FMRP cooperates with miRISC components to repress translation and regulate neurite morphogenesis in Drosophila.

Fragile X Syndrome (FXS) is the most common inherited form of intellectual disability and is caused by mutations in the gene encoding the Fragile X messenger ribonucleoprotein (FMRP). FMRP is an evolutionarily conserved and neuronally enriched RNA-binding protein (RBP) with functions in RNA editing, RNA transport, and protein translation. Specific target RNAs play critical roles in neurodevelopment, including the regulation of neurite morphogenesis, synaptic plasticity, and cognitive function. The different biological functions of FMRP are modulated by its cooperative interaction with distinct sets of neuronal RNA and protein-binding partners. Here, we focus on interactions between FMRP and components of the microRNA (miRNA) pathway. Using the Drosophila S2 cell model system, we show that the Drosophila ortholog of FMRP (dFMRP) can repress translation when directly tethered to a reporter mRNA. This repression requires the activity of AGO1, GW182, and MOV10/Armitage, conserved proteins associated with the miRNA-containing RNA-induced silencing complex (miRISC). Additionally, we find that untagged dFMRP can interact with a short stem-loop sequence in the translational reporter, a prerequisite for repression by exogenous miR-958. Finally, we demonstrate that dFmr1 interacts genetically with GW182 to control neurite morphogenesis. These data suggest that dFMRP may recruit the miRISC to nearby miRNA binding sites and repress translation via its cooperative interactions with evolutionarily conserved components of the miRNA pathway.

The barriers to uptake of disaster risk management science in urban planning: A political economy analysis.

There is increasing effort in science to support disaster risk management (DRM) and climate change adaptation in urban environments. It is now common for research calls and projects to reference coproduction methods and science uptake goals. This paper identifies lessons for researchers, research funders, and research users wishing to enable useful, useable, and used science based on the perspectives of research users in urban planning from low- and middle-income countries. DRM-supporting science is viewed by policy actors as: complicated and poorly communicated; presenting inadequate, partial, and outdated information; misaligned with policy cycles; and costly to access and inadequately positioned to overcome the policy barriers that hinder integration of DRM into urban planning. Addressing these specific concerns points to more systematic collection and organisation of data and enhancement of supporting administrative structures to facilitate better sight of human vulnerability and its link to development decision-making and wider processes of urban risk creation.

Reducing the Frequency of Pulse Oximetry Alarms at a Children's Hospital.

BACKGROUND AND OBJECTIVES: Alarm fatigue is exacerbated by frequent, nonactionable physiologic monitor alarms. Overutilization of pulse oximetry (SpO2) compounds this alarm burden. Narrow default alarm limits and overutilization of continuous (CSpO2) rather than intermittent monitoring contribute to nonactionable alarms. There were 1.12 million SpO2 alarms on included units during the baseline period, of which 41.0% were for SpO2 ≥ 88%. We aimed to decrease SpO2 alarms per patient day by 20% within 12 months. METHODS: This quality improvement study included patients admitted January 2019 to June 2022. Intensive care and cardiology units were excluded. Interventions included (1) changing default alarm SpO2 limits on monitors from <90% to <88%, (2) changing SpO2 order default from continuous to intermittent, and (3) adding indication requirements for CSpO2. Outcome measures were total SpO2 alarms and alarms for SpO2 ≥ 88% per patient day. Balancing measures were high acuity transfers and code blues without CSpO2 ordered. Control charts were used for each. RESULTS: Our study included 120 408 patient days with 2.98 million SpO2 alarms. Total SpO2 alarms and alarms for SpO2 ≥ 88% per patient day decreased by 5.48 (30.57 to 25.09; 17.9%) and 4.48 (12.50 to 8.02; 35.8%), respectively. Special cause improvement was associated with changing default monitor alarm parameters. Balancing measures remained stable. CONCLUSIONS: SpO2 monitors alarm frequently at our children's hospital. Widening default alarm limits was associated with decreased SpO2 alarms, particularly nonactionable alarms (≥88%). This high-reliability intervention may be applied, when appropriate, to other monitor alarm parameters to further mitigate alarm burden.

Vps54 Regulates Lifespan and Locomotor Behavior in Adult Drosophila melanogaster.

Vps54 is an integral subunit of the Golgi-associated retrograde protein (GARP) complex, which is involved in tethering endosome-derived vesicles to the trans-Golgi network (TGN). A destabilizing missense mutation in Vps54 causes the age-progressive motor neuron (MN) degeneration, muscle weakness, and muscle atrophy observed in the wobbler mouse, an established animal model for human MN disease. It is currently unclear how the disruption of Vps54, and thereby the GARP complex, leads to MN and muscle phenotypes. To develop a new tool to address this question, we have created an analogous model in Drosophila by generating novel loss-of-function alleles of the fly Vps54 ortholog (scattered/scat). We find that null scat mutant adults are viable but have a significantly shortened lifespan. Like phenotypes observed in the wobbler mouse, we show that scat mutant adults are male sterile and have significantly reduced body size and muscle area. Moreover, we demonstrate that scat mutant adults have significant age-progressive defects in locomotor function. Interestingly, we see sexually dimorphic effects, with scat mutant adult females exhibiting significantly stronger phenotypes. Finally, we show that scat interacts genetically with rab11 in MNs to control age-progressive muscle atrophy in adults. Together, these data suggest that scat mutant flies share mutant phenotypes with the wobbler mouse and may serve as a new genetic model system to study the cellular and molecular mechanisms underlying MN disease.

Vps54 regulates Drosophila neuromuscular junction development and interacts genetically with Rab7 to control composition of the postsynaptic density.

Vps54 is a subunit of the Golgi-associated retrograde protein (GARP) complex, which is involved in tethering endosome-derived vesicles to the trans-Golgi network (TGN). In the wobbler mouse, a model for human motor neuron (MN) disease, reduction in the levels of Vps54 causes neurodegeneration. However, it is unclear how disruption of the GARP complex leads to MN dysfunction. To better understand the role of Vps54 in MNs, we have disrupted expression of the Vps54 ortholog in Drosophila and examined the impact on the larval neuromuscular junction (NMJ). Surprisingly, we show that both null mutants and MN-specific knockdown of Vps54 leads to NMJ overgrowth. Reduction of Vps54 partially disrupts localization of the t-SNARE, Syntaxin-16, to the TGN but has no visible impact on endosomal pools. MN-specific knockdown of Vps54 in MNs combined with overexpression of the small GTPases Rab5, Rab7, or Rab11 suppresses the Vps54 NMJ phenotype. Conversely, knockdown of Vps54 combined with overexpression of dominant negative Rab7 causes NMJ and behavioral abnormalities including a decrease in postsynaptic Dlg and GluRIIB levels without any effect on GluRIIA. Taken together, these data suggest that Vps54 controls larval MN axon development and postsynaptic density composition through a mechanism that requires Rab7.

Impact analysis of age on radiation casualty estimations for nuclear detonation scenarios.

Purpose: The purpose of this research was to demonstrate the impact of accounting for age-based radiation response when estimating radiation casualties in a nuclear detonation scenario.Materials and methods: Three nuclear device detonation scenarios were simulated using densely populated regions to compare traditional casualty estimates with age-dependent casualty estimates. Fatalities were estimated using age-based dose-response curves. The surviving population was assumed injured (requiring medical care) if their dose exceeded a lower bound, represented by the minimum dose required to cause deterministic effects, for each age group.Results: In each of the three scenarios, the affected area increased significantly for radiosensitive age groups. In two of the three scenarios, accounting for age-dependent radiosensitivity resulted in up to a 10% increase in fatalities and up to a 12% increase in radiation injuries compared to traditional estimates. This study demonstrates that the differences in casualty estimates are dependent on the relative density and location of radiosensitive populations.Conclusions: These results demonstrate that the inclusion of age-based demographic data and associated dose responses may result in significantly higher estimates of casualties depending on the location and age of the affected population. This information could be useful for the emergency management planning community.

Identifying Common Features in the Activation of Melanocortin-2 Receptors: Studies on the Xenopus tropicalis Melanocortin-2 Receptor.

The interaction between the pituitary hormone, adrenocorticotropin (ACTH), and melanocortin-2 receptor (MC2R) orthologs involves the H6 F7 R8 W9 and R/K15 K16 R17 R18 motifs in ACTH making contact with corresponding contact sites on MC2R. Earlier studies have localized the common HFRW binding site of all melanocortin receptors to residues in TM2, TM3, and TM6 that are located close to the extracellular space. The current study has identified residues in Xenopus tropicalis (xt) MC2R in TM4 (I158, F161), in EC2 (M166), and in TM5 (V172) that also are involved in activation of xtMC2R, and may be in the R/KKRR contact site of xtMC2R. These results are compared to earlier studies on the corresponding domains of human MC2R and rainbow trout MC2R in an effort to identify common features in the activation of teleost and tetrapod MC2R orthologs following stimulation with ACTH.

TNF-α-mediated bronchial barrier disruption and regulation by src-family kinase activation.

BACKGROUND: Because TNF-α is increased in severe asthma, we hypothesized that TNF-α contributes to barrier dysfunction and cell activation in bronchial epithelial cells. We further hypothesized that src-family kinase inhibition would improve barrier function in healthy cells in the presence of TNF-α and directly in cultures of severe asthmatic cells where the barrier is disrupted. OBJECTIVES: We assessed the effect of TNF-α, with or without src-family kinase inhibitor SU6656, on barrier properties and cytokine release in differentiated human bronchial epithelial cultures. Further, we tested the effect of SU6656 on differentiated primary cultures from severe asthma. METHODS: Barrier properties of differentiated human bronchial epithelial air-liquid interface cultures from healthy subjects and subjects with severe asthma were assessed with transepithelial electrical resistance and fluorescent dextran passage. Proteins were detected by immunostaining or Western blot analysis and cytokines by immunoassay. Mechanisms were investigated with src kinase and other inhibitors. RESULTS: TNF-α lowered transepithelial electrical resistance and increased fluorescent dextran permeability, caused loss of occludin and claudins from tight junctions with redistribution of p120 catenin and E-cadherin from adherens junctions, and also increased endogenous TNF-α, IL-6, IL-1ß, IL-8, thymic stromal lymphoprotein, and pro-matrix metalloprotease 9 release. SU6656 reduced TNF-α-mediated paracellular permeability changes, restored occludin, p120, and E-cadherin and lowered autocrine TNF-α release. Importantly, SU6656 improved the barrier properties of severe asthmatic air-liquid interface cultures. Redistribution of E-cadherin and p120 was observed in bronchial biopsies from severe asthmatic airways. CONCLUSIONS: Inhibiting TNF-α or src kinases may be a therapeutic option to normalize barrier integrity and cytokine release in airway diseases associated with barrier dysfunction.

Neuregulin-1-human epidermal receptor-2 signaling is a central regulator of pulmonary epithelial permeability and acute lung injury.

The mechanisms behind the loss of epithelial barrier function leading to alveolar flooding in acute lung injury (ALI) are incompletely understood. We hypothesized that the tyrosine kinase receptor human epidermal growth factor receptor-2 (HER2) would be activated in an inflammatory setting and participate in ALI. Interleukin-1ß (IL-1ß) exposure resulted in HER2 activation in human epithelial cells and markedly increased conductance across a monolayer of airway epithelial cells. Upon HER2 blockade, conductance changes were significantly decreased. Mechanistic studies revealed that HER2 trans-activation by IL-1ß required a disintegrin and metalloprotease 17 (ADAM17)-dependent shedding of the ligand neuregulin-1 (NRG-1). In murine models of ALI, NRG-1-HER2 signaling was activated, and ADAM17 blockade resulted in decreased NRG-1 shedding, HER2 activation, and lung injury in vivo. Finally, NRG-1 was detectable and elevated in pulmonary edema fluid from patients with ALI. These results suggest that the ADAM17-NRG-1-HER2 axis modulates the alveolar epithelial barrier and contributes to the pathophysiology of ALI.

Outcome of patients with nonspecific pleuritis/fibrosis on thoracoscopic pleural biopsies.

OBJECTIVE: Medical thoracoscopy is recommended in the investigation of patients with exudative pleural effusions, especially when pleural fluid analysis is uninformative. The histological finding of 'nonspecific pleuritis/fibrosis' is common in thoracoscopic biopsies and presents a great uncertainty for clinicians and patients as the long-term outcome of these patients is unclear, and anxieties about undiagnosed malignancy persist. METHOD: A retrospective case-note study of 142 patients who underwent medical thoracoscopy over a 58-month period in a tertiary referral centre with a high incidence of mesothelioma. Patients with 'nonspecific pleuritis/fibrosis' were followed up until death or for a mean (±SD) period of 21.3 (±12.0) months. RESULTS: A definitive histological diagnosis was achieved in 98 (69%) patients. A total of 44 (31%) patients had 'nonspecific pleuritis/fibrosis'. Five (12%) were subsequently diagnosed with malignant pleural disease after a mean interval of 9.8 (±4.6) months. All five patients had histologically confirmed mesothelioma. In 26 patients with 'nonspecific pleuritis/fibrosis', no cause for the pleural effusion was discovered. The false-negative rate of thoracoscopic biopsy for the detection of pleural malignancy was 5%, with a diagnostic sensitivity of 95% and negative predictive value of 90%. Pleural effusion recurrence was more frequently associated with a false-negative pleural biopsy result. However, there was no correlation with other patient characteristics or the thoracoscopist's prediction based on macroscopic appearances. CONCLUSION: Thoracoscopic pleural biopsy is valuable in the diagnosis of pleural malignancies. Patients with 'nonspecific pleuritis/fibrosis' require follow-up as a malignant diagnosis (especially mesothelioma) may eventually be established in approximately 12% of cases.

A rare presentation of a common disease: orificial tuberculosis.

Tuberculosis is a common condition with increasing incidence worldwide. Clinicians should be aware of cutaneous manifestations, even though these are uncommon, as recognition can lead to early diagnosis. Here, we present a case of orificial tuberculosis in a young HIV-negative man.

Activated protein C protects against ventilator-induced pulmonary capillary leak.

The coagulation system is central to the pathophysiology of acute lung injury. We have previously demonstrated that the anticoagulant activated protein C (APC) prevents increased endothelial permeability in response to edemagenic agonists in endothelial cells and that this protection is dependent on the endothelial protein C receptor (EPCR). We currently investigate the effect of APC in a mouse model of ventilator-induced lung injury (VILI). C57BL/6J mice received spontaneous ventilation (control) or mechanical ventilation (MV) with high (HV(T); 20 ml/kg) or low (LV(T); 7 ml/kg) tidal volumes for 2 h and were pretreated with APC or vehicle via jugular vein 1 h before MV. In separate experiments, mice were ventilated for 4 h and received APC 30 and 150 min after starting MV. Indices of capillary leakage included bronchoalveolar lavage (BAL) total protein and Evans blue dye (EBD) assay. Changes in pulmonary EPCR protein and Rho-associated kinase (ROCK) were assessed using SDS-PAGE. Thrombin generation was measured via plasma thrombin-antithrombin complexes. HV(T) induced pulmonary capillary leakage, as evidenced by significant increases in BAL protein and EBD extravasation, without significantly increasing thrombin production. HV(T) also caused significant decreases in pulmonary, membrane-bound EPCR protein levels and increases in pulmonary ROCK-1. APC treatment significantly decreased pulmonary leakage induced by MV when given either before or after initiation of MV. Protection from capillary leakage was associated with restoration of EPCR protein expression and attenuation of ROCK-1 expression. In addition, mice overexpressing EPCR on the pulmonary endothelium were protected from HV(T)-mediated injury. Finally, gene microarray analysis demonstrated that APC significantly altered the expression of genes relevant to vascular permeability at the ontology (e.g., blood vessel development) and specific gene (e.g., MAPK-associated kinase 2 and integrin-beta(6)) levels. These findings indicate that APC is barrier-protective in VILI and that EPCR is a critical participant in APC-mediated protection.