933 research outputs found

    Generation of Lung Epithelium from Pluripotent Stem Cells

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    The understanding of key processes and signaling mechanisms in lung development has been mainly demonstrated through gain and loss of function studies in mice, while human lung development remains largely unexplored due to inaccessibility. Several recent reports have exploited the identification of key signaling mechanisms that regulate lineage commitment and restriction in mouse lung development, to direct differentiation of both mouse and human pluripotent stem cells towards lung epithelial cells. In this review, we discuss the recent advances in the generation of respiratory epithelia from pluripotent stem cells and the potential of these engineered cells for novel scientific discoveries in lung diseases and future translation into regenerative therapies

    Inhibition of IFN-γ Signaling by an Epstein-Barr Virus Immediate-Early Protein

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    AbstractViruses have evolved elaborate mechanisms to target many aspects of the host's immune response. The cytokine IFN-γ plays a central role in resistance of the host to infection via direct antiviral effects as well as modulation of the immune response. In this study, we demonstrate that the Epstein-Barr virus (EBV) immediate-early protein, BZLF1, inhibits the IFN-γ signaling pathway. BZLF1 decreases the ability of IFN-γ to activate a variety of important downstream target genes, such as IRF-1, p48, and CIITA, and prevents IFN-γ-induced class II MHC surface expression. Additionally, BZLF1 inhibits IFN-γ-induced STAT1 tyrosine phosphorylation and nuclear translocation. Finally, we demonstrate that BZLF1 decreases expression of the IFN-γ receptor, suggesting a mechanism by which EBV may escape antiviral immune responses during primary infection

    Alcohol promotes breast cancer cell invasion by regulating the Nm23-ITGA5 pathway

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    <p>Abstract</p> <p>Background</p> <p>Alcohol consumption is an established risk factor for breast cancer metastasis. Yet, the mechanism by which alcohol promotes breast cancer metastases is unknown. The ability of cancer cells to invade through tissue barriers (such as basement membrane and interstitial stroma) is an essential step towards establishing cancer metastasis. In the present study, we identify and examine the roles of two genes, <it>Nm23 </it>and <it>ITGA5</it>, in alcohol-induced breast cancer cell invasion.</p> <p>Methods</p> <p>Human breast cancer T47D cells were treated with ethanol at various concentrations. Boyden chamber invasion assays were used to measure cellular invasive ability. The mRNA expression level of metastasis suppressor genes including <it>Nm23 </it>was determined by qRT-PCR. <it>ITGA5 </it>was identified using a qRT-PCR array of 84 genes important for cell-cell and cell-extracellular matrix interactions. <it>Nm23 </it>overexpression in addition to <it>Nm23</it>- and <it>ITGA5 </it>knock-down were used to determine the role of the Nm23-ITGA5 pathway on cellular invasive ability of T47D cells. Protein expression levels were verified by Western blot.</p> <p>Results</p> <p>Alcohol increased the invasive ability of human breast cancer T47D cells in a dose-dependent manner through the suppression of the <it>Nm23 </it>metastatic suppressor gene. In turn, <it>Nm23 </it>down-regulation increased expression of fibronectin receptor subunit <it>ITGA5</it>, which subsequently led to increased cellular invasion. Moreover, <it>Nm23 </it>overexpression was effective in suppressing the effects of alcohol on cell invasion. In addition, we show that the effects of alcohol on invasion were also inhibited by knock-down of <it>ITGA5</it>.</p> <p>Conclusions</p> <p>Our results suggest that the Nm23-ITGA5 pathway plays a critical role in alcohol-induced breast cancer cell invasion. Thus, regulation of this pathway may potentially be used to prevent the establishment of alcohol-promoted metastases in human breast cancers.</p

    Help in Time: An Evaluation of Philadelphia\u27s Community-Based Homelessness Prevention Program

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    This report provides an evaluation of Philadelphia\u27s neighborhood-based homelessness prevention initiative. Results indicate that nearly all households served do not become homeless. But it is unclear if households would have become homeless had they not been served. Recommendations are made for targeting prevention interventions to families requesting shelter

    Stage-Specific Generation of Human Pluripotent Stem Cell Derived Lung Models to Measure CFTR Function

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    Human embryonic stem cells (ES) and induced pluripotent stem cells (iPSC) are powerful tools that have the potential to generate in vitro human lung epithelial cells. However, challenges in efficiency and reproducibility remain in utilizing the cells for therapy discovery platforms. Here, we optimize our previously published protocols to efficiently generate three developmental stages of the lung model (fetal lung epithelial progenitors, fLEP; immature airway epithelial spheroid, AES; air-liquid interface culture, ALI), and demonstrate its potential for cystic fibrosis (CF) drug discovery platforms. The stepwise approach directs differentiation from hPSC to definitive endoderm, anterior ventral foregut endoderm, and fetal lung progenitor cells. The article also describes the generation of immature airway epithelial spheroids in Matrigel with epithelial cells sorted by a magnetic-activated cell sorting system, and the generation of adult-like airway epithelia through air-liquid interface conditions. We demonstrate that this optimized procedure generates remarkably higher cystic fibrosis transmembrane conductance regulator (CFTR) expression and function than our previous method, and thus is uniquely suitable for CF research applications. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: hESC/hiPSC differentiation to fetal lung progenitors Basic Protocol 2: Formation of airway epithelial spheroids Alternate Protocol 1: Cryopreservation of airway epithelial spheroids Basic Protocol 3: Differentiation and maturation in air-liquid interface culture Alternate Protocol 2: Differentiation and maturation of epithelial progenitors from airway epithelial spheroids in ALI culture

    Motifs, themes and thematic maps of an integrated Saccharomyces cerevisiae interaction network

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    BACKGROUND: Large-scale studies have revealed networks of various biological interaction types, such as protein-protein interaction, genetic interaction, transcriptional regulation, sequence homology, and expression correlation. Recurring patterns of interconnection, or 'network motifs', have revealed biological insights for networks containing either one or two types of interaction. RESULTS: To study more complex relationships involving multiple biological interaction types, we assembled an integrated Saccharomyces cerevisiae network in which nodes represent genes (or their protein products) and differently colored links represent the aforementioned five biological interaction types. We examined three- and four-node interconnection patterns containing multiple interaction types and found many enriched multi-color network motifs. Furthermore, we showed that most of the motifs form 'network themes' – classes of higher-order recurring interconnection patterns that encompass multiple occurrences of network motifs. Network themes can be tied to specific biological phenomena and may represent more fundamental network design principles. Examples of network themes include a pair of protein complexes with many inter-complex genetic interactions – the 'compensatory complexes' theme. Thematic maps – networks rendered in terms of such themes – can simplify an otherwise confusing tangle of biological relationships. We show this by mapping the S. cerevisiae network in terms of two specific network themes. CONCLUSION: Significantly enriched motifs in an integrated S. cerevisiae interaction network are often signatures of network themes, higher-order network structures that correspond to biological phenomena. Representing networks in terms of network themes provides a useful simplification of complex biological relationships

    Changes in primary care visits for respiratory illness during the COVID-19 pandemic: a multinational study by the International Consortium of Primary Care Big Data Researchers (INTRePID)

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    Objectives: The majority of patients with respiratory illness are seen in primary care settings. Given COVID-19 is predominantly a respiratory illness, the INTernational ConsoRtium of Primary Care BIg Data Researchers (INTRePID), assessed the pandemic impact on primary care visits for respiratory illnesses. Design: Definitions for respiratory illness types were agreed on collectively. Monthly visit counts with diagnosis were shared centrally for analysis. Setting: Primary care settings in Argentina, Australia, Canada, China, Norway, Peru, Singapore, Sweden and the United States. Participants: Over 38 million patients seen in primary care settings in INTRePID countries before and during the pandemic, from January 1st, 2018, to December 31st, 2021. Main outcome measures: Relative change in the monthly mean number of visits before and after the onset of the pandemic for acute infectious respiratory disease visits including influenza, upper and lower respiratory tract infections and chronic respiratory disease visits including asthma, chronic obstructive pulmonary disease, respiratory allergies, and other respiratory diseases. Results: INTRePID countries reported a marked decrease in the average monthly visits for respiratory illness. Changes in visits varied from −10.9% [95% confidence interval (CI): −33.1 to +11.3%] in Norway to −79.9% (95% CI: −86.4% to −73.4%) in China for acute infectious respiratory disease visits and − 2.1% (95% CI: −12.1 to +7.8%) in Peru to −59.9% (95% CI: −68.6% to −51.3%) in China for chronic respiratory illness visits. While seasonal variation in allergic respiratory illness continued during the pandemic, there was essentially no spike in influenza illness during the first 2 years of the pandemic. Conclusion: The COVID-19 pandemic had a major impact on primary care visits for respiratory presentations. Primary care continued to provide services for respiratory illness, although there was a decrease in infectious illness during the COVID pandemic. Understanding the role of primary care may provide valuable information for COVID-19 recovery efforts and planning for future global emergencies

    Image guidance using 3D-ultrasound (3D-US) for daily positioning of lumpectomy cavity for boost irradiation

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    <p>Abstract</p> <p>Purpose</p> <p>The goal of this study was to evaluate the use of 3D ultrasound (3DUS) breast IGRT for electron and photon lumpectomy site boost treatments.</p> <p>Materials and methods</p> <p>20 patients with a prescribed photon or electron boost were enrolled in this study. 3DUS images were acquired both at time of simulation, to form a coregistered CT/3DUS dataset, and at the time of daily treatment delivery. Intrafractional motion between treatment and simulation 3DUS datasets were calculated to determine IGRT shifts. Photon shifts were evaluated isocentrically, while electron shifts were evaluated in the beam's-eye-view. Volume differences between simulation and first boost fraction were calculated. Further, to control for the effect of change in seroma/cavity volume due to time lapse between the 2 sets of images, interfraction IGRT shifts using the first boost fraction as reference for all subsequent treatment fractions were also calculated.</p> <p>Results</p> <p>For photon boosts, IGRT shifts were 1.1 ± 0.5 cm and 50% of fractions required a shift >1.0 cm. Volume change between simulation and boost was 49 ± 31%. Shifts when using the first boost fraction as reference were 0.8 ± 0.4 cm and 24% required a shift >1.0 cm. For electron boosts, shifts were 1.0 ± 0.5 cm and 52% fell outside the dosimetric penumbra. Interfraction analysis relative to the first fraction noted the shifts to be 0.8 ± 0.4 cm and 36% fell outside the penumbra.</p> <p>Conclusion</p> <p>The lumpectomy cavity can shift significantly during fractionated radiation therapy. 3DUS can be used to image the cavity and correct for interfractional motion. Further studies to better define the protocol for clinical application of IGRT in breast cancer is needed.</p

    A new platform for high-throughput therapy testing on iPSC-derived lung progenitor cells from cystic fibrosis patients

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    For those people with cystic fibrosis carrying rare CFTR mutations not responding to currently available therapies, there is an unmet need for relevant tissue models for therapy development. Here, we describe a new testing platform that employs patient-specific induced pluripotent stem cells (iPSCs) differentiated to lung progenitor cells that can be studied using a dynamic, high-throughput fluorescence-based assay of CFTR channel activity. Our proof-of-concept studies support the potential use of this platform, together with a Canadian bioresource that contains iPSC lines and matched nasal cultures from people with rare mutations, to advance patient-oriented therapy development. Interventions identified in the high-throughput, stem cell-based model and validated in primary nasal cultures from the same person have the potential to be advanced as therapies
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