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1.
Adv Nutr ; 15(3): 100181, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38280724

RESUMO

Through diverse roles, zinc determines a greater number of critical life functions than any other single micronutrient. Beyond the well-recognized importance of zinc for child growth and resistance to infections, zinc has numerous specific roles covering the regulation of glucose metabolism, and growing evidence links zinc deficiency with increased risk of diabetes and cardiometabolic disorders. Zinc nutriture is, thus, vitally important to health across the life course. Zinc deficiency is also one of the most common forms of micronutrient malnutrition globally. A clearer estimate of the burden of health disparity attributable to zinc deficiency in adulthood and later life emerges when accounting for its contribution to global elevated fasting blood glucose and related noncommunicable diseases (NCDs). Yet progress attenuating its prevalence has been limited due, in part, to the lack of sensitive and specific methods to assess human zinc status. This narrative review covers recent developments in our understanding of zinc's role in health, the impact of the changing climate and global context on zinc intake, novel functional biomarkers showing promise for monitoring population-level interventions, and solutions for improving population zinc intake. It aims to spur on implementation of evidence-based interventions for preventing and controlling zinc deficiency across the life course. Increasing zinc intake and combating global zinc deficiency requires context-specific strategies and a combination of complementary, evidence-based interventions, including supplementation, food fortification, and food and agricultural solutions such as biofortification, alongside efforts to improve zinc bioavailability. Enhancing dietary zinc content and bioavailability through zinc biofortification is an inclusive nutrition solution that can benefit the most vulnerable individuals and populations affected by inadequate diets to the greatest extent.


Assuntos
Desnutrição , Oligoelementos , Criança , Humanos , Alimentos Fortificados , Estado Nutricional , Zinco , Micronutrientes
2.
Int J Mol Sci ; 24(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37047530

RESUMO

Zinc is an essential micronutrient, and its deficiency is perhaps the most prevalent and least understood worldwide. Recent advances have expanded the understanding of zinc's unique chemistry and molecular roles in a vast array of critical functions. However, beyond the concept of zinc absorption, few studies have explored the molecular basis of zinc bioavailability that determines the proportion of dietary zinc utilized in zinc-dependent processes in the body. The purpose of this review is to merge the concepts of zinc molecular biology and bioavailability with a focus on the molecular determinants of zinc luminal availability, absorption, transport, and utilization.


Assuntos
Oligoelementos , Zinco , Disponibilidade Biológica , Micronutrientes , Ácido Fítico
3.
Methods Enzymol ; 680: 35-83, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36710018

RESUMO

Aromatic aminotransferases (Aro ATs) are pyridoxal-5-phosphate (PLP)-dependent enzymes that catalyze the transamination reactions of an aromatic amino acid (AAA) or a keto acid. Aro ATs are involved in biosynthesis or degradation of AAAs and play important functions in controlling the production of plant hormones and secondary metabolites, such as auxin, tocopherols, flavonoids, and lignin. Most Aro ATs show substrate promiscuity and can accept multiple aromatic and non-aromatic amino and keto acid substrates, which complicates and limits our understanding of their in planta functions. Considering the critical roles Aro ATs play in plant primary and secondary metabolism, it is important to accurately determine substrate specificity and kinetic properties of Aro ATs. This chapter describes various methodologies of protein expression, purification and enzymatic assays, which can be used for biochemical characterization of Aro ATs.


Assuntos
Fosfato de Piridoxal , Transaminases , Transaminases/química , Transaminases/metabolismo , Fosfato de Piridoxal/química , Fosfato de Piridoxal/metabolismo , Cetoácidos , Aminoácidos Aromáticos , Especificidade por Substrato
4.
Nutrients ; 14(19)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36235548

RESUMO

Zinc, through its structural and cofactor roles, affects a broad range of critical physiological functions, including growth, metabolism, immune and neurological functions. Zinc deficiency is widespread among populations around the world, and it may, therefore, underlie much of the global burden of malnutrition. Current zinc fortification strategies include biofortification and fortification with zinc salts with a primary focus on staple foods, such as wheat or rice and their products. However, zinc fortification presents unique challenges. Due to the influences of phytate and protein on zinc absorption, successful zinc fortification strategies should consider the impact on zinc bioavailability in the whole diet. When zinc is absorbed with food, shifts in plasma zinc concentrations are minor. However, co-absorbing zinc with food may preferentially direct zinc to cellular compartments where zinc-dependent metabolic processes primarily occur. Although the current lack of sensitive biomarkers of zinc nutritional status reduces the capacity to assess the impact of fortifying foods with zinc, new approaches for assessing zinc utilization are increasing. In this article, we review the tools available for assessing bioavailable zinc, approaches for evaluating the zinc nutritional status of populations consuming zinc fortified foods, and recent trends in fortification strategies to increase zinc absorption.


Assuntos
Desnutrição , Zinco , Biomarcadores , Alimentos Fortificados , Humanos , Ácido Fítico , Sais
5.
Biol Trace Elem Res ; 200(6): 2606-2613, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34453311

RESUMO

Progress improving zinc nutrition globally is slowed by limited understanding of population zinc status. This challenge is compounded when small differences in measurement can bias the determination of zinc deficiency rates. Our objective was to evaluate zinc analytical accuracy and precision among different instrument types and sample matrices using a standardized method. Participating laboratories analyzed zinc content of plasma, serum, liver samples, and controls, using a standardized method based on current practice. Instrument calibration and drift were evaluated using a zinc standard. Accuracy was evaluated by percent error vs. reference, and precision by coefficient of variation (CV). Seven laboratories in 4 countries running 9 instruments completed the exercise: 4 atomic absorbance spectrometers (AAS), 1 inductively coupled plasma optical emission spectrometer (ICP-OES), and 4 ICP mass spectrometers (ICP-MS). Calibration differed between individual instruments up to 18.9% (p < 0.001). Geometric mean (95% CI) percent error was 3.5% (2.3%, 5.2%) and CV was 2.1% (1.7%, 2.5%) overall. There were no significant differences in percent error or CV among instrument types (p = 0.91, p = 0.15, respectively). Among sample matrices, serum and plasma zinc measures had the highest CV: 4.8% (3.0%, 7.7%) and 3.9% (2.9%, 5.4%), respectively (p < 0.05). When using standardized materials and methods, similar zinc concentration values, accuracy, and precision were achieved using AAS, ICP-OES, or ICP-MS. However, method development is needed for improvement in serum and plasma zinc measurement precision. Differences in calibration among instruments demonstrate a need for harmonization among laboratories.


Assuntos
Laboratórios , Zinco , Fígado , Espectrometria de Massas/métodos , Análise Espectral
6.
Am J Clin Nutr ; 115(3): 724-737, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-34792094

RESUMO

BACKGROUND: Zinc biofortification of rice could sustainably improve zinc status in countries where zinc deficiency is common and rice is a staple, but its efficacy has not been tested. Fatty acid desaturases (FADS) are putative new zinc status biomarkers. OBJECTIVES: Our objective was to test the efficacy of zinc-biofortified rice (BFR) in preschool-aged children with zinc deficiency. Our hypothesis was that consumption of BFR would increase plasma zinc concentration (PZC). METHODS: We conducted a 9-mo, double-masked intervention trial in 12-36-mo-old rural Bangladeshi children, most of whom were zinc-deficient (PZC <70 µg/dL) and stunted (n = 520). The children were randomly assigned to receive either control rice (CR) or BFR provided in cooked portions to their households daily, with compliance monitoring. The primary outcome was PZC. Secondary outcomes were zinc deficiency, linear growth, infection-related morbidity, FADS activity indices, intestinal fatty acid binding protein (I-FABP) and fecal calprotectin. We applied sparse serial sampling for midpoint measures and analyzed data by intention-to-treat using mixed-effects models. RESULTS: At baseline, median (IQR) PZC was 60.4 (56.3-64.3) µg/dL, 78.1% of children were zinc deficient, and 59.7% were stunted. Mean ± SD daily zinc intakes from the CR and BFR during the trial were 1.20 ± 0.34 and 2.22 ± 0.47 mg/d, respectively (P < 0.001). There were no significant time-by-treatment effects on PZC, zinc deficiency prevalence, FADS activity, I-FABP, or fecal calprotectin (all P > 0.05). There was a time-treatment interaction for height-for-age z-scores (P < 0.001) favoring the BFR group. The morbidity longitudinal prevalence ratio was 1.08 (95% CI: 1.05, 1.12) comparing the BFR and CR groups, due to more upper respiratory tract illness in the BFR group. CONCLUSIONS: Consumption of BFR for 9 mo providing ∼1 mg of additional zinc daily to Bangladeshi children did not significantly affect PZC, prevalence of zinc deficiency, or FADS activity.The trial was registered at clinicaltrials.gov as NCT03079583.


Assuntos
Desnutrição , Oryza , Pré-Escolar , Humanos , Complexo Antígeno L1 Leucocitário , Estado Nutricional , Zinco
7.
J Nutr ; 151(9): 2583-2589, 2021 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-34236435

RESUMO

BACKGROUND: Zinc intake is associated with reduced risk of metabolic disease in adults, possibly due in part to zinc's role in essential fatty acid (EFA) desaturation. Although plasma zinc is the accepted indicator of zinc status, product-to-precursor activity indices of fatty acid desaturase (FADS) 1 and 2 have also been proposed as response indicators for changes in zinc intake. OBJECTIVES: To examine zinc supplement effects on plasma zinc concentration (PZC) and estimated FADS 1 and 2 activities, when zinc supplements are taken with food compared with fasted. METHODS: Apparently healthy adult men were randomly allocated to take 25 mg zinc as zinc gluconate either in the fasted state 30 min before breakfast [zinc before breakfast (ZBB)] or with breakfast [zinc with breakfast (ZWB)] daily for 13 d. Fasting PZC was measured by inductively coupled plasma optical emission spectrometry. Selected EFAs for FADS activity indices were measured by LC-MS/MS at study baseline and end. RESULTS: A total of 35 men completed the study (ZBB, n = 18; ZWB, n = 17). Mean ± SEM PZC was 86.2 ± 1.64 µg/dL at baseline. After 2 wk of zinc supplementation, the PZCs were 18% higher in the ZBB compared with the ZWB groups (105 ± 5.88 compared with 88.7 ± 2.36 µg/dL, P = < 0.05). However, the geometric mean (95% CI) FADS1 activity indices were 15% higher in the ZWB than the ZBB participants, 6.45 (5.84, 7.13) compared with 5.57 (5.05, 6.14), P < 0.05. CONCLUSIONS: These data demonstrate a lack of congruence between the effects of zinc supplements on PZC and EFA metabolism in response to whether a zinc supplement is taken with or without food. Additional research is needed to determine how absorbed zinc may be directed differently toward metabolic processes, when coabsorbed with food. This trial was registered at clinicaltrials.gov as NCT03619421.


Assuntos
Jejum , Zinco , Adulto , Cromatografia Líquida , Suplementos Nutricionais , Ácidos Graxos Essenciais , Humanos , Masculino , Espectrometria de Massas em Tandem
8.
Cancers (Basel) ; 14(1)2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35008187

RESUMO

Chronic lymphocytic leukaemia (CLL) is a heterogeneous disease with a highly variable clinical outcome. There are well-established CLL prognostic biomarkers that have transformed treatment and improved the understanding of CLL biology. Here, we have studied the clinical significance of two crucial B cell regulators, BACH2 (BTB and CNC homology 1, basic leucine zipper transcription factor 2) and BCL6 (B-cell CLL/lymphoma 6), in a cohort of 102 CLL patients and determined the protein interaction networks that they participate in using MEC-1 CLL cells. We observed that CLL patients expressing low levels of BCL6 and BACH2 RNA had significantly shorter overall survival (OS) than high BCL6- and BACH2-expressing cases. Notably, their low expression specifically decreased the OS of immunoglobulin heavy chain variable region-mutated (IGHV-M) CLL patients, as well as those with 11q and 13q deletions. Similar to the RNA data, a low BACH2 protein expression was associated with a significantly shorter OS than a high expression. There was no direct interaction observed between BACH2 and BCL6 in MEC-1 CLL cells, but they shared protein networks that included fifty different proteins. Interestingly, a prognostic index (PI) model that we generated, using integrative risk score values of BACH2 RNA expression, age, and 17p deletion status, predicted patient outcomes in our cohort. Taken together, these data have shown for the first time a possible prognostic role for BACH2 in CLL and have revealed protein interaction networks shared by BCL6 and BACH2, indicating a significant role for BACH2 and BCL6 in key cellular processes, including ubiquitination mediated B-cell receptor functions, nucleic acid metabolism, protein degradation, and homeostasis in CLL biology.

10.
J Nutr ; 147(6): 1200-1207, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28424257

RESUMO

Background: Few studies have examined the impact of local animal-source foods (ASFs) on the nutritional status of reproductive-age women in developing countries.Objective: We hypothesized that a midmorning snack of local ASF for 6 mo would reduce dietary micronutrient deficiencies [usual intake less than the estimated average requirement (EAR)] and improve blood biomarkers of iron, zinc, and vitamins A and B-12 status among nonpregnant, reproductive-age women in rural Vietnam.Methods: One hundred seventeen women, 18-30 y old, were randomly assigned to receive either an ASF (mean: 144 kcal, 8.9 mg Fe, 2.7 mg Zn, 1050 µg retinoic acid equivalent vitamin A, and 5.5 µg vitamin B-12) or a control snack (mean: 150 kcal, 2.0 mg Fe, 0.9 mg Zn, 0 µg retinoic acid equivalent vitamin A, and 0 µg vitamin B-12) 5 d/wk for 6 mo. Usual nutrient intakes were estimated by repeated 24-h dietary recalls. Blood samples were collected at baseline and 3 and 6 mo. Because of the relation between nutritional status and inflammation, serum C-reactive protein, α-1-acid-glycoprotein, and urinary tract infections (UTIs) were also monitored.Results: Eighty-nine women (47 in the ASF group and 42 controls) completed the study. In the ASF group, intakes of iron and vitamins A and B-12 below the EAR were eliminated, and the prevalence of a low zinc intake was reduced to 9.6% compared with 64.7% in controls (P < 0.001). At 6 mo, a modest increase (P < 0.05) in hemoglobin and iron status occurred in the ASF group compared with the control group, but plasma zinc, retinol, and serum vitamin B-12 concentrations did not differ. UTI relative risk was 3.9 (P < 0.05) among women assigned to the ASF group who had a low whole-body iron status at baseline.Conclusions: Adding a small amount of locally produced ASF to the diets of reproductive-age Vietnamese women improved micronutrient intakes and iron status. However, the increased UTI incidence in women in the ASF group with initially lower iron stores warrants further investigation.


Assuntos
Deficiências Nutricionais/dietoterapia , Ovos , Ferro , Carne , Lanches , Vitamina A , Vitamina B 12 , Adolescente , Adulto , Anemia Ferropriva/sangue , Anemia Ferropriva/dietoterapia , Animais , Deficiência de Vitaminas/sangue , Deficiência de Vitaminas/dietoterapia , Deficiências Nutricionais/sangue , Suplementos Nutricionais , Feminino , Hemoglobinas/metabolismo , Humanos , Ferro/administração & dosagem , Ferro/sangue , Deficiências de Ferro , Micronutrientes/administração & dosagem , Micronutrientes/sangue , Micronutrientes/deficiência , Estado Nutricional , População Rural , Vietnã , Vitamina A/administração & dosagem , Vitamina A/sangue , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/dietoterapia , Vitamina B 12/administração & dosagem , Vitamina B 12/sangue , Deficiência de Vitamina B 12/sangue , Deficiência de Vitamina B 12/dietoterapia , Vitaminas/administração & dosagem , Vitaminas/sangue , Adulto Jovem , Zinco/administração & dosagem , Zinco/sangue , Zinco/deficiência
11.
Nat Commun ; 8: 14175, 2017 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-28165464

RESUMO

Several chronic lymphocytic leukaemia (CLL) susceptibility loci have been reported; however, much of the heritable risk remains unidentified. Here we perform a meta-analysis of six genome-wide association studies, imputed using a merged reference panel of 1,000 Genomes and UK10K data, totalling 6,200 cases and 17,598 controls after replication. We identify nine risk loci at 1p36.11 (rs34676223, P=5.04 × 10-13), 1q42.13 (rs41271473, P=1.06 × 10-10), 4q24 (rs71597109, P=1.37 × 10-10), 4q35.1 (rs57214277, P=3.69 × 10-8), 6p21.31 (rs3800461, P=1.97 × 10-8), 11q23.2 (rs61904987, P=2.64 × 10-11), 18q21.1 (rs1036935, P=3.27 × 10-8), 19p13.3 (rs7254272, P=4.67 × 10-8) and 22q13.33 (rs140522, P=2.70 × 10-9). These new and established risk loci map to areas of active chromatin and show an over-representation of transcription factor binding for the key determinants of B-cell development and immune response.


Assuntos
Formação de Anticorpos/genética , Cromossomos Humanos/genética , Predisposição Genética para Doença , Leucemia Linfocítica Crônica de Células B/genética , Adulto , Linfócitos B/imunologia , Linfócitos B/fisiologia , Estudos de Casos e Controles , Mapeamento Cromossômico , Feminino , Estudo de Associação Genômica Ampla , Humanos , Leucemia Linfocítica Crônica de Células B/imunologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Adulto Jovem
12.
J Nutr ; 146(9): 1783-92, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27466608

RESUMO

BACKGROUND: Provitamin A carotenoid-biofortified maize is a conventionally bred staple crop designed to help prevent vitamin A deficiency. Lactating women are a potential target group, because regularly eating biofortified maize may increase vitamin A in breast milk-a critical source of vitamin A for breastfeeding infants. OBJECTIVE: We assessed whether daily consumption of biofortified orange maize would increase the retinol concentration in the breast milk of Zambian women. METHODS: Lactating women (n = 149) were randomly assigned to receive orange maize delivering 600 µg retinol equivalents (REs)/d as carotenoid plus placebo (OM), low-carotenoid white maize plus 600 µg REs/d as retinyl palmitate (VA), or white maize plus placebo (WM). Boiled maize (287 g dry weight/d) was served as 2 meals/d, 6 d/wk for 3 wk. We measured initial and final breast milk plasma retinol and ß-carotene concentrations, and plasma inflammatory protein concentrations. RESULTS: Groups were comparable at enrollment, with an overall geometric mean milk retinol concentration of 0.95 µmol/L (95% CI: 0.86, 1.05 µmol/L); 56% of samples had milk retinol <1.05 µmol/L. Median capsule and maize intake was 97% and 258 g dry weight/d, respectively. Final milk ß-carotene did not vary across groups (P = 0.76). Geometric mean (95% CI) milk retinol concentration tended to be higher in the OM [1.15 µmol/L (0.96, 1.39 µmol/L)] and VA [1.17 µmol/L (0.99, 1.38 µmol/L)] groups than in the WM group [0.91 µmol/L (0.72, 1.14 µmol/L); P = 0.13], and the proportion of women with milk retinol <1.05 µmol/L was 52.1%, 42.9%, and 36.7% in the WM, OM, and VA groups, respectively (P-trend = 0.16). CONCLUSIONS: Daily biofortified maize consumption did not increase mean milk retinol concentration in lactating Zambian women; however, there was a plausible downward trend in the risk of low milk retinol across intervention groups. This trial was registered at clinicaltrials.gov as NCT01922713.


Assuntos
Alimentos Fortificados , Leite Humano/química , Provitaminas/administração & dosagem , Vitamina A/administração & dosagem , Vitamina A/química , Zea mays/química , Adulto , Índice de Massa Corporal , Diterpenos , Feminino , Hemoglobinas/metabolismo , Humanos , Lactação , Estado Nutricional , Provitaminas/sangue , Ésteres de Retinil , Resultado do Tratamento , Vitamina A/análogos & derivados , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/prevenção & controle , Adulto Jovem , Zâmbia
13.
Cell Cycle ; 14(22): 3602-12, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26506264

RESUMO

p21(WAF1) is a well-characterized mediator of cell cycle arrest and may also modulate chemotherapy-induced cell death. The role of p21(WAF1) in drug-induced cell cycle arrest and apoptosis of acute lymphoblastic leukemia (ALL) cells was investigated using p53-functional patient-derived xenografts (PDXs), in which p21(WAF1) was epigenetically silenced in T-cell ALL (T-ALL), but not in B-cell precursor (BCP)-ALL PDXs. Upon exposure to diverse cytotoxic drugs, T-ALL PDX cells exhibited markedly increased caspase-3/7 activity and phosphatidylserine (PS) externalization on the plasma membrane compared with BCP-ALL cells. Despite dramatic differences in apoptotic characteristics between T-ALL and BCP-ALL PDXs, both ALL subtypes exhibited similar cell death kinetics and were equally sensitive to p53-inducing drugs in vitro, although T-ALL PDXs were significantly more sensitive to the histone deacetylase inhibitor vorinostat. Transient siRNA suppression of p21(WAF1) in the BCP-ALL 697 cell line resulted in a moderate depletion of the cell fraction in G1 phase and marked increase in PS externalization following exposure to etoposide. Furthermore, stable lentiviral p21(WAF1) silencing in the BCP-ALL Nalm-6 cell line accelerated PS externalization and cell death following exposure to etoposide and vorinostat, supporting previous findings. Finally, the Sp1 inhibitor, terameprocol, inhibited p21(WAF1) expression in Nalm-6 cells exposed to vorinostat and also partially augmented vorinostat-induced cell death. Taken together, these findings demonstrate that p21(WAF1) regulates the early stages of drug-induced apoptosis in ALL cells and significantly modulates their sensitivity to vorinostat.


Assuntos
Linfócitos B/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação Leucêmica da Expressão Gênica , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Linfócitos B/metabolismo , Linfócitos B/patologia , Caspase 3/genética , Caspase 3/metabolismo , Caspase 7/genética , Caspase 7/metabolismo , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/antagonistas & inibidores , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Etoposídeo/farmacologia , Humanos , Masoprocol/análogos & derivados , Masoprocol/farmacologia , Fosfatidilserinas/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Fator de Transcrição Sp1/antagonistas & inibidores , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Linfócitos T/patologia , Transcrição Gênica , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Vorinostat
14.
Br J Haematol ; 171(4): 595-605, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26310606

RESUMO

Glucocorticoid (GC) resistance is a continuing clinical problem in childhood acute lymphoblastic leukaemia (ALL) but the underlying mechanisms remain unclear. A proteomic approach was used to compare profiles of the B-lineage ALL GC-sensitive cell line, PreB 697, and its GC-resistant sub-line, R3F9, pre- and post-dexamethasone exposure. PAX5, a transcription factor critical to B-cell development was differentially regulated in the PreB 697 compared to the R3F9 cell line in response to GC. PAX5 basal protein expression was less in R3F9 compared to its GC-sensitive parent and confirmed to be lower in other GC-resistant sub-lines of Pre B 697 and was associated with a decreased expression of the PAX5 transcriptional target, CD19. Gene set enrichment analysis showed that increasing GC-resistance was associated with differentiation from preB-II to an immature B-lymphocyte stage. GC-resistant sub-lines were shown to have higher levels of phosphorylated JNK compared to the parent line and JNK inhibition caused re-sensitization to GC. Exploiting this maturation may be key to overcoming GC resistance and targeting signalling pathways linked to the maturation state, such as JNK, may be a novel approach.


Assuntos
Antineoplásicos/farmacologia , Linfócitos B/efeitos dos fármacos , Dexametasona/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , MAP Quinase Quinase 4/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Neoplasias/biossíntese , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteômica/métodos , Apoptose/efeitos dos fármacos , Linfócitos B/patologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/fisiologia , Éxons/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Reação em Cadeia da Polimerase Multiplex , Mutação , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/fisiologia , Fosforilação/efeitos dos fármacos , Leucemia-Linfoma Linfoblástico de Células Precursoras B/enzimologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real , Espectrometria de Massas em Tandem
15.
JMIR Res Protoc ; 4(2): e40, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25854293

RESUMO

BACKGROUND: The prevalence of long-term or chronic conditions that limit activity and reduce quality of life in young people aged 10-24 years is rising. This group has distinct health care needs and requires tailored support strategies to facilitate increasing personal responsibility for the management of their condition wherever possible, as they mature. Mobile phone and tablet mobile technologies featuring software program apps are already well used by young people for social networking or gaming. They have also been utilized in health care to support personal condition management, using condition-specific and patient-tailored software. Such apps have much potential, and there is an emerging body of literature on their use in a health context making this review timely. OBJECTIVE: The objective of this paper is to develop a systematic review protocol focused on identifying and assessing the effectiveness of mobile phone and tablet apps that support young people's management of their chronic conditions. METHODS: The search strategy will include a combination of standardized indexed search terms and free-text terms related to the key concepts of young people; long-term conditions and mobile technology. Peer-reviewed journal articles published from 2003 that meet the inclusion and exclusion criteria will be identified through searching the generated hits from 5 bibliographical databases. Two independent reviewers will screen the titles and abstracts to determine which articles focus on testing interventions identified as a mobile phone or tablet apps, and that have been designed and delivered to support the management of long-term conditions in young people aged 10-24 years. Data extraction and quality assessment tools will be used to facilitate consistent analysis and synthesis. It is anticipated that several studies will meet the selection criteria but that these are likely to be heterogeneous in terms of study design, reported outcomes, follow-up times, participants' age, and health condition. Sub-group analyses will be undertaken and where possible meta-analyses will take place. RESULTS: This review will synthesize available knowledge surrounding tablet and mobile phone apps that support management of long term physical health conditions in young people. The findings will be synthesized to determine which elements of the technologies were most effective for this population. CONCLUSIONS: This systematic review aims to synthesize existing literature in order to generate findings that will facilitate the development of an app intervention. The review will form the first phase of development and evaluation of a complex intervention as recommended by the United Kingdom Medical Research Council. The knowledge gained from the review will be verified in subsequent phases, which will include primary qualitative work with health professionals and young people with long term conditions as research participants. Young people living with long-term conditions will be involved as co-researchers and consumer advisors in all subsequent phases to develop and evaluate an app to support the management of long-term physical health conditions. TRIAL REGISTRATION: PROSPERO International prospective register of systematic reviews: CRD42014015418; http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42014015418#.VRqCpTpnL8E (Archived by Webcite at http://www.webcitation.org/6XREcWqQY).

16.
JMIR Res Protoc ; 3(4): e69, 2014 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-25472567

RESUMO

BACKGROUND: Families living with chronic or long-term conditions such as chronic kidney disease (CKD), stages 3-5, face multiple challenges and respond to these challenges in various ways. Some families adapt well while others struggle, and family response to a condition is closely related to outcome. With families and professionals, we developed a novel condition-specific interactive health communication app to improve parents' management ability-the online parent information and support (OPIS) program. OPIS consists of a comprehensive mix of clinical caregiving and psychosocial information and support. OBJECTIVE: The purpose of this study was to (1) assess feasibility of a future full-scale randomized controlled trial (RCT) of OPIS in terms of recruitment and retention, data collection procedures, and psychometric performance of the study measures in the target population, and (2) investigate trends in change in outcome measures in a small-scale RCT in parents of children with CKD stages 3-5. METHODS: Parents were recruited from a pediatric nephrology clinic and randomly assigned to one of two treatment groups: usual support for home-based clinical caregiving (control) or usual support plus password-protected access to OPIS for 20 weeks (intervention). Both groups completed study measures at study entry and exit. We assessed feasibility descriptively in terms of recruitment and retention rates overall; assessed recruitment, retention, and uptake of the intervention between groups; and compared family condition management, empowerment to deliver care, and fathers' involvement between groups. RESULTS: We recruited 55 parents of 39 children (42% of eligible families). Of those, about three-quarters of intervention group parents (19/26, 73%) and control group parents (22/29, 76%) were retained through completion of 20-week data collection. The overall retention rate was 41/55 (75%). The 41 parents completing the trial were asked to respond to the same 10 questionnaire scales at both baseline and 20 weeks later; 10 scores were missing at baseline and nine were missing at 20 weeks. Site user statistics provided evidence that all intervention group parents accessed OPIS. Analysis found that intervention group parents showed a greater improvement in perceived competence to manage their child's condition compared to control group parents: adjusted mean Family Management Measure (FaMM) Condition Management Ability Scale intervention group 44.5 versus control group 41.9, difference 2.6, 95% CI -1.6 to 6.7. Differences between the groups in the FaMM Family Life Difficulty Scale (39.9 vs 36.3, difference 3.7, 95% CI -4.9 to 12.2) appeared to agree with a qualitative observation that OPIS helped parents achieve understanding and maintain awareness of the impact of their child's condition. CONCLUSIONS: A full-scale RCT of the effectiveness of OPIS is feasible. OPIS has the potential to beneficially affect self-reported outcomes, including parents' perceived competence to manage home-based clinical care for children with CKD stage 3-5. Our design and methodology can be transferred to the management of other childhood conditions. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN): 84283190; http://www.controlled-trials.com/ISRCTN84283190 (Archived by WebCite at http://www.webcitation.org/6TuPdrXTF).

17.
BMC Nephrol ; 15: 34, 2014 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-24548640

RESUMO

BACKGROUND: There is a lack of online, evidence-based information and resources to support home-based care of childhood CKD stages 3-5. METHODS: Qualitative interviews were undertaken with parents, patients and professionals to explore their views on content of the proposed online parent information and support (OPIS) web-application. Data were analysed using Framework Analysis, guided by the concept of Self-efficacy. RESULTS: 32 parents, 26 patients and 12 professionals were interviewed. All groups wanted an application that explains, demonstrates, and enables parental clinical care-giving, with condition-specific, continously available, reliable, accessible material and a closed communication system to enable contact between families living with CKD. Professionals advocated a regularly updated application to empower parents to make informed health-care decisions. To address these requirements, key web-application components were defined as: (i) Clinical care-giving support (information on treatment regimens, video-learning tools, condition-specific cartoons/puzzles, and a question and answer area) and (ii) Psychosocial support for care-giving (social-networking, case studies, managing stress, and enhancing families' health-care experiences). CONCLUSIONS: Developing a web-application that meets parents' information and support needs will maximise its utility, thereby augmenting parents' self-efficacy for CKD caregiving, and optimising outcomes. Self-efficacy theory provides a schema for how parents' self-efficacy beliefs about management of their child's CKD could potentially be promoted by OPIS.


Assuntos
Atitude do Pessoal de Saúde , Comportamento do Consumidor , Serviços de Assistência Domiciliar/organização & administração , Internet , Avaliação das Necessidades , Insuficiência Renal Crônica/terapia , Software , Cuidadores , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Design de Software , Terapia Assistida por Computador/métodos , Reino Unido
18.
Nat Genet ; 46(1): 56-60, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24292274

RESUMO

Genome-wide association studies (GWAS) of chronic lymphocytic leukemia (CLL) have shown that common genetic variation contributes to the heritable risk of CLL. To identify additional CLL susceptibility loci, we conducted a GWAS and performed a meta-analysis with a published GWAS totaling 1,739 individuals with CLL (cases) and 5,199 controls with validation in an additional 1,144 cases and 3,151 controls. A combined analysis identified new susceptibility loci mapping to 3q26.2 (rs10936599, P = 1.74 × 10(-9)), 4q26 (rs6858698, P = 3.07 × 10(-9)), 6q25.2 (IPCEF1, rs2236256, P = 1.50 × 10(-10)) and 7q31.33 (POT1, rs17246404, P = 3.40 × 10(-8)). Additionally, we identified a promising association at 5p15.33 (CLPTM1L, rs31490, P = 1.72 × 10(-7)) and validated recently reported putative associations at 5p15.33 (TERT, rs10069690, P = 1.12 × 10(-10)) and 8q22.3 (rs2511714, P = 2.90 × 10(-9)). These findings provide further insights into the genetic and biological basis of inherited genetic susceptibility to CLL.


Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Leucemia Linfocítica Crônica de Células B/genética , Polimorfismo de Nucleotídeo Único , Idoso , Estudos de Casos e Controles , Cromossomos Humanos Par 3 , Humanos , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Recombinação Genética , Complexo Shelterina , Proteínas de Ligação a Telômeros/genética
19.
Nat Med ; 19(8): 1014-22, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23852341

RESUMO

The B cell-specific transcription factor BACH2 is required for affinity maturation of B cells. Here we show that Bach2-mediated activation of p53 is required for stringent elimination of pre-B cells that failed to productively rearrange immunoglobulin VH-DJH gene segments. After productive VH-DJH gene rearrangement, pre-B cell receptor signaling ends BACH2-mediated negative selection through B cell lymphoma 6 (BCL6)-mediated repression of p53. In patients with pre-B acute lymphoblastic leukemia, the BACH2-mediated checkpoint control is compromised by deletions, rare somatic mutations and loss of its upstream activator, PAX5. Low levels of BACH2 expression in these patients represent a strong independent predictor of poor clinical outcome. In this study, we demonstrate that Bach2(+/+) pre-B cells resist leukemic transformation by Myc through Bach2-dependent upregulation of p53 and do not initiate fatal leukemia in transplant-recipient mice. Chromatin immunoprecipitation sequencing and gene expression analyses carried out by us revealed that BACH2 competes with BCL6 for promoter binding and reverses BCL6-mediated repression of p53 and other cell cycle checkpoint-control genes. These findings identify BACH2 as a crucial mediator of negative selection at the pre-B cell receptor checkpoint and a safeguard against leukemogenesis.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Receptores de Células Precursoras de Linfócitos B/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina Básica/genética , Morte Celular , Diferenciação Celular/genética , Sobrevivência Celular/genética , Transformação Celular Neoplásica/patologia , Proteínas de Ligação a DNA/metabolismo , Deleção de Genes , Regulação Leucêmica da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , Cadeias mu de Imunoglobulina/metabolismo , Camundongos , Dados de Sequência Molecular , Fator de Transcrição PAX5/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Células Precursoras de Linfócitos B/metabolismo , Células Precursoras de Linfócitos B/patologia , Proteínas Proto-Oncogênicas c-bcl-6 , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT5/metabolismo , Resultado do Tratamento , Recombinação V(D)J/genética
20.
EMBO Mol Med ; 5(1): 38-51, 2013 01.
Artigo em Inglês | MEDLINE | ID: mdl-23229821

RESUMO

Leukaemia-propagating cells are more frequent in high-risk acute B lymphoblastic leukaemia than in many malignancies that follow a hierarchical cancer stem cell model. It is unclear whether this characteristic can be more universally applied to patients from non-'high-risk' sub-groups and across a broad range of cellular immunophenotypes. Here, we demonstrate in a wide range of primary patient samples and patient samples previously passaged through mice that leukaemia-propagating cells are found in all populations defined by high or low expression of the lymphoid differentiation markers CD10, CD20 or CD34. The frequency of leukaemia-propagating cells and their engraftment kinetics do not differ between these populations. Transcriptomic analysis of CD34(high) and CD34(low) blasts establishes their difference and their similarity to comparable normal progenitors at different stages of B-cell development. However, consistent with the functional similarity of these populations, expression signatures characteristic of leukaemia propagating cells in acute myeloid leukaemia fail to distinguish between the different populations. Together, these findings suggest that there is no stem cell hierarchy in acute B lymphoblastic leukaemia.


Assuntos
Células-Tronco Neoplásicas/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Animais , Antígenos CD34/metabolismo , Diferenciação Celular , Redes Reguladoras de Genes , Humanos , Imunofenotipagem , Camundongos , Modelos Biológicos , Transplante de Neoplasias , Células-Tronco Neoplásicas/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/imunologia , Transcriptoma , Transplante Heterólogo
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