PAX3-FOXO1 coordinates enhancer architecture, eRNA transcription, and RNA polymerase pause release at select gene targets.

Transcriptional control is a highly dynamic process that changes rapidly in response to various cellular and extracellular cues, making it difficult to define the mechanism of transcription factor function using slow genetic methods. We used a chemical-genetic approach to rapidly degrade a canonical transcriptional activator, PAX3-FOXO1, to define the mechanism by which it regulates gene expression programs. By coupling rapid protein degradation with the analysis of nascent transcription over short time courses and integrating CUT&RUN, ATAC-seq, and eRNA analysis with deep proteomic analysis, we defined PAX3-FOXO1 function at a small network of direct transcriptional targets. PAX3-FOXO1 degradation impaired RNA polymerase pause release and transcription elongation at most regulated gene targets. Moreover, the activity of PAX3-FOXO1 at enhancers controlling this core network was surprisingly selective, affecting single elements in super-enhancers. This combinatorial analysis indicated that PAX3-FOXO1 was continuously required to maintain chromatin accessibility and enhancer architecture at regulated enhancers.

Definition of a small core transcriptional circuit regulated by AML1-ETO.

Transcription factors regulate gene networks controlling normal hematopoiesis and are frequently deregulated in acute myeloid leukemia (AML). Critical to our understanding of the mechanism of cellular transformation by oncogenic transcription factors is the ability to define their direct gene targets. However, gene network cascades can change within minutes to hours, making it difficult to distinguish direct from secondary or compensatory transcriptional changes by traditional methodologies. To overcome this limitation, we devised cell models in which the AML1-ETO protein could be quickly degraded upon addition of a small molecule. The rapid kinetics of AML1-ETO removal, when combined with analysis of transcriptional output by nascent transcript analysis and genome-wide AML1-ETO binding by CUT&RUN, enabled the identification of direct gene targets that constitute a core AML1-ETO regulatory network. Moreover, derepression of this gene network was associated with RUNX1 DNA binding and triggered a transcription cascade ultimately resulting in myeloid differentiation.

Histone deacetylase 3 controls a transcriptional network required for B cell maturation.

Histone deacetylase 3 (Hdac3) is a target of the FDA approved HDAC inhibitors, which are used for the treatment of lymphoid malignancies. Here, we used Cd19-Cre to conditionally delete Hdac3 to define its role in germinal center B cells, which represent the cell of origin for many B cell malignancies. Cd19-Cre-Hdac3-/- mice showed impaired germinal center formation along with a defect in plasmablast production. Analysis of Hdac3-/- germinal centers revealed a reduction in dark zone centroblasts and accumulation of light zone centrocytes. RNA-seq revealed a significant correlation between genes up-regulated upon Hdac3 loss and those up-regulated in Foxo1-deleted germinal center B cells, even though Foxo1 typically activates transcription. Therefore, to determine whether gene expression changes observed in Hdac3-/- germinal centers were a result of direct effects of Hdac3 deacetylase activity, we used an HDAC3 selective inhibitor and examined nascent transcription in germinal center-derived cell lines. Transcriptional changes upon HDAC3 inhibition were enriched for light zone gene signatures as observed in germinal centers. Further comparison of PRO-seq data with ChIP-seq/exo data for BCL6, SMRT, FOXO1 and H3K27ac identified direct targets of HDAC3 function including CD86, CD83 and CXCR5 that are likely responsible for driving the light zone phenotype observed in vivo.

Mutant FOXO1 controls an oncogenic network via enhancer accessibility.

Transcriptional dysregulation is a hallmark of diffuse large B cell lymphoma (DLBCL), as transcriptional regulators are frequently mutated. However, our mechanistic understanding of how normal transcriptional programs are co-opted in DLBCL has been hindered by a lack of methodologies that provide the temporal resolution required to separate direct and indirect effects on transcriptional control. We applied a chemical-genetic approach to engineer the inducible degradation of the transcription factor FOXO1, which is recurrently mutated (mFOXO1) in DLBCL. The combination of rapid degradation of mFOXO1, nascent transcript detection, and assessment of chromatin accessibility allowed us to identify the direct targets of mFOXO1. mFOXO1 was required to maintain accessibility at specific enhancers associated with multiple oncogenes, and mFOXO1 degradation impaired RNA polymerase pause-release at some targets. Wild-type FOXO1 appeared to weakly regulate many of the same targets as mFOXO1 and was able to complement the degradation of mFOXO1 in the context of AKT inhibition.

The utility of universal screening for somatization in a pediatric emergency department: A prospective evaluation.

OBJECTIVE: To evaluate clinical utility and feasibility of universal somatization screening in the pediatric emergency department (ED) using a standardized approach of (1) identifying potential somatizing symptoms within the ED, (2) introducing these patients and their caregivers to the concept of the 'mind-body connection', (3) corroborating the likelihood of a somatization diagnosis via brief psychiatric assessment, and (4) inviting families to a psychoeducational follow-up session. METHODS: We conducted a cross-sectional study to carry out this approach with families visiting a pediatric ED. Our primary outcome of screening utility was measured as the proportion of youth who screened positive for somatization by the ED clinician. Our secondary outcome of screening feasibility was measured as the proportion of patients with positives who (1) agreed to meet with the study psychiatrist, (2) consented to an ED psychiatric assessment, (3) were assessed by the study psychiatrist as likely experiencing somatization, and (4) were invited for follow-up and attended. RESULTS: Of the 344 screened patients, 27 (7.8%) screened positive for somatization. Of these, 25 (92.6%) families verbally consented to meet the study psychiatrist to learn about the mind-body connection, and 21 (77.8%) consented to further psychiatric assessment. Upon assessment, the somatization likelihood was supported for all 21 youth. Twenty families were invited to follow-up and ultimately two (10%) attended. CONCLUSIONS: Somatization can be detected through ED-based universal screening. Few families attended psychoeducational follow-up. Further research is needed to determine appropriate ED-initiated pediatric somatization intervention.

Pearlescent Mica-Doped Alginate as a Stable, Vibrant Medium for Two-Dimensional and Three-Dimensional Art.

Emergent technologies are driving forces in the development of innovative art media that progress the field of modern art. Recently, artists have capitalized on the versatility of a new technology to create, restore, and modify art: additive manufacturing or three-dimensional (3D) printing. Additively manufactured art relies heavily on plastic-based materials, which typically require high heat to induce melting for workability. The necessity for heat limits plastic media to dedicated 3D printers. In contrast, biologically derived polymers such as polysaccharides used to create "bioinks" often do not require heating the material for workability, broadening the types of techniques available for printing. Here, we detail the formulation of a bioink consisting of mica pigments suspended in alginate as a new, vibrant art medium for 2D and 3D compositions. The properties that make alginate an ideal colorant binder are detailed: low cost with wide availability, nontoxicity and biocompatibility, minimal color, and an array of attractive physicochemical properties that offer workability and processing into 2D and 3D structures. Further, the chemical composition, morphology, and dispersibility of an array of mica pigment additives are characterized in detail as they pertain to the quality of an art medium. Alginate-based media with eight mica colors were formulated, where mica addition resulted in vibrantly colored inks with moderate hiding power and coverage of substrates necessary for 2D printing with thin horizontal and vertical lines. The utility of the media is demonstrated via the generation of 2D and 3D vibrant structures.

Working together better for mental health in children and young people during a pandemic: experiences from North Central London during the first wave of COVID-19.

Direct risk from infection from COVID-19 for children and young people (CYP) is low, but impact on services, education and mental health (so-called collateral damage) appears to have been more significant. In North Central London (NCL) during the first wave of the pandemic, in response to the needs and demands for adults with COVID-19, general paediatric wards in acute hospitals and some paediatric emergency departments were closed. Paediatric mental health services in NCL mental health services were reconfigured. Here we describe process and lessons learnt from a collaboration between physical and mental health services to provide care for CYP presenting in mental health crisis. Two new 'hubs' were created to coordinate crisis presentations in the region and to link community mental health teams with emergency departments. All CYP requiring a paediatric admission in the first wave were diverted to Great Ormond Street Hospital, a specialist children's hospital in NCL, and a new ward for CYP mental health crisis admissions was created. This brought together a multidisciplinary team of mental health and physical health professionals. The most common reason for admission to the ward was following a suicide attempt (n=17, 43%). Patients were of higher acute mental health complexity than usually admitted to the hospital, with some CYP needing an extended period of assessment. In this review, we describe the challenges and key lessons learnt for the development of this new ward setting that involved such factors as leadership, training and also new governance processes. We also report some personal perspectives from the professionals involved. Our review provides perspective and experience that can inform how CYP with mental health admissions can be managed in paediatric medical settings.

Pediatric somatization in the emergency department: assessing missed opportunities for early management.

OBJECTIVE: Somatization is a common phenomenon that can severely complicate youths' functioning and health. The burden of somatization on pediatric acute care settings is currently unclear; better understanding it may address challenges clinicians experience in effectively caring for somatizing patients. In this study, we estimate the prevalence of somatization in a pediatric emergency department (ED). METHODS: We conducted a retrospective cross-sectional study of visits for non-critical, non-mental health-related concerns (n = 150) to a quaternary-level pediatric ED between July 2016 and August 2017. Demographic and clinical visit details were collected through chart review and used by two reviewing clinicians to classify whether each visit had a "probable," "unclear" (possible), or "unlikely" somatizing component. RESULTS: Approximately 3.33% (n = 5) of youth displayed probable somatization, and an additional 13.33% (n = 20) possibly experienced a somatizing component but require additional psychosocial and visit documentation to be certain. Longer symptom duration and multiple negative diagnostic tests were associated with a higher likelihood of either probable or possible somatization. CONCLUSIONS: A considerable proportion of non-mental health-related visits may involve a somatizing component, indicating the burden of mental health concerns on the ED may be underestimated. A higher index of suspicion for the possibility of somatization may support clinicians in managing somatizing patients.

Electrolyte Effect on the Electrochemical Performance of Mild Aqueous Zinc-Electrolytic Manganese Dioxide Batteries.

Recently, mild aqueous rechargeable Zn-MnO2 batteries have attracted increasing interest for energy storage due to the low cost of Zn and Mn resources, high safety, and environmental benignity. Extensive types of MnO2 have been proposed as the cathodes in the literature, but the different reported performance and lack of a thorough understanding of reactions in MnO2 cathodes greatly hinder the practical applications of mild aqueous Zn-MnO2 batteries. Here, we revealed the correlation between the reaction mechanisms and the used electrolytes for the mild aqueous zinc-electrolytic manganese dioxide (EMD) batteries. In optimal Zn(TFSI)2-based electrolyte, the EMD cathode exhibits a mixed diffusion-controlled conversion reaction between EMD and H+ and diffusion-free "pseudocapacitance"-like reactions. This mechanism enables excellent cycling stability of an EMD cathode over 5000 cycles with a capacity retention of 94.6%. This study provides a useful insight into developing reversible MnO2 cathodes through rational control of reaction mechanisms for high performance mild aqueous Zn-MnO2 batteries.