Tracking extended mucociliary transport activity of individual deposited particles: longitudinal synchrotron X-ray imaging in live mice

To assess potential therapies for respiratory diseases in which mucociliary transit (MCT) is impaired, such as cystic fibrosis and primary ciliary dyskinesia, a novel and non-invasive MCT quantification method has been developed in which the transit rate and behaviour of individual micrometre-sized deposited particles are measured in live mice using synchrotron phase-contrast X-ray imaging. Particle clearance by MCT is known to be a two-phase process that occurs over a period of minutes to days. Previous studies have assessed MCT in the fast-clearance phase, ∼20 min after marker particle dosing. The aim of this study was to non-invasively image changes in particle presence and MCT during the slow-clearance phase, and simultaneously determine whether repeat synchrotron X-ray imaging of mice was feasible over periods of 3, 9 and 25 h. All mice tolerated the repeat imaging procedure with no adverse effects. Quantitative image analysis revealed that the particle MCT rate and the number of particles present in the airway both decreased with time. This study successfully demonstrated for the first time that longitudinal synchrotron X-ray imaging studies are possible in live small animals, provided appropriate animal handling techniques are used and care is taken to reduce the delivered radiation dose.Martin Donnelley, Kaye S. Morgan, Karen K. W. Siu, Andreas Fouras, Nigel R. Farrow, Richard P. Carnibella and David W. Parson

High resolution propagation-based imaging system for in vivo dynamic computed tomography of lungs in small animals

We have developed an x-ray imaging system for in vivo four-dimensional computed tomography (4DCT) of small animals for pre-clinical lung investigations. Our customized laboratory facility is capable of high resolution in vivo imaging at high frame rates. Characterization using phantoms demonstrate a spatial resolution of slightly below 50 μm at imaging rates of 30 Hz, and the ability to quantify material density differences of at least 3%. We benchmark our system against existing small animal pre-clinical CT scanners using a quality factor that combines spatial resolution, image noise, dose and scan time. In vivo 4DCT images obtained on our system demonstrate resolution of important features such as blood vessels and small airways, of which the smallest discernible were measured as 55-60 μm in cross section. Quantitative analysis of the images demonstrate regional differences in ventilation between injured and healthy lungs.M. Preissner , R. P. Murrie, I. Pinar, F. Werdiger, R. P. Carnibella, G. R. Zosky, A. Fouras and S. Dubsk

DNA-PKcs modulates progenitor cell proliferation and fibroblast senescence in idiopathic pulmonary fibrosis

Published online: 29 August 2019BACKGROUND: Recent studies have highlighted the contribution of senescent mesenchymal and epithelial cells in Idiopathic Pulmonary Fibrosis (IPF), but little is known regarding the molecular mechanisms that regulate the accumulation of senescent cells in this disease. Therefore, we addressed the hypothesis that the loss of DNA repair mechanisms mediated by DNA protein kinase catalytic subunit (DNA-PKcs) in IPF, promoted the accumulation of mesenchymal progenitors and progeny, and the expression of senescent markers by these cell types. METHODS: Surgical lung biopsy samples and lung fibroblasts were obtained from patients exhibiting slowly, rapidly or unknown progressing IPF and lung samples lacking any evidence of fibrotic disease (i.e. normal; NL). The expression of DNA-Pkcs in lung tissue was assessed by quantitative immunohistochemical analysis. Chronic inhibition of DNA-PKcs kinase activity was mimicked using a highly specific small molecule inhibitor, Nu7441. Proteins involved in DNA repair (stage-specific embryonic antigen (SSEA)-4+ cells) were determined by quantitative Ingenuity Pathway Analysis of transcriptomic datasets (GSE103488). Lastly, the loss of DNA-PKc was modeled in a humanized model of pulmonary fibrosis in NSG SCID mice genetically deficient in PRKDC (the transcript for DNA-PKcs) and treated with Nu7441. RESULTS: DNA-PKcs expression was significantly reduced in IPF lung tissues. Chronic inhibition of DNA-PKcs by Nu7441 promoted the proliferation of SSEA4+ mesenchymal progenitor cells and a significant increase in the expression of senescence-associated markers in cultured lung fibroblasts. Importantly, mesenchymal progenitor cells and their fibroblast progeny derived from IPF patients showed a loss of transcripts encoding for DNA damage response and DNA repair components. Further, there was a significant reduction in transcripts encoding for PRKDC (the transcript for DNA-PKcs) in SSEA4+ mesenchymal progenitor cells from IPF patients compared with normal lung donors. In SCID mice lacking DNA-PKcs activity receiving IPF lung explant cells, treatment with Nu7441 promoted the expansion of progenitor cells, which was observed as a mass of SSEA4+ CgA+ expressing cells. CONCLUSIONS: Together, our results show that the loss of DNA-PKcs promotes the expansion of SSEA4+ mesenchymal progenitors, and the senescence of their mesenchymal progeny.David M. Habiel, Miriam S. Hohmann, Milena S. Espindola, Ana Lucia Coelho, Isabelle Jones, Heather Jones, Richard Carnibella, Isaac Pinar, Freda Werdiger and Cory M. Hogaboa

Framing of policy responses to migrant horticultural labour shortages during Covid-19 in the Italian print media

The Covid-19 pandemic led to a global food crisis. Like previous food crises how the debate is framed by food policy actors can have a bearing on policy outcomes. This study researches how the policy responses to migrant horticultural labour shortages, due to the pandemic, were framed in the Italian print media and how this relates to longer-term food policy making. Data were gathered from the six highest-circulation Italian daily newspapers. The coverage was dominated by left-leaning outlets and peaked in relation to Covid-19 recovery policies and political processes. Farmer industry bodies were the most quoted group, and the legalisation of undocumented migrant workers was the most frequently discussed policy response. A frames analysis was conducted and identified three principal frames: food security, worker exploitation and immigration. The worker exploitation and immigration frames were most frequently used by left-leaning newspapers, while centre-right papers used the food security frame the most often. The results suggest that media framing could contribute to both policy change, helping to open policy windows, as well as policy lock-ins, side-lining certain debates, actors and policy solutions. The research aims to contribute to growing empirical work which seeks to understand the impact of Covid-19 on migrant agricultural workers and food policy

Can the FIFA world cup football (soccer) tournament be associated with an increase in domestic abuse?

This study aims to establish whether empirical evidence exists to support the anecdotal view that the FIFA world cup football (soccer) tournament can be associated with a rise in reported domestic abuse incidents, when viewed remotely via television. Methods A quantitative analysis, using Poisson and negative binomial regression models looked at monthly and daily domestic abuse incidents reported to a police force in the North West of England across three separate tournaments (2002, 2006, 2010). Results The study found two statistically significant trends. A match day trend showed the risk of domestic abuse rose by 26% when the English national team won or drew, and a 38% increase when the national team lost. Secondly a tournament trend was apparent, as reported domestic abuse incidents increased in frequency with each new tournament. Conclusions Although this is a relatively small study it has significant ramifications due to the global nature of televised football (soccer) tournaments. If replicated it presents significant opportunities to identify and reduce incidents of domestic abuse associated with televised soccer games