Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 17(1): e0261109, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35025919

RESUMO

A primary criticism of organic agriculture is its lower yield and nutritional quality compared to conventional systems. Nutritionally, dry pea (Pisum sativum L.) is a rich source of low digestible carbohydrates, protein, and micronutrients. This study aimed to evaluate dry pea cultivars and advanced breeding lines using on-farm field selections to inform the development of biofortified organic cultivars with increased yield and nutritional quality. A total of 44 dry pea entries were grown in two USDA-certified organic on-farm locations in South Carolina (SC), United States of America (USA) for two years. Seed yield and protein for dry pea ranged from 61 to 3833 kg ha-1 and 12.6 to 34.2 g/100 g, respectively, with low heritability estimates. Total prebiotic carbohydrate concentration ranged from 14.7 to 26.6 g/100 g. A 100-g serving of organic dry pea provides 73.5 to 133% of the recommended daily allowance (%RDA) of prebiotic carbohydrates. Heritability estimates for individual prebiotic carbohydrates ranged from 0.27 to 0.82. Organic dry peas are rich in minerals [iron (Fe): 1.9-26.2 mg/100 g; zinc (Zn): 1.1-7.5 mg/100 g] and have low to moderate concentrations of phytic acid (PA:18.8-516 mg/100 g). The significant cultivar, location, and year effects were evident for grain yield, thousand seed weight (1000-seed weight), and protein, but results for other nutritional traits varied with genotype, environment, and interactions. "AAC Carver," "Jetset," and "Mystique" were the best-adapted cultivars with high yield, and "CDC Striker," "Fiddle," and "Hampton" had the highest protein concentration. These cultivars are the best performing cultivars that should be incorporated into organic dry pea breeding programs to develop cultivars suitable for organic production. In conclusion, organic dry pea has potential as a winter cash crop in southern climates. Still, it will require selecting diverse genetic material and location sourcing to develop improved cultivars with a higher yield, disease resistance, and nutritional quality.


Assuntos
Biofortificação , Valor Nutritivo , Pisum sativum/metabolismo , Genótipo , Humanos , Minerais/análise , Pisum sativum/genética , Pisum sativum/crescimento & desenvolvimento , Ácido Fítico/análise , Melhoramento Vegetal , Prebióticos/análise , Amido/análise
2.
Front Plant Sci ; 10: 1489, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31803218

RESUMO

Investigations regarding the incorporation of better sustainable production strategies into current agricultural-food systems are necessary to grow crops that reduce negative impacts on the environment yet will meet the production and nutritional demand of 10 billion people by 2050. The introduction of organic, alternative staple food crops, such as nutrient-dense field pea (Pisum sativum L.), to the everyday diet, may alleviate micronutrient malnutrition and incorporate more sustainable agriculture practices globally. Varieties are grown in organic systems currently yield less than conventionally produced foods, with less bioavailable nutrients, due to poor soil nutrient content. One of the most limiting nutrients for field pea is phosphorus (P) because this legume crop requires significant inputs for nodule formation. Therefore, P use efficiency (PUE) should be a breeding target for sustainable agriculture and biofortification efforts; the important role of the soil microbiome in nutrient acquisition should also be examined. The objectives of this review are to highlight the benefits of field pea for organic agriculture and human health, and discuss nutritional breeding strategies to increase field pea production in organic systems. Field pea and other pulse crops are underrepresented in agricultural research, yet are important crops for a sustainable future and better food systems. Furthermore, because field pea is consumed globally by both developed and at-risk populations, research efforts could help increase global health overall and combat micronutrient malnutrition.

3.
Cell Rep ; 24(9): 2443-2456, 2018 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-30157436

RESUMO

Expression of vast repertoires of antigen receptors by lymphocytes, with each cell expressing a single receptor, requires stochastic activation of individual variable (V) genes for transcription and recombination. How this occurs remains unknown. Using single-cell RNA sequencing (scRNA-seq) and allelic variation, we show that individual pre-B cells monoallelically transcribe divergent arrays of Vκ genes, thereby opening stochastic repertoires for subsequent Vκ-Jκ recombination. Transcription occurs upon translocation of Vκ genes to RNA polymerase II arrayed on the nuclear matrix in transcription factories. Transcription is anchored by CTCF-bound sites or E2A-loaded Vκ promotors and continues over large genomic distances delimited only by topological associating domains (TADs). Prior to their monoallelic activation, Vκ loci are transcriptionally repressed by cyclin D3, which prevents capture of Vκ gene containing TADs by transcription factories. Cyclin D3 also represses protocadherin, olfactory, and other monoallelically expressed genes, suggesting a widely deployed mechanism for coupling monoallelic gene activation with cell cycle exit.


Assuntos
Região Variável de Imunoglobulina/genética , Transcrição Gênica/genética , Animais , Humanos
4.
J Pediatr Adolesc Gynecol ; 28(1): 43-46, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25555300

RESUMO

OBJECTIVE: The purpose of this study is to identify trends in the clinical workup, diagnosis, and treatment of polycystic ovary syndrome by pediatric endocrinologists, pediatric gynecologists, and adolescent medicine specialists. DESIGN: Retrospective chart review. SETTING: Tertiary care medical center. PARTICIPANTS: Females aged 11-18 y who were evaluated for PCOS from June 2009 to October 2011 were included. Any patients with coexisting diagnoses of other primary etiology for amenorrhea were excluded. Patients were identified by ICD-9 codes for PCOS, hypersecretion of ovarian androgens, irregular menses, hirsutism, oligomenorrhea, or amenorrhea. 261 patients were included: 144 from endocrinology, 9 from gynecology, and 108 from adolescent pediatric practices. RESULTS: There were no significant differences in the androgen labs ordered by the subspecialties. Gynecologists ordered pelvic ultrasonography for 89% (n = 8) of patients, compared to 9% (n = 10) by adolescent medicine specialists and 24% (n = 34) by endocrinologists (P < .0001). Endocrinologists were most likely to treat patients who met diagnostic criteria for PCOS with metformin (58%, n = 66), compared to gynecologists (14%, n = 1) and adolescent medicine specialists (5%, n = 3) (P < .0001). Gynecologists (43%, n = 3) and adolescent medicine specialists (58%, n = 39) were more likely than endocrinologists (24%, n = 27) to treat patients with oral contraceptive pills (P < .0001). CONCLUSIONS: Inconsistent diagnosis and treatment strategies for young women with PCOS are evident among pediatric subspecialties, reflecting lack of standardized care for adolescents. Quantifying outcomes based on diagnostic and therapeutic approaches are important next steps.


Assuntos
Medicina do Adolescente/métodos , Endocrinologia/métodos , Ginecologia/métodos , Pediatria/métodos , Síndrome do Ovário Policístico/diagnóstico , Padrões de Prática Médica/tendências , Adolescente , Androgênios/metabolismo , Criança , Anticoncepcionais Orais/uso terapêutico , Feminino , Hirsutismo/etiologia , Humanos , Hipoglicemiantes/uso terapêutico , Distúrbios Menstruais/etiologia , Metformina/uso terapêutico , Síndrome do Ovário Policístico/complicações , Síndrome do Ovário Policístico/tratamento farmacológico , Estudos Retrospectivos , Adulto Jovem
5.
J Exp Med ; 209(12): 2199-213, 2012 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-23109711

RESUMO

Ubiquitously expressed D-type cyclins are required for hematopoiesis but are dispensable in other cell lineages. Furthermore, within different hematopoietic progenitor populations the D-type cyclins play nonredundant roles. The basis of this lineage and developmental specificity is unknown. In pro-B cells we demonstrate four distinct nuclear D-type cyclin compartments, including one cyclin D3 fraction associated with CDK4 and another phosphoinositide 3-kinase-regulated fraction not required for proliferation. A third fraction of cyclin D3 was associated with the nuclear matrix and repression of >200 genes including the variable (V) gene segments Igkv1-117, Iglv1, and Igh-VJ558. Consistent with different subnuclear compartments and functions, distinct domains of cyclin D3 mediated proliferation and Igk V gene segment repression. None of the cyclin D3 nuclear compartments overlapped with cyclin D2, which was distributed, unbound to CDK4, throughout the nucleus. Furthermore, compartmentalization of the cyclins appeared to be lineage restricted because in fibroblasts, cyclin D2 and cyclin D3 occupied a single nuclear compartment and neither bound CDK4 efficiently. These data suggest that subnuclear compartmentalization enables cyclin D3 to drive cell cycle progression and repress V gene accessibility, thereby ensuring coordination of proliferation with immunoglobulin recombination.


Assuntos
Ciclo Celular/fisiologia , Núcleo Celular/metabolismo , Proliferação de Células , Ciclina D3/metabolismo , Regulação da Expressão Gênica/imunologia , Região Variável de Imunoglobulina/metabolismo , Células Precursoras de Linfócitos B/metabolismo , Animais , Células Cultivadas , Ciclina D3/genética , Quinase 4 Dependente de Ciclina/metabolismo , Primers do DNA/genética , Proteínas de Ligação a DNA/genética , Citometria de Fluxo , Immunoblotting , Região Variável de Imunoglobulina/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise em Microsséries , Microscopia Confocal , Análise de Sequência de DNA
6.
Nat Immunol ; 12(12): 1212-20, 2011 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-22037603

RESUMO

During B lymphopoiesis, recombination of the locus encoding the immunoglobulin κ-chain complex (Igk) requires expression of the precursor to the B cell antigen receptor (pre-BCR) and escape from signaling via the interleukin 7 receptor (IL-7R). By activating the transcription factor STAT5, IL-7R signaling maintains proliferation and represses Igk germline transcription by unknown mechanisms. We demonstrate that a STAT5 tetramer bound the Igk intronic enhancer (E(κi)), which led to recruitment of the histone methyltransferase Ezh2. Ezh2 marked trimethylation of histone H3 at Lys27 (H3K27me3) throughout the κ-chain joining region (J(κ)) to the κ-chain constant region (C(κ)). In the absence of Ezh2, IL-7 failed to repress Igk germline transcription. H3K27me3 modifications were lost after termination of IL-7R-STAT5 signaling, and the transcription factor E2A bound E(κi), which resulted in acquisition of H3K4me1 and acetylated histone H4 (H4Ac). Genome-wide analyses showed a STAT5 tetrameric binding motif associated with transcriptional repression. Our data demonstrate how IL-7R signaling represses Igk germline transcription and provide a general model for STAT5-mediated epigenetic transcriptional repression.


Assuntos
Epigênese Genética , Histona-Lisina N-Metiltransferase/metabolismo , Imunoglobulinas/genética , Fator de Transcrição STAT5/metabolismo , Animais , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sítios de Ligação/genética , Ligação Competitiva , Células COS , Chlorocebus aethiops , Análise por Conglomerados , Proteína Potenciadora do Homólogo 2 de Zeste , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Histonas/metabolismo , Metilação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complexo Repressor Polycomb 2 , Ligação Proteica , Receptores de Interleucina-7/metabolismo , Transdução de Sinais
7.
Mol Immunol ; 48(11): 1281-6, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21144589

RESUMO

Signals through the B cell antigen receptor (BCR) are necessary but not sufficient for cellular activation. Co-stimulatory signals must be provided through other immune recognition receptor systems, such as MHC class II/CD40 and the toll-like receptor (TLR) 9 that can only productively acquire their ligands in the processive environment of specialized late endosomes (MHC class II containing compartment or MIIC). It has long been appreciated that the BCR, by effectively capturing complex antigens and delivering them to late endosomes, is the link between activation events on the cell surface and those dependent on late endosomes. However, it has become increasingly apparent that the BCR also directs the translocation of MHC class II and TLR9 into the MIIC and that the endocytic flow of these receptors coincides with that of the BCR. This likely ensures close apposition of receptor complexes within the MIIC and the efficient transfer of ligands from the BCR to MHC class II and TLR9. This complex orchestration of receptor endocytic movement is dependent upon the quality of signals elicited through the BCR. Failure to activate specific signaling pathways, such as occurs in anergic B cells, prevents the entry of the BCR and TLR9 into the MIIC and abrogates TLR9 activation. Like anergy, this block in endocytic trafficking is rapidly reversible. These findings indicate that cellular responsiveness can be determined by mechanisms that control the subcellular location of important immune recognition receptors.


Assuntos
Linfócitos B/imunologia , Anergia Clonal/imunologia , Espaço Intracelular/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Animais , Antígenos CD40/imunologia , Endocitose/imunologia , Endossomos/imunologia , Genes MHC da Classe II/imunologia , Humanos , Camundongos , Receptor Toll-Like 9/imunologia , Ubiquitinação/imunologia
8.
Nat Immunol ; 10(10): 1110-7, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19734904

RESUMO

Signals through the pre-B cell antigen receptor (pre-BCR) and interleukin 7 receptor (IL-7R) coordinate pre-B cell population expansion with subsequent recombination of the locus encoding immunoglobulin kappa-chain (Igk). Although many 'downstream' effectors of each receptor are known, how they integrate to mediate development has remained unclear. Here we report that pre-BCR-mediated activation of the Ras-MEK-Erk signaling pathway silenced transcription of Ccnd3 (encoding cyclin D3) and coordinated exit from the cell cycle with induction of the transcription factor E2A and the initiation of Igk recombination. IL-7R-mediated activation of the transcription factor STAT5 opposed this pathway by promoting Ccnd3 expression and concomitantly inhibiting Igk transcription by binding to the Igk intronic enhancer and preventing E2A recruitment. Our data show how pre-BCR signaling poises pre-B cells to undergo differentiation after escape from IL-7R signaling.


Assuntos
Linfócitos B/citologia , Ciclo Celular/imunologia , Diferenciação Celular/imunologia , Cadeias Leves de Imunoglobulina/genética , Transdução de Sinais/imunologia , Proteínas ras/imunologia , Animais , Linfócitos B/imunologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/imunologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Ciclo Celular/genética , Ciclina D3 , Ciclinas/imunologia , Ciclinas/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , MAP Quinases Reguladas por Sinal Extracelular/imunologia , Citometria de Fluxo , Regulação da Expressão Gênica/imunologia , Inativação Gênica/imunologia , Immunoblotting , MAP Quinase Quinase Quinases/imunologia , Camundongos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Receptores de Interleucina-7/imunologia , Receptores de Interleucina-7/metabolismo , Recombinação Genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT5/imunologia , Fator de Transcrição STAT5/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
9.
Nat Immunol ; 7(5): 489-97, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16582912

RESUMO

During hematopoiesis, stem cell proliferation is dependent on expression of the D-type cyclins. However, little is known about how each cyclin D contributes to the development of specific hematopoietic lineages. Here, analysis of Ccnd1(-/-), Ccnd2(-/-), Ccnd3(-/-) and Ccnd2(-/-)Ccnd3(-/-) mice showed that cyclin D3 was uniquely required for the development of pre-B cells. Transcription of Ccnd3 was dependent on expression of the common gamma-chain. In contrast, expression of the pre-B cell receptor and activation of 'downstream' signaling pathways prevented proteasome-mediated degradation of cyclin D3. Cyclin D3 has a key function in B cell development by integrating cytokine and pre-B cell receptor-dependent signals to expand the pool of pre-B cells that have successfully rearranged immunoglobulin heavy chain.


Assuntos
Linfócitos B/imunologia , Diferenciação Celular/imunologia , Ciclinas/fisiologia , Animais , Linfócitos B/citologia , Linhagem Celular , Ciclina D3 , Ciclinas/genética , Camundongos , Camundongos Knockout , Reação em Cadeia da Polimerase
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...