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Compared to normal cells, tumour cells exhibit an upregulation of glucose transporters and an increased rate of glycolytic activity. In previous research, we successfully identified a promising hit compound BH10 through a rigorous screening process, which demonstrates a potent capacity for inhibiting cancer cell proliferation by targeting glucose metabolism. In the current study, we identify Kelch-like ECH-associated protein 1 (Keap1) as a potential protein target of BH10via avidin pull-down assays with biotinylated-BH10. Subsequently, we present a comprehensive analysis of a series of BH10 analogues characterized by the incorporation of a naphthoimidazole scaffold and the introduction of a triazole ring with diverse terminal functional groups. Notably, compound 4d has emerged as the most potent candidate, exhibiting better anti-cancer activities against HEC1A cancer cells with an IC50 of 2.60 µM, an extended biological half-life, and an improved pharmacokinetic profile (compared to BH10) in mice.
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To cope with growth in low-phosphate (Pi) soils, plants have evolved adaptive responses that involve both developmental and metabolic changes. Phosphate Starvation Response 1 (PHR1) and related transcription factors play a central role in the control of Pi starvation responses (PSRs). How Pi levels control PHR1 activity, and thus PSRs, remains to be elucidated. Here, we identify a direct Pi-dependent inhibitor of PHR1 in Arabidopsis, SPX1, a nuclear protein that shares the SPX domain with yeast Pi sensors and with several Pi starvation signaling proteins from plants. Double mutation of SPX1 and of a related gene, SPX2, resulted in molecular and physiological changes indicative of increased PHR1 activity in plants grown in Pi-sufficient conditions or after Pi refeeding of Pi-starved plants but had only a limited effect on PHR1 activity in Pi-starved plants. These data indicate that SPX1 and SPX2 have a cellular Pi-dependent inhibitory effect on PHR1. Coimmunoprecipitation assays showed that the SPX1/PHR1 interaction in planta is highly Pi-dependent. DNA-binding and pull-down assays with bacterially expressed, affinity-purified tagged SPX1 and ΔPHR1 proteins showed that SPX1 is a competitive inhibitor of PHR1 binding to its recognition sequence, and that its efficiency is highly dependent on the presence of Pi or phosphite, a nonmetabolizable Pi analog that can repress PSRs. The relative strength of the SPX1/PHR1 interaction is thus directly influenced by Pi, providing a link between Pi perception and signaling.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Nucleares/metabolismo , Fosfatos/farmacologia , Fatores de Transcrição/metabolismo , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/genética , DNA de Plantas/metabolismo , Modelos Biológicos , Mutação/genética , Proteínas Nucleares/genética , Ligação Proteica/efeitos dos fármacos , Fatores de Transcrição/antagonistas & inibidoresRESUMO
Stress constantly challenges plant adaptation to the environment. Of all stress types, arsenic was a major threat during the early evolution of plants. The most prevalent chemical form of arsenic is arsenate, whose similarity to phosphate renders it easily incorporated into cells via the phosphate transporters. Here, we found that arsenate stress provokes a notable transposon burst in plants, in coordination with arsenate/phosphate transporter repression, which immediately restricts arsenate uptake. This repression was accompanied by delocalization of the phosphate transporter from the plasma membrane. When arsenate was removed, the system rapidly restored transcriptional expression and membrane localization of the transporter. We identify WRKY6 as an arsenate-responsive transcription factor that mediates arsenate/phosphate transporter gene expression and restricts arsenate-induced transposon activation. Plants therefore have a dual WRKY-dependent signaling mechanism that modulates arsenate uptake and transposon expression, providing a coordinated strategy for arsenate tolerance and transposon gene silencing.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Arseniatos/metabolismo , Elementos de DNA Transponíveis/genética , Fatores de Transcrição/metabolismo , Arabidopsis/efeitos dos fármacos , Arseniatos/toxicidade , Sequência de Bases , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Regulação para Baixo/efeitos dos fármacos , Histonas/metabolismo , Lisina/metabolismo , Dados de Sequência Molecular , Fenótipo , Proteínas de Transporte de Fosfato/metabolismo , Fosfatos/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Proteínas Repressoras/metabolismoRESUMO
MicroRNAs (miRNA) regulate key aspects of development and physiology in animals and plants. These regulatory RNAs act as guides of effector complexes to recognize specific mRNA sequences based on sequence complementarity, resulting in translational repression or site-specific cleavage. In plants, most miRNA targets are cleaved and show almost perfect complementarity with the miRNAs around the cleavage site. Here, we examined the non-protein coding gene IPS1 (INDUCED BY PHOSPHATE STARVATION 1) from Arabidopsis thaliana. IPS1 contains a motif with sequence complementarity to the phosphate (Pi) starvation-induced miRNA miR-399, but the pairing is interrupted by a mismatched loop at the expected miRNA cleavage site. We show that IPS1 RNA is not cleaved but instead sequesters miR-399. Thus, IPS1 overexpression results in increased accumulation of the miR-399 target PHO2 mRNA and, concomitantly, in reduced shoot Pi content. Engineering of IPS1 to be cleavable abolishes its inhibitory activity on miR-399. We coin the term 'target mimicry' to define this mechanism of inhibition of miRNA activity. Target mimicry can be generalized beyond the control of Pi homeostasis, as demonstrated using artificial target mimics.
Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/metabolismo , Proteínas de Plantas/genética , RNA de Plantas/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Arabidopsis/metabolismo , Mimetismo Molecular , Dados de Sequência Molecular , Proteínas de Plantas/metabolismoRESUMO
During the past two decades, nitric oxide (NO) has evolved from a mere gaseous free radical to become a new messenger in plant biology with an important role in a plethora of physiological processes. This molecule is involved in the regulation of plant growth and development, pathogen defence and abiotic stress responses, and in most cases this is achieved through its interaction with phytohormones. Understanding the role of plant growth regulators is essential to elucidate how plants activate the appropriate set of responses to a particular developmental stage or a particular stress. The first task to achieve this goal is the identification of molecular targets, especially those involved in the regulation of the crosstalk. The nature of NO targets in these growth and development processes and stress responses remains poorly described. Currently, the molecular mechanisms underlying the effects of NO in these processes and their interaction with other plant hormones are beginning to unravel. In this review, we made a compilation of the described interactions between NO and phytohormones during early plant developmental processes (i.e. seed dormancy and germination, hypocotyl elongation and root development).
Assuntos
Regulação da Expressão Gênica de Plantas , Óxido Nítrico/metabolismo , Desenvolvimento Vegetal , Reguladores de Crescimento de Plantas/genética , Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Plantas/metabolismo , Receptor Cross-TalkRESUMO
The study was aimed at analysing the reciprocal relationships of several clinical and neurobiological items in order to predict alcohol misuse in patients with bulimia nervosa (BN). Seventy BN patients and 70 healthy controls were assessed for depression, impulsivity, borderline personality traits and self-defeating behaviours using specific scales; serum cortisol and 24-hour urinary excretion of serotonin and 5-hydroxiindolacetic acid were also assessed. The study confirmed the implications of these clinical factors for alcohol misuse in BN patients, but the results suggested that depressive symptoms and hypercortisolism could lie behind these relationships.
Assuntos
Alcoolismo/complicações , Bulimia Nervosa/complicações , Bulimia Nervosa/psicologia , Hidrocortisona/metabolismo , Neurobiologia , Serotonina/urina , Ácido Acético/urina , Adolescente , Adulto , Alcoolismo/psicologia , Transtorno da Personalidade Borderline , Depressão/complicações , Depressão/psicologia , Transtorno Depressivo/complicações , Transtorno Depressivo/psicologia , Feminino , Humanos , Hidrocortisona/sangue , Comportamento Impulsivo , Indóis/urina , Masculino , Modelos Psicológicos , Serotonina/metabolismo , Adulto JovemRESUMO
BACKGROUND: Central line-associated bloodstream infections (CLABSIs) are among the most epidemiologically relevant health care-associated infections. The aseptic non-touch technique (ANTT) is a standardized practice used to prevent CLABSIs. In a pediatric hospital, the overall CLABSI rate was 1.92/1000 catheter days (CD). However, in one unit, the rate was 5.7/1000 CD. METHODS: Nurses were trained in ANTT. For the implementation, plan-do-study-act (PDSA) cycles were completed. Adherence monitoring of the ANTT and epidemiological surveillance were performed. RESULTS: ANTT adherence of 95% was achieved after 6 PDSA cycles. Hand hygiene and general cleaning reached 100% adherence. Port disinfection and material collection had the lowest adherence rates, with 76.2% and 84.7%, respectively. The CLABSI rate decreased from 5.7 to 1.26/1000 CD. CONCLUSION: The implementation of ANTT helped reduce the CLABSI rate. Training and continuous monitoring are key to maintaining ANTT adherence.
INTRODUCCIÓN: Las infecciones relacionadas con catéteres venosos centrales son unas de las infecciones asociadas a la atención de salud con mayor relevancia epidemiológica. La técnica aséptica «no tocar¼ es una práctica estandarizada que se utiliza para prevenir estas infecciones. En un hospital pediátrico, la tasa de infecciones relacionadas con catéteres venosos centrales fue de 1.92/1000 días de catéter. Sin embargo, en una de las unidades la tasa fue de 5.7/1000 días de catéter. MÉTODO: Se capacitaron enfermeras en la técnica aséptica «no tocar¼. Para la implementación se cumplieron ciclos de planificar-hacer-estudiar-actuar (PHEA). Se realizaron seguimiento de la adherencia a la técnica y vigilancia epidemiológica. RESULTADOS: Se logró una adherencia a la técnica aséptica «no tocar¼ del 95% después de seis ciclos. La higiene de manos y la limpieza general alcanzaron un 100% de cumplimiento. La desinfección de los puertos y la recolección de material alcanzaron la menor adherencia, con un 76.2% y un 84.7%, respectivamente. La tasa de infecciones relacionadas con catéteres venosos centrales disminuyó de 5.7 a 1.26 por 1000 días de catéter. CONCLUSIONES: La implementación de la técnica aséptica «no tocar¼ ayudó en la reducción de infecciones relacionadas con catéteres venosos centrales. La capacitación y el seguimiento continuo son clave para mantener el cumplimiento de la técnica.
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Infecções Relacionadas a Cateter , Cateterismo Venoso Central , Infecção Hospitalar , Fidelidade a Diretrizes , Hospitais Pediátricos , Humanos , Infecções Relacionadas a Cateter/prevenção & controle , Infecções Relacionadas a Cateter/epidemiologia , Infecção Hospitalar/prevenção & controle , Cateterismo Venoso Central/efeitos adversos , Higiene das Mãos/normas , Higiene das Mãos/métodos , Criança , Assepsia/métodos , Desinfecção/métodosRESUMO
The Trunk Control Measurement Scale (TCMS) is a valid and reliable tool to assess static and dynamic trunk control in cerebral palsy. However, there is no evidence informing about differences between novice and expert raters. A cross-sectional study was conducted with participants between the ages of 6 and 18 years with a CP diagnosis. The TCMS Spanish version (TCMS-S) was administered in-person by an expert rater, and video recordings were taken for later scoring by the expert and three other raters with varying levels of clinical experience. The intraclass correlation coefficient (ICC) was used to evaluate reliability between raters for the total and subscales of the TCMS-S scores. Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC) were also calculated. There was a high level of agreement between expert raters (ICC ≥ 0.93), while novice raters demonstrated good agreement (ICC > 0.72). Additionally, it was observed that novice raters had a slightly higher SEM and MDC than expert raters. The Selective Movement Control subscale exhibited slightly higher SEM and MDC values compared to the TCMS-S total and other subscales, irrespective of the rater's level of expertise. Overall, the study showed that the TCMS-S is a reliable tool for evaluating trunk control in the Spanish pediatric population with cerebral palsy, regardless of the rater's experience level.
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The interplay between the phytohormone abscisic acid (ABA) and the gasotransmitter nitric oxide (NO) regulates seed germination and post-germinative seedling growth. We show that GAP1 (germination in ABA and cPTIO 1) encodes the transcription factor ANAC089 with a critical membrane-bound domain and extranuclear localization. ANAC089 mutants lacking the membrane-tethered domain display insensitivity to ABA, salt, and osmotic and cold stresses, revealing a repressor function. Whole-genome transcriptional profiling and DNA-binding specificity reveals that ANAC089 regulates ABA- and redox-related genes. ANAC089 truncated mutants exhibit higher NO and lower ROS and ABA endogenous levels, alongside an altered thiol and disulfide homeostasis. Consistently, translocation of ANAC089 to the nucleus is directed by changes in cellular redox status after treatments with NO scavengers and redox-related compounds. Our results reveal ANAC089 to be a master regulator modulating redox homeostasis and NO levels, able to repress ABA synthesis and signaling during Arabidopsis seed germination and abiotic stress.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Retroalimentação Fisiológica , Germinação , Sementes , Transdução de Sinais , Estresse Fisiológico , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Sequência de Bases , Sítios de Ligação , Dissulfetos/metabolismo , DNA de Plantas/metabolismo , Regulação para Baixo/genética , Mutação com Ganho de Função/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Germinação/genética , Óxido Nítrico/metabolismo , Oxirredução , Ligação Proteica , Sementes/genética , Sementes/crescimento & desenvolvimento , Frações Subcelulares/metabolismo , Compostos de Sulfidrila/metabolismo , Transcriptoma/genética , Regulação para Cima/genéticaRESUMO
Plant survival depends on seed germination and progression through post-germinative developmental checkpoints. These processes are controlled by the stress phytohormone abscisic acid (ABA). ABA regulates the basic leucine zipper transcriptional factor ABI5, a central hub of growth repression, while the reactive nitrogen molecule nitric oxide (NO) counteracts ABA during seed germination. However, the molecular mechanisms by which seeds sense more favourable conditions and start germinating have remained elusive. Here we show that ABI5 promotes growth via NO, and that ABI5 accumulation is altered in genetic backgrounds with impaired NO homeostasis. S-nitrosylation of ABI5 at cysteine-153 facilitates its degradation through CULLIN4-based and KEEP ON GOING E3 ligases, and promotes seed germination. Conversely, mutation of ABI5 at cysteine-153 deregulates protein stability and inhibition of seed germination by NO depletion. These findings suggest an inverse molecular link between NO and ABA hormone signalling through distinct posttranslational modifications of ABI5 during early seedling development.
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Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Germinação , Óxido Nítrico/metabolismo , Arabidopsis , Proteínas Culina/metabolismo , Regulação da Expressão Gênica de Plantas , Homeostase , Processamento de Proteína Pós-Traducional , S-Nitrosoglutationa , Plântula/crescimento & desenvolvimento , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Despite evolutionary conserved mechanisms to silence transposable element activity, there are drastic differences in the abundance of transposable elements even among closely related plant species. We conducted a de novo assembly for the 375â Mb genome of the perennial model plant, Arabis alpina. Analysing this genome revealed long-lasting and recent transposable element activity predominately driven by Gypsy long terminal repeat retrotransposons, which extended the low-recombining pericentromeres and transformed large formerly euchromatic regions into repeat-rich pericentromeric regions. This reduced capacity for long terminal repeat retrotransposon silencing and removal in A. alpina co-occurs with unexpectedly low levels of DNA methylation. Most remarkably, the striking reduction of symmetrical CG and CHG methylation suggests weakened DNA methylation maintenance in A. alpina compared with Arabidopsis thaliana. Phylogenetic analyses indicate a highly dynamic evolution of some components of methylation maintenance machinery that might be related to the unique methylation in A. alpina.
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Four different cDNAs encoding alpha-expansins have been identified in Cicer arietinum (Ca-EXPA1, Ca-EXPA2, Ca-EXPA3 and Ca-EXPA4). The shared amino acid sequence similarity among the four alpha-expansin proteins ranged from 67 to 89%. All of them display common characteristics such as molecular mass (around 24 kDa), amino acid numbers, and also the presence of a signal peptide. The transcription pattern of chickpea alpha-expansin genes in seedlings and plants suggests a specific role for each of the four alpha-expansins in different phases of development or in different plant organs. High levels of Ca-EXPA2 transcripts coincide with maximum epicotyl and stem growth, indicating an important involvement of this particular alpha-expansin in elongating tissues. Ca-EXPA3 would be related to radicle development, while Ca-EXPA4 seems to be involved in pod development. A considerable increase in the level of all Ca-EXPA transcripts accompanied the indole acetic acid (IAA) plus brassinolide (BR)-induced elongation of excised epicotyl segments. This IAA + BR induction was seen even for the chickpea expansin genes whose transcription was not affected by IAA or BR alone.