17 research outputs found
Temporal changes in plasma membrane lipid content induce endocytosis to regulate developmental epithelial-to-mesenchymal transition
Epithelial-to-mesenchymal transition (EMT) is a dramatic change in cellular physiology during development and metastasis which involves coordination between cell signaling, adhesion, and membrane protrusions. These processes all involve dynamic changes in the plasma membrane, yet how membrane lipid content regulates membrane function during developmental EMT remains incompletely understood. By screening for differential expression of lipid-modifying genes over the course of EMT in avian neural crest, we have identified the ceramide-producing enzyme neutral sphingomyelinase 2 (nSMase2) as a critical regulator of a developmental EMT. nSMase2 expression begins at the onset of EMT, and in vivo knockdown experiments demonstrate that nSMase2 is necessary for neural crest migration. Further, we find that nSMase2 promotes Wnt and BMP signaling, and is required to activate the mesenchymal gene expression program. Mechanistically, we show that nSMase2 is sufficient to induce endocytosis, and that inhibition of endocytosis mimics nSMase2 knockdown. Our results support a model in which nSMase2 is expressed at the onset of neural crest EMT to produce ceramide and induce membrane curvature, thus increasing endocytosis of Wnt and BMP signaling complexes and activating pro-migratory gene expression. These results highlight the critical role of plasma membrane lipid metabolism in regulating transcriptional changes during developmental EMT programs
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Temporal changes in plasma membrane lipid content induce endocytosis to regulate developmental epithelial-to-mesenchymal transition
Epithelial-to-mesenchymal transition (EMT) is a dramatic change in cellular physiology during development and metastasis, which requires coordination between cell signaling, adhesion, and membrane protrusions. These processes all involve dynamic changes in the plasma membrane; yet, how membrane lipid content regulates membrane function during EMT remains incompletely understood. By screening for differential expression of lipid-modifying genes over the course of EMT in the avian neural crest, we have identified the ceramide-producing enzyme neutral sphingomyelinase 2 (nSMase2) as a critical regulator of a developmental EMT. nSMase2 expression begins at the onset of EMT, and in vivo knockdown experiments demonstrate that nSMase2 is necessary for neural crest migration. We find that nSMase2 promotes Wnt and BMP signaling and is required to activate the mesenchymal gene expression program. Mechanistically, we show that nSMase2-dependent ceramide production is necessary for and sufficient to up-regulate endocytosis and is required for Wnt co-receptor internalization. Finally, inhibition of endocytosis in the neural crest mimics the loss of migration and Wnt signaling observed following nSMase2 knockdown. Our results support a model in which nSMase2 is expressed at the onset of neural crest EMT to produce ceramide and facilitate receptor-mediated endocytosis of Wnt and BMP signaling complexes, thereby activating promigratory gene expression. These results highlight the critical role of plasma membrane lipid metabolism in regulating transcriptional changes during developmental EMT programs
Television - The Housewife's Choice? the 1949 Mass Observation Television Directive, Reluctance and Revision
This article considers the responses of women, many of whom describe themselves as housewives, in the 1949 Mass Observation Television Directive, in order to interrogate some of the broader assumptions around television's relationship with the housewife as key to its success. Against the backcloth of social histories revising ideas about gender, modernity and suburbia in the post-war period, this article considers some of the ways in which initial reluctance towards television was recorded and negotiated. It presents three themes around tensions between home and leisure, the domestication of entertainment and going out, and the appreciation of particular genre, which suggest that the adoption of television as mass entertainment by women might not have been as smooth a process as we have come to understand
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Behavioral Deficits at 18-22 Months of Age Are Associated with Early Cerebellar Injury and Cognitive and Language Performance in Children Born Extremely Preterm
To investigate associations in toddlers born extremely preterm (<28 weeks) between neonatal neuroimaging and 18- to 22-month developmental and behavioral outcomes.
Cohort analysis from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network Surfactant Positive Airway Pressure and Pulse Oximetry Trial Neuroimaging and Neurodevelopmental Outcomes Study of infants born extremely preterm. Subjects underwent cranial ultrasonography and near-term magnetic resonance imaging (MRI). At 18-22 months of corrected age, the assessment included the Brief Infant Toddler Social Emotional Assessment (BITSEA) Problem and Competence Scale scores and the Bayley Scales of Infant Development, Third Edition (Bayley-III). The BITSEA Problem Scale assesses dysregulation; the Competence Scale assesses social-emotional competence. We examined associations of Problem and Competence scores and positive screen rates with cranial ultrasonography and near-term MRI. Mean BITSEA and Bayley-III scores were compared using ANOVA and positive screen rates with the χ2 test. We computed correlations between BITSEA and Bayley-III scores.
Of the 397 children, positive BITSEA screens were found in 34% for the Problem score and 26% for the Competence score. Presence of lesions on near-term MRI that included cerebellar lesions were significantly associated with lower BITSEA Competence but not with Problem scores; Competence scores were inversely related to the presence/significance of lesions. Positive screens on Competence scores and on both Competence and Problem scores were significantly associated with Bayley-III cognitive and language scores <85 (P < .001).
Social–emotional competence contributes to deficits in cognitive and language development. Presence of injury on near-term MRI that includes cerebellar lesions is associated with later social–emotional competence and may be a useful predictor to guide early assessment and intervention.
ClinicalTrials.gov: NCT00063063 and NCT00233324
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De Novo Variants in WDR37 Are Associated with Epilepsy, Colobomas, Dysmorphism, Developmental Delay, Intellectual Disability, and Cerebellar Hypoplasia
WD40 repeat-containing proteins form a large family of proteins present in all eukaryotes. Here, we identified five pediatric probands with de novo variants in WDR37, which encodes a member of the WD40 repeat protein family. Two probands shared one variant and the others have variants in nearby amino acids outside the WD40 repeats. The probands exhibited shared phenotypes of epilepsy, colobomas, facial dysmorphology reminiscent of CHARGE syndrome, developmental delay and intellectual disability, and cerebellar hypoplasia. The WDR37 protein is highly conserved in vertebrate and invertebrate model organisms and is currently not associated with a human disease. We generated a null allele of the single Drosophila ortholog to gain functional insights and replaced the coding region of the fly gene CG12333/wdr37 with GAL4. These flies are homozygous viable but display severe bang sensitivity, a phenotype associated with seizures in flies. Additionally, the mutant flies fall when climbing the walls of the vials, suggesting a defect in grip strength, and repeat the cycle of climbing and falling. Similar to wall clinging defect, mutant males often lose grip of the female abdomen during copulation. These phenotypes are rescued by using the GAL4 in the CG12333/wdr37 locus to drive the UAS-human reference WDR37 cDNA. The two variants found in three human subjects failed to rescue these phenotypes, suggesting that these alleles severely affect the function of this protein. Taken together, our data suggest that variants in WDR37 underlie a novel syndromic neurological disorder
Using trained dogs and organic semi-conducting sensors to identify asymptomatic and mild SARS-CoV-2 infections: an observational study
Background A rapid, accurate, non-invasive diagnostic screen is needed to identify people with SARS-CoV-2 infection. We investigated whether organic semi-conducting (OSC) sensors and trained dogs could distinguish between people infected with asymptomatic or mild symptoms, and uninfected individuals, and the impact of screening at ports-of-entry. Methods Odour samples were collected from adults, and SARS-CoV-2 infection status confirmed using RT-PCR. OSC sensors captured the volatile organic compound (VOC) profile of odour samples. Trained dogs were tested in a double-blind trial to determine their ability to detect differences in VOCs between infected and uninfected individuals, with sensitivity and specificity as the primary outcome. Mathematical modelling was used to investigate the impact of bio-detection dogs for screening. Results About, 3921 adults were enrolled in the study and odour samples collected from 1097 SARS-CoV-2 infected and 2031 uninfected individuals. OSC sensors were able to distinguish between SARS-CoV-2 infected individuals and uninfected, with sensitivity from 98% (95% CI 95–100) to 100% and specificity from 99% (95% CI 97–100) to 100%. Six dogs were able to distinguish between samples with sensitivity ranging from 82% (95% CI 76–87) to 94% (95% CI 89–98) and specificity ranging from 76% (95% CI 70–82) to 92% (95% CI 88–96). Mathematical modelling suggests that dog screening plus a confirmatory PCR test could detect up to 89% of SARS-CoV-2 infections, averting up to 2.2 times as much transmission compared to isolation of symptomatic individuals only. Conclusions People infected with SARS-CoV-2, with asymptomatic or mild symptoms, have a distinct odour that can be identified by sensors and trained dogs with a high degree of accuracy. Odour-based diagnostics using sensors and/or dogs may prove a rapid and effective tool for screening large numbers of people