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1.
BMC Infect Dis ; 24(1): 466, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38698304

RESUMO

BACKGROUND: Hospital-acquired influenza (HAI) is under-recognized despite its high morbidity and poor health outcomes. The early detection of HAI is crucial for curbing its transmission in hospital settings. AIM: This study aimed to investigate factors related to HAI, develop predictive models, and subsequently compare them to identify the best performing machine learning algorithm for predicting the occurrence of HAI. METHODS: This retrospective observational study was conducted in 2022 and included 111 HAI and 73,748 non-HAI patients from the 2011-2012 and 2019-2020 influenza seasons. General characteristics, comorbidities, vital signs, laboratory and chest X-ray results, and room information within the electronic medical record were analysed. Logistic Regression (LR), Random Forest (RF), Extreme Gradient Boosting (XGB), and Artificial Neural Network (ANN) techniques were used to construct the predictive models. Employing randomized allocation, 80% of the dataset constituted the training set, and the remaining 20% comprised the test set. The performance of the developed models was assessed using metrics such as the area under the receiver operating characteristic curve (AUC), the count of false negatives (FN), and the determination of feature importance. RESULTS: Patients with HAI demonstrated notable differences in general characteristics, comorbidities, vital signs, laboratory findings, chest X-ray result, and room status compared to non-HAI patients. Among the developed models, the RF model demonstrated the best performance taking into account both the AUC (83.3%) and the occurrence of FN (four). The most influential factors for prediction were staying in double rooms, followed by vital signs and laboratory results. CONCLUSION: This study revealed the characteristics of patients with HAI and emphasized the role of ventilation in reducing influenza incidence. These findings can aid hospitals in devising infection prevention strategies, and the application of machine learning-based predictive models especially RF can enable early intervention to mitigate the spread of influenza in healthcare settings.


Assuntos
Infecção Hospitalar , Influenza Humana , Aprendizado de Máquina , Humanos , Influenza Humana/epidemiologia , Influenza Humana/diagnóstico , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Infecção Hospitalar/epidemiologia , Idoso , Adulto , Algoritmos , Curva ROC , Redes Neurais de Computação , Adulto Jovem , Idoso de 80 Anos ou mais , Modelos Logísticos
2.
Curr Psychol ; : 1-11, 2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36855640

RESUMO

This meta-analysis examines the correlation between goal orientation and related variables in online learning to examine the influence of individual goal orientation on online learning as well as the differences arising from diverse cultural backgrounds. The study analyzed 27 papers from 2000 to 2022, comprising 8 US and 19 Korean studies. The average effect size of goal orientation and related variables, such as learning satisfaction, self-efficacy, and task value, were also analyzed. In addition, moderating effect according to the country and type of goal orientation was examined to evaluate differences arising from cultures. It was found that learning immersion, learning participation, and intention to continue learning, showed a high average effect size with goal orientation, with the other related variables also demonstrating a significant average effect size. There was no moderating effect of the state in the relationship between goal orientation and academic achievement, although a moderating effect existed according to the type of goal orientation. Based on the results of this study, we analyzed the variables that can reinforce learning along with goal orientation in online learning situations. Therefore, our findings will help formulate various educational support directions that can lead students to successfully gain knowledge through online learning, which has been growing expeditiously in the wake of the COVID-19 pandemic.

3.
Heliyon ; 7(9): e07985, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34589624

RESUMO

The number of English Language Learners (ELLs) has been growing worldwide. ELLs are at risk for reading disabilities due to dual difficulties with linguistic and cultural factors. This raises the need for finding practical and efficient reading interventions for ELLs to improve their literacy development and English reading skills. The purpose of this study is to examine the evidence-based reading interventions for English Language Learners to identify the components that create the most effective and efficient interventions. This article reviewed literature published between January 2008 and March 2018 that examined the effectiveness of reading interventions for ELLs. We analyzed the effect sizes of reading intervention programs for ELLs and explored the variables that affect reading interventions using a multilevel meta-analysis. We examined moderator variables such as student-related variables (grades, exceptionality, SES), measurement-related variables (standardization, reliability), intervention-related variables (contents of interventions, intervention types), and implementation-related variables (instructor, group size). The results showed medium effect sizes for interventions targeting basic reading skills for ELLs. Medium-size group interventions and strategy-embedded interventions were more important for ELLs who were at risk for reading disabilities. These findings suggested that we should consider the reading problems of ELLs and apply the Tier 2 approach for ELLs with reading problems.

4.
BMC Med Inform Decis Mak ; 21(1): 218, 2021 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-34273990

RESUMO

BACKGROUND: Electronic health record (EHR) systems often face user resistance in hospitals, which results in a failure to acquire their full benefits. To implement the EHR successfully, it is crucial to reduce nurses' resistance to use the system. This study aimed to investigate the factors associated with nurses' resistance to use the EHR system. METHODS: A descriptive correlational study was conducted with nurses working at four university hospitals in Korea using self-administered questionnaires to measure user resistance behavior, resistance to change, perceived usefulness, perceived ease of use, perceived value, colleagues' opinions, self-efficacy for change, and organizational support for change. Path analysis was performed to examine direct and indirect association with user resistance behavior. RESULTS: A total of 223 nurses completed the questionnaires. All seven factors were found to be significantly associated with user resistance, either directly or indirectly. The total effect on user resistance behavior was highest in resistance to change (0.65), followed by perceived usefulness (- 0.33); both had direct but no indirect effects. Conversely, self-efficacy for change (- 0.25), perceived value (- 0.21), colleagues' opinions (- 0.16), perceived ease of use (- 0.16), and organizational support for change (- 0.05) had indirect but no direct effects. CONCLUSIONS: The study examined the factors associated with nurses' user resistance behavior after the implementation of a new EHR system. These findings could help hospitals develop better EHR implementation strategies to reduce user resistance behavior among the nursing staff.


Assuntos
Enfermeiras e Enfermeiros , Recursos Humanos de Enfermagem Hospitalar , Atitude do Pessoal de Saúde , Registros Eletrônicos de Saúde , Hospitais Universitários , Humanos , República da Coreia , Inquéritos e Questionários
5.
Nature ; 591(7849): 288-292, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33658715

RESUMO

The evolutionarily conserved target of rapamycin (TOR) kinase acts as a master regulator that coordinates cell proliferation and growth by integrating nutrient, energy, hormone and stress signals in all eukaryotes1,2. Research has focused mainly on TOR-regulated translation, but how TOR orchestrates the global transcriptional network remains unclear. Here we identify ethylene-insensitive protein 2 (EIN2), a central integrator3-5 that shuttles between the cytoplasm and the nucleus, as a direct substrate of TOR in Arabidopsis thaliana. Glucose-activated TOR kinase directly phosphorylates EIN2 to prevent its nuclear localization. Notably, the rapid global transcriptional reprogramming that is directed by glucose-TOR signalling is largely compromised in the ein2-5 mutant, and EIN2 negatively regulates the expression of a wide range of target genes of glucose-activated TOR that are involved in DNA replication, cell wall and lipid synthesis and various secondary metabolic pathways. Chemical, cellular and genetic analyses reveal that cell elongation and proliferation processes that are controlled by the glucose-TOR-EIN2 axis are decoupled from canonical ethylene-CTR1-EIN2 signalling, and mediated by different phosphorylation sites. Our findings reveal a molecular mechanism by which a central signalling hub is shared but differentially modulated by diverse signalling pathways using distinct phosphorylation codes that can be specified by upstream protein kinases.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Núcleo Celular/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Desenvolvimento Vegetal , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Arabidopsis/citologia , Arabidopsis/genética , Domínio Catalítico , Proteínas de Ligação a DNA/metabolismo , Etilenos/metabolismo , Glucose/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Meristema/metabolismo , Fosforilação , Reguladores de Crescimento de Plantas/metabolismo , Proteínas Quinases/metabolismo , Especificidade por Substrato , Fatores de Transcrição/metabolismo , Transcriptoma
6.
Artigo em Inglês | MEDLINE | ID: mdl-35281696

RESUMO

Engaging students in research is a high impact practice that improves student retention and persistence in behavioral and biomedical sciences and engineering. The California State University Long Beach (CSULB) Building Infrastructure Leading to Diversity (BUILD) Program offers an intensive research training experience to undergraduate students from a wide range of health-related disciplines. The goal of this program is to provide students with research skills, psychosocial resources, and graduate school application guidance that will make them competitive for Ph.D. programs. With the COVID-19 pandemic forcing the campus closure of many universities, including CSULB, our student training had to transition from in-person training to online training. This paper discusses the development and implementation of a series of eight online modules for guiding students through the application process for summer research experiences and graduate schools. Overall, the BUILD trainees were positive about the online modules. Specifically, they indicated that the modules were useful, informative, easy to access/use, good use of their time, and a good supplemental activity to their learning community activities. Most trainees indicated that they preferred the modules to be implemented in a hybrid format, where the students can view the modules on their own first and then have an opportunity to engage in in-person/synchronous online discussions.

7.
Sci Rep ; 9(1): 17812, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31780701

RESUMO

Ultrasonic melt treatment (UST) was applied to Al-7Si-2Cu-1Mg melt at various temperatures of 620, 650, 700 and 785 °C. MgAl2O4 particles which were often found to be densely populated along oxide films, became effectively dispersed and well-wetted by UST. Transmission electron microscopy work combined with crystallography analysis clearly indicates that MgAl2O4 particles can act as α-Al nucleation site with the aid of UST. However, with UST, grain refinement occurred only at temperature of 620 °C and the grain size increased from 97 to 351 µm with increase of melt temperature to 785 °C for UST. In quantitative analysis of grain size and MgAl2O4 particle diameter, it was found that ultrasonic de-agglomeration decreased mean particle size of the MgAl2O4 particles, significantly reducing size from 1.2 to 0.4 µm when temperature increased from 620 to 785 °C. Such a size reduction with increased number of MgAl2O4 particles does not always guarantee grain refinement. Thus, in this work, detailed condition for achieving grain refinement by UST is discussed based on quantitative measurement. Furthermore, we tried to suggest the most valid grain refinement mechanism among the known mechanisms by investigation of the relationship between grain size and particle size with variation of melt temperature.

8.
Adv Food Nutr Res ; 88: 47-84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31151728

RESUMO

Proteins are one of the essential components of nutritional food materials and an excellent source for food-grade nanomaterials. This review focuses on select examples of nanoparticles assembled naturally, found in food-relevant materials, major approaches in assembling nanoscale structure from proteins, and general applications of protein nanoparticles in food or nutrition. Animal-sourced casein and non-animal grain storage proteins and legume storage proteins are discussed in terms of their structural assemblies. Protein solubility is a key factor in assembling protein nanoparticles with desired functional properties. Desolvation is the most common technique to prepare protein nanoparticles for insoluble proteins. Well-hydrated protein assemblies have been extensively studied through electrostatic complexes, assembled with fatty acid and starch, reassembled protein structure, and nanogels. These protein-based nanoparticles have been utilized for filler materials of films, encapsulation of bioactive molecules, and stabilization of emulsions. Most studies exploiting protein-based nanoparticles have focused on developing technologies in extraction of proteins from sources and assembly of nanoparticles in different environmental conditions.


Assuntos
Proteínas Alimentares/normas , Alimentos/normas , Nanopartículas , Fenômenos Fisiológicos da Nutrição , Animais , Emulsões/normas , Hidrogéis/química , Nanogéis , Polímeros , Polissacarídeos/química , Suspensões/química
9.
Curr Res Food Sci ; 1: 17-23, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32914101

RESUMO

Interfacial and emulsifying properties of fractionated cricket powder were assessed to identify whether emulsification properties originate from protein or chitin particles. Fractions extracted in alkaline water, containing high protein and mineral contents, increased the surface pressure of heptane-water interfaces with near-saturation equilibrium surface pressure of 31 mN/m. Dynamic surface pressure profiles indicated adsorption of protein clusters to the interface. Emulsification capacity of protein fraction was 50% greater than that of the source cricket flour, although oil-in-water emulsions prepared with 1-2% (w/w) protein fraction formed a cream layer within one day of storage. Emulsified layers persisted for up to 20 days, and light scattering measurements described a stable population with surface-volume-mean diameter of approximately 3 µm. Chitin-rich fractions milled to a particle size of 0.5-200 µm contributed negligible surface pressure, and its emulsification capacity was 5% of the value for the source cricket flour. Emulsions prepared with chitin-rich fractions coexisted with an unstable precipitate layer comprising 60% of the added solid, which was attributed to larger particles with poor emulsifying capability. Stable chitin-stabilized emulsion phases were resistant to creaming, yet volume-mean droplet diameter surpassed 50 µm within 24 h of storage. Both protein and chitin fractions have emulsifying capabilities but would require further processing or secondary additives to achieve desirable storage stability.

10.
Aging Clin Exp Res ; 30(9): 1101-1110, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29372541

RESUMO

BACKGROUND: Multicomponent intervention programs have been shown to be effective in reducing risk factors associated with falls, but the primary target population of these interventions is often low-functioning older adults. AIMS: The purpose of this study was to investigate the effectiveness of a multicomponent intervention program focusing on balance and muscle strength for independently functioning community-dwelling older adults. METHODS: Fifty-three independently functioning older adults, aged 80.09 ± 6.62 years, participated in a group exercise class (conducted 2 times/week for 8 weeks) emphasizing balance. Outcome measures were balance performance using the Fullerton Advanced Balance (FAB) scale and muscle strength using the Senior Fitness Test (SFT). RESULTS: The intervention improved balance (P < 0.001), and older adults who were classified as having high fall risks based on the FAB scores at pre-testing improved more than older adults who were classified as having low fall risks (P = 0.017). As a result, 22 participants transitioned from a high fall risk group at pre-testing to a low fall risk group at post-testing (P < 0.001). The intervention also enhanced both upper and lower muscle extremity strength based on SFT results (P < 0.001) regardless of participants' classification of fall risk status. CONCLUSIONS AND DISCUSSION: The multicomponent intervention conducted two times per week for 8 weeks was effective in improving balance and enhancing muscle strength of independently functioning older adults. The results underscore the importance of providing fall prevention interventions to healthy older adults, a population often not a target of balance interventions.


Assuntos
Acidentes por Quedas/prevenção & controle , Exercício Físico/fisiologia , Força Muscular/fisiologia , Equilíbrio Postural/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Vida Independente , Extremidade Inferior , Masculino , Fatores de Risco
11.
Plant Signal Behav ; 13(2): e1432955, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29381447

RESUMO

To overcome high temperature stress, plants have developed transcriptional cascades which express a large amount of chaperone proteins called heat shock proteins (HSPs). In our recent publication, we reported that STABILIZED1, as an U5-snRNP-interacting protein, is involved in the splicing of heat shock factor (HSF) and HSP transcripts during high temperature stress. This indicates that not only transcriptional regulation, but also post-transcriptional regulation by STA1, is essential for the full activation of HSF-HSP cascades and for thermotolerance. Here, we observed that the splicing of HSP transcripts was induced independent of STA1 at room temperature after heat acclimation, indicating that STA1 acts as a high temperature-specific splicing factor for the splicing of HSP transcripts. Our findings suggest the molecular mechanism for how HSF and HSP transcripts are spliced well under high temperature stress that blocks the splicing of overall transcripts.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Nucleares/metabolismo , Splicing de RNA/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Proteínas Nucleares/genética
12.
Sci Rep ; 7(1): 17360, 2017 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-29234060

RESUMO

Lactic acid bacteria (LAB) are the common probiotics. Here, we investigated the antiviral protective effects of heat-killed LAB strain Lactobacillus casei DK128 (DK128) on influenza viruses. Intranasal treatment of mice with DK128 conferred protection against different subtypes of influenza viruses by lessening weight loss and lowering viral loads. Protection via heat-killed DK128 was correlated with an increase in alveolar macrophage cells in the lungs and airways, early induction of virus specific antibodies, reduced levels of pro-inflammatory cytokines and innate immune cells. Importantly, the mice that were protected against primary viral infection as a result of heat-killed DK128 pretreatment developed subsequent heterosubtypic immunity against secondary virus infection. For protection against influenza virus via heat-killed DK128 pretreatment, B cells and partially CD4 T cells but not CD8 T cells were required as inferred from studies using knockout mouse models. Our study provides insight into how hosts can be equipped with innate and adaptive immunity via heat-killed DK128 treatment to protect against influenza virus, supporting that heat-killed LAB may be developed as anti-virus probiotics.


Assuntos
Coinfecção/prevenção & controle , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Influenza Humana/prevenção & controle , Lacticaseibacillus casei/imunologia , Probióticos/administração & dosagem , Administração Intranasal , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Coinfecção/imunologia , Coinfecção/virologia , Proteção Cruzada/efeitos dos fármacos , Proteção Cruzada/imunologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Temperatura Alta , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/imunologia , Influenza Humana/mortalidade , Influenza Humana/virologia , Camundongos , Camundongos Knockout , Resultado do Tratamento , Carga Viral/efeitos dos fármacos
13.
Gait Posture ; 57: 136-140, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28624710

RESUMO

While cognitive-motor interference in dual-task activities is well established, it is still unknown how such interference is influenced by concurrent visual challenges. Nineteen community-dwelling healthy, cognitively intact, older adults (Mean±SD=71.45±1.25years, 6 males) and nineteen young adults (Mean±SD=22.25±0.68years, 4 males) performed a cognitive-single-task (serial subtraction by 3), a walking-single-task and a cognitive-walking-dual-task under normal, blurred and peripheral-vision-loss conditions (artificially imposed using goggles). Gait parameters and the number of correct responses were measured. Dual task costs for both walking and cognition were computed. Results showed that higher walking cost was seen with impaired vision (p=0.05) and with older adults (p=0.03); greater cognitive cost was seen with impaired vision (p=0.01), but no difference in cognitive cost was seen between young and older adults. Thus, when faced with impaired vision, both young and older adults appear to allocate less attention to cognition than to walking, and thus prioritize walking. Future work should explore whether dual-task training under visual challenge could reduce cognitive-motor interference and reduce fall risks in older adults.


Assuntos
Envelhecimento/fisiologia , Cognição/fisiologia , Marcha/fisiologia , Transtornos da Visão/fisiopatologia , Acuidade Visual , Caminhada/legislação & jurisprudência , Idoso , Atenção , Feminino , Humanos , Masculino , Prognóstico , Análise e Desempenho de Tarefas , Caminhada/fisiologia , Adulto Jovem
14.
Sci Rep ; 7(1): 2767, 2017 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-28584283

RESUMO

For photoautotrophic plants, light-dependent photosynthesis plays an important role in organismal growth and development. Under light, Arabidopsis hypocotyl growth is promoted by the phytohormone ethylene. Despite well-characterized ethylene signaling pathways, the functions of light in the hormone-inducible growth response still remain elusive. Our cell-based functional and plant-system-based genetic analyses with biophysical and chemical tools showed that a chemical blockade of photosystem (PS) II activity affects ethylene-induced hypocotyl response under light. Interestingly, ethylene responsiveness modulates PSII activity in retrospect. The lack of ethylene responsiveness-inducible PSII inefficiency correlates with the induction of AKIN10 expression. Consistently, overexpression of AKIN10 in transgenic plants suppresses ethylene-inducible hypocotyl growth promotion under illumination as in other ethylene-insensitive mutants. Our findings provide information on how ethylene responsiveness-dependent photosynthetic activity controls evolutionarily conserved energy sensor AKIN10 that fine-tunes EIN3-mediated ethylene signaling responses in organ growth under light.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Fotossíntese , Complexo de Proteína do Fotossistema II/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Alelos , Metabolismo Energético , Deleção de Genes , Genótipo , Luz , Fenótipo , Processos Fotoquímicos , Complexo de Proteína do Fotossistema II/metabolismo , Desenvolvimento Vegetal
15.
Sci Rep ; 7(1): 3193, 2017 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-28600557

RESUMO

Aging of living organisms is governed by intrinsic developmental programs, of which progression is often under the regulation of their cellular energy status. For example, calorie restriction is known to slow down aging of heterotrophic organisms from yeasts to mammals. In autotrophic plants cellular energy deprivation by perturbation of photosynthesis or sugar metabolism is also shown to induce senescence delay. However, the underlying molecular and biochemical mechanisms remain elusive. Our plant cell-based functional and biochemical assays have demonstrated that SNF1-RELATED KINASE1 (SnRK1) directly interacts, phosphorylates, and destabilizes the key transcription factor ETHYLENE INSENSITIVE3 (EIN3) in senescence-promoting hormone ethylene signaling. Combining chemical manipulation and genetic validation using extended loss-of-function mutants and gain-of-function transgenic lines, we further revealed that a SnRK1 elicitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea enables to slow down senescence-associated leaf degreening through the regulation of EIN3 in Arabidopsis. Our findings enlighten that an evolutionary conserved cellular energy sensor SnRK1 plays a role in fine-tuning of organ senescence progression to avoid sudden death during the last step of leaf growth and development.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Metabolismo Energético/genética , Folhas de Planta/genética , Proteínas Serina-Treonina Quinases/genética , Envelhecimento/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Fosforilação , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/genética
16.
Plant Physiol ; 173(4): 2370-2382, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28223317

RESUMO

High-temperature stress often leads to differential RNA splicing, thus accumulating different types and/or amounts of mature mRNAs in eukaryotic cells. However, regulatory mechanisms underlying plant precursor mRNA (pre-mRNA) splicing in the environmental stress conditions remain elusive. Herein, we describe that a U5-snRNP-interacting protein homolog STABILIZED1 (STA1) has pre-mRNA splicing activity for heat-inducible transcripts including HEAT STRESS TRANSCRIPTION FACTORs and various HEAT SHOCK PROTEINs for the establishment of heat stress tolerance in Arabidopsis (Arabidopsis thaliana). Our cell-based splicing reporter assay demonstrated STA1 acts on pre-mRNA splicing for specific subsets of stress-related genes. Cellular reconstitution of heat-inducible transcription cascades supported the view that STA1-dependent pre-mRNA splicing plays a role in DREB2A-dependent HSFA3 expression for heat-responsive gene expression. Further genetic analysis with a loss-of-function mutant sta1-1, STA1-expressing transgenic plants in Col background, and STA1-expressing transgenic plants in the sta1-1 background verified that STA1 is essential in expression of necessary genes including HSFA3 for two-step heat stress tolerance in plants. However, constitutive overexpression of the cDNA version of HSFA3 in the sta1-1 background is unable to execute plant heat stress tolerance in sta1-1 Consistently our global target analysis of STA1 showed that its splicing activity modulates a rather broad range of gene expression in response to heat treatment. The findings of this study reveal that heat-inducible STA1 activity for pre-mRNA splicing serves as a molecular regulatory mechanism underlying the plant stress tolerance to high-temperature stress.


Assuntos
Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas Nucleares/genética , Precursores de RNA/genética , Splicing de RNA , Termotolerância/genética , Arabidopsis/genética , Temperatura Alta , Modelos Genéticos , Mutação , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estresse Fisiológico
17.
Gels ; 3(2)2017 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-30920511

RESUMO

Thermal treatment of protein⁻polysaccharide complexes will form nanogel particles, wherein the polysaccharide controls nanogel formation by limiting protein aggregation. To determine the impact of the chitosan molecular weight and non-interactive chains on the formation of nanogels, mixtures of α-lactalbumin were prepared with selectively-hydrolyzed chitosan containing covalently-attached polyethylene glycol chains (PEG) and heated near the protein's isoelectric point to induce formation of nanogels. Turbidity of heated mixtures indicated the formation of suspended aggregates, with greater values observed at higher pH, without attached PEG, and among samples with 8.9 kDa chitosan. Mixtures containing 113 kDa chitosan-PEG formed precipitating aggregates above pH 5, coinciding with a low-magnitude colloidal charge and average hydrodynamic radii > 400 nm. All other tested mixtures were stable to precipitation and possessed average hydrodynamic radii ~100 nm, with atomic force microscopy showing homogeneous distributions of spherical nanogel aggregates. Over all of the tested conditions, attached PEG led to no additional significant changes in the size or morphology of nanogels formed from the protein and chitosan. While PEG may have interfered with the interactions between protein and the 113 kDa chitosan, prompting greater aggregation and precipitation, PEG did not indicate any such interference for shorter chitosan chains.

18.
Plant Cell Rep ; 34(9): 1605-14, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26021844

RESUMO

KEY MESSAGE: Arabidopsis BIK1 negatively regulates EIN3-depedent gene expression as an immediate cellular response. BIK1 localizes to the plasma membrane and its autophosphorylation and kinase activity involves in EIN3 repression. BOTRYTIS INDUCED KINASE1 (BIK1) is a multifunctional receptor-like kinase that involves in ethylene-mediated plant defense signaling. The loss of function BIK1 becomes insensitive to ethylene, but it still accumulates a higher level of ETHYLENE INSENSITIVE3 (EIN3) that serves as the key transcription activator in ethylene signaling. To unequivocally elucidate BIK1 function on EIN3 regulation in ethylene signaling, we took a combined approach of transient expression assay and stable expression analysis of BIK1. In our cell-based functional assay BIK1 destabilized EIN3 and down-regulated EIN3-dependent transcription. Membrane localization and autophosphorylation of BIK1 were required for full repression of EIN3 function, but its kinase activity potential compromised such regulatory action. Consistently, the analysis of transgenic plants verified BIK1 function on EIN3 repression. Our findings have clarified that autophosphorylated BIK1 in the plasma membrane negatively regulates EIN3-dependent gene expression. Thus, ethylene insensitivity in bik1 appears to be an indirect or a feedback long-term response.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Transcrição/metabolismo , Membrana Celular/metabolismo , Proteínas de Ligação a DNA , Fosforilação , Plantas Geneticamente Modificadas , Estabilidade Proteica , Transporte Proteico , Proteínas Repressoras/metabolismo , Frações Subcelulares/metabolismo , Transcrição Gênica
19.
PLoS Genet ; 11(3): e1004973, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25730098

RESUMO

Plant growth depends on stem cell niches in meristems. In the root apical meristem, the quiescent center (QC) cells form a niche together with the surrounding stem cells. Stem cells produce daughter cells that are displaced into a transit-amplifying (TA) domain of the root meristem. TA cells divide several times to provide cells for growth. SHORTROOT (SHR) and SCARECROW (SCR) are key regulators of the stem cell niche. Cytokinin controls TA cell activities in a dose-dependent manner. Although the regulatory programs in each compartment of the root meristem have been identified, it is still unclear how they coordinate one another. Here, we investigate how PHABULOSA (PHB), under the posttranscriptional control of SHR and SCR, regulates TA cell activities. The root meristem and growth defects in shr or scr mutants were significantly recovered in the shr phb or scr phb double mutant, respectively. This rescue in root growth occurs in the absence of a QC. Conversely, when the modified PHB, which is highly resistant to microRNA, was expressed throughout the stele of the wild-type root meristem, root growth became very similar to that observed in the shr; however, the identity of the QC was unaffected. Interestingly, a moderate increase in PHB resulted in a root meristem phenotype similar to that observed following the application of high levels of cytokinin. Our protoplast assay and transgenic approach using ARR10 suggest that the depletion of TA cells by high PHB in the stele occurs via the repression of B-ARR activities. This regulatory mechanism seems to help to maintain the cytokinin homeostasis in the meristem. Taken together, our study suggests that PHB can dynamically regulate TA cell activities in a QC-independent manner, and that the SHR-PHB pathway enables a robust root growth system by coordinating the stem cell niche and TA domain.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Homeodomínio/genética , Meristema/genética , Nicho de Células-Tronco/genética , Fatores de Transcrição/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/biossíntese , Proteínas de Arabidopsis/metabolismo , Divisão Celular/genética , Citocininas/genética , Citocininas/metabolismo , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/biossíntese , Homeostase , Meristema/crescimento & desenvolvimento , Fenótipo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Fatores de Transcrição/metabolismo
20.
J Colloid Interface Sci ; 447: 182-90, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-25446955

RESUMO

HYPOTHESIS: Factors influencing fabrication and size of microgels formed from ß-lactoglobulin with or without pectin can tune selected attributes for material applications. Protein aggregation was expected to be influenced by pH, added anions, and reducing agents, while ionic strength was expected to be more influenced by electrostatically interacting pectin. EXPERIMENTS: Turbidity measurements during thermal aggregation to form microgels were determined for pure ß-lactoglobulin as a function of pH, added ionic strength, anion type (chloride, sulfate, and thiocyanate), and reducing agent concentration. ß-lactoglobulin and pectin complexation pH values and thermal aggregation were determined by turbidity measurements with added potassium chloride, sulfate, and thiocyanate. Microgel size and morphology were determined by light scattering and atomic force microscopy, respectively. FINDINGS: Thermal aggregation of pure ß-lactoglobulin increased with decreased pH, reducing conditions, and increased ionic strength with no observed anion effect. ß-lactoglobulin microgel radii increased from 86 to 115nm with decreasing pH and increased to 124nm in reducing conditions, while salts promoted agglomeration. Increased ionic strength (0-100mmol/kg) decreased ß-lactoglobulin-pectin complexation pH from 5.40 to 5.00, while first increasing and then decreasing thermal aggregation. Thermal aggregation and microgel size were greatest with potassium thiocyanate, followed by potassium chloride and potassium sulfate.

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