Stretch regulates alveologenesis and homeostasis via mesenchymal Gαq/11-mediated TGFß2 activation.

Alveolar development and repair require tight spatiotemporal regulation of numerous signalling pathways that are influenced by chemical and mechanical stimuli. Mesenchymal cells play key roles in numerous developmental processes. Transforming growth factor-ß (TGFß) is essential for alveologenesis and lung repair, and the G protein α subunits Gαq and Gα11 (Gαq/11) transmit mechanical and chemical signals to activate TGFß in epithelial cells. To understand the role of mesenchymal Gαq/11 in lung development, we generated constitutive (Pdgfrb-Cre+/-;Gnaqfl/fl;Gna11-/-) and inducible (Pdgfrb-Cre/ERT2+/-;Gnaqfl/fl;Gna11-/-) mesenchymal Gαq/11 deleted mice. Mice with constitutive Gαq/11 gene deletion exhibited abnormal alveolar development, with suppressed myofibroblast differentiation, altered mesenchymal cell synthetic function, and reduced lung TGFß2 deposition, as well as kidney abnormalities. Tamoxifen-induced mesenchymal Gαq/11 gene deletion in adult mice resulted in emphysema associated with reduced TGFß2 and elastin deposition. Cyclical mechanical stretch-induced TGFß activation required Gαq/11 signalling and serine protease activity, but was independent of integrins, suggesting an isoform-specific role for TGFß2 in this model. These data highlight a previously undescribed mechanism of cyclical stretch-induced Gαq/11-dependent TGFß2 signalling in mesenchymal cells, which is imperative for normal alveologenesis and maintenance of lung homeostasis.

Differential remodeling in small and large murine airways revealed by novel whole lung airway analysis.

Airway remodeling occurs in chronic asthma leading to increased airway smooth muscle (ASM) mass and extracellular matrix (ECM) deposition. Although extensively studied in murine airways, studies report only selected larger airways at one time-point meaning the spatial distribution and resolution of remodeling are poorly understood. Here we use a new method allowing comprehensive assessment of the spatial and temporal changes in ASM, ECM, and epithelium in large numbers of murine airways after allergen challenge. Using image processing to analyze 20-50 airways per mouse from a whole lung section revealed increases in ASM and ECM after allergen challenge were greater in small and large rather than intermediate airways. ASM predominantly accumulated adjacent to the basement membrane, whereas ECM was distributed across the airway wall. Epithelial hyperplasia was most marked in small and intermediate airways. After challenge, ASM changes resolved over 7 days, whereas ECM and epithelial changes persisted. The new method suggests large and small airways remodel differently, and the long-term consequences of airway inflammation may depend more on ECM and epithelial changes than ASM. The improved quantity and quality of unbiased data provided by the method reveals important spatial differences in remodeling and could set new analysis standards for murine asthma models.

The myofibroblast at a glance.

In 1971, Gabbiani and co-workers discovered and characterized the "modification of fibroblasts into cells which are capable of an active spasm" (contraction) in rat wound granulation tissue and, accordingly, named these cells 'myofibroblasts'. Now, myofibroblasts are not only recognized for their physiological role in tissue repair but also as cells that are key in promoting the development of fibrosis in all organs. In this Cell Science at a Glance and the accompanying poster, we provide an overview of the current understanding of central aspects of myofibroblast biology, such as their definition, activation from different precursors, the involved signaling pathways and most widely used models to study their function. Myofibroblasts will be placed into context with their extracellular matrix and with other cell types communicating in the fibrotic environment. Furthermore, the challenges and strategies to target myofibroblasts in anti-fibrotic therapies are summarized to emphasize their crucial role in disease progression.

Review of the British Thoracic Society Winter Meeting 2021, 24-26 November 2021.

The Winter Meeting of the British Thoracic Society (BTS) is a platform for the latest clinical and scientific research in respiratory medicine. This review summarises the key symposia and presentations from the BTS Winter Meeting 2021 held online due to the COVID-19 pandemic.

Human Tat-specific factor 1 binds the HIV-1 genome and selectively transports HIV-1 RNAs.

Human immunodeficiency virus type 1 (HIV-1) propagation requires many human cofactors. Multiple groups have demonstrated that Tat-specific factor 1 (Tat-SF1) is an HIV-1 dependency factor. Depletion of this protein lowers HIV-1 infectivity, however, it does not affect the overall levels of viral RNA. Rather, Tat-SF1 regulates the relative levels of each RNA size class. This would be consistent with roles in splicing, transport, and/or stability of viral RNAs. We hypothesized that if Tat-SF1 plays any of these roles, then we should detect binding of the protein to the RNA genome. Furthermore, knocking down Tat-SF1 should result in altered RNA stability and/or localization in human cells. Fragments of the HIV-1 genome were used as RNA probes in electrophoretic mobility shift assays and fluorescence correlation spectroscopy experiments. Our results show that Tat-SF1 can form a complex with TAR RNA in vitro, independent of Tat. This factor interacts with at least one additional location in the 5' end of the HIV-1 genome. Tat seems to enhance the formation of this complex. To analyze HIV-1 RNA localization, HeLa cells with Tat-SF1 knocked down were also transfected with a proviral clone. RNA from nuclear and cytoplasmic fractions was purified, followed by RT-qPCR analysis. Tat-SF1 likely binds the HIV-1 RNA genome at TAR and potentially other locations and selectively transports HIV-1 RNAs, facilitating the unspliced RNA's nuclear export while retaining singly spliced RNAs in the nucleus. This is a novel role for this HIV-1 dependency factor.

Review of the British Thoracic Society Winter Meeting 2018, 5-7 December 2018, London, UK.

INTRODUCTION: The Winter Meeting of the British Thoracic Society (BTS) is a platform for the latest clinical and scientific research in respiratory medicine. This review summarises some key symposia and presentations from the BTS Winter Meeting 2018. METHODS: Key symposia and research presentations from the BTS Winter Meeting 2018 were attended and reviewed by the authors. RESULTS: The seminal messages from the latest clinical and scientific research covering a range of respiratory diseases, including asthma, interstitial lung disease, infection, cystic fibrosis, pulmonary vascular disease, pleural disease and occupational lung disease were summarised in this review. DISCUSSION: The BTS Winter Meeting 2018 brought the very best of respiratory research to an audience of scientists, physicians, nurses and allied health professionals. The Winter Meeting continues to be a highlight of the UK respiratory research calendar, and we look forward to the next meeting in December 2019.

Caffeine inhibits TGFß activation in epithelial cells, interrupts fibroblast responses to TGFß, and reduces established fibrosis in ex vivo precision-cut lung slices.

Caffeine is a commonly used food additive found naturally in many products. In addition to potently stimulating the central nervous system caffeine is able to affect various systems within the body including the cardiovascular and respiratory systems. Importantly, caffeine is used clinically to treat apnoea and bronchopulmonary dysplasia in premature babies. Recently, caffeine has been shown to exhibit antifibrotic effects in the liver in part through reducing collagen expression and deposition, and reducing expression of the profibrotic cytokine TGFß. The potential antifibrotic effects of caffeine in the lung have not previously been investigated. Using a combined in vitro and ex vivo approach we have demonstrated that caffeine can act as an antifibrotic agent in the lung by acting on two distinct cell types, namely epithelial cells and fibroblasts. Caffeine inhibited TGFß activation by lung epithelial cells in a concentration-dependent manner but had no effect on TGFß activation in fibroblasts. Importantly, however, caffeine abrogated profibrotic responses to TGFß in lung fibroblasts. It inhibited basal expression of the α-smooth muscle actin gene and reduced TGFß-induced increases in profibrotic genes. Finally, caffeine reduced established bleomycin-induced fibrosis after 5 days treatment in an ex vivo precision-cut lung slice model. Together, these findings suggest that there is merit in further investigating the potential use of caffeine, or its analogues, as antifibrotic agents in the lung.

Evaluation of outpatient treatment for non-hospitalised patients with COVID-19: The experience of a regional centre in the UK.

INTRODUCTION: Antivirals, such as molnupiravir, and SARS-CoV-2 neutralising monoclonal antibodies (nMAbs), such as sotrovimab, reduced the risk of hospitalisation and death in clinical trials of high-risk non-hospitalised patients with Covid-19. However, the real-world benefits of these drugs are unclear. AIMS: To evaluate the characteristics and outcomes of high-risk patients referred for outpatient antiviral or nMAb treatment for symptomatic Covid-19. METHODS: The records of patients referred to a large UK Covid Medicines Delivery Unit (CMDU) over nine weeks (December 2021-February 2022) were reviewed. Data were collected on demographics, referral indications, vaccination, deprivation, treatment, complications, hospital admission, and mortality. RESULTS: 1820 patients were referred to the CMDU, with 604 (33.2%) suitable for further assessment. 169 patients received sotrovimab, 80 patients received molnupiravir, 70 patients declined treatment, and 266 were ineligible for treatment because of resolving symptoms. There were trends towards higher proportions of female and white patients, lower deprivation scores, and malignancy- or transplant-related indications in the groups receiving treatment compared with untreated patients. Covid-19-related hospitalisations occurred in 1.2% of the treated group and 3.0% of the untreated group indicating a potential treatment effect, however Covid-related hospitalisations were lower than reported in the original clinical trials (2.2% compared with 7-10%). CONCLUSION: The referral pathways for outpatient treatment of Covid-19 are inefficient, and the UK system may not be serving all groups equitably. Hospitalisation with Covid-19 was rare regardless of treatment. Ongoing service evaluation is required to ensure efficient use of resources for the outpatient management of Covid-19.

Adenosine receptor signalling as a driver of pulmonary fibrosis.

Pulmonary fibrosis is a debilitating and life-limiting lung condition in which the damage- response mechanisms of mixed-population cells within the lungs go awry. The tissue microenvironment is drastically remodelled by aberrantly activated fibroblasts which deposit ECM components into the surrounding lung tissue, detrimentally affecting lung function and capacity for gas exchange. Growing evidence suggests a role for adenosine signalling in the pathology of tissue fibrosis in a variety of organs, including the lung, but the molecular pathways through which this occurs remain largely unknown. This review explores the role of adenosine in fibrosis and evaluates the contribution of the different adenosine receptors to fibrogenesis. Therapeutic targeting of the adenosine receptors is also considered, along with clinical observations pointing towards a role for adenosine in fibrosis. In addition, the interaction between adenosine signalling and other profibrotic signalling pathways, such as TGFß1 signalling, is discussed.

Highlights of the ERS Lung Science Conference and Sleep and Breathing Conference 2021 and the new ECMC members.

This article provides a brief description of some of the most remarkable sessions of the @EuroRespSoc Lung Science Conference and the Sleep and Breathing Conference 2021 and presents the new incoming members of the ECMC (@EarlyCareerERS) https://bit.ly/2RSDP40.

Supportive care of patients with fibrosing interstitial lung disease: answering a great clinical need.

Fibrosing interstitial lung disease (F-ILD) significantly reduces quality of life. F-ILD care includes symptom management, end-of-life planning and supportive measures, as well as antifibrotics. Patients and carers should be central to all care decisions. https://bit.ly/2ZAE2Ks.

Morphological Supports: Investigating Differences in How Morphological Knowledge Supports Reading Comprehension for Middle School Students With Limited Reading Vocabulary.

Purpose The current study takes a practical and theoretically grounded look at assessment of morphological knowledge and its potential to deepen understanding of how morphological knowledge supports reading comprehension for students with limited reading vocabulary. Specifically, we explore how different morphological skills support reading comprehension for students with typical reading vocabulary development compared to students with limited reading vocabulary. Method A sample of 1,140 fifth through eighth graders were assessed via a gamified, computer-adaptive measure of language that contained a morphological knowledge assessment. Links to standardized reading comprehension were explored with a focus on determining differences for the 184 students in the sample who showed limited reading vocabulary knowledge. Specifically, multiple regression analyses were used to test for the relation between morphology skills and standardized reading comprehension, as well as the moderator effect of reading vocabulary on the relation between morphological knowledge and standardized reading comprehension. Results Findings indicate that the four instructionally malleable morphological skills identified by the assessment differentially supported reading comprehension. These skills were (a) Morphological Awareness, (b) Syntactic Morphological Knowledge, (c) Semantic Morphological Knowledge, and (d) Phonological/Orthographic Morphological Knowledge. Significant interactions for students with limited reading vocabulary were shown in how the skills of Syntactic Morphological Knowledge, Semantic Morphological Knowledge, and Phonological/Orthographic Morphological Knowledge supported standardized Reading Comprehension. Conclusions Given the challenges students with limited reading vocabulary have with semantic information, Syntactic Morphological Knowledge and Phonological/Orthographic Morphological Knowledge were particularly supportive, suggesting the compensatory role of these morphological skills. In contrast, Semantic Morphological Knowledge had a negative relationship with Reading Comprehension for students with limited reading vocabulary. Implications for theory, research, and practice are discussed.

Role of integrin-mediated TGFbeta activation in the pathogenesis of pulmonary fibrosis.

IPF (idiopathic pulmonary fibrosis) is a chronic progressive disease of unknown aetiology without effective treatment. IPF is characterized by excessive collagen deposition within the lung. Recent evidence suggests that the lung epithelium plays a key role in driving the fibrotic response. The current paradigm suggests that, after epithelial injury, there is impaired epithelial proliferation and enhanced epithelial apoptosis. This in turn promotes lung fibrosis through impaired basement membrane repair and increased epithelial-mesenchymal transition. Furthermore, fibroblasts are recruited to the wounded area and adopt a myofibroblast phenotype, with the up-regulation of matrix-synthesizing genes and down-regulation of matrix-degradation genes. There is compelling evidence that the cytokine TGFbeta (transforming growth factor beta) plays a central role in this process. In normal lung, TGFbeta is maintained in an inactive state that is tightly regulated temporally and spatially. One of the major TGFbeta-activation pathways involves integrins, and the role of the (alpha)vbeta6 integrin has been particularly well described in the pathogenesis of IPF. Owing to the pleiotropic nature of TGFbeta, strategies that inhibit activation of TGFbeta in a cell- or disease-specific manner are attractive for the treatment of chronic fibrotic lung conditions. Therefore the molecular pathways that lead to integrin-mediated TGFbeta activation must be precisely defined to identify and fully exploit novel therapeutic targets that might ultimately improve the prognosis for patients with IPF.

Exploring the Dimensionality of Morphological Knowledge for Adolescent Readers.

This study examined the dimensionality of morphological knowledge. The performance of 371 seventh- and eighth-graders on seven morphological knowledge tasks was investigated using confirmatory factor analysis. Results suggested that morphological knowledge was best fit by a bifactor model with a general factor of morphological knowledge and seven specific factors, representing tasks that tap different facets of morphological knowledge. Next, structural equation modelling was used to explore links to literacy outcomes. Results indicated the general factor and the specific factor of morphological meaning processing showed significant positive associations with reading comprehension and vocabulary. Also, the specific factor of generating morphologically related words showed significant positive associations with vocabulary, while specific factors of morphological word reading and spelling processing showed small negative relationships to reading comprehension and vocabulary. Findings highlight the complexity of morphological knowledge and suggest the importance of being cognizant of the nature of morphology when designing and interpreting studies.

Molecular Endotyping of Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a devastating and incurable progressive fibrotic lung condition associated with a significant disease burden. In recent years there has been an exponential increase in the number of preclinical and clinical studies performed in IPF. IPF is defined according to rigid diagnostic criteria; hence, a significant subset of patients with unclassifiable disease has been excluded from these studies. The traditional diagnostic classification of all progressive fibrotic lung diseases uses specific clinical, radiological, and histopathological features to define each condition. However, the considerable heterogeneity within each form of pulmonary fibrosis has raised the possibility of distinct pathophysiological mechanisms culminating in a common phenotype. Thus, the classification of fibrotic lung diseases according to the driving molecular mechanisms rather than specific user-defined histopathological and radiological features could improve several aspects of clinical care. Discoveries from basic science research have defined multiple complex molecular pathways involved in the pathogenesis of pulmonary fibrosis that may provide markers for the molecular endotyping of this disease. In addition, these molecular pathways have revealed potential therapeutic targets. Reclassifying progressive fibrotic lung diseases according to molecular endotypes may allow for more accurate assessment of prognosis and individualized treatment. Furthermore, recent developments that have been applied to a narrow group of patients with IPF may be applicable to those with other progressive fibrotic lung diseases. This review presents the latest developments from translational research in this area and explains how molecular endotyping could revolutionize the diagnosis, stratification, and treatment of pulmonary fibrosis.

Modeling Learning in Doubly Multilevel Binary Longitudinal Data Using Generalized Linear Mixed Models: An Application to Measuring and Explaining Word Learning.

When word learning is supported by instruction in experimental studies for adolescents, word knowledge outcomes tend to be collected from complex data structure, such as multiple aspects of word knowledge, multilevel reader data, multilevel item data, longitudinal design, and multiple groups. This study illustrates how generalized linear mixed models can be used to measure and explain word learning for data having such complexity. Results from this application provide deeper understanding of word knowledge than could be attained from simpler models and show that word knowledge is multidimensional and depends on word characteristics and instructional contexts.

Modeling Polymorphemic Word Recognition: Exploring Differences Among Children With Early-Emerging and Late-Emerging Word Reading Difficulty.

Comprehensive models of derived polymorphemic word recognition skill in developing readers, with an emphasis on children with reading difficulty (RD), have not been developed. The purpose of the present study was to model individual differences in polymorphemic word recognition ability at the item level among 5th-grade children (N = 173) oversampled for children with RD using item-response crossed random-effects models. We distinguish between two subtypes of RD children with word recognition problems, those with early-emerging RD and late-emerging RD. An extensive set of predictors representing item-specific knowledge, child-level characteristics, and word-level characteristics were used to predict item-level variance in polymorphemic word recognition. Results indicate that item-specific root word recognition and word familiarity; child-level RD status, morphological awareness, and orthographic choice; word-level frequency and root word family size; and the interactions between morphological awareness and RD status and root word recognition and root transparency predicted individual differences in polymorphemic word recognition item performance. Results are interpreted within a multisource individual difference model of polymorphemic word recognition skill spanning item-specific, child-level, and word-level knowledge.