothetically trigger a self-regulatory mechanism for the reduction of the intestinal absorption of iron. In addition, some food substances may modulate intestinal iron absorption and may be useful in the dietary management of patients with IOL. This scoping review aimed to systematize studies that support dietary prescriptions for IOL patients. It was carried out according to the method proposed by the Joanna Briggs Institute and the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Although the need to restrict iron in the diet of individuals with hemochromatosis is quite clear, there is a consensus that IOL diminishes the rate of iron absorption. Reduced iron absorption is also present and has been reported in some diseases with transfusion IOL, in which serum hepcidin is usually high. The consumption of polyphenols and 6-shogaol seems to reduce iron absorption or serum ferritin concentration, while procyanidins do not cause any changes. Vitamin C deficiency is often found in IOL patients. However, vitamin C supplementation and alcohol consumption should be avoided not only because they increase iron absorption, but also because they provoke toxic oxidative reactions when the iron is excessive. Dietary approaches must consider the differences in the pathophysiology and treatment of IOL diseases.

Prevalência de anemia e deficiência de vitamina A e consumo de ferro e de vitamina A entre crianças usuárias do Sistema Único de Saúde na cidade do Rio de Janeiro, Brasil / Prevalence of anemia and vitamin A deficiency and iron and vitamin A intake in children that use the Brazilian Unified National Health System in Rio de Janeiro, Brazil / Prevalencia de anemia, deficiencia de vitamina A, y consumo de hierro y de vitamina A entre niños pacientes del Sistema Único de Salud en la ciudad de Río de Janeiro, Brasil

Estratégias nacionais para o controle de anemia e deficiência de vitamina A em crianças estão baseadas em estimativas de suas prevalências produzidas em âmbito nacional em 2006 com métodos não validados para este grupo etário e com nível de desagregação para macrorregiões. Com o intuito de subsidiar a gestão local para o (re)direcionamento de medidas de controle desses agravos, o presente trabalho apresenta estimativas de sua prevalência e, também, de marcadores de consumo alimentar de fontes de micronutrientes e do uso de suplementos de vitaminas e minerais em amostra probabilística de crianças de 6 a 59 meses, usuárias da atenção básica de saúde do Município do Rio de Janeiro, Brasil (n = 536). Foram coletadas amostras de sangue venoso para análise de hemoglobina, ferritina e retinol sérico e dados sobre o consumo alimentar, o uso de suplementos de vitaminas e minerais e as características sociodemográficas. As prevalências de anemia, anemia ferropriva e deficiência de vitamina A foram de, respectivamente, 13,7%, 5,5% e 13%. Quase todas as crianças haviam consumido alimentos ricos em ferro no dia anterior à entrevista, sendo altas as prevalências de consumo de fontes de origem animal. Somente 49,4% haviam consumido alimentos ricos em vitamina A. As prevalências de uso de algum suplemento, de suplemento com ferro e com vitamina A foram de, respectivamente, 51%, 14,7% e 24,4%. Os resultados apontam a necessidade de redirecionamento das estratégias de prevenção e controle de anemia e deficiência de vitamina A. Estudos futuros são necessários para examinar a evolução desses indicadores, tendo em vista as políticas de austeridade que entraram em vigor nos últimos anos e a crise econômica decorrente da pandemia da COVID-19.

Brazilian national strategies for the control of anemia and vitamin A deficiency in children are based on estimates of their nationwide prevalence rates in 2006 with methods not validated for this age group and with disaggregation at the level of major geographic regions. To back local administrations in (re)directing control measures for these two disorders, the current study presents estimates of their prevalence and markers of dietary intake of sources of micronutrients and use of vitamin and mineral supplements in a probabilistic sample of children 6 to 59 months of age, users of primary healthcare in the city of Rio de Janeiro, Brazil (n = 536). Venous blood samples were drawn for analysis of hemoglobin, ferritin, and serum retinol, besides collection of data on food consumption, use of vitamin and mineral supplements, and sociodemographic characteristics. Prevalence rates for anemia, iron deficiency anemia, and vitamin A deficiency were 13.7%, 5.5%, and 13%, respectively. Nearly all the children had consumed iron-rich food the day before the interview, with high prevalence of animal sources. Only 49.4% had consumed foods high in vitamin A. The prevalence rates for use of any supplement, iron supplements, and vitamin A supplements were 51%, 14.7%, and 24.4%, respectively. The findings point to the need to redirect the strategies for prevention and control of anemia and vitamin A deficiency. Future studies are necessary to examine trends in these indicators, focusing on austerity policies implemented in recent years and the economic crisis resulting from the COVID-19 pandemic.

Las estrategias brasileñas para el control de anemia y deficiencia de vitamina A en niños están basadas en estimaciones de sus prevalencias, producidas en el ámbito nacional en 2006 con métodos no validados para este grupo etario, y con un nivel de desagregación en las macrorregiones. Con el fin de apoyar la gestión local para la (re)orientación de medidas de control de esos problemas de salud, este trabajo presenta estimaciones de su prevalencia y, también, de los marcadores de consumo alimentario de fuentes de micronutrientes y del uso de suplementos de vitaminas y minerales, en una muestra probabilística de niños de 6 a 59 meses, pacientes de atención básica de salud del Municipio de Río de Janeiro, Brasil (n = 536). Se recogieron muestras de sangre venosa para el análisis de hemoglobina, ferritina y retinol sérico, así como datos sobre el consumo alimentario, de suplementos de vitaminas y minerales, así como de características sociodemográficas. Las prevalencias de anemia, anemia ferropénica y deficiencia de vitamina A fueron de, respectivamente, 13,7%, 5,5% y 13%. Casi todos los niños habían consumido alimentos ricos en hierro el día anterior a la entrevista, siendo altas las prevalencias de consumo de fuentes de origen animal. Solamente un 49,4% habían consumido alimentos ricos en vitamina A. Las prevalencias de consumo de algún suplemento, de suplemento con hierro y de suplemento con vitamina A fueron de, respectivamente, 51%, 14,7% y 24,4%. Los resultados apuntan la necesidad de reorientar las estrategias de prevención y control de la anemia y deficiencia de vitamina A. Se necesitan estudios futuros para examinar la evolución de esos indicadores, teniendo en vista las políticas de austeridad que entraron en vigor en los últimos años y la crisis económica a consecuencia de la pandemia de COVID-19.

Methodological aspects of the micronutrient assessment in the Brazilian National Survey on Child Nutrition (ENANI-2019): a population-based household survey / Aspectos metodológicos da avaliação de micronutrientes no Estudo Nacional de Alimentação e Nutrição Infantil (ENANI-2019): inquérito domiciliar de base populacional / Aspectos metodológicos de la evaluación de micronutrientes en el Estudio Nacional de Alimentación y Nutrición Infantil (ENANI-2019): encuesta domiciliaria de base poblacional

This article aims to present methodological aspects on the collection, analyses, coverage, challenges, and the lessons learned from laboratory assessment of micronutrients on the Brazilian National Survey on Child Nutrition (ENANI-2019). This is a household survey on a probability sample of children under five years of age from 123 Brazilian municipalities in all 26 states and the Federal District. Blood samples were drawn by venipuncture at the homes of children 6 to 59 months of age. This procedure was performed by experienced phlebotomists from the laboratories located in the selected municipalities and scheduled in advance. Blood and serum levels were measured for biomarkers of nutritional status, using the services of a clinical test laboratory with nationwide coverage, for the following micronutrients: iron (hemoglobin and ferritin), zinc, selenium, folic acid, and vitamins A, B1, B6, B12, D, and E. C-reactive protein was analyzed as a marker of inflammation. A barcode identifier was used to track the blood samples and to link the biochemical test results to the other data collected in the survey. A total of 14,558 children were studied. Of the 12,598 eligible children, 8,829 (70.1%) had blood samples drawn. Of the total number of children who had samples drawn, 91.8% (n = 8,025) have results for at least nine of the 12 analyses performed. Coverage of the analysis varied from 95% (for vitamins A and E) to 84.2% (for folic acid). Aliquots of whole blood and serum were stored in a biorepository for future analyses. The results of this pioneering study in the country will back the formulation and, when necessary, the reorientation of public policies in food and nutrition.

O objetivo deste artigo é apresentar os aspectos metodológicos referentes à coleta e análise de dados laboratoriais do Estudo Nacional de Alimentação e Nutrição Infantil (ENANI-2019), a cobertura das análises laboratoriais, os desafios enfrentados e as lições aprendidas. Trata-se de um inquérito populacional de base domiciliar de crianças menores de cinco anos realizado em 123 municípios dos 26 estados da Federação e o Distrito Federal. A coleta de sangue por punção venosa foi realizada em domicílio em crianças com idade entre 6 e 59 meses, por coletador experiente de laboratório(s) existente(s) nos municípios amostrados. Foram determinadas as concentrações sanguíneas e séricas de biomarcadores do estado nutricional utilizando os serviços de um laboratório de análises clínicas com abrangência nacional para os seguintes micronutrientes: ferro (hemoglobina e ferritina), zinco, selênio, ácido fólico, vitaminas A, B1, B6, B12, D e E. A proteína C reativa foi analisada como marcador de inflamação. Um código de barras identificador das amostras de sangue foi utilizado para o rastreio da amostra e para a junção dos resultados dos exames bioquímicos com os demais dados coletados na pesquisa. Foram estudadas 14.558 crianças. Das 12.598 elegíveis, 8.829 (70,1%) realizaram coleta de sangue. Do total de crianças que realizaram coleta de sangue, 91,8% (n = 8.025) têm resultados para pelo menos nove das 12 análises realizadas. A cobertura por análise variou de 95% (para vitaminas A e E) a 84,2% (para ácido fólico). Os resultados deste estudo pioneiro subsidiarão a formulação e, quando for o caso, o redirecionamento de políticas públicas de alimentação e nutrição.

El objetivo de este artículo es presentar aspectos metodológicos, respecto a la recogida y análisis de datos de laboratorio del Estudio Nacional de Alimentación y Nutrición Infantil (ENANI-2019), así como la cobertura de los mismos, los desafíos enfrentados y lecciones aprendidas. Se trata de una encuesta poblacional de base domiciliaria con niños menores de cinco años, realizada en 123 municipios de los 26 estados de la Federación y el Distrito Federal. La recogida de sangre por punción venosa se realizó en domicilios con niños, de edades comprendidas entre los 6 y los 59 meses, con la intervención de un flebotomista con experiencia en laboratorio(s) existente(s) en los municipios de muestra. Se determinaron las concentraciones sanguíneas y séricas de biomarcadores del estado nutricional, utilizando los servicios de un laboratorio de análisis clínicos con alcance nacional para los siguientes micronutrientes: hierro (hemoglobina y ferritina), zinc, selenio, ácido fólico, vitaminas A, B1, B6, B12, D y E. La proteína C reactiva se analizó como marcador de inflamación. Un código de barras identificador de las muestras de sangre se utilizó para el rastreo de la muestra y para la conjunción de los resultados de los exámenes bioquímicos con los demás datos recogidos en la investigación. Se estudiaron 14.558 niños. De los 12.598 elegibles, a 8.829 (70,1%) se les sacó sangre. Del total de niños, a quienes se les tomó muestras de sangre, un 91,8% (n = 8.025) obtuvieron resultados para por lo menos nueve de los 12 análisis realizados. La cobertura por análisis varió de un 95% (para vitaminas A y E), a un 84,2% (para ácido fólico). Los resultados de este estudio pionero apoyarán la formulación y, cuando fuera necesario, la redirección de políticas públicas de alimentación y nutrición.

Impact of Long-Term Supplementation with Fish Oil in Individuals with Non-Alcoholic Fatty Liver Disease: A Double Blind Randomized Placebo Controlled Clinical Trial.

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease affecting up to 25% of the population worldwide. n-3 long-chain polyunsaturated fatty acids (n-3 PUFA) have been associated with improved clinical parameters of NAFLD. Our purpose was to conduct a pilot study to evaluate the effects of n-3 PUFA supplementation in a randomized, double-blind, placebo-controlled clinical study performed on NAFLD individuals diagnosed by ultrasound. Patients received n-3 PUFA (n = 13) or placebo (n = 11) supplementation for six months. Circulating miR-122 expression (determined by quantitative real time-polymerase chain reaction (qRT-PCR), liver fibrosis (FibroScan®), red blood cells (RBC) fatty acids (gas chromatography), and biochemical tests were performed at baseline and after intervention. After the intervention, in the n-3 PUFA group, docosahexaenoic acid (DHA) and omega index increased significantly in RBC (p = 0.022 and p = 0.012, respectively), in addition to a significant reduction in alkaline phosphatase (ALP) (p = 0.002) and liver fibrosis (p = 0.039). However, there was no change in the expression of circulating miR-122 in both groups. Our results showed that omega-3 PUFA were incorporated in erythrocytes after six months of fish oil supplementary intake, and that n-3 PUFA were effective in reducing ALP and liver fibrosis without altering the expression of circulating miR-122 in individuals with NAFLD.

Chia oil induces browning of white adipose tissue in high-fat diet-induced obese mice.

Previous research suggests that omega-3 fatty acids from animal origin may promote the browning of subcutaneous white adipose tissue. We evaluated if supplementation with a plant oil (chia, Salvia hispanica L.) rich in alpha-linolenic fatty acid (C18:3; ω-3) would promote browning and improve glucose metabolism in animals subjected to an obesogenic diet. Swiss male mice (n = 28) were divided into 4 groups: C: control diet; H: high-fat diet; HC: animals in the H group supplemented with chia oil after reaching obesity; HCW: animals fed since weaning on a high-fat diet supplemented with chia oil. Glucose tolerance, inflammatory markers, and expression of genes and proteins involved in the browning process were examined. When supplemented since weaning, chia oil improved glucose metabolism and promoted the browning process and a healthier phenotype. Results of this study suggested that chia oil has potential to protect against the development of obesity-related diseases.

Nutritional Status, Nutrient Intake, and Food Diversity Among Children With Sickle Cell Anemia.

Children with sickle cell anemia (SCA) often exhibit nutritional deficiencies and are at high risk of dying before the age of 5 years. Ensuring adequate nutrition is a critical part of health care for such children. This study aimed to investigate the association between nutritional status, nutrient intake, and food diversity in children with SCA. A descriptive cross-sectional study was conducted on 74 children with SCA, between 24 and 71 months of age. Anthropometric measurements, food and nutrients consumption were determined. The prevalence of low weight, stunting, and overweight/obesity were 16.2%, 35.1%, and 16.2%, respectively. Mean folic acid intake was low (49.05%±51.22%), whereas the intakes of protein (426.71%±171.93%), retinol (292.97%±403.88%), phosphorus (204.55%±151.35%), magnesium (233.02%±151.14%), iron (250.76%±165.81%), and zinc (243.21%±148.40%) were high. The dietary phosphorus/protein ratio was high for 31.1% of the children, and 44.6% of the children had low dietary diversity score. No correlation was found between food diversity, nutrient adequacy, and nutritional status. Despite the adequacy of the intake of most micronutrients, diet quality was inadequate, constituting mainly ultraprocessed foods. Knowing the food consumption pattern of these children enables a more resolute nutritional intervention.

Chia oil supplementation changes body composition and activates insulin signaling cascade in skeletal muscle tissue of obese animals.

OBJECTIVE: Chia seed oil is the richest source of plant-based ω-3 fatty acid, α-linolenic acid, but its potential and mechanisms of action to treat obesity are unclear. The aim of the study was to evaluate the effects of chia oil (ChOi) supplementation on body composition and insulin signaling in skeletal muscles of obese mice. METHODS: Male C57 BL/6 mice (n = 8/group) were fed regular control chow or a high-fat diet (HFD) for 135 d. Another HFD group additionally received ChOi from 90 to 135 d. RESULTS: Consumption of ChOi reduced fat mass accumulation and increased lean mass as evidenced by nuclear magnetic resonance. Moreover, obese mice treated with ChOi showed higher tyrosine phosphorylation of insulin receptor substrate 1, greater activation of protein kinase B, and increased translocation of glucose transporter type 4 in skeletal muscle tissue in response to insulin. ChOi supplementation improved glucose levels and insulin tolerance; decreased serum insulin, leptin, and triacylglycerols; and increased blood high-density lipoprotein cholesterol levels. All these effects caused by the use of ChOi seemed to be independent of the resolution of inflammation because the markers of inflammation were not altered in animals fed the HFD. CONCLUSION: The molecular effects observed in muscle tissue together with changes in body composition may have contributed to the increased glucose tolerance and to the healthy phenotype presented by obese animals treated with ChOi.

Serum Hepcidin Concentration in Individuals with Sickle Cell Anemia: Basis for the Dietary Recommendation of Iron.

Dietary iron requirements in patients with sickle cell disease (SCD) remain unclear. SCD is a neglected hemoglobinopathy characterized by intense erythropoietic activity and anemia. Hepcidin is the hormone mainly responsible for iron homeostasis and intestinal absorption. Intense erythropoietic activity and anemia may reduce hepcidin transcription. By contrast, iron overload and inflammation may induce it. Studies on SCD have not evaluated the role of hepcidin in the presence and absence of iron overload. We aimed to compare serum hepcidin concentrations among individuals with sickle cell anemia, with or without iron overload, and those without the disease. Markers of iron metabolism and erythropoietic activity such as hepcidin, ferritin, and growth differentiation factor 15 were evaluated. Three groups participated in the study: the control group, comprised of individuals without SCD (C); those with the disease but without iron overload (SCDw); and those with the disease and iron overload (SCDio). Results showed that hepcidin concentration was higher in the SCDio > C > SCDw group. These data suggest that the dietary iron intake of the SCDio group should not be reduced as higher hepcidin concentrations may reduce the intestinal absorption of iron.

Obesity modifies bone marrow microenvironment and directs bone marrow mesenchymal cells to adipogenesis.

OBJECTIVE: To investigate the role of obesity on the bone marrow microenvironment and evaluate its possible impact on the adipogenic potential of mesenchymal stem cells (MSC). METHODS: C57BL/6 male mice were fed with a high-fat diet (HFD) for 10 weeks. Femurs and tibiae were collected, and bone marrow mesenchymal stem cells (BM-MSC) were isolated and analyzed for proliferative potential, immunophenotype, and expression of adipogenesis markers. Their capacity to produce extracellular matrix proteins and proinflammatory cytokines in vitro was also evaluated. RESULTS: HFD mice presented a significant increase in bone marrow cellularity and higher tumor necrosis factor-α production in vitro. BM-MSC from HFD mice had higher proliferative capacity, produced more extracellular matrix proteins associated with adipogenesis, collagen I, and collagen IV, and showed increased constitutive expression of adipogenic markers, peroxisome proliferator-activated receptor-γ, and CCAAT/enhanced binding protein family-α, without changes in preadipocyte factor-1 expression. Incubation with adipocyte-differentiation medium induced further increase in CCAAT/enhanced binding protein family-α and augmented adiponectin expression in obese BM-MSC. These alterations did not result in increased adipogenic differentiation within the bone marrow. Moreover, BM-HSC from HFD mice, co-cultivated with BM-MSCs from lean mice, exerted paracrine effects on these cells, inducing augment of peroxisome proliferator-activated receptor-γ. CONCLUSIONS: The data suggest that obesity promotes an inflammatory microenvironment in bone marrow that commits BM-MSC to adipogenesis.

Identification of a selenium-dependent glutathione peroxidase in the blood-sucking insect Rhodnius prolixus.

The selenium-dependent glutathione peroxidase (SeGPx) is a well-studied enzyme that detoxifies organic and hydrogen peroxides and provides cells or extracellular fluids with a key antioxidant function. The presence of a SeGPx has not been unequivocally demonstrated in insects. In the present work, we identified the gene and studied the function of a Rhodnius prolixus SeGPx (RpSeGPx). The RpSeGPx mRNA presents the UGA codon that encodes the active site selenocysteine (Sec) and a corresponding Sec insertion sequence (SECIS) in the 3' UTR region. The encoded protein includes a signal peptide, which is consistent with the high levels of GPx enzymatic activity in the insect's hemolymph, and clusters phylogenetically with the extracellular mammalian GPx03. This result contrasts with all other known insect GPxs, which use a cysteine residue instead of Sec and cluster with the mammalian phospholipid hydroperoxide GPx04. RpSeGPx is widely expressed in insect organs, with higher expression levels in the fat body. RNA interference (RNAi) was used to reduce RpSeGPx gene expression and GPx activity in the hemolymph. Adult females were apparently unaffected by RpSeGPx RNAi, whereas first instar nymphs showed a three-day delay in ecdysis. Silencing of RpSeGPx did not alter the gene expression of the antioxidant enzymes catalase, xanthine dehydrogenase and a cysteine-GPx, but it reduced the levels of the dual oxidase and NADPH oxidase 5 transcripts that encode for enzymes releasing extracellular hydrogen peroxide/superoxide. Collectively, our data suggest that RpSeGPx functions in the regulation of extracellular (hemolymph) redox homeostasis of R. prolixus.

Obesity promotes alterations in iron recycling.

Hepcidin is a key hormone that induces the degradation of ferroportin (FPN), a protein that exports iron from reticuloendothelial macrophages and enterocytes. The aim of the present study was to experimentally evaluate if the obesity induced by a high-fat diet (HFD) modifies the expression of FPN in macrophages and enterocytes, thus altering the iron bioavailability. In order to directly examine changes associated with iron metabolism in vivo, C57BL/6J mice were fed either a control or a HFD. Serum leptin levels were evaluated. The hepcidin, divalent metal transporter-1 (DMT1), FPN and ferritin genes were analyzed by real-time polymerase chain reaction. The amount of iron present in both the liver and spleen was determined by flame atomic absorption spectrometry. Ferroportin localization within reticuloendothelial macrophages was observed by immunofluorescence microscopy. Obese animals were found to exhibit increased hepcidin gene expression, while iron accumulated in the spleen and liver. They also exhibited changes in the sublocation of splenic cellular FPN and a reduction in the FPN expression in the liver and the spleen, while no changes were observed in enterocytes. Possible explanations for the increased hepcidin expression observed in HFD animals may include: increased leptin levels, the liver iron accumulation or endoplasmic reticulum (ER) stress. Together, the results indicated that obesity promotes changes in iron bioavailability, since it altered the iron recycling function.

Pea protein provides a promising matrix for microencapsulating iron.

Worldwide, the most prevalent nutritional deficiency is iron. The strategies for iron supplementation often fail due to poor adherence to supplementation methods contributed to unpleasant sensory characteristics. An alternative is the use of microencapsulated nutrients for home fortification in order to mask undesirable tastes and to allow its release in strategic sites of the gastrointestinal tract. Toward this end, pea protein concentrate was tested as a natural, edible and alternative material and the spray-drying technique was utilized for the preparation of microparticles containing ferrous sulfate. Their physical and chemical characteristics were evaluated. The microparticles had a spherical shape and grooves with an average size ranging between 2 and 3 µm. Analysis by in vitro assays tested the release of iron in simulated salivary and gastric fluids and its intestinal absorption in Caco-2 cells. No dissolution of iron occurred in the salivary medium whereas the sensory analysis showed good acceptance of a product which incorporated 5.5 mg of iron per 100 g portion of food. Thus, the effectiveness of microencapsulation was demonstrated by utilizing a plant protein as an encapsulating matrix for the controlled release of iron and capable of preserving the bioaccessibility of ferrous sulfate.

Vitamin A modulates the expression of genes involved in iron bioavailability.

Iron bioavailability seems to be regulated by vitamin A (VA) but the molecular events involved in this mechanism are not well understood. It is also known that retinoids mediate most of their function via interaction with retinoid receptors, which act as ligand-activated transcription factors controlling the expression of a number of target genes. Here, we evaluated the VA effects on the modulation of the levels of mRNA encoding proteins involved in the iron bioavailability, whether in the intestinal absorption process or in the liver iron metabolism. The expression of genes involved in iron intestinal absorption (divalent metal transporter 1, duodenal cytochrome B, ferroportin 1 FPN1, and ferritin) were evaluated in vitro by treating Caco-2 cells with retinoic acid or in vivo by observing the effects of vitamin A deficiency (VAD) in BALB/C mice. Liver hepcidin and ferritin mRNA levels were upregulated by VAD; however, this condition did not promote any change on the expression of those genes that participate in the iron absorption. Moreover, data from the in vitro analysis showed that VA induced FPN1 gene expression by a hepcidin-independent manner. Therefore, the in vivo results support the idea that VAD may not affect iron absorption but would rather affect iron mobilization mechanisms. On the other hand, our results using Caco-2 cells raises the possibility that VA addition to intestinal epithelium may improve iron absorption through the induction of FPN1 gene expression.