RESUMO
Polycomb repressive complexes (PRCs) play a key role in gene repression and are indispensable for proper development. Canonical PRC1 forms condensates in vitro and in cells that are proposed to contribute to the maintenance of repression. However, how chromatin and the various subunits of PRC1 contribute to condensation is largely unexplored. Using a reconstitution approach and single-molecule imaging, we demonstrate that nucleosomal arrays and PRC1 act synergistically, reducing the critical concentration required for condensation by more than 20-fold. We find that the exact combination of PHC and CBX subunits determines condensate initiation, morphology, stability, and dynamics. Particularly, PHC2's polymerization activity influences condensate dynamics by promoting the formation of distinct domains that adhere to each other but do not coalesce. Live-cell imaging confirms CBX's role in condensate initiation and highlights PHC's importance for condensate stability. We propose that PRC1 composition can modulate condensate properties, providing crucial regulatory flexibility across developmental stages.
Assuntos
Proteínas de Ciclo Celular , Cromatina , Nucleossomos , Complexo Repressor Polycomb 1 , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 1/genética , Cromatina/metabolismo , Cromatina/genética , Humanos , Nucleossomos/metabolismo , Nucleossomos/genética , Animais , Imagem Individual de MoléculaRESUMO
Genetically encoded biosensors are powerful tools to monitor cellular behavior, but the difficulty in generating appropriate reporters for chromatin factors hampers our ability to dissect epigenetic pathways. Here, we present TRACE (transgene reporters across chromatin environments), a high-throughput, genome-wide technique to generate fluorescent human reporter cell lines responsive to manipulation of epigenetic factors. By profiling GFP expression from a large pool of individually barcoded lentiviral integrants in the presence and absence of a perturbation, we identify reporters responsive to pharmacological inhibition of the histone lysine demethylase LSD1 and genetic ablation of the PRC2 subunit SUZ12. Furthermore, by manipulating the HIV-1 host factor LEDGF through targeted deletion or fusion to chromatin reader domains, we alter lentiviral integration site preferences, thus broadening the types of chromatin examined by TRACE. The phenotypic reporters generated through TRACE will allow the genetic interrogation of a broad range of epigenetic pathways, furthering our mechanistic understanding of chromatin biology.
Assuntos
Técnicas Biossensoriais , Epigênese Genética , Genes Reporter , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Lentivirus/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Montagem e Desmontagem da Cromatina , Epigenoma , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Células HeLa , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Humanos , Lentivirus/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Células THP-1 , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
The CBX family of proteins is central to proper mammalian development via key roles in Polycomb-mediated maintenance of repression. CBX proteins in differentiated lineages have chromatin compaction and phase separation activities that might contribute to maintaining repressed chromatin. The predominant CBX protein in pluripotent cells, CBX7, lacks the domain required for these activities. We inserted this functional domain into CBX7 in embryonic stem cells (ESCs) to test the hypothesis that it contributes a key epigenetic function. ESCs expressing this chimeric CBX7 were impaired in their ability to properly form embryoid bodies and neural progenitor cells and showed reduced activation of lineage-specific genes across differentiation. Neural progenitors exhibited a corresponding inappropriate maintenance of Polycomb binding at neural-specific loci over the course of differentiation. We propose that a switch in the ability to compact and phase separate is a central aspect of Polycomb group function during the transition from pluripotency to differentiated lineages.
Assuntos
Cromatina/química , Proteínas de Drosophila/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Animais , Diferenciação Celular , Linhagem da Célula , Drosophila/metabolismo , Corpos Embrioides , Células-Tronco Embrionárias/citologia , Epigênese Genética , Perfilação da Expressão Gênica , Genômica , Células HeLa , Humanos , Espectrometria de Massas , Camundongos , Microscopia Eletrônica , Neurônios/metabolismo , Peptídeos/química , Fenótipo , Células-Tronco Pluripotentes/citologia , Complexo Repressor Polycomb 1/metabolismo , Ligação Proteica , Domínios Proteicos , Proteínas Recombinantes de Fusão/química , Células-Tronco/citologiaRESUMO
Extreme weather conditions associated with climate change affect many aspects of plant and animal life, including the response to infectious diseases. Production of salicylic acid (SA), a central plant defence hormone1-3, is particularly vulnerable to suppression by short periods of hot weather above the normal plant growth temperature range via an unknown mechanism4-7. Here we show that suppression of SA production in Arabidopsis thaliana at 28 °C is independent of PHYTOCHROME B8,9 (phyB) and EARLY FLOWERING 310 (ELF3), which regulate thermo-responsive plant growth and development. Instead, we found that formation of GUANYLATE BINDING PROTEIN-LIKE 3 (GBPL3) defence-activated biomolecular condensates11 (GDACs) was reduced at the higher growth temperature. The altered GDAC formation in vivo is linked to impaired recruitment of GBPL3 and SA-associated Mediator subunits to the promoters of CBP60g and SARD1, which encode master immune transcription factors. Unlike many other SA signalling components, including the SA receptor and biosynthetic genes, optimized CBP60g expression was sufficient to broadly restore SA production, basal immunity and effector-triggered immunity at the elevated growth temperature without significant growth trade-offs. CBP60g family transcription factors are widely conserved in plants12. These results have implications for safeguarding the plant immune system as well as understanding the concept of the plant-pathogen-environment disease triangle and the emergence of new disease epidemics in a warming climate.
Assuntos
Aclimatação , Proteínas de Arabidopsis , Arabidopsis , Meio Ambiente , Aquecimento Global , Imunidade Vegetal , Temperatura , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/imunologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a Calmodulina/genética , Regulação da Expressão Gênica de Plantas , Aquecimento Global/estatística & dados numéricos , Interações Hospedeiro-Patógeno , Fitocromo B , Doenças das Plantas/genética , Imunidade Vegetal/genética , Ácido Salicílico/metabolismo , Fatores de TranscriçãoRESUMO
Mammalian development requires effective mechanisms to repress genes whose expression would generate inappropriately specified cells. The Polycomb-repressive complex 1 (PRC1) family complexes are central to maintaining this repression. These include a set of canonical PRC1 complexes, each of which contains four core proteins, including one from the CBX family. These complexes have been shown previously to reside in membraneless organelles called Polycomb bodies, leading to speculation that canonical PRC1 might be found in a separate phase from the rest of the nucleus. We show here that reconstituted PRC1 readily phase-separates into droplets in vitro at low concentrations and physiological salt conditions. This behavior is driven by the CBX2 subunit. Point mutations in an internal domain of Cbx2 eliminate phase separation. These same point mutations eliminate the formation of puncta in cells and have been shown previously to eliminate nucleosome compaction in vitro and generate axial patterning defects in mice. Thus, the domain of CBX2 that is important for phase separation is the same domain shown previously to be important for chromatin compaction and proper development, raising the possibility of a mechanistic or evolutionary link between these activities.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento/genética , Complexo Repressor Polycomb 1/química , Animais , Linhagem Celular , Escherichia coli/genética , Camundongos , Camundongos Endogâmicos C57BL , Células NIH 3T3 , Organelas/metabolismo , Mutação Puntual , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Domínios Proteicos , Células Sf9RESUMO
BACKGROUND: The impact of social frailty on older adults is profound including mortality risk, functional decline, falls, and disability. However, effective strategies that respond to the needs of socially frail older adults are lacking and few studies have unpacked how social determinants operate or how interventions can be adapted during periods requiring social distancing and isolation such as the COVID-19 pandemic. To address these gaps, we conducted a scoping review using JBI methodology to identify interventions that have the best potential to help socially frail older adults (age ≥65 years). METHODS: We searched MEDLINE, CINAHL (EPSCO), EMBASE and COVID-19 databases and the grey literature. Eligibility criteria were developed using the PICOS framework. Our results were summarized descriptively according to study, patient, intervention and outcome characteristics. Data synthesis involved charting and categorizing identified interventions using a social frailty framework. RESULTS: Of 263 included studies, we identified 495 interventions involving ~124,498 older adults who were mostly female. The largest proportion of older adults (40.5%) had a mean age range of 70-79 years. The 495 interventions were spread across four social frailty domains: social resource (40%), self-management (32%), social behavioural activity (28%), and general resource (0.4%). Of these, 189 interventions were effective for improving loneliness, social and health and wellbeing outcomes across psychological self-management, self-management education, leisure activity, physical activity, Information Communication Technology and socially assistive robot interventions. Sixty-three interventions were identified as feasible to be adapted during infectious disease outbreaks (e.g., COVID-19, flu) to help socially frail older adults. CONCLUSIONS: Our scoping review identified promising interventions with the best potential to help older adults living with social frailty.
Assuntos
COVID-19 , Idoso Fragilizado , Humanos , Idoso , COVID-19/psicologia , COVID-19/epidemiologia , Idoso Fragilizado/psicologia , Isolamento Social/psicologia , Fragilidade/psicologia , Idoso de 80 Anos ou mais , SARS-CoV-2RESUMO
INTRODUCTION: Osteoporosis is a major disease state associated with significant morbidity, mortality, and health care costs. Less than half of the individuals sustaining a low energy hip fracture are diagnosed and treated for the underlying osteoporosis. OBJECTIVE: A multidisciplinary Canadian hip fracture working group has developed practical recommendations to meet Canadian quality indicators in post hip fracture care. METHODS: A comprehensive narrative review was conducted to identify and synthesize key articles on post hip fracture orthogeriatric care for each of the individual sections and develop recommendations. These recommendations are based on the best evidence available today. CONCLUSION: Recommendations are anticipated to reduce recurrent fractures, improve mobility and healthcare outcomes post hip fracture, and reduce healthcare costs. Key messages to enhance postoperative care are also provided.
Assuntos
Fraturas do Quadril , Osteoporose , Humanos , Canadá/epidemiologia , Fraturas do Quadril/cirurgia , Fraturas do Quadril/complicações , Osteoporose/complicações , Osteoporose/terapia , Indicadores de Qualidade em Assistência à Saúde , Resultado do TratamentoRESUMO
GERAS DANcing for Cognition and Exercise is a therapeutic dance program for older adults with cognitive or mobility impairments. Using a pre-/posttest study design, we investigated the effect of 12 weeks of dance on the short performance physical battery (SPPB). In 107 participants aged 61-93 (mean 76.1, SD = 7.0; 20% men), over 90% had multifrailty and/or cognitive impairment. The mean attendance rate was 18/24 classes (75%). A substantial minimal clinically important difference (>0.4) occurred for SPPB total (+0.53, SD = 2.04, p = .002) and chair stands (+0.45, SD = 0.92, p < .001). Individuals with baseline SPPB ≤8 points (n = 38)-indicative of sarcopenia and physical frailty-had the most marked improvement (SPPB total: +1.45, SD = 1.97, p < .001; balance: +0.65, SD = 1.27, p = .006; chair stands: +0.68, SD = 0.97, p < .001). GERAS DANcing for Cognition and Exercise may be a promising rehabilitation intervention to improve daily physical function.
Assuntos
Disfunção Cognitiva , Dança , Masculino , Humanos , Idoso , Feminino , Exercício Físico , Cognição , Terapia por ExercícioRESUMO
BACKGROUND: dance is a mind-body activity that stimulates neuroplasticity. We explored the effect of dance on cognitive function in older adults. METHODS: we searched MEDLINE, EMBASE, CENTRAL and PsycInfo databases from inception to August 2020 (PROSPERO:CRD42017057138). Inclusion criteria were (i) randomised controlled trials (ii) older adults (aged ≥ 55 years), (iii) intervention-dance and (iv) outcome-cognitive function. Cognitive domains were classified with the Diagnostic and Statistical Manual of Mental Disorders-5 Neurocognitive Framework. Meta-analyses were performed in RevMan5.3 and certainty of evidence with GradePro. RESULTS: we reviewed 3,997 records and included 11 studies (N = 1,412 participants). Seven studies included only healthy older adults and four included those with mild cognitive impairment (MCI). Dance interventions varied in frequency (1-3×/week), time (35-60 minutes), duration (3-12 months) and type. We found a mean difference (MD) = 1.58 (95% confidence interval [CI) = 0.21-2.95) on the Mini Mental State Examination for global cognitive function (moderate-certainty evidence), and the Wechsler Memory Test for learning and memory had an MD = 3.02 (95% CI = 1.38-4.65; low-certainty evidence). On the Trail Making Test-A for complex attention, MD = 3.07 (95% CI = -0.81 to 6.95; high-certainty evidence) and on the Trail Making Test-B for executive function, MD = -4.12 (95% CI = -21.28 to 13.03; moderate-certainty evidence). Subgroup analyses did not suggest consistently greater effects in older adults with MCI. Evidence is uncertain for language, and no studies evaluated social cognition or perceptual-motor function. CONCLUSIONS: dance probably improves global cognitive function and executive function. However, there is little difference in complex attention, and evidence also suggests little effect on learning and memory. Future research is needed to determine the optimal dose and if dance results in greater cognitive benefits than other types of physical activity and exercise.
Assuntos
Cognição , Disfunção Cognitiva , Idoso , Função Executiva , HumanosRESUMO
The transcription elongation factor Spt6 and the H3K36 methyltransferase Set2 are both required for H3K36 methylation and transcriptional fidelity in Saccharomyces cerevisiae. However, the nature of the requirement for Spt6 has remained elusive. By selecting for suppressors of a transcriptional defect in an spt6 mutant, we have isolated several highly clustered, dominant SET2 mutations (SET2sup mutations) in a region encoding a proposed autoinhibitory domain. SET2sup mutations suppress the H3K36 methylation defect in the spt6 mutant, as well as in other mutants that impair H3K36 methylation. We also show that SET2sup mutations overcome the requirement for certain Set2 domains for H3K36 methylation. In vivo, SET2sup mutants have elevated levels of H3K36 methylation and the purified Set2sup mutant protein has greater enzymatic activityin vitro. ChIP-seq studies demonstrate that the H3K36 methylation defect in the spt6 mutant, as well as its suppression by a SET2sup mutation, occurs at a step following the recruitment of Set2 to chromatin. Other experiments show that a similar genetic relationship between Spt6 and Set2 exists in Schizosaccharomyces pombe. Taken together, our results suggest a conserved mechanism by which the Set2 autoinhibitory domain requires multiple Set2 interactions to ensure that H3K36 methylation occurs specifically on actively transcribed chromatin.
Assuntos
Regulação Fúngica da Expressão Gênica , Chaperonas de Histonas/genética , Histonas/genética , Metiltransferases/genética , Processamento de Proteína Pós-Traducional , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Fatores de Elongação da Transcrição/genética , Sequência de Aminoácidos , Animais , Baculoviridae/genética , Baculoviridae/metabolismo , Cromatina/química , Cromatina/metabolismo , Clonagem Molecular , Sequência Conservada , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Chaperonas de Histonas/metabolismo , Histonas/metabolismo , Metilação , Metiltransferases/metabolismo , Mutação , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Schizosaccharomyces/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Células Sf9 , Spodoptera , Transcrição Gênica , Fatores de Elongação da Transcrição/metabolismoRESUMO
Many practicing health care providers find themselves ill-prepared to meet the complex care needs of older adults. The Geriatric Certificate Program (GCP) represents a collaborative partnership leveraging existing educational courses, with new courses developed to fill existing education gaps, aimed at improving quality of care for older adults. This paper describes the GCP and examines its impact on knowledge, skills, clinical practice, as well as confidence, comfort, and competence in providing geriatric care. Upon program completion, all graduates (N = 146; 100%) completed an online evaluation survey. The majority of graduates reported (5-point scale: 1 = much less now; 5 = much more now) being more confident (88%), comfortable (83%), and competent (89%) to provide optimal geriatric care than prior to the program. The GCP provides a significant opportunity for health care providers to build their capacity for the care of older adults. Key lessons learned in implementing the GCP and suggestions for further development are discussed.
Assuntos
Fortalecimento Institucional/métodos , Currículo/normas , Geriatria/educação , Serviços de Saúde para Idosos , Mão de Obra em Saúde/normas , Desenvolvimento de Pessoal , Idoso , Competência Clínica , Serviços de Saúde para Idosos/normas , Serviços de Saúde para Idosos/tendências , Humanos , Educação Interprofissional/métodos , Melhoria de Qualidade , Desenvolvimento de Pessoal/métodos , Desenvolvimento de Pessoal/organização & administraçãoRESUMO
Salicylic acid (SA) is a major defense signal in plants. In Arabidopsis (Arabidopsis thaliana), the chloroplast-localized isochorismate pathway is the main source of SA biosynthesis during abiotic stress or pathogen infections. In the first step of the pathway, the enzyme ISOCHORISMATE SYNTHASE1 (ICS1) converts chorismate to isochorismate. An unknown enzyme subsequently converts isochorismate to SA. Here, we show that ICS1 protein levels increase during UV-C stress. To identify proteins that may play roles in SA production by regulating ICS1, we analyzed proteins that coimmunoprecipitated with ICS1 via mass spectrometry. The ICS1 complexes contained a large number of peptides from the PROHIBITIN (PHB) protein family, with PHB3 the most abundant. PHB proteins have diverse biological functions that include acting as scaffolds for protein complex formation and stabilization. PHB3 was reported previously to localize to mitochondria. Using fractionation, protease protection, and live imaging, we show that PHB3 also localizes to chloroplasts, where ICS1 resides. Notably, loss of PHB3 function led to decreased ICS1 protein levels in response to UV-C stress. However, ICS1 transcript levels remain unchanged, indicating that ICS1 is regulated posttranscriptionally. The phb3 mutant displayed reduced levels of SA, the SA-regulated protein PR1, and hypersensitive cell death in response to UV-C and avirulent strains of Pseudomonas syringae and, correspondingly, supported increased growth of P. syringae The expression of a PHB3 transgene in the phb3 mutant complemented all of these phenotypes. We suggest a model in which the formation of PHB3-ICS1 complexes stabilizes ICS1 to promote SA production in response to stress.
Assuntos
Arabidopsis/metabolismo , Transferases Intramoleculares/metabolismo , Proteínas Repressoras/metabolismo , Ácido Salicílico/metabolismo , Arabidopsis/genética , Arabidopsis/microbiologia , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Transferases Intramoleculares/genética , Mitocôndrias/metabolismo , Mutação , Plantas Geneticamente Modificadas , Proibitinas , Pseudomonas syringae/patogenicidade , Proteínas Repressoras/genética , Estresse Fisiológico , Raios UltravioletaRESUMO
Seniors account for a high number of emergency department (ED) visits, yet little is known about how they decide to visit the ED. This paper reports on the results of surveys completed by 264 seniors who visited the ED and their caregivers and interviews with a subset (N = 51) of survey respondents, aimed at understanding how they decide to visit the ED. Although older adults rely on others to help them decide whether to visit the ED, only a small proportion consult healthcare providers in doing so. Opportunities exist for enhancing seniors' decision-making process regarding ED visits and access to community-based healthcare to avoid ED visits.
Assuntos
Cuidadores/psicologia , Serviço Hospitalar de Emergência , Pacientes Ambulatoriais/psicologia , Idoso , Idoso de 80 Anos ou mais , Tomada de Decisões , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Masculino , Ontário , Fatores de Risco , Inquéritos e Questionários , TelemedicinaRESUMO
INTRODUCTION: More than half of older adults (age ≥ 65 yr) have 2 or more high-burden multimorbidity conditions (i.e., highly prevalent chronic diseases, which are associated with increased health care utilization; these include diabetes [DM], dementia, depression, chronic obstructive pulmonary disease [COPD], cardiovascular disease [CVD], arthritis, and heart failure [HF]), yet most existing interventions for managing chronic disease focus on a single disease or do not respond to the specialized needs of older adults. We conducted a systematic review and meta-analysis to identify effective multimorbidity interventions compared with a control or usual care strategy for older adults. METHODS: We searched bibliometric databases for randomized controlled trials (RCTs) evaluating interventions for managing multiple chronic diseases in any language from 1990 to December 2017. The primary outcome was any outcome specific to managing multiple chronic diseases as reported by studies. Reviewer pairs independently screened citations and full-text articles, extracted data and assessed risk of bias. We assessed statistical and methodological heterogeneity and performed a meta-analysis of RCTs with similar interventions and components. RESULTS: We included 25 studies (including 15 RCTs and 6 cluster RCTs) (12 579 older adults; mean age 67.3 yr). In patients with [depression + COPD] or [CVD + DM], care-coordination strategies significantly improved depressive symptoms (standardized mean difference -0.41; 95% confidence interval [CI] -0.59 to -0.22; I2 = 0%) and reduced glycosylated hemoglobin (HbA1c) levels (mean difference -0.51; 95% CI -0.90 to -0.11; I2 = 0%), but not mortality (relative risk [RR] 0.79; 95% CI 0.53 to 1.17; I2 = 0%). Among secondary outcomes, care-coordination strategies reduced functional impairment in patients with [arthritis + depression] (between-group difference -0.82; 95% CI -1.17 to -0.47) or [DM + depression] (between-group difference 3.21; 95% CI 1.78 to 4.63); improved cognitive functioning in patients with [DM + depression] (between-group difference 2.44; 95% CI 0.79 to 4.09) or [HF + COPD] (p = 0.006); and increased use of mental health services in those with [DM + (CVD or depression)] (RR 2.57; 95% CI 1.90 to 3.49; I2 = 0%). INTERPRETATION: Subgroup analyses showed that older adults with diabetes and either depression or cardiovascular disease, or with coexistence of chronic obstructive pulmonary disease and heart failure, can benefit from care-coordination strategies with or without education to lower HbA1c, reduce depressive symptoms, improve health-related functional status, and increase the use of mental health services. PROTOCOL REGISTRATION: PROSPERO-CRD42014014489.
Assuntos
Doença Crônica/terapia , Efeitos Psicossociais da Doença , Administração dos Cuidados ao Paciente , Idoso , Comorbidade , Depressão/prevenção & controle , Depressão/terapia , Humanos , Serviços de Saúde Mental , Desempenho Físico Funcional , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
BACKGROUND: Physical frailty is associated with significant morbidity and mortality in community-dwelling older adults. Burden in informal caregivers of older adults causes significant physical and psychological distress. However, the relationship between these two clinical phenomena has not been extensively studied. This cross-sectional study evaluated the relationship between physical frailty of community-dwelling older adults attending an outpatient geriatric clinic and the subjective burden reported by their informal caregivers. METHODS: We measured the following characteristics of 45 patient-caregiver dyads attending an outpatient geriatric assessment clinic: Physical frailty using the Fried Frail Scale (FFS); self-reported independence in activities of daily living (ADL) using the Katz Index; clinical diagnosis of dementia; and subjective caregiver burden using the short 12-item version of the Zarit Burden Interview (ZBI). Multivariable linear regression was performed with FFS, Katz Index score, gender, age, and diagnosis of dementia as independent variables, and ZBI score as the dependent variable. RESULTS: Only physical frailty significantly predicted caregiver burden (ß = 8.98 95% confidence interval [CI]: 2.15, 15.82). CONCLUSIONS: Physical frailty is independently associated with caregiver burden in a population of community-dwelling older adults. Despite limitations related to sample size and lack of data about caregiver characteristics, this study suggests that the relationship between physical frailty and caregiver burden merits further study.
Assuntos
Cuidadores , Efeitos Psicossociais da Doença , Demência , Idoso Fragilizado , Nível de Saúde , Vida Independente , Atividades Cotidianas/psicologia , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Canadá/epidemiologia , Cuidadores/psicologia , Cuidadores/estatística & dados numéricos , Estudos Transversais , Demência/diagnóstico , Demência/epidemiologia , Demência/psicologia , Demência/reabilitação , Saúde da Família , Feminino , Avaliação Geriátrica/métodos , Disparidades nos Níveis de Saúde , Humanos , Vida Independente/psicologia , Vida Independente/estatística & dados numéricos , MasculinoRESUMO
Transcription factor (TF)IID is a central player in activated transcription initiation. Recent evidence suggests that the role and composition of TFIID are more diverse than previously understood. To investigate the effects of changing the composition of TFIID in a simple system, we depleted TATA box-binding protein-associated factor (TAF)1 from Drosophila cells and determined the consequences on metal-induced transcription at an inducible gene, metallothionein B. We observe a marked increase in the levels of both the mature message and pre-mRNA in TAF1-depleted cells. Under conditions of continued metal exposure, we show that TAF1 depletion increases the magnitude of the initial transcription burst but has no effect on the timing of that burst. We also show that TAF1 depletion causes delay in the shutoff of transcription upon removal of the stimulus. Thus, TAFs are involved in both establishing an upper limit of transcription during induction and efficiently turning the gene off once the inducer is removed. Using genome-wide nascent sequencing, we identify hundreds of genes that are controlled in a similar manner, indicating that the findings at this inducible gene are likely generalizable to a large set of promoters. There is a long-standing appreciation for the importance of the spatial and temporal control of transcription. Here we uncover an important third dimension of control: the magnitude of the response. Our results show that the magnitude of the transcriptional response to the same signaling event, even at the same promoter, can vary greatly depending on the composition of the TFIID complex in the cell.
Assuntos
Proteínas de Drosophila/metabolismo , Regulação da Expressão Gênica , Histona Acetiltransferases/metabolismo , Metalotioneína/metabolismo , Fator de Transcrição TFIID/metabolismo , Transcrição Gênica , Animais , Cádmio/farmacologia , Cobre/farmacologia , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Escherichia coli/metabolismo , Perfilação da Expressão Gênica , Genoma , Histona Acetiltransferases/genética , Interferência de RNA , RNA Mensageiro/metabolismo , Fatores Associados à Proteína de Ligação a TATA , Fator de Transcrição TFIID/genéticaRESUMO
BACKGROUND: Osteoporosis is a major global health problem, especially among long-term care (LTC) facilities. Despite the availability of effective clinical guidelines to prevent osteoporosis and bone fractures, few LTC homes actually adhere to these practical recommendations. The purpose of this study was to identify barriers to the implementation of evidence-based practices for osteoporosis and fracture prevention in LTC facilities and elicit practical strategies to address these barriers. METHODS: We performed a qualitative analysis of action plans formulated by Professional Advisory Committee (PAC) teams at 12 LTC homes in the intervention arm of the Vitamin D and Osteoporosis Study (ViDOS) in Ontario, Canada. PAC teams were comprised of medical directors, administrators, directors of care, pharmacists, dietitians, and other staff. Thematic content analysis was performed to identify the key themes emerging from the action plans. RESULTS: LTC teams identified several barriers, including lack of educational information and resources prior to the ViDOS intervention, difficulty obtaining required patient information for fracture risk assessment, and inconsistent prescribing of vitamin D and calcium at the time of admission. The most frequently suggested recommendations was to establish and adhere to standard admission orders regarding vitamin D, calcium, and osteoporosis therapies, improve the use of electronic medical records for osteoporosis and fracture risk assessment, and require bone health as a topic at quarterly reviews and multidisciplinary conferences. CONCLUSIONS: This qualitative study identified several important barriers and practical recommendations for improving the implementation of osteoporosis and fracture prevention guidelines in LTC settings.
Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Barreiras de Comunicação , Fraturas Ósseas , Conhecimentos, Atitudes e Prática em Saúde , Assistência de Longa Duração , Osteoporose , Idoso , Atitude do Pessoal de Saúde , Feminino , Fraturas Ósseas/etiologia , Fraturas Ósseas/prevenção & controle , Humanos , Assistência de Longa Duração/métodos , Assistência de Longa Duração/psicologia , Assistência de Longa Duração/normas , Masculino , Ontário , Osteoporose/complicações , Osteoporose/terapia , Serviços Preventivos de Saúde/métodos , Serviços Preventivos de Saúde/normas , Pesquisa Qualitativa , Medição de Risco/métodosRESUMO
Reverse genetic analyses of negative-strand RNA (NSR) viruses have provided enormous advances in our understanding of animal viruses over the past 20 years, but technical difficulties have hampered application to plant NSR viruses. To develop a reverse genetic approach for analysis of plant NSR viruses, we have engineered Sonchus yellow net nucleorhabdovirus (SYNV) minireplicon (MR) reporter cassettes for Agrobacterium tumefaciens expression in Nicotiana benthamiana leaves. Fluorescent reporter genes substituted for the SYNV N and P protein open reading frames (ORFs) exhibited intense single-cell foci throughout regions of infiltrated leaves expressing the SYNV MR derivatives and the SYNV nucleocapsid (N), phosphoprotein (P), and polymerase (L) proteins. Genomic RNA and mRNA transcription was detected for reporter genes substituted for both the SYNV N and P ORFs. These activities required expression of the N, P, and L core proteins in trans and were enhanced by codelivery of viral suppressor proteins that interfere with host RNA silencing. As is the case with other members of the Mononegavirales, we detected polar expression of fluorescent proteins and chloramphenicol acetyltransferase substitutions for the N and P protein ORFs. We also demonstrated the utility of the SYNV MR system for functional analysis of SYNV core proteins in trans and the cis-acting leader and trailer sequence requirements for transcription and replication. This work provides a platform for construction of more complex SYNV reverse genetic derivatives and presents a general strategy for reverse genetic applications with other plant NSR viruses.
Assuntos
Nicotiana/virologia , Vírus de Plantas/genética , Vírus de RNA/genética , Replicon , Infecções por Rhabdoviridae/virologia , Rhabdoviridae/fisiologia , Proteínas Virais/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Vírus de Plantas/metabolismo , Plasmídeos , Vírus de RNA/metabolismo , RNA de Plantas/genética , Infecções por Rhabdoviridae/genética , Sonchus , Nicotiana/genética , Nicotiana/metabolismo , Transcrição Gênica , Proteínas Virais/genéticaRESUMO
MTF-1 is a sequence-specific DNA binding protein that activates the transcription of metal responsive genes. The extent of activation is dependent on the nature of the metal challenge. Here we identify separate regions within the Drosophila MTF-1 (dMTF-1) protein that are required for efficient copper- versus cadmium-induced transcription. dMTF-1 contains a number of potential metal binding regions that might allow metal discrimination including a DNA binding domain containing six zinc fingers and a highly conserved cysteine-rich C-terminus. We find that four of the zinc fingers in the DNA binding domain are essential for function but the DNA binding domain does not contribute to the metal discrimination by dMTF-1. We find that the conserved C-terminus of the cysteine-rich domain provides cadmium specificity while copper specificity maps to the previously described copper-binding region (Chen et al.). In addition, both metal specific domains are autorepressive in the absence of metal and contribute to the low level of basal transcription from metal inducible promoters.
Assuntos
Cádmio , Cobre , Proteínas de Ligação a DNA/química , Fatores de Transcrição/química , Ativação Transcricional , Animais , Cádmio/metabolismo , Cádmio/farmacologia , Cobre/metabolismo , Cobre/farmacologia , Cisteína/química , Proteínas de Ligação a DNA/genética , Drosophila melanogaster , Regiões Promotoras Genéticas , Estrutura Terciária de Proteína , Fatores de Transcrição/genética , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Dedos de Zinco , Fator MTF-1 de TranscriçãoRESUMO
BACKGROUND: The impact of geriatric medicine educational programs on patient level outcomes, as opposed to educational measures, is not well studied. We aimed to determine whether completion of a mandatory geriatrics rotation changed the clinical behaviors of clerks caring for older patients admitted to a medical clinical teaching unit. METHODS: We reviewed the charts of 132 older (>70y) patients, admitted to one medical clinical teaching unit (CTU) during 2005, and cared for by a clinical clerk, for documented functional assessment, cognitive assessment, recognition of medications that cause confusion, and early removal of indwelling urinary catheters. Performance of these outcomes was compared between clerks who had completed a mandatory 2-week geriatrics rotation immediately before the medical CTU rotation (n = 62) and those who completed geriatrics immediately after (n = 74). Patient outcomes were also measured and compared between groups. RESULTS: Compared to clerks without prior geriatric exposure, clerks with geriatrics exposure were almost 3 times as likely to assess function of their older patients within two days of assuming care (27% vs. 12%, OR: 2.73, 95% CI: 1.12 to 6.66). There were no significant differences in the other clinical behaviors. Patients cared for by geriatrics-exposed clerks were less likely to die or be institutionalized (10% vs. 31%, OR: 0.24, 95% CI: 0.09 to 0.63), and they had shorter lengths of stay by an average of -7.14 days (95% CI: -12.2 to -2.07). Adjustment for baseline differences in age and cognitive impairment did not alter the results. CONCLUSIONS: Clinical clerks who had completed a mandatory geriatrics rotation were more likely to document functional status upon assuming care of their older medical CTU patients, and there was also an association with better clinical outcomes. This highlights the value of including a geriatric medicine rotation as part of the core clerkship curriculum.