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1.
bioRxiv ; 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36993264

RESUMO

Environmental influences on immune phenotypes are well-documented, but our understanding of which elements of the environment affect immune systems, and how, remains vague. Behaviors, including socializing with others, are central to an individual's interaction with its environment. We tracked behavior of rewilded laboratory mice of three inbred strains in outdoor enclosures and examined contributions of behavior, including social associations, to immune phenotypes. We found that the more associated two individuals were, the more similar their immune phenotypes were. Social association was particularly predictive of similar memory T and B cell profiles and was more influential than sibling relationships or worm infection status. These results highlight the importance of social networks for immune phenotype and reveal important immunological correlates of social life.

2.
Plant J ; 115(1): 220-235, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36999611

RESUMO

PROTEIN l-ISOASPARTYL O-METHYLTRANSFERASE (PIMT) affects seed vigor by repairing damaged proteins. While PIMT is capable of isoaspartyl (isoAsp) repair in all proteins, those proteins most susceptible to isoAsp formation have not been well characterized, and the mechanisms by which PIMT affects seed vigor remain largely unknown. Using co-immunoprecipitation and LC-MS/MS, we found that maize (Zea mays) PIMT2 (ZmPIMT2) interacted predominantly with both subunits of maize 3-METHYLCROTONYL COA CARBOXYLASE (ZmMCC). ZmPIMT2 is specifically expressed in the maize embryo. Both mRNA and protein levels of ZmPIMT2 increased during seed maturation and declined during imbibition. Maize seed vigor was decreased in the zmpimt2 mutant line, while overexpression of ZmPIMT2 in maize and Arabidopsis thaliana increased seed vigor upon artificial aging. ZmPIMT2 was localized in the mitochondria, as determined by subcellular localization assays using maize protoplasts. ZmPIMT2 binding to ZmMCCα was confirmed by luciferase complementation tests in both tobacco (Nicotiana benthamiana) leaves and maize protoplasts. Knockdown of ZmMCCα decreased maize seed aging tolerance. Furthermore, overexpression of ZmPIMT2 decreased the accumulation of isoAsp of ZmMCCα protein in seed embryos that underwent accelerated aging treatment. Taken together, our results demonstrate that ZmPIMT2 binds ZmMCCα in mitochondria, repairs isoAsp damage, and positively affects maize seed vigor.


Assuntos
Arabidopsis , Zea mays , Zea mays/genética , Cromatografia Líquida , Espectrometria de Massas em Tandem , Arabidopsis/metabolismo , Mitocôndrias , Sementes/genética , Sementes/metabolismo
3.
Plant J ; 114(1): 55-67, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36703577

RESUMO

Drought stress is one of the major constraints of global crop production. Raffinose, a non-reducing trisaccharide, has been considered to regulate positively the plant drought stress tolerance; however, evidence that augmenting raffinose production in leaves results in enhanced plant drought stress tolerance is lacking. The biochemical mechanism through which raffinose might act to mitigate plant drought stress remains unidentified. ZmRAFS encodes Zea mays RAFFINOSE SYNTHASE, a key enzyme that transfers galactose from the galactoside galactinol to sucrose for raffinose production. Overexpression of ZmRAFS in maize increased the RAFS protein and the raffinose content and decreased the water loss of leaves and enhanced plant drought stress tolerance. The biomass of the ZmRAFS overexpressing plants was similar to that of non-transgenic control plants when grown under optimal conditions, but was significantly greater than that of non-transgenic plants when grown under drought stress conditions. In contrast, the percentage of water loss of the detached leaves from two independent zmrafs mutant lines, incapable of synthesizing raffinose, was greater than that from null segregant controls and this phenomenon was partially rescued by supplementation of raffinose to detached zmrafs leaves. In addition, while there were differences in water loss among different maize lines, there was no difference in stomata density or aperture. Taken together, our work demonstrated that overexpression of the ZmRAFS gene in maize, in contrast to Arabidopsis, increased the raffinose content in leaves, assisted the leaf to retain water, and enhanced the plant drought stress tolerance without causing a detectable growth penalty.


Assuntos
Arabidopsis , Zea mays , Zea mays/metabolismo , Rafinose , Resistência à Seca , Arabidopsis/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Secas , Plantas Geneticamente Modificadas/metabolismo , Água/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas
4.
J Agric Food Chem ; 69(39): 11606-11615, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34553917

RESUMO

Raffinose family oligosaccharides (RFOs) are accumulated during the late stage of seed development and hydrolyzed during seed germination. The process of raffinose hydrolysis during seed germination and how this process affects seed vigor remains unknown. We report here that maize alkaline α-galactosidase 1 (ZmAGA1) protein is translationally induced and is capable of hydrolyzing RFOs as well as a precursor, galactinol, during seed germination. Constitutively overexpressing ZmAGA1 in Arabidopsis decreased both RFOs and galactinol contents of mature, desiccated, and 30 hours after imbibition (HAI) seeds, yet enhanced the seed germination percentage under either salt or somewhat osmotic-stress conditions at earlier times during the time course. However, ZmAGA1 overexpression also decreased the seed aging tolerance of mature, desiccated seeds as compared with wild type (WT) or those overexpressing GFP. Compared to that of WT control seeds, the atsip2 (mutant of Arabidopsis AtSIP2 (seed imbibition protein 2, encoding alkaline α-galactosidase)) seeds have similar RFOs and galactinol contents in mature, desiccated seeds but significantly increased the amount of these metabolites at 30 HAI. This retention of RFOs and galactinol in atsip2 results in seeds that exhibit lowered seed germination percentage under either salt or osmotic stress conditions, and yet, increased seed aging tolerance relative to WT. Similarly, when maize seeds were imbibed in the presence of a specific α-galactosidase inhibitor (1-deoxygalactonojirimycin) as compared to those imbibed in water, greater amounts of raffinose and galactinol were detected; the seeds exhibited decreased seed germination percentages but increased seed aging tolerance. Taken together, these data suggest that both maize seed germination and seed aging tolerance can be simultaneously regulated through careful temporal manipulation of ZmAGA1 expression.


Assuntos
Arabidopsis , Germinação , Arabidopsis/genética , Oligossacarídeos , Rafinose , Sementes
5.
Plant J ; 104(1): 268-282, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32662115

RESUMO

Seed aging tolerance and rapid seedling growth are important agronomic traits for crop production; however, how these traits are controlled at the molecular level remains largely unknown. The unaged seeds of two independent maize DEHYDRATION-RESPONSIVE ELEMENT-BINDING2A mutant (zmdreb2a) lines, with decreased expression of GRETCHEN HAGEN3.2 (ZmGH3.2, encoding indole-3-acetic acid [IAA] deactivating enzyme), and increased IAA in their embryo, produced longer seedling shoots and roots, than the null segregant (NS) controls. However, the zmdreb2a seeds, with decreased expression of RAFFINOSE SYNTHASE (ZmRAFS) and less raffinose in their embryo, exhibit decreased seed aging tolerance, than the NS controls. Overexpression of ZmDREB2A in maize protoplasts increased the expression of ZmGH3.2, ZmRAFS genes and that of a Rennila LUCIFERASE reporter (Rluc) gene, which was controlled by either the ZmGH3.2- or ZmRAFS-promoter. Electrophoretic mobility shift assays and chromatin immunoprecipitation assay quantitative polymerase chain reaction showed that ZmDREB2A directly binds to the DRE motif of the promoters of both ZmGH3.2 and ZmRAFS. Exogenous supplementation of IAA to the unaged, germinating NS seeds increased subsequent seedling growth making them similar to the zmdreb2a seedlings from unaged seeds. These findings provide evidence that ZmDREB2A regulates the longevity of maize seed by stimulating the production of raffinose while simultaneously acting to limit auxin-mediated cell expansion.


Assuntos
Proteínas de Plantas/fisiologia , Plântula/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimento , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Plântula/metabolismo , Plântula/fisiologia , Zea mays/metabolismo , Zea mays/fisiologia
6.
J Therm Biol ; 90: 102582, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32479385

RESUMO

Marine ectotherms are often sensitive to thermal stress, and certain life stages can be particularly vulnerable (e.g., larvae or spawners). In this study, we investigated the critical thermal maxima (CTmax) of larval and early juvenile life stages of three tropical marine fishes (Acanthochromis polyacanthus, Amphiprion melanopus, and Lates calcarifer). We tested for potential effects of developmental acclimation, life stage, and experimental heating rates, and we measured metabolic enzyme activities from aerobic (citrate synthase, CS) and anaerobic pathways (lactate dehydrogenase, LDH). A slightly elevated rearing temperature neither influenced CTmax nor CS activity, which otherwise could have indicated thermal acclimation. However, we found CTmax to either remain stable (Acanthrochromis polyacanthus) or increase with body mass during early ontogeny (Amphiprion melanopus and Lates calcarifer). In all three species, faster heating rates lead to higher CTmax. Acute temperature stress did not change CS or LDH activities, suggesting that overall aerobic and anaerobic metabolism remained stable. Lates calcarifer, a catadromous species that migrates from oceanic to riverine habitats upon metamorphosis, had higher CTmax than the two coral reef fish species. We highlight that, for obtaining conservative estimates of a fish species' upper thermal limits, several developmental stages and body mass ranges should be examined. Moreover, upper thermal limits should be assessed using standardized heating rates. This will not only benefit comparative approaches but also aid in assessing geographic (re-) distributions and climate change sensitivity of marine fishes.


Assuntos
Aclimatação/fisiologia , Peixes/fisiologia , Temperatura Alta , Estágios do Ciclo de Vida/fisiologia , Animais , Citrato (si)-Sintase/fisiologia , Feminino , L-Lactato Desidrogenase/fisiologia , Masculino , Clima Tropical
7.
Plant J ; 103(5): 1679-1694, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32445409

RESUMO

Arabidopsis thaliana ABSCISIC ACID INSENSITIVE3 (ABI3) is a transcription factor in the B3 domain family. ABI3, along with B3 domain transcription factors LEAFY COTYLEDON2 (LEC2) and FUSCA3 (FUS3), and LEC1, a subunit of the CCAAT box-binding complex, form the so-called LAFL network to control various aspects of seed development and maturation. ABI3 also contributes to the abscisic acid (ABA) response. We report on chromatin immunoprecipitation-tiling array experiments to map binding sites for ABI3 globally. We also assessed transcriptomes in response to ABI3 by comparing developing abi3-5 and wild-type seeds and combined this information to ascertain direct and indirect responsive ABI3 target genes. ABI3 can induce and repress its transcription of target genes directly and some intriguing differences exist in cis motifs between these groups of genes. Directly regulated targets reflect the role of ABI3 in seed maturation, desiccation tolerance, entry into a quiescent state and longevity. Interestingly, ABI3 directly represses a gene encoding a microRNA (MIR160B) that targets AUXIN RESPONSE FACTOR (ARF)10 and ARF16 that are involved in establishment of dormancy. In addition, ABI3, like FUS3, regulates genes encoding MIR156 but while FUS3 only induces genes encoding this product, ABI3 induces these genes during the early stages of seed development, but represses these genes during late development. The interplay between ABI3, the other LAFL genes, and the VP1/ABI3-LIKE (VAL) genes, which are involved in the transition to seedling development are examined and reveal complex interactions controlling development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Sementes/metabolismo , Fatores de Transcrição/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Dormência de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Sementes/crescimento & desenvolvimento
8.
J Biol Chem ; 295(23): 8064-8077, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32366461

RESUMO

Raffinose and its precursor galactinol accumulate in plant leaves during abiotic stress. RAFFINOSE SYNTHASE (RAFS) catalyzes raffinose formation by transferring a galactosyl group of galactinol to sucrose. However, whether RAFS contributes to plant drought tolerance and, if so, by what mechanism remains unclear. In this study, we report that expression of RAFS from maize (or corn, Zea mays) (ZmRAFS) is induced by drought, heat, cold, and salinity stresses. We found that zmrafs mutant maize plants completely lack raffinose and hyper-accumulate galactinol and are more sensitive to drought stress than the corresponding null-segregant (NS) plants. This indicated that ZmRAFS and its product raffinose contribute to plant drought tolerance. ZmRAFS overexpression in Arabidopsis enhanced drought stress tolerance by increasing myo-inositol levels via ZmRAFS-mediated galactinol hydrolysis in the leaves due to sucrose insufficiency in leaf cells and also enhanced raffinose synthesis in the seeds. Supplementation of sucrose to detached leaves converted ZmRAFS from hydrolyzing galactinol to synthesizing raffinose. Taken together, we demonstrate that ZmRAFS enhances plant drought tolerance through either raffinose synthesis or galactinol hydrolysis, depending on sucrose availability in plant cells. These results provide new avenues to improve plant drought stress tolerance through manipulation of the raffinose anabolic pathway.


Assuntos
Arabidopsis/metabolismo , Dissacarídeos/metabolismo , Secas , Galactosiltransferases/metabolismo , Rafinose/biossíntese , Estresse Fisiológico , Zea mays/metabolismo , Arabidopsis/enzimologia , Galactosiltransferases/genética , Hidrólise , Mutação , Especificidade por Substrato , Zea mays/enzimologia
9.
Palliat Support Care ; 18(6): 713-721, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-31957626

RESUMO

OBJECTIVE: The objective of this study is to map the existent research undertaken in Australia into broad thematic areas and identify the characteristics of the studies and areas of future research in the literature. METHODS: A scoping review methodology was employed to map the current areas of research undertaken in Australia since January 2000 until the end of December 2018 according to years of publications, types of studies, populations studied, research themes, and areas of focus. RESULTS: Our review identified 1,405 Australian palliative care research publications between January 2000 and December 2018. Nearly 40% of the studies were quantitative (39%) and a third were qualitative studies (31%). The remainder of the studies were reviews, mixed methods, quality improvement projects, and others. One-third (30%) of the research was done with carers' participants followed by nurses (22%) and doctors and physicians (18%). The most frequently reported diagnosis in the studies was cancer with 42% of the publication total. The most frequently explored theme was physical symptoms (such as pain, breathlessness, nausea, delirium, and dyspnea) with a total of 16% of all articles followed by communication (15%). There was a large gap to the next most frequently explored theme with service delivery (9%) and coordination of care (8%). Assessment of patients (7%), end-of-life decision-making (6%), and rural/regional (6%) all produced a similar number of publications. Very few studies addressed topics such as quality of life, E-Health, after-hours care, spirituality, and health economics. Moreover, there were only 15 (1%) studies focused on the last days of life. SIGNIFICANCE OF THE RESULTS: The current review presented a comprehensive search of the literature across almost two decades in Australia in the palliative care setting. It has covered a breadth of research topics and highlighted urgent areas for further research.


Assuntos
Cuidados Paliativos/classificação , Pesquisa/classificação , Austrália , Humanos , Cuidados Paliativos/estatística & dados numéricos , Pesquisa/estatística & dados numéricos
10.
Plant Cell Physiol ; 61(2): 331-341, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31638155

RESUMO

Raffinose accumulation is positively correlated with plant chilling stress tolerance; however, the understanding of the function and regulation of raffinose metabolism under chilling stress remains in its infancy. RAFFINOSE SYNTHASE (RAFS) is the key enzyme for raffinose biosynthesis. In this study, we report that two independent maize (Zea mays) zmrafs mutant lines, in which raffinose was completely abolished, were more sensitive to chilling stress and their net photosynthetic product (total soluble sugars and starch) accumulation was significantly decreased compared with controls after chilling stress. A similar characterization of the maize dehydration responsive element (DRE)-binding protein 1A mutant (zmdreb1a) showed that ZmRAFS expression and raffinose content were significantly decreased compared with its control under chilling stress. Overexpression of maize ZmDREB1A in maize leaf protoplasts increased ZmDREB1A amounts, which consequently upregulated the expression of maize ZmRAFS and the Renilla LUCIFERASE (Rluc), which was controlled by the ZmRAFS promoter. Deletion of the single dehydration-responsive element (DRE) in the ZmRAFS promoter abolished ZmDREB1A's influence on Rluc expression, while addition of three copies of the DRE in the ZmRAFS promoter dramatically increased Rluc expression when ZmDREB1A was simultaneously overexpressed. Electrophoretic mobility shift assays and chromatin immunoprecipitation-quantitative PCR demonstrated that ZmDREB1A directly binds to the DRE motif in the promoter of ZmRAFS both in vitro and in vivo. These data demonstrate that ZmRAFS, which was directly regulated by ZmDREB1A, enhances both raffinose biosynthesis and plant chilling stress tolerance.


Assuntos
Galactosiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Rafinose/biossíntese , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Zea mays/genética , Zea mays/metabolismo , Aclimatação/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis , Temperatura Baixa , Resposta ao Choque Frio , Regulação da Expressão Gênica de Plantas , Redes e Vias Metabólicas/genética , Redes e Vias Metabólicas/fisiologia , Fotossíntese , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Protoplastos/metabolismo
11.
Plant J ; 100(1): 128-142, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31180156

RESUMO

Raffinose is thought to play an important role in plant tolerance of abiotic stress. We report here that maize HEAT SHOCK FACTOR A2 (ZmHSFA2) and HEAT SHOCK BINDING PROTEIN 2 (ZmHSBP2) physically interact with each other and antagonistically modulate expression of GALACTINOL SYNTHASE2 (ZmGOLS2) and raffinose biosynthesis in transformed maize protoplasts and Arabidopsis plants. Overexpression of ZmHSFA2 in Arabidopsis increased the expression of Arabidopsis AtGOLS1, AtGOLS2 and AtRS5 (RAFFINOSE SYNTHASE), increased the raffinose content in leaves and enhanced plant heat stress tolerance. Contrary to ZmHSFA2, overexpression of ZmHSBP2 in Arabidopsis decreased expression of AtGOLS1, AtGOLS2 and AtRS5, decreased the raffinose content in leaves and reduced plant heat stress tolerance. ZmHSFA2 and ZmHSBP2 also interact with their Arabidopsis counterparts AtHSBP and AtHSFA2 as determined using bimolecular fluorescence complementation assays. Furthermore, endogenous ZmHSBP2 and Rluc, controlled by the ZmHSBP2 promoter, are transcriptionally activated by ZmHSFA2 and inhibited by ZmHSBP2 in maize protoplasts. These findings provide insights into the transcriptional regulation of raffinose biosynthetic genes, and the tolerance their product confers to plant heat stress.


Assuntos
Arabidopsis/genética , Fatores de Transcrição de Choque Térmico/genética , Proteínas de Plantas/genética , Rafinose/biossíntese , Termotolerância/genética , Zea mays/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Galactosiltransferases/genética , Galactosiltransferases/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Estresse Fisiológico , Zea mays/metabolismo
12.
J Agric Food Chem ; 67(15): 4214-4223, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30915847

RESUMO

Raffinose, an oligosaccharide found in many seeds, plays an important role in seed vigor; however, the regulatory mechanism governing raffinose biosynthesis remains unclear. We report here that maize W22 wild type (WT) seeds, but not W22 viviparous1 ( zmvp1) mutant seeds, start accumulating galactinol and raffinose 28 days after pollination (DAP). Transcriptome analysis of the zmvp1 embryo showed that the expression of GALACTINOL SYNTHASE2 ( GOLS2) was down-regulated relative to WT. Further experiments showed that the expression of ZmGOLS2 was up-regulated by ZmABI5 but not by ZmVP1, and it was further increased by the coexpression of ZmABI5 and ZmVP1 in maize protoplasts. ZmABI5 interacted with ZmVP1, while ZmABI5, but not ZmVP1, directly binds to the ZmGOLS2 promoter. Together, all of the findings suggest that ZmVP1 interacts with ZmABI5 and regulates ZmGOLS2 expression and raffinose accumulation in maize seeds.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Galactosiltransferases/metabolismo , Proteínas de Plantas/metabolismo , Rafinose/metabolismo , Sementes/metabolismo , Zea mays/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Galactosiltransferases/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Ligação Proteica , Sementes/enzimologia , Sementes/genética , Zea mays/enzimologia , Zea mays/genética
13.
Osteoarthritis Cartilage ; 27(2): 257-265, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30347226

RESUMO

OBJECTIVE: There is significant variability in the trajectory of structural progression across people with knee osteoarthritis (OA). We aimed to identify distinct trajectories of femorotibial cartilage thickness over 2 years and develop a prediction model to identify individuals experiencing progressive cartilage loss. METHODS: We analysed data from the Osteoarthritis Initiative (OAI) (n = 1,014). Latent class growth analysis (LCGA) was used to identify trajectories of medial femorotibial cartilage thickness assessed on magnetic resonance imaging (MRI) at baseline, 1 and 2 years. Baseline characteristics were compared between trajectory-based subgroups and a prediction model was developed including those with frequent knee symptoms at baseline (n = 686). To examine clinical relevance of the trajectories, we assessed their association with concurrent changes in knee pain and incidence of total knee replacement (TKR) over 4 years. RESULTS: The optimal model identified three distinct trajectories: (1) stable (87.7% of the population, mean change -0.08 mm, SD 0.19); (2) moderate cartilage loss (10.0%, -0.75 mm, SD 0.16) and (3) substantial cartilage loss (2.2%, -1.38 mm, SD 0.23). Higher Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) pain scores, family history of TKR, obesity, radiographic medial joint space narrowing (JSN) ≥1 and pain duration ≤1 year were predictive of belonging to either the moderate or substantial cartilage loss trajectory [area under the curve (AUC) 0.79, 95% confidence interval (CI) 0.74, 0.84]. The two progression trajectories combined were associated with pain progression (OR 1.99, 95% CI 1.34, 2.97) and incidence of TKR (OR 4.34, 1.62, 11.62). CONCLUSIONS: A minority of individuals follow a progressive cartilage loss trajectory which was strongly associated with poorer clinical outcomes. If externally validated, the prediction model may help to select individuals who may benefit from cartilage-targeted therapies.


Assuntos
Cartilagem Articular/patologia , Osteoartrite do Joelho/patologia , Idoso , Artroplastia do Joelho/estatística & dados numéricos , Cartilagem Articular/diagnóstico por imagem , Dor Crônica/diagnóstico por imagem , Dor Crônica/etiologia , Dor Crônica/patologia , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/complicações , Osteoartrite do Joelho/diagnóstico por imagem , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Índice de Gravidade de Doença
14.
Plant Signal Behav ; 13(10): e1525999, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30296201

RESUMO

In Arabidopsis thaliana, the basic Helix Loop Helix transcription factor, PHYTOCHROME INTERACTING FACTOR1 (PIF1) is known to orchestrate the seed transcriptome such that, ultimately, proteins repressing the completion of germination are produced in darkness. While PIF1-mediated control of abscisic acid (ABA) and gibberellic acid (GA) anabolism/catabolism is indirect, PIF1 action favors ABA while discriminating against GA, firmly establishing ABA's repressive influence on the completion of germination. The result is tissue that is more sensitive to and producing more ABA; and is less responsive to and deficient in GA. Illumination of the appropriate wavelength activates phytochrome which enters the nucleus, and binds to PIF1, initiating PIF1's phosphorylation by diverse kinases, subsequent polyubiquitination, and hydrolysis. One mechanism by which phosphorylated PIF1 is eliminated from the cells of the seed upon illumination involves an F-BOX protein, COLD TEMPERATURE GERMINATING10 (CTG10). Discovered in an unbiased screen of activation tagged lines hastening the completion of seed germination at 10°C, one indirect consequence of CTG10 action in reducing PIF1 titer, should be to enhance the transcription of genes whose products work to increase bioactive GA titer, shifting the intracellular milieu from one that is repressive to, toward one conducive to, the completion of seed germination. We have tested this hypothesis using a variety of Arabidopsis lines altered in CTG10 amounts. Here we demonstrate using bimolecular fluorescence complementation that PIF1 interacts with CTG10 and show that, in light exposed seeds, PIF1 is more persistent in ctg10 relative to WT seeds while it is less stable in seeds over-expressing CTG10. These results are congruent with the relative transcript abundance from three genes whose products are involved in bioactive GA accumulation. We put forth a model of how PIF1 interactions in imbibed seeds change during germination and how a permissive light signal influences these changes, leading to the completion of germination of these positively photoblastic propagules.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Germinação/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fosfoproteínas/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Luz , Proteínas de Membrana , Sementes/metabolismo , Sementes/fisiologia
15.
Proc Natl Acad Sci U S A ; 115(17): E4120-E4129, 2018 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-29632208

RESUMO

Seeds employ sensory systems that assess various environmental cues over time to maximize the successful transition from embryo to seedling. Here we show that the Arabidopsis F-BOX protein COLD TEMPERATURE-GERMINATING (CTG)-10, identified by activation tagging, is a positive regulator of this process. When overexpressed (OE), CTG10 hastens aspects of seed germination. CTG10 is expressed predominantly in the hypocotyl, and the protein is localized to the nucleus. CTG10 interacts with PHYTOCHROME-INTERACTING FACTOR 1 (PIF1) and helps regulate its abundance in plantaCTG10-OE accelerates the loss of PIF1 in light, increasing germination efficiency, while PIF1-OE lines fail to complete germination in darkness, which is reversed by concurrent CTG10-OE Double-mutant (pif1 ctg10) lines demonstrated that PIF1 is epistatic to CTG10. Both CTG10 and PIF1 amounts decline during seed germination in the light but reaccumulate in the dark. PIF1 in turn down-regulates CTG10 transcription, suggesting a feedback loop of CTG10/PIF1 control. The genetic, physiological, and biochemical evidence, when taken together, leads us to propose that PIF1 and CTG10 coexist, and even accumulate, in the nucleus in darkness, but that, following illumination, CTG10 assists in reducing PIF1 amounts, thus promoting the completion of seed germination and subsequent seedling development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Germinação/fisiologia , Sementes/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Repetição Kelch , Sementes/genética
16.
Mol Plant ; 10(12): 1540-1555, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29122666

RESUMO

Raffinose family oligosaccharides (RFOs) accumulate in seeds during maturation desiccation in many plant species. However, it remains unclear whether RFOs have a role in establishing seed vigor. GALACTINOL SYNTHASE (GOLS), RAFFINOSE SYNTHASE (RS), and STACHYOSE SYNTHASE (STS) are the enzymes responsible for RFO biosynthesis in plants. Interestingly, only raffinose is detected in maize seeds, and a unique maize RS gene (ZmRS) was identified. In this study, we found that two independent mutator (Mu)-interrupted zmrs lines, containing no raffinose but hyperaccumulating galactinol, have significantly reduced seed vigor, compared with null segregant controls. Unlike maize, Arabidopsis thaliana seeds contain several RFOs (raffinose, stachyose, and verbascose). Manipulation of A. thaliana RFO content by overexpressing ZmGOLS2, ZmRS, or AtSTS demonstrated that co-overexpression of ZmGOLS2 and ZmRS, or overexpression of ZmGOLS2 alone, significantly increased the total content of RFOs and enhanced Arabidopsis seed vigor. Surprisingly, while overexpression of ZmRS increased seed raffinose content, its overexpression dramatically decreased seed vigor and reduced the seed amounts of galactinol, stachyose, and verbascose. In contrast, the atrs5 mutant seeds are similar to those of the wild type with regard to seed vigor and RFO content, except for stachyose, which accumulated in atrs5 seeds. Total RFOs, RFO/sucrose ratio, but not absolute individual RFO amounts, positively correlated with A. thaliana seed vigor, to which stachyose and verbascose contribute more than raffinose. Taken together, these results provide new insights into regulatory mechanisms of seed vigor and reveal distinct requirement for RFOs in modulating seed vigor in a monocot and a dicot.


Assuntos
Arabidopsis/metabolismo , Oligossacarídeos/metabolismo , Rafinose/metabolismo , Sementes/metabolismo , Zea mays/metabolismo , Sementes/fisiologia
18.
Scott Med J ; 61(2): 106-110, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27543329

RESUMO

INTRODUCTION: Acute renal transplant emboli can be disastrous and result in loss of the renal transplant. This case was successfully treated with thrombolysis. CASE PRESENTATION: A 66-year-old female underwent a right-sided deceased heart-beating donor renal transplant. She had excellent transplant function but presented acutely three years later with pain in the transplanted kidney, an acute rise in serum creatinine and new onset atrial fibrillation. Bedside ultrasound scan demonstrated absent transplant perfusion. Emergency angiogram confirmed acute emboli in the transplant renal artery with some kidney perfusion. Thrombolysis with alteplase and anticoagulation with heparin was commenced. Serial imaging at 24 and 36 h demonstrated significant improvement in transplant perfusion. Following a period of supportive therapy, her transplant function recovered, although not to pre-morbid baseline levels. CONCLUSION: Consider acute embolus in a renal transplant patient with acute kidney injury, transplant tenderness and cardiac arrhythmia. Early thrombolysis may salvage renal transplants and good transplant function may be regained.


Assuntos
Cateterismo Periférico/métodos , Embolia/diagnóstico por imagem , Embolia/cirurgia , Obstrução da Artéria Renal/diagnóstico por imagem , Obstrução da Artéria Renal/cirurgia , Terapia Trombolítica/métodos , Idoso , Anticoagulantes/administração & dosagem , Feminino , Fibrinolíticos/administração & dosagem , Heparina/administração & dosagem , Humanos , Transplante de Rim , Ativador de Plasminogênio Tecidual/administração & dosagem
19.
Mol Genet Metab Rep ; 6: 64-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27014580

RESUMO

m.3291T > C mutation in the MT-TL1 gene has been infrequently encountered in association with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), however remains poorly characterized from a clinical perspective. In the following report we describe in detail the phenotypic features, long term follow up (> 7 years) and management in a Caucasian family with MELAS due to the m.3291T > C mutation and review the literature on m.3291T > C mutation. The clinical phenotype in the proposita included overlapping features of MELAS, MERRF (Myoclonic epilepsy and ragged-red fiber syndrome), MNGIE (Mitochondrial neurogastrointestinal encephalopathy), KSS (Kearns-Sayre Syndrome) and CPEO (Chronic progressive external ophthalmoplegia).

20.
J Vis Exp ; (84): e50685, 2014 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-24637694

RESUMO

Using recombinant phage as a scaffold to present various protein portions encoded by a directionally cloned cDNA library to immobilized bait molecules is an efficient means to discover interactions. The technique has largely been used to discover protein-protein interactions but the bait molecule to be challenged need not be restricted to proteins. The protocol presented here has been optimized to allow a modest number of baits to be screened in replicates to maximize the identification of independent clones presenting the same protein. This permits greater confidence that interacting proteins identified are legitimate interactors of the bait molecule. Monitoring the phage titer after each affinity selection round provides information on how the affinity selection is progressing as well as on the efficacy of negative controls. One means of titering the phage, and how and what to prepare in advance to allow this process to progress as efficiently as possible, is presented. Attributes of amplicons retrieved following isolation of independent plaque are highlighted that can be used to ascertain how well the affinity selection has progressed. Trouble shooting techniques to minimize false positives or to bypass persistently recovered phage are explained. Means of reducing viral contamination flare up are discussed.


Assuntos
Técnicas de Visualização da Superfície Celular/métodos , Proteínas Imobilizadas/genética , Proteínas Recombinantes/genética , DNA Complementar/genética
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