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1.
Genome Biol ; 24(1): 227, 2023 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-37828516

RESUMO

BACKGROUND: In several eukaryotes, DNA methylation occurs within the coding regions of many genes, termed gene body methylation (GbM). Whereas the role of DNA methylation on the silencing of transposons and repetitive DNA is well understood, gene body methylation is not associated with transcriptional repression, and its biological importance remains unclear. RESULTS: We report a newly discovered type of GbM in plants, which is under constitutive addition and removal by dynamic methylation modifiers in all cells, including the germline. Methylation at Dynamic GbM genes is removed by the DRDD demethylation pathway and added by an unknown source of de novo methylation, most likely the maintenance methyltransferase MET1. We show that the Dynamic GbM state is present at homologous genes across divergent lineages spanning over 100 million years, indicating evolutionary conservation. We demonstrate that Dynamic GbM is tightly associated with the presence of a promoter or regulatory chromatin state within the gene body, in contrast to other gene body methylated genes. We find Dynamic GbM is associated with enhanced gene expression plasticity across development and diverse physiological conditions, whereas stably methylated GbM genes exhibit reduced plasticity. Dynamic GbM genes exhibit reduced dynamic range in drdd mutants, indicating a causal link between DNA demethylation and enhanced gene expression plasticity. CONCLUSIONS: We propose a new model for GbM in regulating gene expression plasticity, including a novel type of GbM in which increased gene expression plasticity is associated with the activity of DNA methylation writers and erasers and the enrichment of a regulatory chromatin state.


Assuntos
Metilação de DNA , Plantas , Plantas/genética , Evolução Biológica , Expressão Gênica , Cromatina
2.
BMC Bioinformatics ; 24(1): 178, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37127563

RESUMO

BACKGROUND: The field of epigenomics holds great promise in understanding and treating disease with advances in machine learning (ML) and artificial intelligence being vitally important in this pursuit. Increasingly, research now utilises DNA methylation measures at cytosine-guanine dinucleotides (CpG) to detect disease and estimate biological traits such as aging. Given the challenge of high dimensionality of DNA methylation data, feature-selection techniques are commonly employed to reduce dimensionality and identify the most important subset of features. In this study, our aim was to test and compare a range of feature-selection methods and ML algorithms in the development of a novel DNA methylation-based telomere length (TL) estimator. We utilised both nested cross-validation and two independent test sets for the comparisons. RESULTS: We found that principal component analysis in advance of elastic net regression led to the overall best performing estimator when evaluated using a nested cross-validation analysis and two independent test cohorts. This approach achieved a correlation between estimated and actual TL of 0.295 (83.4% CI [0.201, 0.384]) on the EXTEND test data set. Contrastingly, the baseline model of elastic net regression with no prior feature reduction stage performed less well in general-suggesting a prior feature-selection stage may have important utility. A previously developed TL estimator, DNAmTL, achieved a correlation of 0.216 (83.4% CI [0.118, 0.310]) on the EXTEND data. Additionally, we observed that different DNA methylation-based TL estimators, which have few common CpGs, are associated with many of the same biological entities. CONCLUSIONS: The variance in performance across tested approaches shows that estimators are sensitive to data set heterogeneity and the development of an optimal DNA methylation-based estimator should benefit from the robust methodological approach used in this study. Moreover, our methodology which utilises a range of feature-selection approaches and ML algorithms could be applied to other biological markers and disease phenotypes, to examine their relationship with DNA methylation and predictive value.


Assuntos
Metilação de DNA , Epigenômica , Homeostase do Telômero , Algoritmos , Epigenômica/métodos , Análise de Regressão , Aprendizado de Máquina , Humanos
3.
Clin Exp Optom ; 106(1): 41-46, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-34902293

RESUMO

CLINICAL RELEVANCE: Macular drusen are associated with age-related maculopathy but are not an ocular manifestation or biomarker of systemic ageing. BACKGROUND: Macular drusen are the first sign of age-related maculopathy, an eye disease for which age is the strongest risk factor. The aim of this cohort study was to investigate whether macular drusen in midlife - a sign of the earliest stages of age-related macular degeneration (AMD) - are associated with accelerated biological ageing more generally. METHODS: Members of the long-running Dunedin Multidisciplinary Health and Development Study (hereafter the Dunedin Study, n = 1037) underwent retinal photography at their most recent assessment at the age of 45 years. Images were graded for the presence of AMD using a simplified scale from the Age-Related Eye Disease Study (AREDS). Accelerated ageing was assessed by (i) a measure of Pace of Ageing defined from a combination of clinical and serum biomarkers obtained at ages 26, 32, 38, and 45 years and (ii) Facial Ageing, defined from photographs obtained at age 38 and 45 years. RESULTS: Of the 938 participants who participated at the age 45 assessments, 834 had gradable retinal photographs, and of these 165 (19.8%) had macular drusen. There was no significant difference in Pace of Ageing (p = .743) or Facial Ageing (p = .945) among participants with and without macular drusen. CONCLUSIONS: In this representative general population sample, macular drusen in midlife were not associated with accelerated ageing. Future studies tracking longitudinal changes in drusen number and severity at older ages may reveal whether drusen are a biomarker of accelerated ageing.


Assuntos
Degeneração Macular , Drusas Retinianas , Humanos , Adulto , Pessoa de Meia-Idade , Estudos de Coortes , Degeneração Macular/diagnóstico , Degeneração Macular/etiologia , Envelhecimento , Retina
4.
Cities Health ; 6(5): 1004-1019, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36618774

RESUMO

Several studies have investigated the impact of neighbourhood design on health and wellbeing, yet there are limited reviews investigating the quality of the evidence and the most effective interventions at a population level. This systematic review aims to clarify the impact of the neighbourhood design on health and wellbeing and evaluate the quality of the evidence underpinning such associations. Eight electronic databases were searched for studies conducted between 2000 and 2016. Additional searches were conducted on Google to identify potentially eligible grey literature. A total of 7694 studies were returned from the literature search, and a final selection of 39 studies were deemed eligible for inclusion. Quality appraisal was conducted using the Quality Assessment Tool for Quantitative Studies. Findings from the studies showed important associations between neighbourhood design principles such as walkability, access to green space and amenities on health and wellbeing. Findings from this review also highlight areas with inconsistent findings and gaps in the evidence for future research.

5.
Commun Chem ; 5(1): 102, 2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36697958

RESUMO

The visualization of chemical processes that occur in the solid-state is key to the design of new functional materials. One of the challenges in these studies is to monitor the processes across a range of timescales in real-time. Here, we present a pump-multiprobe single-crystal X-ray diffraction (SCXRD) technique for studying photoexcited solid-state species with millisecond-to-minute lifetimes. We excite using pulsed LEDs and synchronise to a gated X-ray detector to collect 3D structures with sub-second time resolution while maximising photo-conversion and minimising beam damage. Our implementation provides complete control of the pump-multiprobe sequencing and can access a range of timescales using the same setup. Using LEDs allows variation of the intensity and pulse width and ensures uniform illumination of the crystal, spreading the energy load in time and space. We demonstrate our method by studying the variable-temperature kinetics of photo-activated linkage isomerism in [Pd(Bu4dien)(NO2)][BPh4] single-crystals. We further show that our method extends to following indicative Bragg reflections with a continuous readout Timepix3 detector chip. Our approach is applicable to a range of physical and biological processes that occur on millisecond and slower timescales, which cannot be studied using existing techniques.

6.
Plant Cell ; 34(4): 1189-1206, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-34954804

RESUMO

Cytosine methylation is a reversible epigenetic modification of DNA. In plants, removal of cytosine methylation is accomplished by the four members of the DEMETER (DME) family of 5-methylcytosine DNA glycosylases, named DME, DEMETER-LIKE2 (DML2), DML3, and REPRESSOR OF SILENCING1 (ROS1) in Arabidopsis thaliana. Demethylation by DME is critical for seed development, preventing experiments to determine the function of the entire gene family in somatic tissues by mutant analysis. Here, we bypassed the reproductive defects of dme mutants to create somatic quadruple homozygous mutants of the entire DME family. dme; ros1; dml2; and dml3 (drdd) leaves exhibit hypermethylated regions compared with wild-type leaves and rdd triple mutants, indicating functional redundancy among all four demethylases. Targets of demethylation include regions co-targeted by RNA-directed DNA methylation and, surprisingly, CG gene body methylation, indicating dynamic methylation at these less-understood sites. Additionally, many tissue-specific methylation differences are absent in drdd, suggesting a role for active demethylation in generating divergent epigenetic states across wild-type tissues. Furthermore, drdd plants display an early flowering phenotype, which involves 5'-hypermethylation and transcriptional down-regulation of FLOWERING LOCUS C. Active DNA demethylation is therefore required for proper methylation across somatic tissues and defines the epigenetic landscape of intergenic and coding regions.


Assuntos
Proteínas de Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Desmetilação do DNA , Metilação de DNA/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética
7.
Br J Anaesth ; 128(4): 623-635, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34924175

RESUMO

BACKGROUND: Postoperative hypotension is associated with adverse outcomes, but intraoperative prediction of postanaesthesia care unit (PACU) hypotension is not routine in anaesthesiology workflow. Although machine learning models may support clinician prediction of PACU hypotension, clinician acceptance of prediction models is poorly understood. METHODS: We developed a clinically informed gradient boosting machine learning model using preoperative and intraoperative data from 88 446 surgical patients from 2015 to 2019. Nine anaesthesiologists each made 192 predictions of PACU hypotension using a web-based visualisation tool with and without input from the machine learning model. Questionnaires and interviews were analysed using thematic content analysis for model acceptance by anaesthesiologists. RESULTS: The model predicted PACU hypotension in 17 029 patients (area under the receiver operating characteristic [AUROC] 0.82 [95% confidence interval {CI}: 0.81-0.83] and average precision 0.40 [95% CI: 0.38-0.42]). On a random representative subset of 192 cases, anaesthesiologist performance improved from AUROC 0.67 (95% CI: 0.60-0.73) to AUROC 0.74 (95% CI: 0.68-0.79) with model predictions and information on risk factors. Anaesthesiologists perceived more value and expressed trust in the prediction model for prospective planning, informing PACU handoffs, and drawing attention to unexpected cases of PACU hypotension, but they doubted the model when predictions and associated features were not aligned with clinical judgement. Anaesthesiologists expressed interest in patient-specific thresholds for defining and treating postoperative hypotension. CONCLUSIONS: The ability of anaesthesiologists to predict PACU hypotension was improved by exposure to machine learning model predictions. Clinicians acknowledged value and trust in machine learning technology. Increasing familiarity with clinical use of model predictions is needed for effective integration into perioperative workflows.


Assuntos
Hipotensão , Complicações Pós-Operatórias , Humanos , Hipotensão/diagnóstico , Hipotensão/etiologia , Aprendizado de Máquina , Estudos Prospectivos , Curva ROC
8.
Health Promot Int ; 37(2)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-34651168

RESUMO

School-based programs may be more effective when an array of stakeholders, including users, are involved during the relevant stages of program co-creation-specifically during key development stages such as design, implementation and evaluation. How such programs can be operationally co-created and tested is less known and is therefore the purpose of this article. Two sequential co-design phases underpin this study. First, a co-design session with 20 health and physical education (HPE) teachers focussed on reviewing, testing and critically discussing initial prototype online modules for an alcohol education program. Teacher insights were assessed and incorporated, and the updated online modules were tested with secondary school students (n = 120) capturing their experience in a classroom setting. Insights from each group were analysed using thematic analysis. Teachers and students serve important roles in program co-creation. Teachers remain an underutilized stakeholder group whom are however critical in delivering important insights to enhance educational program design. Teachers demanded more relevance to the national curriculum, further alignment with curriculum assessment standards, and age appropriate content. Student feedback focussed largely on realistic content, personalization and gamification elements. This study represents an application of the seven-step co-design process and advances understanding of the 'fuzzy back-end' of the process, namely reflecting on feasibility of integrating teacher and student feedback and ideas. More specifically, how these key-yet distinct-stakeholder groups can be involved, and the merits of their involvement are discussed.


There is much research existing for designing change programs across many contexts. Commonly, involving consumers and other related people in the design of these programs is recommended. However less is known about who to involve in the design of programs, what they can be expected to tell you when involved, and when in the design they should be involved. This study explores these questions when involving teachers and students in the design of a school based online education program. Focussing on alcohol education and moderation strategies, the findings of this study support that different stakeholders contribute their own unique insights, whether based on personal bias or based on the nature of their involvement as stakeholders (e.g. as teachers, as parents, as loyal consumers etc.). Furthermore, this study highlights the need for research to distinguish which recommendations to adopt between students and teachers, in a manner generalizable to other contexts and stakeholder groups. From the findings of the current study, the authors recommend multi-disciplinary teams to contrast and enhance a research teams' perceptions regarding stakeholder insights.


Assuntos
Pessoal de Educação , Estudantes , Currículo , Humanos , Educação Física e Treinamento , Instituições Acadêmicas
9.
Int J Burns Trauma ; 11(3): 267-274, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34336394

RESUMO

Traumatic injury is a major cause of morbidity and mortality in pediatric patients. Hemorrhage is a known but treatable component of these outcomes. Evidence exists that major trauma patients are at high risk for hypocalcemia but the rate of pediatric occurrence is not documented. The purpose of this study was to determine the incidence of hypocalcemia in pediatric trauma patients, as well as to investigate any correlation between hypocalcemia and the need for transfusion and operative intervention. After IRB approval a retrospective analysis was conducted of all pediatric trauma patients seen in our Adult Level One, Pediatric Level Two trauma center. Significance testing for mortality was performed using Pearson's χ2 test. For the remaining numeric variables, association was determined one-way analysis of variance (when comparing all classes) or Welch's two-sample t-test (when comparing subsets based on calcium or mortality). In any event, significance was determined using α=0.05. A total of 2,928 patients were identified, 1623 were excluded, primarily due to incomplete data. Patients were predominantly male following blunt trauma. Initial calcium levels were 8.73 mg/dL, 95% CI [4-10.9] and 8.97 mg/dL, 95% CI [6.42-13.1] when correcting for albumin levels. Acute declines were noted when comparing initial and corrected serum calcium levels in patients requiring transfusion (7.99 mg/dL and 8.72 mg/dL) and operative intervention (8.54 mg/dL and 8.91 mg/dL). 456 (34.9%) patients required operative intervention, 138 (10.6%) required transfusion and 29 (2.2%) required massive transfusion. Patients in our cohort arrived with calcium values on the low end of normal, with a trend towards hypocalcemia if operative intervention or blood transfusion was required. This has been previously associated with increased mortality. Patients requiring operative intervention and transfusion are at increased risk for hypocalcemia and recognition of this potential is key for improved outcomes.

10.
Brain Behav Immun ; 97: 79-88, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34224821

RESUMO

Stressful life events have been linked to declining health, and inflammation has been proposed as a physiological mechanism that might explain this association. Using 828 participants from the Dunedin Longitudinal Study, we tested whether people who experienced more stressful life events during adulthood would show elevated systemic inflammation when followed up in midlife, at age 45. We studied three inflammatory biomarkers: C-reactive protein (CRP), interleukin-6 (IL-6), and a newer biomarker, soluble urokinase plasminogen activator receptor (suPAR), which is thought to index systemic chronic inflammation. Stressful life events were not associated with CRP or IL-6. However, people who experienced more stressful life events from age 38 to 44 had elevated suPAR at age 45, and had significantly greater increases in suPAR from baseline to follow-up across the same period. When examining stressful life events across the lifespan, both adverse childhood experiences (ACEs) and adult stressful life events were independently associated with suPAR at age 45. ACEs moderated the association of adult stressful life events and suPAR at age 45-children with more ACEs showed higher suPAR levels after experiencing stressful life events as adults. The results suggest systemic chronic inflammation is one physiological mechanism that could link stressful life events and health, and support the use of suPAR as a useful biomarker for such research.


Assuntos
Proteína C-Reativa , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Adulto , Biomarcadores , Proteína C-Reativa/análise , Humanos , Inflamação , Estudos Longitudinais , Pessoa de Meia-Idade
11.
Nat Plants ; 7(6): 730-738, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34059805

RESUMO

Seeds are a key life cycle stage for many plants. Seeds are also the basis of agriculture and the primary source of calories consumed by humans1. Here, we employ single-nucleus RNA-sequencing to generate a transcriptional atlas of developing Arabidopsis thaliana seeds, with a focus on endosperm. Endosperm, the primary site of gene imprinting in flowering plants, mediates the relationship between the maternal parent and the embryo2. We identify transcriptionally uncharacterized nuclei types in the chalazal endosperm, which interfaces with maternal tissue for nutrient unloading3,4. We demonstrate that the extent of parental bias of maternally expressed imprinted genes varies with cell-cycle phase, and that imprinting of paternally expressed imprinted genes is strongest in chalazal endosperm. Thus, imprinting is spatially and temporally heterogeneous. Increased paternal expression in the chalazal region suggests that parental conflict, which is proposed to drive imprinting evolution, is fiercest at the boundary between filial and maternal tissues.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Impressão Genômica , Sementes/genética , Arabidopsis/citologia , Arabidopsis/metabolismo , Ciclo Celular/genética , Núcleo Celular/genética , Endosperma/genética , Regulação da Expressão Gênica de Plantas , Sementes/citologia , Sementes/metabolismo , Análise de Sequência de RNA , Análise de Célula Única
12.
J Urban Health ; 98(3): 415-427, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33939069

RESUMO

This paper sets out the main findings from two rounds of interviews with senior representatives from the UK's urban development industry: the third and final phase of a 3-year pilot, Moving Health Upstream in Urban Development' (UPSTREAM). The project had two primary aims: firstly, to attempt to value economically the health cost-benefits associated with the quality of urban environments and, secondly, to interview those in control of urban development in the UK in order to reveal the potential barriers to, and opportunities for, the creation of healthy urban environments, including their views on the use of economic valuation of (planetary) health outcomes. Much is known about the 'downstream' impact of urban environments on human and planetary health and about how to design and plan healthy towns and cities ('midstream'), but we understand relatively little about how health can be factored in at key governance tipping points further 'upstream', particularly within dominant private sector areas of control (e.g. land, finance, delivery) at sub-national level. Our findings suggest that both public and private sector appeared well aware of the major health challenges posed by poor-quality urban environments. Yet they also recognized that health is not factored adequately into the urban planning process, and there was considerable support for greater use of non-market economic valuation to help improve decision-making. There was no silver bullet however: 110 barriers and 76 opportunities were identified across a highly complex range of systems, actors and processes, including many possible points of targeted intervention for economic valuation. Eight main themes were identified as key areas for discussion and future focus. This findings paper is the second of two on this phase of the project: the first sets out the rationale, approach and methodological lessons learned.


Assuntos
Planejamento de Cidades , Reforma Urbana , Cidades , Tomada de Decisões , Humanos , Reino Unido
13.
Nature ; 593(7859): 351-361, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34012079

RESUMO

High-energy-density physics is the field of physics concerned with studying matter at extremely high temperatures and densities. Such conditions produce highly nonlinear plasmas, in which several phenomena that can normally be treated independently of one another become strongly coupled. The study of these plasmas is important for our understanding of astrophysics, nuclear fusion and fundamental physics-however, the nonlinearities and strong couplings present in these extreme physical systems makes them very difficult to understand theoretically or to optimize experimentally. Here we argue that machine learning models and data-driven methods are in the process of reshaping our exploration of these extreme systems that have hitherto proved far too nonlinear for human researchers. From a fundamental perspective, our understanding can be improved by the way in which machine learning models can rapidly discover complex interactions in large datasets. From a practical point of view, the newest generation of extreme physics facilities can perform experiments multiple times a second (as opposed to approximately daily), thus moving away from human-based control towards automatic control based on real-time interpretation of diagnostic data and updates of the physics model. To make the most of these emerging opportunities, we suggest proposals for the community in terms of research design, training, best practice and support for synthetic diagnostics and data analysis.

14.
J Urban Health ; 98(3): 404-414, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33988827

RESUMO

This paper sets out the rationale and process for the interviewing methodology utilized during a 3-year research pilot, 'Moving Health Upstream in Urban Development' (UPSTREAM). The project had two primary aims: firstly, to attempt to value economically the health cost benefits associated with the quality of urban environments and secondly, to engage with those in control of urban development in the UK in order to determine what are the barriers to and opportunities for creating healthy urban environments, including those identified through the utilisation of economic valuation. Engagement at senior level with those who have most control over key facets of planning and development implementation-such as land disposal, investment, development delivery and planning permission-was central to the approach, which encompassed the adoption of 'elite interviewing', a method developed in the USA in the 1950s and used in the political sciences but relatively unutilized in the health and environmental sciences [1]. Two rounds of semi-structured interviews were undertaken with 15 senior decision-makers from the UK's main urban development delivery agencies, both public and private. The 'elite interviewing' approach successfully enabled the UPSTREAM project to capture and analyse the information received from the interviewees, all of whom held influential or leadership posts in organisations that are important actors in the process of planning, developing and constructing the built environment in the UK. Having academic and practitioner research leads on an equal footing created some minor tensions, but it also appeared to strengthen the rigor of the approach through a broad knowledge of context 'in-house'. This form of co-production at times challenged academic traditions in qualitative analysis, but it also appeared to build trust with interviewees and provided greater clarity of the real-world context under investigation. Findings from this study are written up in a separate paper.


Assuntos
Pesquisa Interdisciplinar , Saúde da População Urbana , Serviços de Saúde , Humanos , Liderança
15.
J Surg Case Rep ; 2021(1): rjaa562, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33505655

RESUMO

This case of bowel obstruction with multiple postoperative complications provides unique insight into the challenges faced by providers caring for intellectually disabled patients with acute surgical abdominal pathology and poor compliance. In this case, the component separation was utilized as a method of facilitated wound closure and compliance in a postoperative course highlighted by both dehiscence and wound infection. The patient, only able to communicate the presence of abdominal pain due to his disability, was surgically managed for a bowel obstruction secondary to a cecal volvulus. The difficulty in initial communication and patient noncompliance help illustrate the individualized care these patients require. This report will demonstrate both the challenges present in the management of intellectually disabled patients with abdominal wounds, as well as the use of component separation in providing both initial wound closure and continued wound integrity with the goal of reducing postoperative complications in patients with decreased compliance.

16.
Int J Pharm ; 592: 119980, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33069892

RESUMO

A new approach is proposed to support prediction of tablet tensile strength as a function of both solid fraction (and/or compression pressure) and extent of lubrication by using empirical data to parameterise the model. This is a pre-requisite for simulation of the compaction unit operation where a linkage from tablet press operating parameters and formulation material properties to output tensile strength is required. The approach extends the previously published Kushner and Moore model to allow calculation across a range of solid fractions. The applicability of the approach is supported by testing using formulations with different commonly used pharmaceutical excipients.


Assuntos
Excipientes , Composição de Medicamentos , Lubrificação , Pós , Comprimidos , Resistência à Tração
17.
Trends Genet ; 36(10): 751-763, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32711945

RESUMO

In diverse eukaryotes, epigenetic information such as DNA methylation is stably propagated over many cell divisions and generations, and can remain the same over thousands or millions of years. However, this stability is the product of dynamic processes that add and remove DNA methylation by specialized enzymatic pathways. The activities of these dynamic pathways must therefore be finely orchestrated in order to ensure that the DNA methylation landscape is maintained with high fidelity - a concept we term epigenetic homeostasis. In this review, we summarize recent insights into epigenetic homeostasis mechanisms in flowering plants and mammals, highlighting analogous mechanisms that have independently evolved to achieve the same goal of stabilizing the epigenetic landscape.


Assuntos
Cromatina/genética , Metilação de DNA , Epigênese Genética , Regulação da Expressão Gênica , Homeostase , Magnoliopsida/genética , Mamíferos/genética , Animais , Humanos , Mamíferos/classificação
18.
JAMA Netw Open ; 3(6): e206095, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32478847

RESUMO

Importance: DNA methylation has been proposed as an epigenetic mechanism by which the childhood neighborhood environment may have implications for the genome that compromise adult health. Objective: To ascertain whether childhood neighborhood socioeconomic disadvantage is associated with differences in DNA methylation by age 18 years. Design, Setting, and Participants: This longitudinal cohort study analyzed data from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative birth cohort of children born between 1994 and 1995 in England and Wales and followed up from age 5 to 18 years. Data analysis was performed from March 15, 2019, to June 30, 2019. Exposures: High-resolution neighborhood data (indexing deprivation, dilapidation, disconnection, and dangerousness) collected across childhood. Main Outcomes and Measures: DNA methylation in whole blood was drawn at age 18 years. Associations between neighborhood socioeconomic disadvantage and methylation were tested using 3 prespecified approaches: (1) testing probes annotated to candidate genes involved in biological responses to growing up in socioeconomically disadvantaged neighborhoods and investigated in previous epigenetic research (stress reactivity-related and inflammation-related genes), (2) polyepigenetic scores indexing differential methylation in phenotypes associated with growing up in disadvantaged neighborhoods (obesity, inflammation, and smoking), and (3) a theory-free epigenome-wide association study. Results: A total of 1619 participants (806 female individuals [50%]) had complete neighborhood and DNA methylation data. Children raised in socioeconomically disadvantaged neighborhoods exhibited differential DNA methylation in genes involved in inflammation (ß = 0.12; 95% CI, 0.06-0.19; P < .001) and smoking (ß = 0.18; 95% CI, 0.11-0.25; P < .001) but not obesity (ß = 0.05; 95% CI, -0.01 to 0.11; P = .12). An epigenome-wide association study identified multiple CpG sites at an arraywide significance level of P < 1.16 × 10-7 in genes involved in the metabolism of hydrocarbons. Associations between neighborhood disadvantage and methylation were small but robust to family-level socioeconomic factors and to individual-level tobacco smoking. Conclusions and Relevance: Children raised in more socioeconomically disadvantaged neighborhoods appeared to enter young adulthood epigenetically distinct from their less disadvantaged peers. This finding suggests that epigenetic regulation may be a mechanism by which the childhood neighborhood environment alters adult health.


Assuntos
Metilação de DNA/genética , DNA/sangue , Epigênese Genética/genética , Características de Residência/estatística & dados numéricos , Adolescente , Poluentes Atmosféricos/toxicidade , Criança , Pré-Escolar , Inglaterra/epidemiologia , Feminino , Humanos , Inflamação/genética , Estudos Longitudinais , Masculino , Obesidade/genética , Obesidade/metabolismo , Avaliação de Resultados em Cuidados de Saúde , Fenótipo , Fumar/genética , Fatores Socioeconômicos
19.
Sci Total Environ ; 719: 137146, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32229012

RESUMO

Research has demonstrated that housing quality is a key urban intervention in reducing health risks and improving climate resilience, addressing a key ambition of the United Nations Sustainable Development Goals. Yet housing quality remains a problem even in high income countries such as England. In particular, hazards such as excess cold, excess heat and lack of ventilation leading to damp and mould have been identified as a major issue in homes. Research shows that these hazards can lead to a range of health conditions, such as respiratory and cardiovascular disease, infections and mental health problems. This article explores the use of public health research and evidence in policy to regulate new buildings in England to deliver improved public health, climate resilience and a reduced carbon footprint, in particular exploring the policy drivers and awareness of the public health evidence. Findings show that public health evidence is hardly referenced in policy and that the focus on other evidence bases such as on climate mitigation in building regulations results in both positive and negative impacts on health. This reflects a lack of a systems approach around urban interventions leading to weaknesses in standards regulating the private development sector. In conclusion, this paper recommends: 1. the consideration of health impact in future building regulations; 2. the integration and coordination of key policies covering various scales and phases of the development processes and 3. the better education of residents to understand advances in new energy performance technologies.

20.
Psychopharmacology (Berl) ; 237(5): 1317-1330, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31965252

RESUMO

RATIONALE: Methamphetamine (METH) enhances exocytotic dopamine (DA) signals and induces DA transporter (DAT)-mediated efflux in brain striatal regions such as the nucleus accumbens (NAc). Blocking sigma receptors prevents METH-induced DA increases. Sigma receptor activation induces Ca2+ release from intracellular stores, which may be responsible for METH-induced DA increases. OBJECTIVES: The role of intracellular and extracellular Ca2+ in METH-induced DA increases and associated behavior was tested. METHODS: METH-induced Ca2+ release was measured in hNPC-derived DA cells using ratiometric Ca2+ imaging. In mouse brain slices, fast-scan cyclic voltammetry was used to measure METH effects on two measures of dopamine: electrically stimulated and DAT-mediated efflux. Intracellular and extracellular Ca2+ was removed through pharmacological blockade of Ca2+ permeable channels (Cd2+ and IP3 sensitive channels), intracellular Ca2+ chelation (BAPTA-AM), or non-inclusion (zero Ca2+). Lastly, METH effects on dopamine-mediated locomotor behavior were tested in rats. Rats received intra-NAc injections of ACSF or 2-aminoethoxydiphenyl borate (2-APB; IP3 receptor blocker) and intraperitoneal METH (5 mg/kg) to test the role of intracellular Ca2+ release in DA-mediated behaviors. RESULTS: Reducing Ca2+ extracellular levels and Ca2+ release from intracellular stores prevented intracellular Ca2+ release. Intracellular Ca2+ chelation and blocking intracellular Ca2+ release reduced METH effects on voltammetric measures of dopamine. Blocking intracellular Ca2+ release via 2-APB resulted in increased METH-induced circling behavior. CONCLUSIONS: METH induces NAc DA release through intracellular Ca2+ activity. Blocking intracellular Ca2+ release prevents METH effects on DA signals and related behavior.


Assuntos
Cálcio/metabolismo , Inibidores da Captação de Dopamina/farmacologia , Dopamina/metabolismo , Metanfetamina/farmacologia , Núcleo Accumbens/metabolismo , Animais , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Núcleo Accumbens/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo
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