46 results found
Juzenaite G, Secklehner J, Vuononvirta J, et al., 2021, Lung marginated and splenic murine resident neutrophils constitute pioneers in tissue-defense during systemic E. coli challenge, Frontiers in Immunology, Vol: 12, Pages: 1-15, ISSN: 1664-3224
The rapid response of neutrophils throughout the body to a systemic challenge is a critical first step in resolution of bacterial infection such as Escherichia coli (E. coli). Here we delineated the dynamics of this response, revealing novel insights into the molecular mechanisms using lung and spleen intravital microscopy and 3D ex vivo culture of living precision cut splenic slices in combination with fluorescent labelling of endogenous leukocytes. Within seconds after challenge, intravascular marginated neutrophils and lung endothelial cells (ECs) work cooperatively to capture pathogens. Neutrophils retained on lung ECs slow their velocity and aggregate in clusters that enlarge as circulating neutrophils carrying E. coli stop within the microvasculature. The absolute number of splenic neutrophils does not change following challenge; however, neutrophils increase their velocity, migrate to the marginal zone (MZ) and form clusters. Irrespective of their location all neutrophils capturing heat-inactivated E. coli take on an activated phenotype showing increasing surface CD11b. At a molecular level we show that neutralization of ICAM-1 results in splenic neutrophil redistribution to the MZ under homeostasis. Following challenge, splenic levels of CXCL12 and ICAM-1 are reduced allowing neutrophils to migrate to the MZ in a CD29-integrin dependent manner, where the enlargement of splenic neutrophil clusters is CXCR2-CXCL2 dependent. We show directly molecular mechanisms that allow tissue resident neutrophils to provide the first lines of antimicrobial defense by capturing circulating E. coli and forming clusters both in the microvessels of the lung and in the parenchyma of the spleen.
Papakrivopoulou E, Jafree DJ, Dean CH, et al., 2021, The Biological Significance and Implications of Planar Cell Polarity for Nephrology, Frontiers in Physiology, Vol: 12
<jats:p>The orientation of cells in two-dimensional and three-dimensional space underpins how the kidney develops and responds to disease. The process by which cells orientate themselves within the plane of a tissue is termed planar cell polarity. In this Review, we discuss how planar cell polarity and the proteins that underpin it govern kidney organogenesis and pathology. The importance of planar cell polarity and its constituent proteins in multiple facets of kidney development is emphasised, including ureteric bud branching, tubular morphogenesis and nephron maturation. An overview is given of the relevance of planar cell polarity and its proteins for inherited human renal diseases, including congenital malformations with unknown aetiology and polycystic kidney disease. Finally, recent work is described outlining the influence of planar cell polarity proteins on glomerular diseases and highlight how this fundamental pathway could yield a new treatment paradigm for nephrology.</jats:p>
Kim SY, Mongey S, Wang P, et al., 2021, The Acid Injury and Repair (AIR) model: A new ex vivo tool to understand lung repair, Biomaterials, Vol: 267, ISSN: 0142-9612
Research into mechanisms underlying lung injury and subsequent repair responses is currently of paramount importance. There is a paucity of models that bridge the gap between in vitro and in vivo research. Such intermediate models are critical for researchers to decipher the mechanisms that drive repair and to test potential new treatments for lung repair and regeneration. Here we report the establishment of a new tool, the Acid Injury and Repair (AIR) model, that will facilitate studies of lung tissue repair. In this model, injury is applied to a restricted area of a precision-cut lung slice using hydrochloric acid, a clinically relevant driver. The surrounding area remains uninjured, thus mimicking the heterogeneous pattern of injury frequently observed in lung diseases. We show that in response to injury, the percentage of progenitor cells (pro surfactant protein C, proSP-C and TM4SF1 positive) significantly increases in the injured region. Whereas in the uninjured area, the percentage of proSP-C/TM4SF1 cells remains unchanged but proliferating cells (Ki67 positive) increase. These effects are modified in the presence of inhibitors of proliferation (Cytochalasin D) and Wnt secretion (C59) demonstrating that the AIR model is an important new tool for research into lung disease pathogenesis and potential regenerative medicine strategies.
Kim S, Mongey R, Griffiths M, et al., 2020, An ex vivo acid injury and repair (AIR) model using precision-cut lung slices to understand lung injury and repair, Current protocols in mouse biology, Vol: 10, Pages: e85-e85, ISSN: 2161-2617
Recent advances in cell culture models like air‒liquid interface culture and ex vivo models such as organoids have advanced studies of lung biology; however, gaps exist between these models and tools that represent the complexity of the three‐dimensional environment of the lung. Precision‐cut lung slices (PCLS) mimic the in vivo environment and bridge the gap between in vitro and in vivo models. We have established the acid injury and repair (AIR) model where a spatially restricted area of tissue is injured using drops of HCl combined with Pluronic gel. Injury and repair are assessed by immunofluorescence using robust markers, including Ki67 for cell proliferation and prosurfactant protein C for alveolar type 2/progenitor cells. Importantly, the AIR model enables the study of injury and repair in mouse lung tissue without the need for an initial in vivo injury, and the results are highly reproducible. Here, we present detailed protocols for the generation of PCLS and the AIR model. We also describe methods to analyze and quantify injury in AIR‐PCLS by immunostaining with established early repair markers and fluorescence imaging. This novel ex vivo model is a versatile tool for studying lung cell biology in acute lung injury and for semi‐high‐throughput screening of potential therapeutics. © 2020 Wiley Periodicals LLC.
Cheong SS, Akram K, Metellan C, et al., 2020, The planar polarity component Vangl2 is a key regulator of mechanosignaling, Frontiers in Cell and Developmental Biology, Vol: 8, ISSN: 2296-634X
VANGL2 is a component of the planar cell polarity (PCP) pathway, which regulates tissue polarity and patterning. The Vangl2Lp mutation causes lung branching defects due to dysfunctional actomyosin-driven morphogenesis. Since the actomyosin network regulates cell mechanics, we speculated that mechanosignaling could be impaired when VANGL2 is disrupted. Here, we used live-imaging of precision-cut lung slices (PCLS) from Vangl2Lp/+ mice to determine that alveologenesis is attenuated as a result of impaired epithelial cell migration. Vangl2Lp/+ tracheal epithelial cells (TECs) and alveolar epithelial cells (AECs) exhibited highly disrupted actomyosin networks and focal adhesions (FAs). Functional assessment of cellular forces confirmed impaired traction force generation in Vangl2Lp/+ TECs. YAP signaling in Vangl2Lp airway epithelium was reduced, consistent with a role for VANGL2 in mechanotransduction. Furthermore, activation of RhoA signaling restored actomyosin organization in Vangl2Lp/+, confirming RhoA as an effector of VANGL2. This study identifies a pivotal role for VANGL2 in mechanosignaling, which underlies the key role of the PCP pathway in tissue morphogenesis.
Dean C, Taylor B, Rice A, et al., 2020, Mechanism of lung development in the aetiology of adult congenital pulmonary airway malformations, Thorax, Vol: 75, Pages: 1001-1003, ISSN: 0040-6376
Congenital pulmonary airway malformations (CPAMs) are rare lung abnormalities that result in cyst formation and are associated with respiratory distress in infants and malignant potential in adults. The pathogenesis of CPAMs remains unknown but data suggest disruption of the normal proximo-distal programme of airway branching and differentiation. Here, we demonstrate that adult human CPAM are lined with epithelium that retains SOX-2 and thyroid transcription factor-1 immunohistochemical markers, characteristic of the developing lung. However, RALDH-1, another key marker, is absent. This suggests a more complex aetiology for CPAM than complete focal arrest of lung development and may provide insight to the associated risk of malignancy.
RATIONALE: Poor lung health in adult life may occur partly through suboptimal growth and development, as suggested by epidemiological evidence pointing to early life risk factors. OBJECTIVES: To systematically investigate the effects of lung development genes on adult lung function. METHODS: Using UK Biobank data, we tested the association of 391 genes known to influence lung development with FVC and FEV1/FVC. We split the dataset into two random subsets of 207,616 and 138,411 individuals, using the larger to select the most promising signals and the smaller for replication. MEASUREMENTS AND MAIN RESULTS: We identified 55 genes, of which 36 (16 for FVC; 19 for FEV1/FVC; 1 for both) had not been identified in the largest, most recent genome-wide study of lung function. Most of these 36 signals were intronic variants; expression data from blood and lung tissue showed that the majority affect the expression of the genes they lie within. Further testing of 34 of these 36 signals in the CHARGE and SpiroMeta consortia showed that 16 replicated after Bonferroni correction and another 12 at nominal significance level. 53 of the 55 genes fell into four biological categories whose function is to regulate organ size and cell integrity (growth factors; transcriptional regulators; cell-cell adhesion; extra-cellular matrix), suggesting that these specific processes are important for adult lung health. CONCLUSIONS: Our study demonstrates the importance of lung development genes in regulating adult lung function and influencing both restrictive and obstructive patterns. Further investigation of these developmental pathways could lead to druggable targets.
Rao-Bhatia A, Zhu M, Yin W-C, et al., 2020, Hedgehog-activated fat4 and PCP pathways mediate mesenchymal cell clustering and villus formation in gut development, Developmental Cell, Vol: 52, Pages: 647-658.e6, ISSN: 1534-5807
During development, intestinal epithelia undergo dramatic morphogenesis mediated by mesenchymal signaling to form villi, which are required for efficient nutrient absorption and host defense. Although both smooth-muscle-induced physical forces and mesenchymal cell clustering beneath emerging villi are implicated in epithelial folding, the underlying cellular mechanisms are unclear. Hedgehog (Hh) signaling can mediate both processes. We therefore analyzed its direct targetome and revealed GLI2 transcriptional activation of atypical cadherin and planar cell polarity (PCP) genes. By examining Fat4 and Dchs1 knockout mice, we demonstrate their critical roles in villus formation. Analyses of PCP-mutant mice and genetic interaction studies show that the Fat4-Dchs1 axis acts in parallel to the core-Vangl2 PCP axis to control mesenchymal cell clustering. Moreover, live light-sheet fluorescence microscopy and cultured PDGFRα+ cells reveal a requirement for PCP in their oriented cell migration guided by WNT5A. Therefore, mesenchymal PCP induced by Hh signaling drives cell clustering and subsequent epithelial remodeling.
Wilson DH, Jarman EJ, Mellin RP, et al., 2020, Non-canonical Wnt signalling regulates scarring in biliary disease via the planar cell polarity receptors, Nature Communications, Vol: 11, Pages: 1-13, ISSN: 2041-1723
The number of patients diagnosed with chronic bile duct disease is increasing and in most cases these diseases result in chronic ductular scarring, necessitating liver transplantation. The formation of ductular scaring affects liver function; however, scar-generating portal fibroblasts also provide important instructive signals to promote the proliferation and differentiation of biliary epithelial cells. Therefore, understanding whether we can reduce scar formation while maintaining a pro-regenerative microenvironment will be essential in developing treatments for biliary disease. Here, we describe how regenerating biliary epithelial cells express Wnt-Planar Cell Polarity signalling components following bile duct injury and promote the formation of ductular scars by upregulating pro-fibrogenic cytokines and positively regulating collagen-deposition. Inhibiting the production of Wnt-ligands reduces the amount of scar formed around the bile duct, without reducing the development of the pro-regenerative microenvironment required for ductular regeneration, demonstrating that scarring and regeneration can be uncoupled in adult biliary disease and regeneration.
Akram K, Yates L, Mongey R, et al., 2019, Time-lapse imaging of alveologenesis in mouse precision-cut lung slices, Bio-protocol, Vol: 9, ISSN: 2331-8325
Alveoli are the gas-exchange units of lung. The process of alveolar development,alveologenesis, is regulated by a complex network of signaling pathways that act on various cell typesincluding alveolar type I and II epithelial cells, fibroblasts and the vascular endothelium. Dysregulatedalveologenesis results in bronchopulmonary dysplasia in neonates and in adults, disrupted alveolarregeneration is associated with chronic lung diseases including COPD and pulmonary fibrosis.Therefore, visualizing alveologenesis is critical to understand lung homeostasis and for thedevelopment of effective therapies for incurable lung diseases. We have developed a technique tovisualize alveologenesis in real-time using a combination of widefield microscopy and imagedeconvolution of precision-cut lung slices. Here, we describe this live imaging technique in step-by-stepdetail. This time-lapse imaging technique can be used to capture the dynamics of individual cells withintissue slices over a long time period (up to 16 h), with minimal loss of fluorescence or cell toxicity.
Ng-Blichfeldt J-P, Gosens R, Dean C, et al., 2019, Regenerative pharmacology for COPD: breathing new life into old lungs, Thorax, Vol: 74, Pages: 890-897, ISSN: 1468-3296
Chronic obstructive pulmonary disease (COPD) is a major global health concern with few effective treatments. Widespread destruction of alveolar tissue contributes to impaired gas exchange in severe COPD, and recent radiological evidence suggests that destruction of small airways is a major contributor to increased peripheral airway resistance in disease. This important finding might in part explain the failure of conventional anti-inflammatory treatments to restore lung function even in patients with mild disease. There is a clear need for alternative pharmacological strategies for patients with COPD/emphysema. Proposed regenerative strategies such as cell therapy and tissue engineering are hampered by poor availability of exogenous stem cells, discouraging trial results, and risks and cost associated with surgery. An alternative therapeutic approach is augmentation of lung regeneration and/or repair by biologically active factors, which have potential to be employed on a large scale. In favour of this strategy, the healthy adult lung is known to possess a remarkable endogenous regenerative capacity. Numerous preclinical studies have shown induction of regeneration in animal models of COPD/emphysema. Here, we argue that given the widespread and irreversible nature of COPD, serious consideration of regenerative pharmacology is necessary. However, for this approach to be feasible, a better understanding of the cell-specific molecular control of regeneration, the regenerative potential of the human lung and regenerative competencies of patients with COPD are required.
Dean C, Cheong SS, 2019, On the move: the commander IL-4 leads the cell army in collective migration, American Journal of Respiratory Cell and Molecular Biology, Vol: 60, Pages: 377-378, ISSN: 1044-1549
Akram K, Yates L, Mongey R, et al., 2019, Live imaging of alveologenesis in precision-cut lung slices reveals dynamic epithelial cell behaviour, Nature Communications, Vol: 10, Pages: 1-16, ISSN: 2041-1723
Damage to alveoli, the gas-exchanging region of the lungs, is a component of many chronic and acute lung diseases. In addition, insufficient generation of alveoli results in bronchopulmonary dysplasia, a disease of prematurity. Therefore visualising the process of alveolar development (alveologenesis) is critical for our understanding of lung homeostasis and for the development of treatments to repair and regenerate lung tissue. Using long-term, time-lapse imaging of precision-cut lung slices, we show alveologenesis for the first time. We reveal that during this process, epithelial cells are highly mobile and we identify specific cell behaviours that contribute to alveologenesis: cell clustering, hollowing and cell extension. Using the cytoskeleton inhibitors blebbistatin and cytochalasin D, we showed that cell migration is a key driver of alveologenesis. This study reveals important novel information about lung biology and provides a new system in which to manipulate alveologenesis genetically and pharmacologically.
Henderson DJ, Long DA, Dean CH, 2018, Planar cell polarity in organ formation, Current Opinion in Cell Biology, Vol: 55, Pages: 96-103, ISSN: 0955-0674
The planar cell polarity (PCP) pathway controls a variety of morphological events across many species. During embryonic development, the PCP pathway regulates coordinated behaviour of groups of cells to direct morphogenetic processes such as convergent extension and collective cell migration. In this review we discuss the increasingly prominent role of the PCP pathway in organogenesis, focusing on the lungs, kidneys and heart. We also highlight emerging evidence that PCP gene mutations are associated with adult diseases.
Dean CH, Snelgrove RJ, 2018, New rules for club development: new insights into human small airway epithelial club cell ontogeny and function, American Journal of Respiratory and Critical Care Medicine, Vol: 198, Pages: 1355-1366, ISSN: 1073-449X
Dean C, Papakrivopoulou E, Vasilopoulou E, et al., 2018, Vangl2, a planar cell polarity molecule, is implicated in irreversible and reversible kidney glomerular injury, Journal of Pathology, Vol: 246, Pages: 485-496, ISSN: 0022-3417
Planar cell polarity (PCP) pathways control the orientation and alignment of epithelial cells within tissues. Van Gogh‐like 2 (Vangl2) is a key PCP protein that is required for normal differentiation of kidney glomeruli and tubules. Vangl2 has also been implicated in modifying the course of acquired glomerular disease and here we further explored how Vangl2 impacts on glomerular pathobiology in this context. Targeted genetic deletion of Vangl2 in mouse glomerular epithelial podocytes enhanced the severity of not only irreversible accelerated nephrotoxic nephritis but also lipopolysaccharide‐induced reversible glomerular damage. In each proteinuric model, genetic deletion of Vangl2 in podocytes was associated with an increased ratio of active‐MMP9 to inactive MMP9, an enzyme involved in tissue remodelling. Additionally, by interrogating microarray data from two cohorts of renal patients, we report increased VANGL2 transcript levels in glomeruli of individuals with focal segmental glomerulosclerosis, suggesting that the molecule may also be involved in certain human glomerular diseases. These observations support the conclusion that Vangl2 modulates glomerular injury, at least in part by acting as a brake on MMP9, a potentially harmful endogenous enzyme.
Zhang Y, Poobalasingam T, Yates LL, et al., 2018, Manipulation of Dipeptidylpeptidase 10 in mouse and human in vivo and in vitro models indicates a protective role in asthma, Disease Models and Mechanisms, Vol: 11, ISSN: 1754-8403
We previously identified dipeptidylpeptidase 10 (DPP10) on chromosome 2 as a human asthma susceptibility gene, through positional cloning. Initial association results were confirmed in many subsequent association studies but the functional role of DPP10 in asthma remains unclear. Using the MRC Harwell N-ethyl-N-nitrosourea (ENU) DNA archive, we identified a point mutation in Dpp10 that caused an amino acid change from valine to aspartic acid in the β-propeller region of the protein. Mice carrying this point mutation were recovered and a congenic line was established (Dpp10145D). Macroscopic examination and lung histology revealed no significant differences between wild-type and Dpp10145D/145D mice. However, after house dust mite (HDM) treatment, Dpp10 mutant mice showed significantly increased airway resistance in response to 100 mg/ml methacholine. Total serum IgE levels and bronchoalveolar lavage (BAL) eosinophil counts were significantly higher in homozygotes than in control mice after HDM treatment. DPP10 protein is present in airway epithelial cells and altered expression is observed in both tissue from asthmatic patients and in mice following HDM challenge. Moreover, knockdown of DPP10 in human airway epithelial cells results in altered cytokine responses. These results show that a Dpp10 point mutation leads to increased airway responsiveness following allergen challenge and provide biological evidence to support previous findings from human genetic studies.
Dean CH, Lloyd CM, 2017, Lung Alveolar Repair: Not All Cells Are Equal, TRENDS IN MOLECULAR MEDICINE, Vol: 23, Pages: 871-873, ISSN: 1471-4914
The lungs are capable of repair but the extent to which this occurs varies widely. Recent data indicate that, following injury, different progenitor cell populations can arise, depending on the molecular environment. In turn, these result in either normal or aberrant alveolar repair. Thus, a key question in lung regenerative medicine is how to maintain a ‘Goldilocks zone’ of repair.
Crompton M, Purnell T, Tyrer HE, et al., 2017, A mutation in Nischarin causes otitis media via LIMK1 and NF-kappa B pathways, PLoS Genetics, Vol: 13, ISSN: 1553-7390
Otitis media (OM), inflammation of the middle ear (ME), is a common cause of conductive hearing impairment. Despite the importance of the disease, the aetiology of chronic and recurrent forms of middle ear inflammatory disease remains poorly understood. Studies of the human population suggest that there is a significant genetic component predisposing to the development of chronic OM, although the underlying genes are largely unknown. Using N-ethyl-N-nitrosourea mutagenesis we identified a recessive mouse mutant, edison, that spontaneously develops a conductive hearing loss due to chronic OM. The causal mutation was identified as a missense change, L972P, in the Nischarin (NISCH) gene. edison mice develop a serous or granulocytic effusion, increasingly macrophage and neutrophil rich with age, along with a thickened, inflamed mucoperiosteum. We also identified a second hypomorphic allele, V33A, with only modest increases in auditory thresholds and reduced incidence of OM. NISCH interacts with several proteins, including ITGA5 that is thought to have a role in modulating VEGF-induced angiogenesis and vascularization. We identified a significant genetic interaction between Nisch and Itga5; mice heterozygous for Itga5-null and homozygous for edison mutations display a significantly increased penetrance and severity of chronic OM. In order to understand the pathological mechanisms underlying the OM phenotype, we studied interacting partners to NISCH along with downstream signalling molecules in the middle ear epithelia of edison mouse. Our analysis implicates PAK1 and RAC1, and downstream signalling in LIMK1 and NF-κB pathways in the development of chronic OM.
Oozeer F, Yates LL, Dean C, et al., 2017, A role for core planar polarity proteins in cell contact-mediated orientation of planar cell division across the mammalian embryonic skin, SCIENTIFIC REPORTS, Vol: 7, ISSN: 2045-2322
The question of how cell division orientation is determined is fundamentally important for understanding tissue and organ shape in both healthy or disease conditions. Here we provide evidence for cell contact-dependent orientation of planar cell division in the mammalian embryonic skin. We propose a model where the core planar polarity proteins Celsr1 and Frizzled-6 (Fz6) communicate the long axis orientation of interphase basal cells to neighbouring basal mitoses so that they align their horizontal division plane along the same axis. The underlying mechanism requires a direct, cell surface, planar polarised cue, which we posit depends upon variant post-translational forms of Celsr1 protein coupled to Fz6. Our hypothesis has parallels with contact-mediated division orientation in early C. elegans embryos suggesting functional conservation between the adhesion-GPCRs Celsr1 and Latrophilin-1. We propose that linking planar cell division plane with interphase neighbour long axis geometry reinforces axial bias in skin spreading around the mouse embryo body.
Poobalasingam T, Yates LL, Walker SA, et al., 2017, Heterozygous Vangl2 looptail mice reveal novel roles for the planar cell polarity pathway in adult lung homeostasis and repair, Disease Models & Mechanisms, Vol: 10, Pages: 409-423, ISSN: 1754-8403
Lung diseases impose a huge economic and health burden worldwide. A key aspect of several adult lung diseases, such as Idiopathic pulmonary fibrosis (IPF) and Chronic Obstructive pulmonary Disease (COPD), including emphysema, is aberrant tissue repair, which leads to an accumulation of damage and impaired respiratory function. Currently, there are few effective treatments available for these diseases and their incidence is rising.The Planar Cell Polarity (PCP) pathway is critical for the embryonic development of many organs, including kidney and lung. We have previously shown that perturbation of the PCP pathway impairs tissue morphogenesis, which disrupts the number and shape of epithelial tubes formed within these organs during embryogenesis. However, very little is known about the role of the PCP pathway beyond birth, partly due to the perinatal lethality of many PCP mouse mutant lines.Here we have investigated heterozygous Looptail (Lp) mice, in which a single copy of the core PCP gene, Vangl2, is disrupted. We show that these mice are viable but display severe airspace enlargement and impaired adult lung function. Underlying these defects, we find that Vangl2Lp/+ lungs exhibit altered distribution of actin microfilaments and abnormal regulation of the actin modifying protein cofilin. In addition, we show that Vangl2Lp/+ lungs exhibit many of the hallmarks of tissue damage including an altered macrophage population, abnormal elastin deposition and elevated levels of the elastin-modifying enzyme, Mmp12, all of which are observed in the lung disease, emphysema.In vitro, VANGL2 disruption impairs directed cell migration and reduces the rate of repair following scratch wounding of human alveolar epithelial cells. Moreover, using population data from a birth cohort of young adults, all aged 31, we found evidence of an interactive effect between VANGL2 and smoking (a tissue damaging insult) on lung function. Finally, we show that that PCP genes VANGL2 and SCRIBBLE (SC
Ng-Blichfeldt JP, Alçada J, Montero MA, et al., 2017, Deficient retinoid-driven angiogenesis may contribute to failure of adult human lung regeneration in emphysema, Thorax, Vol: 72, Pages: 510-521, ISSN: 0040-6376
BACKGROUND: Molecular pathways that regulate alveolar development and adult repair represent potential therapeutic targets for emphysema. Signalling via retinoic acid (RA), derived from vitamin A, is required for mammalian alveologenesis, and exogenous RA can induce alveolar regeneration in rodents. Little is known about RA signalling in the human lung and its potential role in lung disease. OBJECTIVES: To examine regulation of human alveolar epithelial and endothelial repair by RA, and characterise RA signalling in human emphysema. METHODS: The role of RA signalling in alveolar epithelial repair was investigated with a scratch assay using an alveolar cell line (A549) and primary human alveolar type 2 (AT2) cells from resected lung, and the role in angiogenesis using a tube formation assay with human lung microvascular endothelial cells (HLMVEC). Localisation of RA synthetic (RALDH-1) and degrading (cytochrome P450 subfamily 26 A1 (CYP26A1)) enzymes in human lung was determined by immunofluorescence. Regulation of RA pathway components was investigated in emphysematous and control human lung tissue by quantitative real-time PCR and Western analysis. RESULTS: RA stimulated HLMVEC angiogenesis in vitro; this was partially reproduced with a RAR-α agonist. RA induced mRNA expression of vascular endothelial growth factor A (VEGFA) and VEGFR2. RA did not modulate AT2 repair. CYP26A1 protein was identified in human lung microvasculature, whereas RALDH-1 partially co-localised with vimentin-positive fibroblasts. CYP26A1 mRNA and protein were increased in emphysema. CONCLUSIONS: RA regulates lung microvascular angiogenesis; the endothelium produces CYP26A1 which is increased in emphysema, possibly leading to reduced RA availability. These data highlight a role for RA in maintenance of the human pulmonary microvascular endothelium.
Our understanding of lung biology can be greatly enhanced by studying embryonic and postnatal lung development, and the perturbations which occur during disease. Imaging techniques provide a unique insight into these processes. A wide variety of imaging techniques have been used to study the lungs at various stages of development and disease, ranging from histological stains to more novel techniques such as single plane illumination microscopy (SPIM), intravital microscopy (IVM), and micro-computed tomography (micro-CT). Each of these tools can be used to elicit different information about the lungs and each has its own unique advantages and disadvantages for pulmonary research. In this review we assess some of the most commonly-used and novel imaging techniques available for lung research today.
Löser S, Gregory LG, Zhang Y, et al., 2016, Pulmonary ORMDL3 is critical for induction of Alternaria induced allergic airways disease, Journal of Allergy and Clinical Immunology, Vol: 139, Pages: 1496-1507.e3, ISSN: 1097-6825
BACKGROUND: Genome-wide association studies have identified the ORMDL3 (ORM (yeast)-like protein isoform 3) gene locus on human chromosome 17q to be a highly significant risk factor for childhood-onset asthma. OBJECTIVE: We sought to investigate in vivo the functional role of ORMDL3 in disease inception. METHODS: An Ormdl3 deficient mouse was generated and the role of ORMDL3 in the generation of allergic airways disease to the fungal aeroallergen Alternaria alternata determined. An adeno-associated viral vector was also utilized to reconstitute ORMDL3 expression in airway epithelial cells of Ormdl3 KO mice. RESULTS: Ormdl3 knock-out mice were found to be protected from developing allergic airways disease and showed a marked decrease in pathophysiology, including lung function and airway eosinophilia induced by Alternaria. Alternaria is a potent inducer of cellular stress and the unfolded protein response and ORMDL3 was found to play a critical role in driving the ATF6 mediated arm of this response through Xbp1 and downstream activation of the endoplasmic reticulum-associated degradation pathway. Additionally ORMDL3 mediated uric acid release, another marker of cellular stress. In the knockout mice, reconstitution of Ormdl3 transcript levels specifically in the bronchial epithelium resulted in reinstatement of susceptibility to fungal allergen-induced allergic airways disease. CONCLUSIONS: This study demonstrates that ORMDL3, an asthma susceptibility gene identified by genome-wide association studies, contributes to key pathways that promote changes in airway physiology during allergic immune responses.
Minelli C, Dean CH, Hind M, et al., 2016, Association of Forced Vital Capacity with the Developmental Gene NCOR2, PLOS One, Vol: 11, ISSN: 1932-6203
BackgroundForced Vital Capacity (FVC) is an important predictor of all-cause mortality in the absenceof chronic respiratory conditions. Epidemiological evidence highlights the role of early lifefactors on adult FVC, pointing to environmental exposures and genes affecting lung developmentas risk factors for low FVC later in life. Although highly heritable, a small number ofgenes have been found associated with FVC, and we aimed at identifying further geneticvariants by focusing on lung development genes.PLOS ONE | DOI:10.1371/journal.pone.0147388 February 2, 2016 1 / 17OPEN ACCESSCitation: Minelli C, Dean CH, Hind M, Alves AC,Amaral AFS, Siroux V, et al. (2016) Association ofForced Vital Capacity with the Developmental GeneNCOR2. PLoS ONE 11(2): e0147388. doi:10.1371/journal.pone.0147388Editor: Philipp Latzin, University Children's HospitalBasel, SWITZERLANDReceived: August 28, 2015Accepted: January 4, 2016Published: February 2, 2016Copyright: © 2016 Minelli et al. This is an openaccess article distributed under the terms of theCreative Commons Attribution License, which permitsunrestricted use, distribution, and reproduction in anymedium, provided the original author and source arecredited.Data Availability Statement: All relevant data arewithin the paper and its Supporting Information files.Funding: The authors have no support or funding toreport.Competing Interests: The authors have declaredthat no competing interests exist.MethodsPer-allele effects of 24,728 SNPs in 403 genes involved in lung development were tested in7,749 adults from three studies (NFBC1966, ECRHS, EGEA). The most significant SNP forthe top 25 genes was followed-up in 46,103 adults (CHARGE and SpiroMeta consortia) and5,062 children (ALSPAC). Associations were considered replicated if the replication p-valuesurvived Bonferroni correction (p<0.002; 0.05/25), with a nominal p-value considered assuggestive evidence. For SNPs with evidence of replication, effects on the expression levelsof n
Tateossian H, Morse S, Simon MM, et al., 2015, Interactions between the otitis media gene, Fbxo11, and p53 in the mouse embryonic lung, Disease Models & Mechanisms, Vol: 8, Pages: 1531-1542, ISSN: 1754-8411
Otitis media with effusion (OME) is the most common cause of hearing loss in children, and tympanostomy (ear tube insertion) to alleviate the condition remains the commonest surgical intervention in children in the developed world. Chronic and recurrent forms of otitis media (OM) are known to have a very substantial genetic component; however, until recently, little was known of the underlying genes involved. The Jeff mouse mutant carries a mutation in the Fbxo11 gene, a member of the F-box family, and develops deafness due to a chronic proliferative OM. We previously reported that Fbxo11 is involved in the regulation of transforming growth factor beta (TGF-β) signalling by regulating the levels of phospho-Smad2 in the epithelial cells of palatal shelves, eyelids and airways of the lungs. It has been proposed that FBXO11 regulates the cell's response to TGF-β through the ubiquitination of CDT2. Additional substrates for FBXO11 have been identified, including p53. Here, we have studied both the genetic and biochemical interactions between FBXO11 and p53 in order to better understand the function of FBXO11 in epithelial development and its potential role in OM. In mice, we show that p53 (also known as Tp53) homozygous mutants and double heterozygous mutants (Jf/+ p53/+) exhibit similar epithelial developmental defects to Fbxo11 homozygotes. FBXO11 and p53 interact in the embryonic lung, and mutation in Fbxo11 prevents the interaction with p53. Both p53 and double mutants show raised levels of pSMAD2, recapitulating that seen in Fbxo11 homozygotes. Overall, our results support the conclusion that FBXO11 regulates the TGF-β pathway in the embryonic lung via cross-talk with p53.
Ramsbottom SA, Sharma V, Rhee HJ, et al., 2014, Vangl2-Regulated Polarisation of Second Heart Field-Derived Cells Is Required for Outflow Tract Lengthening during Cardiac Development, PLOS GENETICS, Vol: 10, ISSN: 1553-7390
Zhang Y, Dean C, Chessum L, et al., 2014, Functional analysis of a novel ENU-induced PHD finger 11 (Phf11) mouse mutant, MAMMALIAN GENOME, Vol: 25, Pages: 573-582, ISSN: 0938-8990
Goggolidou P, Hadjirin NF, Bak A, et al., 2014, Atmin mediates kidney morphogenesis by modulating Wnt signaling, HUMAN MOLECULAR GENETICS, Vol: 23, Pages: 5303-5316, ISSN: 0964-6906
Dean CH, 2014, NORMAL AND ABNORMAL LUNG DEVELOPMENT-RECENT ADVANCES, PEDIATRIC PULMONOLOGY, Vol: 49, Pages: S25-S26, ISSN: 8755-6863
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