RESUMO
In virus-host interactions, nucleic acid-directed first lines of defense that allow viral clearance without compromising growth are of paramount importance. Plants use the RNA interference pathway as a basal antiviral immune system, but additional RNA-based mechanisms of defense also exist. The infectivity of a plant positive-strand RNA virus, alfalfa mosaic virus (AMV), relies on the demethylation of viral RNA by the recruitment of the cellular N6-methyladenosine (m6 A) demethylase ALKBH9B, but how demethylation of viral RNA promotes AMV infection remains unknown. Here, we show that inactivation of the Arabidopsis cytoplasmic YT521-B homology domain (YTH)-containing m6 A-binding proteins ECT2, ECT3, and ECT5 is sufficient to restore AMV infectivity in partially resistant alkbh9b mutants. We further show that the antiviral function of ECT2 is distinct from its previously demonstrated function in the promotion of primordial cell proliferation: an ect2 mutant carrying a small deletion in its intrinsically disordered region is partially compromised for antiviral defense but not for developmental functions. These results indicate that the m6 A-YTHDF axis constitutes a novel branch of basal antiviral immunity in plants.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Vírus de RNA , Antivirais , Proteínas de Plantas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Arabidopsis/metabolismo , RNA Viral/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismoRESUMO
N6-methyladenosine (m6A) is an RNA modification involved in RNA processing and widely found in transcripts. In cancer cells, m6A is upregulated, contributing to their malignant transformation. In this study, we analyzed gene expression and m6A modification in cancer tissues, ducts, and acinar cells derived from pancreatic cancer patients using MeRIP-seq. We found that dozens of RNAs highly modified by m6A were detected in cancer tissues compared with ducts and acinar cells. Among them, the m6A-activated mRNA TCEAL8 was observed, for the first time, as a potential marker gene in pancreatic cancer. Spatially resolved transcriptomic analysis showed that TCEAL8 was highly expressed in specific cells, and activation of cancer-related signaling pathways was observed relative to TCEAL8-negative cells. Furthermore, among TCEAL8-positive cells, the cells expressing the m6A-modifying enzyme gene METTL3 showed co-activation of Notch and mTOR signaling, also known to be involved in cancer metastasis. Overall, these results suggest that m6A-activated TCEAL8 is a novel marker gene involved in the malignant transformation of pancreatic cancer.
Assuntos
Adenosina , Biomarcadores Tumorais , Regulação Neoplásica da Expressão Gênica , Metiltransferases , Neoplasias Pancreáticas , RNA Mensageiro , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismo , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/genética , Linhagem Celular Tumoral , Receptores Notch/genética , Receptores Notch/metabolismo , Perfilação da Expressão Gênica/métodosRESUMO
Many genes are co-expressed and form genomic domains of coordinated gene activity. However, the regulatory determinants of domain co-activity remain unclear. Here, we leverage human individual variation in gene expression to characterize the co-regulatory processes underlying domain co-activity and systematically quantify their effect sizes. We employ transcriptional decomposition to extract from RNA expression data an expression component related to co-activity revealed by genomic positioning. This strategy reveals close to 1,500 co-activity domains, covering most expressed genes, of which the large majority are invariable across individuals. Focusing specifically on domains with high variability in co-activity reveals that contained genes have a higher sharing of eQTLs, a higher variability in enhancer interactions, and an enrichment of binding by variably expressed transcription factors, compared to genes within non-variable domains. Through careful quantification of the relative contributions of regulatory processes underlying co-activity, we find transcription factor expression levels to be the main determinant of gene co-activity. Our results indicate that distal trans effects contribute more than local genetic variation to individual variation in co-activity domains.
Assuntos
Regulação da Expressão Gênica , Fatores de Transcrição , Humanos , Fatores de Transcrição/genética , Genoma , GenômicaRESUMO
Adenosine to inosine (A-to-I) RNA editing is one of the most frequent RNA modifications found in the mammalian transcriptome. Recent studies clearly indicate that RNA editing enzymes, adenosine deaminase acting on RNAs (ADARs), are upregulated in stressed cells and under disease conditions, suggesting that monitoring RNA editing patterns might be useful as diagnostic biomarkers of various diseases. Here, we provide an overview of epitranscriptomics, and focus particularly on the detection and analysis of A-to-I RNA editing using bioinformatic tools in RNA-seq data sets, as well as briefly reviewing the existing evidence about its involvement in disease progressions. Finally, we argue for the detection of RNA editing patterns as part of the routine analysis in RNA-based data sets, with the aim of accelerating the identification of RNA editing targets linked to disease.
Assuntos
Edição de RNA , RNA , Animais , Edição de RNA/genética , Transcriptoma/genética , Biomarcadores , MamíferosRESUMO
Regulated transcription controls the diversity, developmental pathways and spatial organization of the hundreds of cell types that make up a mammal. Using single-molecule cDNA sequencing, we mapped transcription start sites (TSSs) and their usage in human and mouse primary cells, cell lines and tissues to produce a comprehensive overview of mammalian gene expression across the human body. We find that few genes are truly 'housekeeping', whereas many mammalian promoters are composite entities composed of several closely separated TSSs, with independent cell-type-specific expression profiles. TSSs specific to different cell types evolve at different rates, whereas promoters of broadly expressed genes are the most conserved. Promoter-based expression analysis reveals key transcription factors defining cell states and links them to binding-site motifs. The functions of identified novel transcripts can be predicted by coexpression and sample ontology enrichment analyses. The functional annotation of the mammalian genome 5 (FANTOM5) project provides comprehensive expression profiles and functional annotation of mammalian cell-type-specific transcriptomes with wide applications in biomedical research.
Assuntos
Atlas como Assunto , Anotação de Sequência Molecular , Regiões Promotoras Genéticas/genética , Transcriptoma/genética , Animais , Linhagem Celular , Células Cultivadas , Análise por Conglomerados , Sequência Conservada/genética , Regulação da Expressão Gênica/genética , Redes Reguladoras de Genes/genética , Genes Essenciais/genética , Genoma/genética , Humanos , Camundongos , Fases de Leitura Aberta/genética , Especificidade de Órgãos , RNA Mensageiro/análise , RNA Mensageiro/genética , Fatores de Transcrição/metabolismo , Sítio de Iniciação de Transcrição , Transcrição Gênica/genéticaRESUMO
Mammalian gene promoters and enhancers share many properties. They are composed of a unified promoter architecture of divergent transcripton initiation and gene promoters may exhibit enhancer function. However, it is currently unclear how expression strength of a regulatory element relates to its enhancer strength and if the unifying architecture is conserved across Metazoa. Here we investigate the transcription initiation landscape and its associated RNA decay in Drosophila melanogaster. We find that the majority of active gene-distal enhancers and a considerable fraction of gene promoters are divergently transcribed. We observe quantitative relationships between enhancer potential, expression level and core promoter strength, providing an explanation for indirectly related histone modifications that are reflecting expression levels. Lowly abundant unstable RNAs initiated from weak core promoters are key characteristics of gene-distal developmental enhancers, while the housekeeping enhancer strengths of gene promoters reflect their expression strengths. The seemingly separable layer of regulation by gene promoters with housekeeping enhancer potential is also indicated by chromatin interaction data. Our results suggest a unified promoter architecture of many D. melanogaster regulatory elements, that is universal across Metazoa, whose regulatory functions seem to be related to their core promoter elements.
Assuntos
Drosophila melanogaster/genética , Elementos Facilitadores Genéticos/genética , Regiões Promotoras Genéticas/genética , Sítio de Iniciação de Transcrição , Transcrição Gênica/genética , Animais , Linhagem Celular , Código das Histonas/fisiologia , RNA/metabolismo , Estabilidade de RNA/genética , Ativação Transcricional/genéticaRESUMO
CONTEXT AND OBJECTIVES: Peer tutoring is a well-researched and established method of learning defined as 'a medical student facilitating the learning of another medical student'. While it has been adopted in many medical schools, other schools may be reluctant to embrace this approach. The attitude of the teaching staff, responsible for organizing and or teaching students in an undergraduate medical course to formal peer teaching will affect how it is introduced and operationalized. This study elicits faculty opinions on how best to introduce peer tutoring for medical students. METHODS: Structured telephone interviews were recorded, transcribed and analyzed using thematic analysis. The interviews were with medically qualified staff responsible for organizing or teaching undergraduate medical students at a New Zealand medical school. Six questions were posed regarding perceived advantages and disadvantages of peer tutoring and how the school and staff could support a peer-tutoring scheme if one was introduced. FINDINGS: Staff generally supported the peer tutoring concept, offering a safe environment for learning with its teachers being so close in career stage to the learners. They also say disadvantages when the student-teachers imparted wrong information and when schools used peer tutoring to justify a reduction in teaching staff. Subjects felt that faculty would be more accepting of peer tutoring if efforts were made to build staff 'buy in' and empowerment, train peer tutors and introduce a solid evaluation process. CONCLUSIONS: Staff of our school expressed some concerns about peer tutoring that are not supported in the literature, signaling a need for better communication about the benefits and disadvantages of peer tutoring.
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Educação Médica/métodos , Docentes de Medicina , Adulto , Atitude do Pessoal de Saúde , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Grupo Associado , Estudantes de MedicinaRESUMO
RNA-binding proteins and chemical modifications to RNA play vital roles in the co- and post-transcriptional regulation of genes. In order to fully decipher their biological roles, it is an essential task to catalogue their precise target locations along with their preferred contexts and sequence-based determinants. Recently, deep learning approaches have significantly advanced in this field. These methods can predict the presence or absence of modification at specific genomic regions based on diverse features, particularly sequence and secondary structure, allowing us to decipher the highly non-linear sequence patterns and structures that underlie site preferences. This article provides an overview of how deep learning is being applied to this area, with a particular focus on the problem of mRNA-RBP binding, while also considering other types of chemical modification to RNA. It discusses how different types of model can handle sequence-based and/or secondary-structure-based inputs, the process of model training, including choice of negative regions and separating sets for testing and training, and offers recommendations for developing biologically relevant models. Finally, it highlights four key areas that are crucial for advancing the field.
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Aprendizado Profundo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Humanos , RNA Mensageiro/genética , RNA Mensageiro/química , RNA Mensageiro/metabolismo , RNA/genética , RNA/química , Conformação de Ácido NucleicoRESUMO
The Supervisor Support Consensus Statement has been developed after consultation with supervisors of surgical training for the Royal Australasian College of Surgeons (RACS) programmes in Australia and Aotearoa New Zealand and other key stakeholders. Six key areas have been recognized with specific recommendations crafted to improve the support and recognition of Supervisors: 1. Clarity of role, 2. Education and Training, 3. Local support, 4. RACS support, 5. Recognition and valuing of the Supervisor role, 6. Risk Management. The purpose of this consensus statement is to clearly articulate supervisor opinions on the support they require to undertake this important role. It has been produced by an independent writing group of experienced surgical supervisors and educators, with support from RACS education department. The consensus statement is a response to a needs assessment of supervisors of surgical training. The statements in this consensus document have been generated from comments and feedback from supervisors that have been refined through process of extensive consultation using a Delphi methodology. We advise specialty training Committees consider these statements and mandate them as part of their accreditation of terms. The role of the supervisor of training requires greater recognition, and incorporation in the Enterprise Bargaining Agreement (EBA) in Australia and the ASMS Te Whatu Ora SECA in Aotearoa New Zealand would ensure the provisions in this document are enacted. The six areas identified have transferability to other specialities and countries and are valuable when considering how to support supervisors involved in training our next generation of specialist doctors.
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Harsh environments in poorly perfused tumor regions may select for traits driving cancer aggressiveness. Here, we investigated whether tumor acidosis interacts with driver mutations to exacerbate cancer hallmarks. We adapted mouse organoids from normal pancreatic duct (mN10) and early pancreatic cancer (mP4, KRAS-G12D mutation, ± p53 knockout) from extracellular pH 7.4 to 6.7, representing acidic niches. Viability was increased by acid adaptation, a pattern most apparent in wild-type (WT) p53 organoids, and exacerbated upon return to pH 7.4. This led to increased survival of acid-adapted organoids treated with gemcitabine and/or erlotinib, and, in WT p53 organoids, acid-induced attenuation of drug effects. New genetic variants became dominant during adaptation, yet they were unlikely to be its main drivers. Transcriptional changes induced by acid and drug adaptation differed overall, but acid adaptation increased the expression of gemcitabine resistance genes. Thus, adaptation to acidosis increases cancer cell viability after chemotherapy.
Assuntos
Desoxicitidina , Resistencia a Medicamentos Antineoplásicos , Gencitabina , Organoides , Neoplasias Pancreáticas , Microambiente Tumoral , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Animais , Organoides/efeitos dos fármacos , Organoides/metabolismo , Organoides/patologia , Resistencia a Medicamentos Antineoplásicos/genética , Camundongos , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Humanos , Concentração de Íons de Hidrogênio , Acidose/patologia , Acidose/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Sobrevivência Celular/efeitos dos fármacosRESUMO
RNA, like DNA and proteins, can undergo modifications. To date, over 170 RNA modifications have been identified, leading to the emergence of a new research area known as epitranscriptomics. RNA editing is the most frequent RNA modification in mammalian transcriptomes, and two types have been identified: (1) the most frequent, adenosine to inosine (A-to-I); and (2) the less frequent, cysteine to uracil (C-to-U) RNA editing. Unlike other epitranscriptomic marks, RNA editing can be readily detected from RNA sequencing (RNA-seq) data without any chemical conversions of RNA before sequencing library preparation. Furthermore, analyzing RNA editing patterns from transcriptomic data provides an additional layer of information about the epitranscriptome. As the significance of epitranscriptomics, particularly RNA editing, gains recognition in various fields of biology and medicine, there is a growing interest in detecting RNA editing sites (RES) by analyzing RNA-seq data. To cope with this increased interest, several bioinformatic tools are available. However, each tool has its advantages and disadvantages, which makes the choice of the most appropriate tool for bench scientists and clinicians difficult. Here, we have benchmarked bioinformatic tools to detect RES from RNA-seq data. We provide a comprehensive view of each tool and its performance using previously published RNA-seq data to suggest recommendations on the most appropriate for utilization in future studies.
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Cancer and cardiovascular disease are the leading causes of death worldwide. Recent evidence suggests that these two life-threatening diseases share several features in disease progression, such as angiogenesis, fibrosis, and immune responses. This has led to the emergence of a new field called cardio-oncology. Doxorubicin is a chemotherapy drug widely used to treat cancer, such as bladder and breast cancer. However, this drug causes serious side effects, including acute ventricular dysfunction, cardiomyopathy, and heart failure. Based on this evidence, we hypothesize that comparing the expression profiles of cells and tissues treated with doxorubicin may yield new insights into the adverse effects of the drug on cellular activities. To test this hypothesis, we analyzed published RNA sequencing (RNA-seq) data from doxorubicin-treated cells to identify commonly differentially expressed genes, including long non-coding RNAs (lncRNAs) as they are known to be dysregulated in diseased tissues and cells. From our systematic analysis, we identified several doxorubicin-induced genes. To confirm these findings, we treated human cardiac fibroblasts with doxorubicin to record expression changes in the selected doxorubicin-induced genes and performed a loss-of-function experiment of the lncRNA MAP3K4-AS1. To further disseminate the analyzed data, we built the web database DoxoDB.
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BACKGROUND: Women remain underrepresented in Surgery in Aotearoa New Zealand (AoNZ). This study described interest in surgical careers by gender in the early postgraduate period and associated influencing factors. METHODS: AoNZ medical graduates between 2012 and 2016 responding to an Exit Questionnaire (EQ) at graduation and 3 years later (PGY3) as part of the Medical Schools Outcomes Database and Longitudinal Tracking Project (MSOD) were included. Analyses of specialty preferences and influences by gender were performed. RESULTS: Of 992 participants, 58% were women. At EQ, 158 participants (16%) had a surgical preference: 21% of men and 14% of women (P < 0.01). By PGY3, this was 20% of men and 10% of women (P < 0.01). A logistic regression found women were half as likely as men to have a surgical preference at PGY3. Those with a surgical preference at EQ were over 23 times more likely to have a surgical preference at PGY3, irrespective of gender. There were significant differences in self-reported career influencing factors between women and men at EQ and PGY3, as well as between PGY3 women with a surgical and those with a non-surgical preference. These included nature of the specialty, training requirements, lifestyle, family and personal factors. CONCLUSIONS: Increasing the proportion of women in Surgery requires a multifaceted approach starting during medical school and continuing through early postgraduate years. More needs to be done to make surgical experiences as an undergraduate and junior doctor appealing to women.
Assuntos
Medicina , Estudantes de Medicina , Masculino , Humanos , Feminino , Estudos Longitudinais , Escolha da Profissão , Inquéritos e QuestionáriosRESUMO
Type II diabetes (T2D) is a growing health problem worldwide due to increased levels of obesity and can lead to other life-threatening diseases, such as cardiovascular and kidney diseases. As the number of individuals diagnosed with T2D rises, there is an urgent need to understand the pathogenesis of the disease in order to prevent further harm to the body caused by elevated blood glucose levels. Recent advances in long non-coding RNA (lncRNA) research may provide insights into the pathogenesis of T2D. Although lncRNAs can be readily detected in RNA sequencing (RNA-seq) data, most published datasets of T2D patients compared to healthy donors focus only on protein-coding genes, leaving lncRNAs to be undiscovered and understudied. To address this knowledge gap, we performed a secondary analysis of published RNA-seq data of T2D patients and of patients with related health complications to systematically analyze the expression changes of lncRNA genes in relation to the protein-coding genes. Since immune cells play important roles in T2D, we conducted loss-of-function experiments to provide functional data on the T2D-related lncRNA USP30-AS1, using an in vitro model of pro-inflammatory macrophage activation. To facilitate lncRNA research in T2D, we developed a web application, T2DB, to provide a one-stop-shop for expression profiling of protein-coding and lncRNA genes in T2D patients compared to healthy donors or subjects without T2D.
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The NLRP3 inflammasome plays a pivotal role in regulating inflammation and immune responses. Its activation can lead to an inflammatory response and pyroptotic cell death. This is beneficial in the case of infections, but excessive activation can lead to chronic inflammation and tissue damage. Moreover, while most of the mammalian genome is transcribed as RNAs, only a small fraction codes for proteins. Among non-protein-coding RNAs, long non-coding RNAs (lncRNAs) have been shown to play key roles in regulating gene expression and cellular processes. They interact with DNA, RNAs, and proteins, and their dysregulation can provide insights into disease mechanisms, including NLRP3 inflammasome activation. Here, we systematically analyzed previously published RNA sequencing (RNA-seq) data of NLRP3 inflammasome activation in monocytes/macrophages to uncover inflammasome-regulated lncRNA genes. To uncover the functional importance of inflammasome-regulated lncRNA genes, one inflammasome-regulated lncRNA, ENSG00000273124, was knocked down in an in vitro model of macrophage polarization. The results indicate that silencing of ENSG00000273124 resulted in the up-regulation tumor necrosis factor (TNF), suggesting that this lncRNA might be involved in pro-inflammatory response in macrophages. To make our analyzed data more accessible, we developed the web database InflammasomeDB.
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Enabling patients to consent to or decline involvement of medical students in their care is an essential aspect of ethically sound, patient-centred, mana-enhancing healthcare. It is required by Aotearoa New Zealand law and Te Kaunihera Rata o Aotearoa Medical Council of New Zealand policy. This requirement was affirmed and explored in a 2015 Consensus Statement jointly authored by the Auckland and Otago Medical Schools. Student reporting through published studies, reflective assignments and anecdotal experiences of students and teachers indicate procedures for obtaining patient consent to student involvement in care remain substandard at times. Between 2020 and 2023 senior leaders of Aotearoa New Zealand's two medical schools, and faculty involved with teaching ethics and professionalism, met to discuss these challenges and reflect on ways they could be addressed. Key stakeholders were engaged to inform proposed responses. This updated consensus statement is the result. It does not establish new standards but outlines Aotearoa New Zealand's existing cultural, ethical, legal and regulatory requirements, and considers how these may be reasonably and feasibly met using some examples.
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Ética Médica , Estudantes de Medicina , Humanos , Nova Zelândia , Consentimento Livre e Esclarecido , Assistência ao PacienteRESUMO
Genetic and environmental exposures cause variability in gene expression. Although most genes are affected in a population, their effect sizes vary greatly, indicating the existence of regulatory mechanisms that could amplify or attenuate expression variability. Here, we investigate the relationship between the sequence and transcription start site architectures of promoters and their expression variability across human individuals. We find that expression variability can be largely explained by a promoter's DNA sequence and its binding sites for specific transcription factors. We show that promoter expression variability reflects the biological process of a gene, demonstrating a selective trade-off between stability for metabolic genes and plasticity for responsive genes and those involved in signaling. Promoters with a rigid transcription start site architecture are more prone to have variable expression and to be associated with genetic variants with large effect sizes, while a flexible usage of transcription start sites within a promoter attenuates expression variability and limits genotypic effects. Our work provides insights into the variable nature of responsive genes and reveals a novel mechanism for supplying transcriptional and mutational robustness to essential genes through multiple transcription start site regions within a promoter.
Assuntos
Fatores de Transcrição , Transcrição Gênica , Humanos , Sequência de Bases , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Sítios de Ligação , MutaçãoRESUMO
Nil.