RESUMO
The correct establishment of DNA methylation patterns is vital for mammalian development and is achieved by the de novo DNA methyltransferases DNMT3A and DNMT3B. DNMT3B localises to H3K36me3 at actively transcribing gene bodies via its PWWP domain. It also functions at heterochromatin through an unknown recruitment mechanism. Here, we find that knockout of DNMT3B causes loss of methylation predominantly at H3K9me3-marked heterochromatin and that DNMT3B PWWP domain mutations or deletion result in striking increases of methylation in H3K9me3-marked heterochromatin. Removal of the N-terminal region of DNMT3B affects its ability to methylate H3K9me3-marked regions. This region of DNMT3B directly interacts with HP1α and facilitates the bridging of DNMT3B with H3K9me3-marked nucleosomes in vitro. Our results suggest that DNMT3B is recruited to H3K9me3-marked heterochromatin in a PWWP-independent manner that is facilitated by the protein's N-terminal region through an interaction with a key heterochromatin protein. More generally, we suggest that DNMT3B plays a role in DNA methylation homeostasis at heterochromatin, a process which is disrupted in cancer, aging and Immunodeficiency, Centromeric Instability and Facial Anomalies (ICF) syndrome.
Assuntos
Metilação de DNA , Face/anormalidades , Heterocromatina , Doenças da Imunodeficiência Primária , Animais , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Mutação , Mamíferos/genética , Mamíferos/metabolismoRESUMO
Background: A gap in the literature exists pertaining to a global research nurse/research midwife resources and communication skill set necessary to engage with participants of diverse populations and geographic regions in the community or home-based conduct of decentralized clinical trials. Aims: An embedded mixed methods study was conducted to examine research nurse/research midwife knowledge base, experiences, and communication skill sets pertaining to decentralized trials across global regions engaged in remote research: the USA, Republic of Ireland, United Kingdom, and Australia. Methods: An online survey was deployed across international research nurse/research midwife stakeholder groups, collecting demographics, decentralized trial experience, barriers and facilitators to optimal trial conduct, and the self-perceived communication competence (SPCC) and interpersonal communication competence (IPCC) instruments. Results: 86 research nurses and research midwives completed the survey across all countries: The SPCC and IPCC results indicated increased clinical research experience significantly correlated with increased SPCC score (p < 0.05). Qualitative content analysis revealed five themes: (1) Implications for Role, (2) Safety and Wellbeing, (3) Training and Education, (4) Implications for Participants, and (5) Barriers and Facilitators. Conclusions: Common trends and observations across the global sample can inform decentralized trial resource allocation and policy pertaining to the research nurse/research midwife workforce. This study demonstrates shared cultural norms of research nursing and midwifery across varied regional clinical trial ecosystems.
RESUMO
INTRODUCTION: Traditionally, wards in acute care hospitals consist predominately of multioccupancy bays with some single rooms. There is an increasing global trend towards a higher proportion of single rooms in hospitals, with the UK National Health Service (NHS) advocating for single-room provision in all new hospital builds. There is limited evidence on the impact of a ward environment incorporating mostly single and some multioccupancy bays on patient care and organisational outcomes. METHODS AND ANALYSES: This study will assess the impact of a newly designed 28-bedded ward environment, with 20 single rooms and two four-bedded bays, on patient and staff experiences and outcomes in an acute NHS Trust in East England. The study is divided into two work packages (WP)-WP1 is a quantitative data extraction of routinely collected patient and staff data while WP2 is a mixed-methods process evaluation consisting of one-to-one, in-depth, semistructured interviews with staff, qualitative observations of work processes on the ward and a quantitative data evaluation of routinely collected process evaluation data from patients and staff. ETHICS AND DISSEMINATION: Ethical approval was obtained from the UK Health Research Authority (IRAS ID: 334395). Study findings will be shared with key stakeholders, published in peer-reviewed high-impact journals and presented at relevant conferences.
Assuntos
Quartos de Pacientes , Medicina Estatal , Humanos , Inglaterra , Ocupação de Leitos , Arquitetura Hospitalar , Reino Unido , Projetos de Pesquisa , Satisfação do PacienteRESUMO
Allosteric modulation of muscarinic acetylcholine receptors (mAChR) has been identified as a potential strategy for regulating cholinergic signaling in the treatment of various neurological disorders. Most positive allosteric modulators (PAMs) of mAChR enhance agonist affinity and potency, while very few PAMs (e.g., amiodarone) selectively enhance G protein coupling efficacy. The key structural features of amiodarone responsible for enhancement of mAChR efficacy were examined in CHO cells expressing M1 receptors. Subsequent incorporation of these structural features into previously identified allosteric modulators of potency (i.e., n-benzyl isatins) generated ligands that demonstrated similar or better enhancement of mAChR efficacy, lower in vivo toxicity, and higher allosteric binding affinity relative to amiodarone. Notable ligands include 8a, c which respectively demonstrated the strongest binding affinity and the most robust enhancement of mAChR efficacy as calculated from an allosteric operational model. Amiodarone derivatives and hybrid ligands were additionally screened in wildtype zebrafish (Danio rerio) to provide preliminary in vivo toxicity data as well as to observe effects on locomotor and turning behaviors relative to other mAChR PAMs. Several compounds, including 8a, c, reduced locomotor activity and increased measures of turning behaviors in zebrafish, suggesting that allosteric modulation of muscarinic receptor efficacy might be useful in the treatment of repetitive behaviors associated with autism spectrum disorder (ASD) and other neuropsychiatric disorders.
Assuntos
Acetilcolina , Cricetulus , Locomoção , Receptor Muscarínico M1 , Peixe-Zebra , Animais , Receptor Muscarínico M1/metabolismo , Regulação Alostérica/efeitos dos fármacos , Células CHO , Acetilcolina/metabolismo , Acetilcolina/farmacologia , Locomoção/efeitos dos fármacos , Ligantes , Agonistas Muscarínicos/farmacologiaRESUMO
Allosteric modulation of muscarinic acetylcholine receptors (mAChR) has been identified as a potential strategy for regulating cholinergic signaling in the treatment of various neurological disorders. Most positive allosteric modulators (PAMs) of mAChR enhance agonist affinity and potency, while very few PAMs selectively enhance G-protein coupling efficacy (e.g., amiodarone). The key structural features of amiodarone responsible for enhancement of mAChR efficacy were examined in CHO cells expressing M1 receptors. Subsequent incorporation of these structural features into previously identified allosteric modulators of potency (i.e., n-benzyl isatins) generated hybrid ligands that demonstrated similar or better enhancement of mAChR efficacy, lower in vivo toxicity, and higher allosteric binding affinity relative to amiodarone. Notable hybrid ligands include 8a and 8b which respectively demonstrated the strongest binding affinity and the most robust enhancement of mAChR efficacy as calculated from an allosteric operational model. Amiodarone derivatives and hybrid ligands were additionally screened in wildtype zebrafish (Danio rerio) to provide preliminary in vivo toxicity data as well as to observe effects on locomotor and turning behaviors relative to other mAChR PAMs. Several compounds, including 8a and 8c, reduced locomotor activity and increased measures of turning behaviors in zebrafish, suggesting that allosteric modulation of muscarinic receptor efficacy might be useful in the treatment of repetitive behaviors associated with autism spectrum disorder (ASD) and other neuropsychiatric disorders.