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1.
Cell Rep Med ; 5(5): 101570, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38749422

RESUMO

While an association between Parkinson's disease (PD) and viral infections has been recognized, the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on PD progression remains unclear. Here, we demonstrate that SARS-CoV-2 infection heightens the risk of PD using human embryonic stem cell (hESC)-derived dopaminergic (DA) neurons and a human angiotensin-converting enzyme 2 (hACE2) transgenic (Tg) mouse model. Our findings reveal that SARS-CoV-2 infection exacerbates PD susceptibility and cellular toxicity in DA neurons pre-treated with human preformed fibrils (hPFFs). Additionally, nasally delivered SARS-CoV-2 infects DA neurons in hACE2 Tg mice, aggravating the damage initiated by hPFFs. Mice infected with SARS-CoV-2 display persisting neuroinflammation even after the virus is no longer detectable in the brain. A comprehensive analysis suggests that the inflammatory response mediated by astrocytes and microglia could contribute to increased PD susceptibility associated with SARS-CoV-2. These findings advance our understanding of the potential long-term effects of SARS-CoV-2 infection on the progression of PD.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Modelos Animais de Doenças , Neurônios Dopaminérgicos , Camundongos Transgênicos , Doença de Parkinson , SARS-CoV-2 , Animais , Neurônios Dopaminérgicos/patologia , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/virologia , Humanos , COVID-19/patologia , COVID-19/virologia , Doença de Parkinson/patologia , Doença de Parkinson/virologia , Camundongos , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Microglia/patologia , Microglia/metabolismo , Microglia/virologia , Células-Tronco Embrionárias Humanas/metabolismo , Astrócitos/patologia , Astrócitos/virologia , Astrócitos/metabolismo , Encéfalo/patologia , Encéfalo/virologia
3.
Nurse Educ Today ; 132: 106008, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37951151

RESUMO

INTRODUCTION: Evidence-based practice (EBP) is essential to ensure patient safety and improve the quality of nursing care. Nursing students' self-efficacy in employing EBP is crucial for the formation of a culture of EBP in healthcare organizations. OBJECTIVE: This study aimed to investigate the changes in nursing students' self-efficacy in employing EBP and the extent to which clinical performance affects these changes. METHODS: This study was a longitudinal descriptive study. Participants were nursing students who had received education on EBP theory and had clinical practice experience. Convenience sampling was used to select nursing students in their third year of study at a nursing college located in the southern region of Korea in 2020. The researcher measured EBP self-efficacy and clinical competence using an online survey tool at three time points (second semester of third year, first semester of fourth year, and second semester of fourth year). Multilevel modeling was used to identify factors affecting changes in EBP self-efficacy. RESULTS: The results showed that nursing students' EBP self-efficacy increased over time. Nursing leadership (p = .022), nursing skills (p = .028), communication (p < .001), and nursing process (p = .003) were significant factors that affected the changes in EBP self-efficacy. Individual differences in initial levels and change rates were still observed. CONCLUSION: Systematic education on EBP theory and practical training should be provided to nursing students from the beginning of their studies to graduation to deepen their EBP and clinical competence.


Assuntos
Estudantes de Enfermagem , Humanos , Competência Clínica , Autoeficácia , Prática Clínica Baseada em Evidências/métodos , Currículo
4.
PLoS One ; 18(8): e0289789, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37561724

RESUMO

OBJECTIVE: The purpose of this scoping review was to determine the underlying design of simulations that help undergraduate nursing students acquire evidence-based practice (EBP) experiences. METHOD: The JBI methodology was used for this review. The inclusion criteria were studies conducted in academic, clinical, or virtual settings that examined simulation programs designed to facilitate the acquisition of EBP by undergraduate nursing students. A comprehensive search was performed on Jan 3, 2022, using the Medical Literature Analysis and Retrieval System Online (MEDLINE; PubMed), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Education Resources Information Center (ERIC), and the Excerpta Medica database (EMBASE). Grey literature was not included. Publication year was limited to 2020 and later. There was no language restriction. Data were extracted using a tool developed by the reviewers and based on the National League for Nursing Jeffries Simulation Theory. RESULT: A total of 12,931 articles were found, and after duplicate articles and articles deemed ineligible based on the title and abstract (12,914 articles), 17 published papers were examined. The full texts of these studies were reviewed for eligibility, and one study was selected for the present scoping review. The selected study examined a mock trial designed to allow undergraduate nursing students to experience the ethical decision-making based on a diversity of evidence. The program reported in the study consisted of a prebriefing-simulation (mock)-debriefing structure with verified positive effects on EBP education. CONCLUSION: A mock trial is a useful educational strategy for allowing undergraduate nursing students to experience EBP, but a creative method should be found that can modify the mock trial for practical operation as the designing the program demands high levels of human and material resources. REGISTRATION: OSF Registries, https://osf.io/gdtyu, We updated OSF registry data for documenting important protocol amendments.


Assuntos
Bacharelado em Enfermagem , Estudantes de Enfermagem , Humanos , Prática Clínica Baseada em Evidências , Competência Clínica
5.
Cells ; 12(13)2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37443739

RESUMO

Steroid-induced cataracts (SIC) are defined as cataracts associated with the administration of corticosteroids. Long-term glucocorticoid treatment for inflammatory diseases reportedly increases the risk of SIC, and steroids can induce cataracts by disrupting ocular growth factor balance or homeostasis. In this study, we verified the effect of chondroitin sulfate proteoglycan 5 (CSPG5) using dexamethasone (dexa)-treated human lens epithelial (HLE-B3) cells and the lens epithelium from the anterior capsule of SIC patients obtained during cataract surgery. CSPG5 expression increased in the lens epithelium of SIC patients. The downregulation of CSPG5 suppressed the dexa-induced epithelial-mesenchymal transition (EMT)-related protein expression and motility in HLE-B3 cells. The disruption of the transcription factors EZH2 and B-Myb downregulated CSPG5, dexa-induced fibronectin expression, and cell migration in HLE-B3 cells, reaffirming that CSPG5 expression regulates EMT in lens epithelial cells. Taken together, these results indicate that the steroid-induced effects on lens epithelial cells are mediated via alterations in CSPG5 expression. Therefore, our study emphasizes the potential of CSPG5 as a therapeutic target for the prevention and treatment of SIC.


Assuntos
Catarata , Cristalino , Humanos , Cristalino/metabolismo , Catarata/induzido quimicamente , Catarata/metabolismo , Epitélio , Células Epiteliais/metabolismo , Proteoglicanas de Sulfatos de Condroitina
6.
Heliyon ; 9(4): e14096, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37025828

RESUMO

Background: The issue of a good death for cancer patients is becoming more prevalent. Hence, nurses' end-of-life work performance and stress levels in medical-surgical wards can significantly impact the quality of life of cancer patients and their caregivers. This study aimed to develop an end-of-life care education program for nurses taking care of cancer patients in medical-surgical ward and verify the program's preliminary effect. Method: Quasi-experimental research using a one-group pretest-posttest design was carried out for this study. The end-of-life care manual for nurses in general wards were developed through expert validation. Initial in-person and follow-on online self-education sessions were conducted based on the end-of-life care manual. A total of 70 nurses participated in the end-of-life care education program. End-of-life care stress and end-of-life care performance were measured as preliminary program effects. An online survey was conducted before the initial in-person education and after the follow-up online education. Results: The end-of-life care education program effectively improved general ward nurses' end-of-life care performance. This performance was improved in the physical and psychological domains. However, this program did not improve the nurses' performance in end-of-life care in the spiritual domain. Furthermore, it did not effectively reduce the stress on end-of-life care, indicating that improvements should be made. Conclusions: The improvement of effective end-of-life care education programs for nurses caring for cancer patients in general wards is required. Most importantly, efforts at the hospital organization level are necessary to reduce the stress of end-of-life care by improving the working environment. Additionally, it is necessary to conduct preemptive tailored intervention programs for nurses, such as a resilience improvement program.

7.
Artigo em Inglês | MEDLINE | ID: mdl-34682713

RESUMO

BACKGROUND: The nursing curriculum should be systematically developed to improve the evidence-based practice (EBP) competencies of undergraduate nursing students. We attempted to identify the factors important for developing or improving the EBP-integrated nursing curriculum. METHODS: This study adopted the qualitative research design using qualitative content analysis. A total of 168 study participants were included in the study. The participants were third-year nursing students at a private university located in southeastern South Korea. An open-ended question was asked: "To improve students' EBP competencies during theory classes, on-campus practicums, or clinical practicums, what do you think is necessary?" RESULT(S): The analysis presented thirty themes, which were grouped into 10 sub-categories and further into four categories, and finally into three main categories. The students responded that they needed to form their own attitudes toward EBP. Regarding educator-related needs, students responded that effective teaching and learning methods should be used in classes. The students also suggested that the EBP process should be applied during clinical practicum. Regarding school-related needs, students suggested that EBP education should be applied at the beginning of the curriculum. Furthermore, the students recommended that repeated teaching should be used for EBP, and that EBP education should be connected to the major courses. CONCLUSIONS: The development of EBP competencies among undergraduate students is an important factor that can impact the nursing quality and patient safety. Based on the findings of this study, multidimensional efforts are needed to improve the liberal arts education of students and strengthen the educators' competencies of EBNP and EBTP. Furthermore, schools should strive to assess students' educational needs regularly and integrate the subsequent EBP-integrated nursing curricula consistent with these needs.


Assuntos
Bacharelado em Enfermagem , Estudantes de Enfermagem , Currículo , Enfermagem Baseada em Evidências , Prática Clínica Baseada em Evidências , Humanos , República da Coreia
8.
Planta ; 247(6): 1439-1448, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29536220

RESUMO

MAIN CONCLUSION: Under normal growth conditions, Arabidopsis VOZ1 interacts with DREB2C and acts as a transcriptional repressor by reducing DNA binding of DREB2C. Under heat stress conditions, VOZ1 is degraded by ubiquitination, and DREB2C, which is freed from VOZ1, functions as a transcription activator. To investigate the mechanism by which the DEHYDRATION-RESPONSIVE ELEMENT-BINDING FACTOR 2C (DREB2C)-dependent signaling cascade regulates heat stress (HS) responses, we performed a yeast two-hybrid screening using the DREB2C APETALA2 (AP2) DNA-binding domain as the bait against a cDNA library derived from Arabidopsis. We identified VASCULAR PLANT ONE-ZINC-FINGER 1 (VOZ1) and further verified positive VOZ1 colonies by repeating the X-α-Gal second screening and pull-down assay in vitro. Deletion analysis of VOZ1 demonstrated that the amino acid residues in its transcriptional regulatory, zinc finger and NAC domains are essential for the DREB2C-AP2 interaction. Although the HsfA3 promoter was strongly transactivated by DREB2C in Arabidopsis protoplasts, transient co-expression of VOZ1 (35S:VOZ1) with DREB2C (35S:DREB2C) in Arabidopsis protoplasts resulted in a significant decrease in the activity of GUS fused to the HsfA3 promoter (Prom HsfA3 :GUS), indicating that VOZ1 acts as a repressor of DREB2C. In electrophoretic mobility shift assays (EMSAs), the signal generated by binding of DREB2C to DRE gradually decreased with increasing VOZ1 level, providing evidence that the interaction of the DREB2C AP2 DNA-binding domain with DRE is blocked by VOZ1. Additionally, a voz1 voz2-2 double knockout mutant exhibited increased HS tolerance, likely due to the suppressive function of VOZs. Taken together, these results demonstrate that VOZ1 functions as a negative regulator of HS-inducible DREB2C signaling by blocking access to the AP2 DNA-binding domain of DREB2C.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Ligação a DNA/metabolismo , Resposta ao Choque Térmico , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Desidratação , Ensaio de Desvio de Mobilidade Eletroforética , Regulação da Expressão Gênica de Plantas , Temperatura Alta , Regiões Promotoras Genéticas/genética , Transdução de Sinais , Termotolerância , Fatores de Transcrição/genética , Técnicas do Sistema de Duplo-Híbrido
9.
Mol Cells ; 40(8): 577-586, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28756655

RESUMO

Phytocystatins (PhyCYSs) are plant-specific proteinaceous inhibitors that are implicated in protein turnover and stress responses. Here, we characterized a PhyCYS from Arabidopsis thaliana, which was designated AtCYS5. RT-qPCR analysis showed that the expression of AtCYS5 in germinating seeds was induced by heat stress (HS) and exogenous abscisic acid (ABA) treatment. Analysis of the expression of the ß-glucuronidase reporter gene under the control of the AtCYS5 promoter showed that AtCYS5 expression during seed germination was induced by HS and ABA. Constitutive overexpression of AtCYS5 driven by the cauliflower mosaic virus 35S promoter led to enhanced HS tolerance in transgenic Arabidopsis, which was characterized by higher fresh weight and root length compared to wild-type (WT) and knockout (cys5) plants grown under HS conditions. The HS tolerance of At-CYS5-overexpressing transgenic plants was associated with increased insensitivity to exogenous ABA during both seed germination and post-germination compared to WT and cys5. Although no HS elements were identified in the 5'-flanking region of AtCYS5, canonical ABA-responsive elements (ABREs) were detected. AtCYS5 was upregulated in ABA-treated protoplasts transiently co-expressing this gene and genes encoding bZIP ABRE-binding factors (ABFs and AREB3). In the absence of ABA, ABF1 and ABF3 directly bound to the ABREs in the AtCYS5 promoter, which activated the transcription of this gene in the presence of ABA. These results suggest that an ABA-dependent pathway plays a positive role in the HS-responsive expression of AtCYS5 during seed germination and post-germination growth.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Germinação , Resposta ao Choque Térmico , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Germinação/genética , Resposta ao Choque Térmico/efeitos dos fármacos , Resposta ao Choque Térmico/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Ligação Proteica/efeitos dos fármacos , Protoplastos/efeitos dos fármacos , Protoplastos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Elementos de Resposta/genética , Plântula/efeitos dos fármacos , Plântula/genética , Sementes/efeitos dos fármacos , Sementes/genética , Transcrição Gênica/efeitos dos fármacos
10.
Mol Cells ; 39(6): 477-83, 2016 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-27109422

RESUMO

Heat shock factors (Hsfs) are central regulators of abiotic stress responses, especially heat stress responses, in plants. In the current study, we characterized the activity of the Hsf gene HsfA3 in Arabidopsis under oxidative stress conditions. HsfA3 transcription in seedlings was induced by reactive oxygen species (ROS), exogenous hydrogen peroxide (H2O2), and an endogenous H2O2 propagator, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB). HsfA3-overexpressing transgenic plants exhibited increased oxidative stress tolerance compared to untransformed wild-type plants (WT), as revealed by changes in fresh weight, chlorophyll fluorescence, and ion leakage under light conditions. The expression of several genes encoding galactinol synthase (GolS), a key enzyme in the biosynthesis of raffinose family oligosaccharides (RFOs), which function as antioxidants in plant cells, was induced in HsfA3 overexpressors. In addition, galactinol levels were higher in HsfA3 overexpressors than in WT under unstressed conditions. In transient transactivation assays using Arabidopsis leaf protoplasts, HsfA3 activated the transcription of a reporter gene driven by the GolS1 or GolS2 promoter. Electrophoretic mobility shift assays showed that GolS1 and GolS2 are directly regulated by HsfA3. Taken together, these findings provide evidence that GolS1 and GolS2 are directly regulated by HsfA3 and that GolS enzymes play an important role in improving oxidative stress tolerance by increasing galactinol biosynthesis in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Ligação a DNA/genética , Galactosiltransferases/genética , Proteínas de Choque Térmico/genética , Estresse Oxidativo , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Arabidopsis/genética , Dibromotimoquinona/metabolismo , Dissacarídeos/biossíntese , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Fatores de Transcrição de Choque Térmico , Peróxido de Hidrogênio/farmacologia , Plantas Geneticamente Modificadas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Plântula/genética , Plântula/fisiologia , Ativação Transcricional
11.
Biochem Biophys Res Commun ; 452(1): 91-8, 2014 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-25150152

RESUMO

Plant dehydration-responsive element binding factors (DREBs) are transcriptional regulators of the APETELA2/Ethylene Responsive element-binding Factor (AP2/ERF) family that control expression of abiotic stress-related genes. We show here that under conditions of mild heat stress, constitutive overexpression seeds of transgenic DREB2C overexpression Arabidopsis exhibit delayed germination and increased abscisic acid (ABA) content compared to untransformed wild-type (WT). Treatment with fluridone, an inhibitor of the ABA biosynthesis abrogated these effects. Expression of an ABA biosynthesis-related gene, 9-cis-epoxycarotenoid dioxygenase 9 (NCED9) was up-regulated in the DREB2C overexpression lines compared to WT. DREB2C was able to trans-activate expression of NCED9 in Arabidopsis leaf protoplasts in vitro. Direct and specific binding of DREB2C to a complete DRE on the NCED9 promoter was observed in electrophoretic mobility shift assays. Exogenous ABA treatment induced DREB2C expression in germinating seeds of WT. Vegetative growth of transgenic DREB2C overexpression lines was more strongly inhibited by exogenous ABA compared to WT. These results suggest that DREB2C is a stress- and ABA-inducible gene that acts as a positive regulator of ABA biosynthesis in germinating seeds through activating NCED9 expression.


Assuntos
Ácido Abscísico/biossíntese , Proteínas de Arabidopsis/fisiologia , Arabidopsis/metabolismo , Proteínas de Ligação a DNA/fisiologia , Germinação , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Ensaio de Desvio de Mobilidade Eletroforética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas
12.
Plant Cell Rep ; 33(8): 1239-54, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24737413

RESUMO

KEY MESSAGE: DREB2C acts as a transcriptional activator of the salt tolerance-related COLD - REGULATED 15A gene. DEHYDRATION-RESPONSIVE ELEMENT BINDING FACTOR 2C (DREB2C) regulates plant responses to heat stress. We report here that DREB2C is induced by NaCl stress in Arabidopsis, based on quantitative RT-PCR analyses of transcript levels and DREB2C promoter-controlled GUS activity assays. Constitutive overexpression of DREB2C from the cauliflower mosaic virus (CaMV) 35S promoter led to enhanced salt tolerance in transgenic Arabidopsis and canola plants that was characterized by higher chlorophyll content, lower tissue Na(+) content, reduced rate of water loss, and tighter membrane integrity in plants grown in NaCl-containing medium. Basal expression of the stress-responsive genes COLD-REGULATED 15A (COR15A), RESPONSIVE TO DEHYDRATION (RD) 29A and RD29B, was higher in transgenic DREB2C-overexpressing Arabidopsis plants than in the wild-type. Promoter transactivation assays and electrophoretic mobility-shift assays showed that DREB2C interacts directly with the three DREs in the COR15A promoter, both in vivo and in vitro. Transgenic Arabidopsis constitutively overexpressing COR15A from the CaMV35S promoter exhibited greater NaCl tolerance than the untransformed wild-type. Taken together, the data suggest that DREB2C functions as transcriptional activator that promotes NaCl tolerance, in part through upregulation of the stress-responsive gene COR15A.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Brassica napus/fisiologia , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Cloreto de Sódio/farmacologia , Proteínas de Arabidopsis/metabolismo , Brassica napus/efeitos dos fármacos , Brassica napus/genética , Clorofila/metabolismo , Proteínas e Peptídeos de Choque Frio/genética , Proteínas e Peptídeos de Choque Frio/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Expressão Gênica , Genes Reporter , Folhas de Planta/genética , Folhas de Planta/fisiologia , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Ligação Proteica , RNA de Plantas/genética , Estresse Fisiológico , Água/análise
13.
Transgenic Res ; 23(1): 109-23, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23868510

RESUMO

Phytocystatins are proteinaceous inhibitors of cysteine proteases. They have been implicated in the regulation of plant protein turnover and in defense against pathogens and insects. Here, we have characterized an Arabidopsis phytocystatin family gene, Arabidopsis thaliana phytocystatin 4 (AtCYS4). AtCYS4 was induced by heat stress. The heat shock tolerance of AtCYS4-overexpressing transgenic plants was greater than that of wild-type and cys4 knock-down plants, as measured by fresh weight and root length. Although no heat shock elements were identified in the 5'-flanking region of the AtCYS4 gene, canonical ABA-responsive elements (ABREs) and dehydration-responsive elements (DREs) were found. Transient promoter activity measurements showed that AtCYS4 expression was up-regulated in unstressed protoplasts by co-expression of DRE-binding factor 2s (DREB2s), especially by DREB2C, but not by bZIP transcription factors that bind to ABREs (ABFs, ABI5 and AREBs). DREB2C bound to and activated transcription from the two DREs on the AtCYS4 promoter although some preference was observed for the GCCGAC DRE element over the ACCGAC element. AtCYS4 transcript and protein levels were elevated in transgenic DREB2C overexpression lines with corresponding decline of endogenous cysteine peptidase activity. We propose that AtCYS4 functions in thermotolerance under the control of the DREB2C cascade.


Assuntos
Proteínas de Arabidopsis/genética , Cistatinas/genética , Proteínas de Ligação a DNA/genética , Estresse Fisiológico/genética , Ativação Transcricional , Arabidopsis/genética , Proteínas de Arabidopsis/biossíntese , Cistatinas/metabolismo , Proteínas de Ligação a DNA/biossíntese , Regulação da Expressão Gênica de Plantas , Golpe de Calor , Resposta ao Choque Térmico/genética , Regiões Promotoras Genéticas
14.
J Integr Plant Biol ; 54(9): 640-51, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22716647

RESUMO

The dehydration-responsive element-binding factor 2C (DREB2C) is a member of the CBF/DREB subfamily of proteins, which contains a single APETALA2/Ethylene responsive element-binding factor (AP2/ERF) domain. To identify the expression pattern of the DREB2C gene, which contains multiple transcription cis-regulatory elements in its promoter, an approximately 1.4 kb upstream DREB2C sequence was fused to the ß-glucuronidase reporter gene (GUS) and the recombinant p1244 construct was transformed into Arabidopsis thaliana (L.) Heynh. The promoter of the gene directed prominent GUS activity in the vasculature in diverse young dividing tissues. Upon applying heat stress (HS), GUS staining was also enhanced in the vasculature of the growing tissues. Analysis of a series of 5'-deletions of the DREB2C promoter revealed that a proximal upstream sequence sufficient for the tissue-specific spatial and temporal induction of GUS expression by HS is localized in the promoter region between -204 and -34 bps relative to the transcriptional start site. Furthermore, electrophoretic mobility shift assay (EMSA) demonstrated that nuclear protein binding activities specific to a -120 to -32 bp promoter fragment increased after HS. These results indicate that the TATA-proximal region and some latent trans-acting factors may cooperate in HS-induced activation of the Arabidopsis DREB2C promoter.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Temperatura Alta , Especificidade de Órgãos/genética , Regiões Promotoras Genéticas , Estresse Fisiológico/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Pareamento de Bases/genética , DNA de Plantas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Glucuronidase/metabolismo , Resposta ao Choque Térmico/genética , Proteínas Nucleares/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica/genética , Proteínas Recombinantes de Fusão/metabolismo , Deleção de Sequência/genética , TATA Box/genética , Fatores de Tempo
15.
Mol Cells ; 33(2): 135-40, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22286229

RESUMO

Dehydration-responsive element-binding proteins (DREBs)regulate plant responses to environmental stresses. In the current study, transcription of DREB2C, a class 2 Arabidopsis DREB, was induced by a superoxide anion propagator, methyl viologen (MV). The oxidative stress tolerance of DREB2C-overexpressing transgenic plants was significantly greater than that of wild-type plants, as measured by ion leakage and chlorophyll fluorescence under light conditions. The transcriptional activity of several ascorbate peroxidase (APX) genes as well as APX protein activity was induced in DREB2C overexpressors. Additionally, the level of H2O2 in the overexpressors was lower than in wt plants under similar oxidative stress conditions. An electrophoretic mobility shift assay and transient activator reporter assay showed that APX2 expression was regulated by heat shock factor A3 (HsfA3) and that HsfA3 is regulated at the transcriptional level by DREB2C. These results suggest that DREB2C plays an important role in promoting oxidative stress tolerance in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Ligação a DNA/metabolismo , Estresse Oxidativo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Ascorbato Peroxidases/genética , Ascorbato Peroxidases/metabolismo , Sobrevivência Celular/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição de Choque Térmico , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Herbicidas/farmacologia , Peróxido de Hidrogênio/metabolismo , Paraquat/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Transgenes/genética
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