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1.
Am J Physiol Endocrinol Metab ; 325(5): E610-E620, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37819193

RESUMO

Brown and beige adipose tissue share similar functionality, being both tissues specialized in producing heat through nonshivering thermogenesis and also playing endocrine roles through the release of their secretion factors called batokines. This review elucidates the influence of physical exercise, and myokines released in response, on the regulation of thermogenic and secretory functions of these adipose tissues and discusses the similarity of batokines actions with physical exercise in the remodeling of adipose tissue. This adipose tissue remodeling promoted by autocrine and paracrine batokines or physical exercise seems to optimize its functionality associated with better health outcomes.


Assuntos
Tecido Adiposo Bege , Tecido Adiposo Marrom , Humanos , Termogênese/fisiologia , Obesidade , Exercício Físico
2.
Am J Bot ; 110(7): e16186, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37183532

RESUMO

PREMISE: Flower damage caused by florivores often has negative consequences for plant reproduction. However, the factors affecting plant-florivore interactions are still poorly understood, especially the role of abiotic factors and interspecific variation in florivory within ecosystems. Thus, the patterns of florivory levels and its consequences for plant communities need to be investigated further. METHODS: We assessed the influence of abiotic factors related to climatic seasonality, of phylogenetic relationships among plants, and of functional attributes associated with attractiveness to pollinators on florivory incidence and intensity in the Pantanal, the world's largest tropical wetland. Between December 2020 and November 2021, the percentage of flowers attacked (incidence) and petal area removed (intensity) by florivores were examined in 51 species from 25 families, considering flowering season, the substrate where the plants occur, and flower attributes as potentially determining factors on florivory levels. RESULTS: Phylogeny and environmental factors did not have a significant influence on florivory. The only determinant of interspecific variation in florivory incidence and intensity was flower size, where larger flowers experienced higher florivory levels regardless of season and substrate, while flower arrangement and color were not significant factors. CONCLUSIONS: Our study is one of the first to estimate the community-wide effects of biotic and abiotic factors on both the incidence and the intensity of florivory. The magnitude of this plant-florivore interaction may reduce reproductive success and entail selective pressures on plant attractiveness to pollinators.


Assuntos
Ecossistema , Áreas Alagadas , Filogenia , Flores , Reprodução , Plantas , Polinização
3.
Clin Exp Rheumatol ; 41(5): 1114-1119, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36377568

RESUMO

OBJECTIVES: Multiple failures to biologic or targeted specific disease-modifying anti-rheumatic drugs (b/tsDMARDs) that lead to difficult-to-treat rheumatoid arthritis (D2TRA) may be the result of multi-drug inefficacy or reflect treatment problems related to adverse events, comorbidities, and/or poor adherence. We aimed to characterise a cohort of D2TRA patients in clinical practice, to analyse the differences between D2TRA due to inefficacy versus D2TRA from other causes, and to compare them with non-D2TRA. METHODS: The D2TRA group included patients who were receiving ≥2b/tsDMARDs due to inefficacy (D2TRA-inef cacy) or because of adverse events, poor adherence, contraindications, comorbidities, drug-intolerance, etc. (D2TRA-other). Patients who achieved low disease activity or remission with the rst bDMARD were classified as non-D2TRA patients. For all patients, demographic, clinical characteristics and laboratory parameters were assessed prior to starting the rst b/tsDMARD. Descriptive analysis was performed and bivariate logistic regression models were assembled. RESULTS: In total, 253 patients were included: 131 non-D2TRA and 122 D2TRA [86 (70.5%) D2TRA-inefficacy and 36 (29.5%) D2TRA-other]. Comparison of the two groups of D2TRA patients: no differences in gender, age at start of b/tsDMARD or age at RA diagnosis were found; this was also true of socioeconomic status, frequency of anxiety-depression and other comorbidities. Patients categorised as D2TRA-other had less extra-articular manifestations than D2TRA-inef cacy, as well as lower values of DAS28 at the start of the rst b/tsDMARD. Comparisons of Non-D2TRA patients versus D2TRA-other resulted in the following observations: no differences in sociodemographic characteristics were evident nor were there any differences in terms of disease activity. CONCLUSIONS: Patients with D2TRA-other are indistinguishable from non-D2TRA patients at baseline, indicating the former cohort does not appear to have any predictive value during the early stages of b/tsDMARD treatment, unlike what occurs in patients with D2TRA-inefficacy.


Assuntos
Antirreumáticos , Artrite Reumatoide , Produtos Biológicos , Humanos , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Antirreumáticos/efeitos adversos , Comorbidade , Produtos Biológicos/uso terapêutico
4.
BMC Public Health ; 23(1): 216, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36721121

RESUMO

BACKGROUND: The Latinx population experiences some of the highest rates of chronic disease, including obesity and type II diabetes. Such conditions may be especially burdensome in rural Latinx communities that often face barriers to accessing disease prevention resources and public health programs. METHODS: Diverse stakeholders (i.e., patients, community members, system of healthcare clinics, community food bank) tailored an existing cookbook, based on the U.S. Department of Agriculture MyPlate healthy eating and dietary guidelines, for local ingredients, health literacy, and language for rural Latinx and Indigenous Latin Americans. The cookbook recipes were disseminated widely via virtual cooking demonstrations, food distribution events, and social media. Pre- and posttest surveys were used to assess changes in diabetes knowledge measured by the 24-item American Diabetes Association Diabetic Knowledge Questionnaire and confidence in dietary behavior change over time measured by 4 questions of the 17-item Mediterranean Diet Index. A mixed effects, repeated measures analysis was conducted with gender ID, age range and educational attainment included as covariates and assessment interval as the predictor (pretest vs posttest) and change in confidence about adhering to four specific components of the Mediterranean diet. Focus groups elicited information on participants' motivation and ability to use the recipes and eat healthy foods following the virtual cooking demonstration participation. RESULTS: A total of 20 virtual cooking demonstrations were conducted and 60 participants completed a pretest survey and 54 a posttest survey, a subsample (n = 19) participated in one of three focus groups. Most participants were female, identified as Latinx/Hispanic, were between the ages of 40-49, and spoke Spanish. 17% identified as Indigenous Latin American specifically as Purépecha, an indigenous group from Michoacán, Mexico. Survey and focus group findings indicated at posttest an increase in diabetes knowledge among participants with no prior diagnosis of chronic health conditions and more confidence in limiting sugary beverages and refined wheat pasta/white rice among indigenous participants. Focus group discussions explicated the quantitative findings. CONCLUSION: This study brought together patients and key stakeholders committed to addressing the social determinants of health and it mobilized the community to develop culturally vetted health education materials. The findings indicate the need for increased access to evidence-based nutrition education and to culturally appropriate food products that can be easily incorporated into daily food preparation.


Assuntos
Diabetes Mellitus Tipo 2 , População Rural , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Masculino , Hispânico ou Latino , Alimentos , Processos Mentais
5.
J Exp Bot ; 73(21): 7126-7138, 2022 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-35640572

RESUMO

The red phytochrome and blue cryptochrome plant photoreceptors play essential roles in promoting genome-wide changes in nuclear and chloroplastic gene expression for photomorphogenesis, plastid development, and greening. While their importance in anterograde signalling has been long recognized, the molecular mechanisms involved remain under active investigation. More recently, the intertwining of the light signalling cascades with the retrograde signals for the optimization of chloroplast functions has been acknowledged. Advances in the field support the participation of phytochromes, cryptochromes, and key light-modulated transcription factors, including HY5 and the PIFs, in the regulation of chloroplastic biochemical pathways that produce retrograde signals, including the tetrapyrroles and the chloroplastic MEP-isoprenoids. Interestingly, in a feedback loop, the photoreceptors and their signalling components are targets themselves of these retrograde signals, aimed at optimizing photomorphogenesis to the status of the chloroplasts, with GUN proteins functioning at the convergence points. High light and shade are also conditions where the photoreceptors tune growth responses to chloroplast functions. Interestingly, photoreceptors and retrograde signals also converge in the modulation of dual-localized proteins (chloroplastic/nuclear) including WHIRLY and HEMERA/pTAC12, whose functions are required for the optimization of photosynthetic activities in changing environments and are proposed to act themselves as retrograde signals.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fitocromo , Fotorreceptores de Plantas/genética , Fotorreceptores de Plantas/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Luz , Cloroplastos/metabolismo , Fitocromo/metabolismo , Criptocromos/metabolismo , Comunicação , Regulação da Expressão Gênica de Plantas
6.
Mol Biol Rep ; 49(6): 5495-5504, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35355209

RESUMO

BACKGROUND: Peanut (Arachis hypogaea L.) production and cropping pattern is highly influenced by the climatic factors including temperature and rain pattern fluctuations. It is one of the most important cash crop in the rain fed areas of Pakistan and its production, under changing climatic conditions, that can be improved by developing short duration varieties. The present study was based on the molecular characterization of the maturity associated gene families in the peanut under two light conditions. METHODS AND RESULTS: Genomic analysis based on the in silico study of important gene families for early maturity associated attributes like flowering time, their pattern, duration and photoperiodism was done for a comprehensive mapping of maturity related genes. Phytochromes genes Phy A, Phy B and Phy E and flowering genes FT2a, Ft5a and COL2 were selected for in silico characterization for protein based analysis including Multiple Sequence Alignment (MSA), and Neighbor Joining (NJ) tree. MSA and NJ trees of the peanut with Arabidopsis thaliana and Glycine max showed a clear picture of the phylogenetic relationship on the basis of selected gene proteins. Expression profile of phytochrome and flowering genes revealed that photoperiod conditions i.e. short and long days, have great influence on the Phy A, Phy B and Phy E, Ft2a, FT5a and COL2 gene expression pattern. In current study, the relative expression of all studied genes was found higher in short day light condition at flower initiation stage of the plants than in the long light day condition with exception of COL2 gene protein. CONCLUSIONS: The molecular characterization based on the in silico study of the particular genes and qPCR based gene expression profiling of the selected genes provided an evidence of the role of these genes and their comparative analysis under two photoperiodic conditions.


Assuntos
Arabidopsis , Fitocromo , Arabidopsis/genética , Arachis/genética , Arachis/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Fotoperíodo , Filogenia , Fitocromo/genética
7.
BMC Public Health ; 22(1): 1019, 2022 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-35596225

RESUMO

BACKGROUND: A novel coronavirus, SARS-CoV-2 (known as COVID-19), spread rapidly around the world, affecting all and creating an ongoing global pandemic. Across the United States, Latinx and Indigenous populations have been disproportionately affected by COVID-19 cases and death rates. An examination of the perceptions and beliefs about the spread of the virus, COVID-19 testing, and vaccination amongst racial-ethnic minority groups, specifically Latinx and Indigenous Latin American immigrant communities, is needed to alleviate the widespread disparity in new cases and deaths. METHODS: This study was carried out from August 2020 to January 2021 and used community-based participatory research to engage community partners and build the capacity of community health workers (i.e., promotores de salud) and pre-medical and medical students in conducting qualitative research. The objective of the study was to examine the structural and social determinants of health on perceptions of the coronavirus, its spread, and decisions around COVID-19 testing and vaccination. Data collection included ethnography involving observations in public settings and focus groups with members of Latinx and Indigenous Mexican farm-working communities in the Eastern Coachella Valley, located in the Inland Southern California desert region. A total of seven focus groups, six in Spanish and one in Purépecha, with a total of 55 participants were conducted. Topics covered include perceptions of the coronavirus and its spread, as well as COVID-19 testing and vaccination. RESULTS: Using theme identification techniques, the findings identify structural and social factors that underly perceptions held by Latinx and Indigenous Mexican immigrants about the virus and COVID-19, which, in turn, shape attitudes and behaviors related to COVID-19 testing and vaccination. Common themes that emerged across focus groups include misinformation, lack of trust in institutions, and insecurity around employment and residency. CONCLUSIONS: This immigrant population is structurally vulnerable to historical and present-day inequalities that put them at increased risk of COVID-19 exposure, morbidity, and mortality. Study findings indicate a significant need for interventions that decrease structural vulnerabilities by addressing issues of (dis)trust in government and public health among this population.


Assuntos
COVID-19 , Emigrantes e Imigrantes , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/prevenção & controle , Teste para COVID-19 , Etnicidade , Humanos , Grupos Minoritários , SARS-CoV-2 , Estados Unidos , Vacinação
8.
Proc Natl Acad Sci U S A ; 115(41): 10523-10528, 2018 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-30254157

RESUMO

In plants, light receptors play a pivotal role in photoperiod sensing, enabling them to track seasonal progression. Photoperiod sensing arises from an interaction between the plant's endogenous circadian oscillator and external light cues. Here, we characterize the role of phytochrome A (phyA) in photoperiod sensing. Our metaanalysis of functional genomic datasets identified phyA as a principal regulator of morning-activated genes, specifically in short photoperiods. We demonstrate that PHYA expression is under the direct control of the PHYTOCHROME INTERACTING FACTOR transcription factors, PIF4 and PIF5. As a result, phyA protein accumulates during the night, especially in short photoperiods. At dawn, phyA activation by light results in a burst of gene expression, with consequences for physiological processes such as anthocyanin accumulation. The combination of complex regulation of PHYA transcript and the unique molecular properties of phyA protein make this pathway a sensitive detector of both dawn and photoperiod.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ritmo Circadiano , Fotoperíodo , Fitocromo A/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Antocianinas/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Luz , Fitocromo A/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento
9.
Physiol Plant ; 169(4): 515-528, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32519399

RESUMO

To promote photomorphogenesis, including plastid development and metabolism, the phytochrome (phy) and the cryptochrome (cry) photoreceptors orchestrate genome-wide changes in gene expression in response to Red (R)- and Blue (B)-light cues. While phys and crys have a clear role in modulating photosynthesis, their role in the coordination of the nuclear genome and the plastome, essential for functional chloroplasts, remains underexplored. Using publicly available genome datasets for WT and phyABCDE or cry1cry2 Arabidopsis seedlings, grown, respectively, under R- or B-light, we bioinformatically analyzed the influence of light inputs and photoreceptors in the control of nuclear genes with a function in the chloroplast, and evaluated the role of phyB in the modulation of plastome-encoded genes. We show gene co-induction by R-phys and B-crys for genes with a chloroplastic function, and also apparent photoreceptor-driven preferential responses. Evidence from phyB in Arabidopsis together with published evidence from CRY2 in tomato also supports the participation of both photoreceptor families in the global modulation of the plastome genes. To begin addressing how these light-sensors orchestrate changes in an organellar genome, we evaluated their effect over genes with potential functions in plastid gene-expression regulation based on their TAIR annotation. Results indicate that both crys and phys modulate 'plastome-regulatory genes' with enrichment in the contribution of crys to all processes and of phys to post-transcription and transcription. Furthermore, we identified a new role for HY5 as a relevant light-signaling component in photoreceptor-based anterograde signaling leading to plastome gene regulation.


Assuntos
Proteínas de Arabidopsis , Arabidopsis/genética , Fitocromo/genética , Cloroplastos , Criptocromos , Regulação da Expressão Gênica de Plantas , Fitocromo B/genética
10.
Plant J ; 96(4): 828-841, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30144333

RESUMO

The plastidial methylerythritol phosphate (MEP) pathway is an essential route for plants as the source of precursors for all plastidial isoprenoids, many of which are of medical and biotechnological importance. The MEP pathway is highly sensitive to environmental cues as many of these compounds are linked to photosynthesis and growth and light is one of the main regulatory factors. However, the mechanisms coordinating the MEP pathway with light cues are not fully understood. Here we demonstrate that by a differential direct transcriptional modulation, via the key-master integrators of light signal transduction HY5 and PIFs which target the genes that encode the rate-controlling DXS1, DXR and HDR enzymes, light imposes a direct, rapid and potentially multi-faceted response that leads to unique protein dynamics of this pathway, resulting in a significant difference in the protein levels. For DXS1, PIF1/HY5 act as a direct activation/suppression module. In contrast, DXR accumulation in response to light results from HY5 induction with minor contribution of de-repression by PIF1. Finally, HDR transcription increases in the light exclusively by suppression of the PIFs repression. This is an example of how light signaling components can differentially multi-target the initial steps of a pathway whose products branch downstream to all chloroplastic isoprenoids. These findings demonstrate the diversity and flexibility of light signaling components that optimize key biochemical pathways essential for plant growth.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Luz , Proteínas Nucleares/metabolismo , Fatores de Transcrição , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Cloroplastos/metabolismo , Cromatina , Regulação da Expressão Gênica de Plantas , Redes e Vias Metabólicas/genética , Proteínas Nucleares/genética , Fotossíntese , Regiões Promotoras Genéticas , Plântula/genética , Plântula/metabolismo , Transdução de Sinais , Terpenos/metabolismo
11.
Pediatr Emerg Care ; 35(7): 498-505, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28225375

RESUMO

OBJECTIVES: Child life specialists and music therapists have a unique and integral role in providing psychosocial care to pediatric patients and families. These professionals are trained to provide clinical interventions that support coping and adjustment and reduce the risk of psychological trauma related to hospital visits and health care encounters. The researchers devised a multimodal approach using a combined child life and music therapy intervention to address procedure-related distress in patients receiving intravenous (IV) placement in the pediatric emergency department. The aim of this study was to investigate the efficacy of this collaborative intervention by evaluating parental perception of their child's distress. METHODS: This study was a prospective analysis investigating the impact of a child life and music therapy intervention on children aged 4 to 11 years old receiving an IV placement in the pediatric emergency department. Efficacy was evaluated by comparing scores between a 4-question pretest and subsequent 4-question posttest that asked the child's parent to evaluate how they anticipated their child would respond to the procedure, and then to evaluate how they perceived their child to have responded after the procedure. Qualitative data were collected in the form of open-ended comments, which were accommodated at the end of the posttest. Data were analyzed by the Cochran-Mantel-Haenszel method for testing repeated ordinal responses and the PROC GENMOD procedure in the SAS system software. RESULTS: A total of 41 participants were enrolled in this study. Results of the statistical analysis revealed significant differences between all pre- and posttest scores (P < 0.05), and significant likelihood that the patient would improve relative to the 4 questions, as a result of the child life and music therapy intervention. CONCLUSIONS: Improvement was demonstrated across all 4 questions, suggesting that the child life and music therapy intervention supported healthy, adaptive coping and helped to minimize distress experienced by patients during IV placement. These results underscore the importance and potential clinical impact of child life psychological preparation and psychotherapy-based music therapy interventions in reducing distress in pediatric patients during common medical procedures.


Assuntos
Musicoterapia , Flebotomia/psicologia , Adaptação Psicológica , Administração Intravenosa , Ansiedade/prevenção & controle , Criança , Pré-Escolar , Humanos , Dor/prevenção & controle , Pais , Flebotomia/efeitos adversos , Estudos Prospectivos
13.
Proteomics ; 17(23-24)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28665015

RESUMO

Most bacteria produce adhesion molecules to facilitate the interaction with host cells and establish successful infections. An important group of bacterial adhesins belong to the autotransporter (AT) superfamily, the largest group of secreted and outer membrane proteins in Gram-negative bacteria. AT adhesins possess diverse functions that facilitate bacterial colonisation, survival and persistence, and as such are often associated with increased bacterial fitness and pathogenic potential. In this review, we will describe AIDA-I type AT adhesins, which comprise the biggest and most diverse group in the AT family. We will focus on Escherichia coli proteins and define general aspects of their biogenesis, distribution, structural properties and key roles in infection.


Assuntos
Infecções por Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Adesinas de Escherichia coli/metabolismo , Aderência Bacteriana , Infecções por Escherichia coli/microbiologia , Regulação Bacteriana da Expressão Gênica
15.
PLoS Genet ; 10(6): e1004416, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24922306

RESUMO

The ability to interpret daily and seasonal alterations in light and temperature signals is essential for plant survival. This is particularly important during seedling establishment when the phytochrome photoreceptors activate photosynthetic pigment production for photoautotrophic growth. Phytochromes accomplish this partly through the suppression of phytochrome interacting factors (PIFs), negative regulators of chlorophyll and carotenoid biosynthesis. While the bZIP transcription factor long hypocotyl 5 (HY5), a potent PIF antagonist, promotes photosynthetic pigment accumulation in response to light. Here we demonstrate that by directly targeting a common promoter cis-element (G-box), HY5 and PIFs form a dynamic activation-suppression transcriptional module responsive to light and temperature cues. This antagonistic regulatory module provides a simple, direct mechanism through which environmental change can redirect transcriptional control of genes required for photosynthesis and photoprotection. In the regulation of photopigment biosynthesis genes, HY5 and PIFs do not operate alone, but with the circadian clock. However, sudden changes in light or temperature conditions can trigger changes in HY5 and PIFs abundance that adjust the expression of common target genes to optimise photosynthetic performance and growth.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Proteínas Nucleares/genética , Fotossíntese/genética , Ativação Transcricional/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/biossíntese , Carotenoides/biossíntese , Clorofila/biossíntese , Fatores de Ligação G-Box/genética , Regulação da Expressão Gênica de Plantas , Fotoperíodo , Regiões Promotoras Genéticas , Receptores de Peptídeos/biossíntese , Estações do Ano , Temperatura , Transcrição Gênica
16.
Plant Physiol ; 169(3): 1584-94, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26082398

RESUMO

Carotenoids are photosynthetic pigments essential for the protection against excess light. During deetiolation, their production is regulated by a dynamic repression-activation module formed by PHYTOCHROME-INTERACTING FACTOR1 (PIF1) and LONG HYPOCOTYL5 (HY5). These transcription factors directly and oppositely control the expression of the gene encoding PHYTOENE SYNTHASE (PSY), the first and main rate-determining enzyme of the carotenoid pathway. Antagonistic modules also regulate the responses of deetiolated plants to vegetation proximity and shade (i.e. to the perception of far-red light-enriched light filtered through or reflected from neighboring plants). These responses, aimed to adapt to eventual shading from plant competitors, include a reduced accumulation of carotenoids. Here, we show that PIF1 and related photolabile PIFs (but not photostable PIF7) promote the shade-triggered decrease in carotenoid accumulation. While HY5 does not appear to be required for this process, other known PIF antagonists were found to modulate the expression of the Arabidopsis (Arabidopsis thaliana) PSY gene and the biosynthesis of carotenoids early after exposure to shade. In particular, PHYTOCHROME-RAPIDLY REGULATED1, a transcriptional cofactor that prevents the binding of true transcription factors to their target promoters, was found to interact with PIF1 and hence directly induce PSY expression. By contrast, a change in the levels of the transcriptional cofactor LONG HYPOCOTYL IN FAR RED1, which also binds to PIF1 and other PIFs to regulate shade-related elongation responses, did not impact PSY expression or carotenoid accumulation. Our data suggest that the fine-regulation of carotenoid biosynthesis in response to shade relies on specific modules of antagonistic transcriptional factors and cofactors.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Carotenoides/biossíntese , Regulação da Expressão Gênica de Plantas/fisiologia , Luz , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regiões Promotoras Genéticas , Plântula , Fatores de Transcrição
17.
Plant Cell ; 25(10): 4183-94, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24104567

RESUMO

Plastids provide plants with metabolic pathways that are unique among eukaryotes, including the methylerythritol 4-phosphate pathway for the production of isoprenoids essential for photosynthesis and plant growth. Here, we show that the first enzyme of the pathway, deoxyxylulose 5-phosphate synthase (DXS), interacts with the J-protein J20 in Arabidopsis thaliana. J-proteins typically act as adaptors that provide substrate specificity to heat shock protein 70 (Hsp70), a molecular chaperone. Immunoprecipitation experiments showed that J20 and DXS are found together in vivo and confirmed the presence of Hsp70 chaperones in DXS complexes. Mutants defective in J20 activity accumulated significantly increased levels of DXS protein (but no transcripts) and displayed reduced levels of DXS enzyme activity, indicating that loss of J20 function causes posttranscriptional accumulation of DXS in an inactive form. Furthermore, J20 promotes degradation of DXS following a heat shock. Together, our data indicate that J20 might identify unfolded or misfolded (damaged) forms of DXS and target them to the Hsp70 system for proper folding under normal conditions or degradation upon stress.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Cloroplastos/enzimologia , Terpenos/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Choque Térmico HSP70/metabolismo , Redes e Vias Metabólicas , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Mapeamento de Interação de Proteínas , Transferases/metabolismo
18.
Plant Cell ; 24(7): 2949-62, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22843485

RESUMO

Phytochrome is a red (R)/far-red (FR) light-sensing photoreceptor that regulates various aspects of plant development. Among the members of the phytochrome family, phytochrome A (phyA) exclusively mediates atypical phytochrome responses, such as the FR high irradiance response (FR-HIR), which is elicited under prolonged FR. A proteasome-based degradation pathway rapidly eliminates active Pfr (the FR-absorbing form of phyA) under R. To elucidate the structural basis for the phyA-specific properties, we systematically constructed 16 chimeric phytochromes in which each of four parts of the phytochrome molecule, namely, the N-terminal extension plus the Per/Arnt/Sim domain (N-PAS), the cGMP phosphodiesterase/adenyl cyclase/FhlA domain (GAF), the phytochrome domain (PHY), and the entire C-terminal half, was occupied by either the phyA or phytochrome B sequence. These phytochromes were expressed in transgenic Arabidopsis thaliana to examine their physiological activities. Consequently, the phyA N-PAS sequence was shown to be necessary and sufficient to promote nuclear accumulation under FR, whereas the phyA sequence in PHY was additionally required to exhibit FR-HIR. Furthermore, the phyA sequence in PHY alone substantially increased the light sensitivity to R. In addition, the GAF phyA sequence was important for rapid Pfr degradation. In summary, distinct structural modules, each of which confers different properties to phyA, are assembled on the phyA molecule.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Luz , Fitocromo A/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Núcleo Celular/metabolismo , Escuridão , Hipocótilo/genética , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/fisiologia , Hipocótilo/efeitos da radiação , Mutação , Fitocromo A/genética , Fitocromo B/genética , Fitocromo B/metabolismo , Plantas Geneticamente Modificadas , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Plântula/efeitos da radiação
19.
J Exp Bot ; 65(11): 2859-71, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24569036

RESUMO

Light and temperature are arguably two of the most important signals regulating the growth and development of plants. In addition to their direct energetic effects on plant growth, light and temperature provide vital immediate and predictive cues for plants to ensure optimal development both spatially and temporally. While the majority of research to date has focused on the contribution of either light or temperature signals in isolation, it is becoming apparent that an understanding of how the two interact is essential to appreciate fully the complex and elegant ways in which plants utilize these environmental cues. This review will outline the diverse mechanisms by which light and temperature signals are integrated and will consider why such interconnected systems (as opposed to entirely separate light and temperature pathways) may be evolutionarily favourable.


Assuntos
Luz , Plantas/metabolismo , Plantas/efeitos da radiação , Transdução de Sinais/efeitos da radiação , Temperatura , Relógios Circadianos/efeitos da radiação , Flores/fisiologia , Flores/efeitos da radiação , Fotorreceptores de Plantas/metabolismo
20.
Ann Hematol ; 93(4): 595-601, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24146232

RESUMO

Mixed phenotype acute leukemia (MPAL) in adults represents nearly 2 to 5 % of all acute leukemia cases. There are two large studies throughout the world and only case reports and small series have been reported in Latin America. This study retrospectively analyses the clinical characteristics and survival of 27 patients with MPAL evaluated in three medical institutions of Mexico. All cases meet World Health Organization 2008 criteria; 70.3 % of patients had B lymphoid/myeloid lineage MPAL. Induction chemotherapy protocols included 7 + 3 hyper-CVAD, high-density schedules, and pediatric-like regimens such as New York II and total XI. Complete remission was achieved in 23/27 patients (85.2 %). Only one patient died due to chemotherapy-induced aplasia during remission induction (5.2 %). In 68 % of cases, we were able to administer maintenance therapy as a regimen in lymphoblastic leukemia. At the time of analysis, 70.4 % of the patients in the entire cohort had died mainly as result of disease progression (73.6 %). Disease-free survival was 13 months (95 % CI, 9.6-16.3 months) and overall survival was 14.8 months (95 % CI 13.4-16.27). Survival rates are low and standardized therapy for the management of this type of leukemia is still lacking. This is the largest series reported in Mexico and to the best of our knowledge in Latin America.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Imunofenotipagem , Leucemia Aguda Bifenotípica/diagnóstico , Leucemia Aguda Bifenotípica/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Leucemia Aguda Bifenotípica/epidemiologia , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento , Adulto Jovem
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