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Large airway wall lamina propria in patients with asthma-COPD overlap is hypovascular with an increase in reticular basement membrane neoangiogenesis, reflecting smoking-related COPD-like pathology and potential epithelial-to-mesenchymal transition https://bit.ly/49DeoFX., Competing Interests: Conflict of interest: S.S. Sohal reports an honorarium for lectures from Chiesi, travel support from Chiesi, AstraZeneca and GSK, and research grants from Boehringer Ingelheim and Lung Therapeutics, outside the submitted work; and has served on the Small Airway Advisory Board for Chiesi Australia for which an honorarium has been received, all disclosures made outside the submitted work. Conflict of interest: The remaining authors have nothing to disclose., (Copyright ©The authors 2024.)

Background: COPD patients suffer from dysregulated and suppressed immune functionality, determined by their loss of degranulating capacity. Here we provide crucial information on the presence of degranulated mast cells (MCs) in COPD airways and demonstrate their relationship to lung physiology and airway remodelling., Methods: Small airway lung resections from non-smoking controls (NC), normal lung function smokers (NLFS), small airway disease (SAD), and mild-to-moderate COPD current smokers (COPD-CS) and ex-smokers (COPD-ES) were dual immuno-stained with MC tryptase and degranulation marker lysosome-associated membrane protein (LAMP)-1. Total MCs, degranulating MCs and non-MCs were enumerated in small airway epithelium and subepithelium, and in alveolar septa., Results: In the small airway wall subepithelial areas, COPD-CS and COPD-ES patients had significantly lower MCs than the NC group (p<0.05), although the numbers were considerably higher in the small airway epithelium (p<0.01). Degranulating non-MCs were higher in SAD (p<0.05) than in COPD in the small airway subepithelium. In contrast, there were significant increases in total MCs (degranulated and non-degranulated) and degranulated non-MCs in the alveolar septum of COPD patients compared with the NC group (p<001). The lower numbers of MCs in the subepithelium correlated with lower forced expiratory volume in 1 s (FEV 1 )/forced vital capacity (FVC) and forced expiratory flow at 25-75% of FVC (FEF 25-75% ), higher smoking rates in COPD patients, and increased small airway wall thickness and extracellular matrix. The increase in MCs in the alveolar septum negatively correlated with FEF 25-75 % ., Conclusions: This study is the first to assess the differential pattern of MC, degranulating MC and non-MC populations in the small airways and alveoli of COPD patients. The spatial positioning of the MCs within the airways showed variable correlations with lung function., Competing Interests: Conflict of interest: M.S. Eapen is currently a full-time employee in Mucpharm Pty Ltd; the work presented was not carried out as part of his employment with Mucpharm Pty Ltd. Conflict of interest: S.S. Sohal has served on the Small Airway Advisory Board for Chiesi Australia and has received the honorarium, outside the submitted work; reports travel support from Chiesi, GSK and AstraZeneca, outside the submitted work; reports a lecture honorarium from Chiesi, outside the submitted work; and has received a research grant from Lung Therapeutics, outside the submitted work. Conflict of interest: All the other authors do not have any conflict of interest to declare., (Copyright ©The authors 2024.)

Background: We have previously reported pulmonary arterial remodelling in smokers and patients with early COPD, which can be attributed to endothelial to mesenchymal transition (EndMT). In this study, we aimed to evaluate if EndMT is an active mechanism in smokers and COPD., Methods: Immunohistochemical staining for the EndMT biomarkers CD31, N-cadherin, vimentin and S100A4 was done on lung resection tissue from 49 subjects. These comprised 15 nonsmoker controls (NC), six normal lung function smokers (NLFS), nine patients with small airway disease (SAD), nine current smokers with mild-moderate COPD (COPD-CS) and 10 ex-smokers with COPD (COPD-ES). Pulmonary arteries were analysed using Image ProPlus software v7.0., Results: We noted reduced junctional CD31 + endothelial cells (p<0.05) in the intimal layer of all smoking groups compared to NC. We also observed increased abundance of the mesenchymal markers N-cadherin (p<0.05) and vimentin (p<0.001) in all smoking groups and across all arterial sizes versus NC, except for N-cadherin in large arteries in COPD-CS. The abundance of S100A4 correlated with arterial thickness (small: r=0.29, p=0.05; medium: r=0.33, p=0.03; large: r=0.35, p=0.02). Vimentin in the small arterial wall negatively correlated with forced expiratory volume in 1 s/forced vital capacity (r= -0.35, p=0.02) and forced expiratory flow rate at 25-75% of forced vital capacity (r= -0.34, p=0.03), while increased cytoplasmic CD31 abundance in the intimal layer of medium and large arteries negatively correlated with predicted diffusing capacity of the lung for carbon monoxide (medium: r= -0.35, p=0.04; large: r= -0.39, p=0.03)., Conclusion: This is the first study showing the acquisition of mesenchymal traits by pulmonary endothelial cells from NLFS, SAD and mild-moderate COPD patients through EndMT. This informs on the potential early origins of pulmonary hypertension in smokers and patients with early COPD., Competing Interests: Conflict of interest: S.S. Sohal reports honoraria for lectures from Chiesi; travel support from Chiesi, AstraZeneca and GSK; and research grants from Boehringer Ingelheim and Lung Therapeutics, outside the submitted work. S.S. Sohal has served on the small airway advisory board for Chiesi Australia, for which an honorarium has been received. Conflict of interest: All the other authors do not have any conflict of interest to declare., (Copyright ©The authors 2024.)

Background: Epithelial-mesenchymal transition (EMT) might be central to lung cancer development in smokers and COPD. We illustrate EMT changes in a broader demographic of patient groups who were diagnosed with nonsmall cell lung cancer (adenocarcinoma and squamous cell carcinoma). These included COPD current and ex-smokers, patients with small airway disease and normal lung function smokers compared to normal controls., Methods: We had access to surgically resected small airway tissue from 46 subjects and assessed for airway wall thickness and immunohistochemically for the EMT biomarkers E-cadherin, N-cadherin, S100A4, vimentin and epidermal growth factor receptor (EGFR). All tissue analysis was done with a computer and microscope-assisted Image-Pro Plus 7.0 software., Results: Airway wall thickness significantly increased across all pathological groups (p<0.05) compared to normal controls. Small airway epithelial E-cadherin expression markedly decreased (p<0.01), and increases in N-cadherin, vimentin, S100A4 and EGFR expression were observed in all pathological groups compared to normal controls (p<0.01). Vimentin-positive cells in the reticular basement membrane, lamina propria and adventitia showed a similar trend to epithelium across all pathological groups (p<0.05); however, such changes were only observed in reticular basement membrane for S100A4 (p<0.05). Vimentin was higher in adenocarcinoma versus squamous cell carcinoma; in contrast, S100A4 was higher in the squamous cell carcinoma group. EGFR and N-cadherin expression in both phenotypes was markedly higher than E-cadherin, vimentin and S100A4 (p<0.0001)., Conclusion: EMT is an active process in the small airway of smokers and COPD diagnosed with nonsmall cell lung cancer, contributing to small airway remodelling and cancer development as seen in these patients., Competing Interests: Conflict of interest: S.S. Sohal has served on the Small Airway Advisory Board for Chiesi Australia and has received honorarium outside the submitted work. S.S. Sohal reports travel support from Chiesi, GSK and AstraZeneca, outside the submitted work. All the other authors do not have any conflict of interest to declare., (Copyright ©The authors 2023.)

Background: We have previously reported arterial remodelling in patients with idiopathic pulmonary fibrosis (IPF) and suggested that endothelial-to-mesenchymal transition (EndMT) might be central to these changes. This study aims to provide evidence for active EndMT in IPF patients., Methods: Lung resections from 13 patients with IPF and 15 normal controls (NCs) were immunostained for EndMT biomarkers: vascular endothelial cadherin (VE-cadherin), neural cadherin (N-cadherin), S100A4 and vimentin. Pulmonary arteries were analysed for EndMT markers by using computer- and microscope-assisted image analysis software Image ProPlus7.0. All the analysis was done with observer blinded to subject and diagnosis., Results: Increased expression of mesenchymal markers N-cadherin (p<0.0001), vimentin (p<0.0001) and S100A4 (p<0.05) was noted with downregulation of junctional endothelial VE-cadherin (p<0.01) in the intimal layer of the arteries from patients with IPF compared to NCs. Cadherin switch was observed in IPF patients, showing increase in endothelial N-cadherin and decrease in VE-cadherin (p<0.01). There was also VE-cadherin shift from junctions to cytoplasm (p<0.01), effecting endothelial cell integrity in patients with IPF. In IPF, individual mesenchymal markers vimentin and N-cadherin negatively correlated with diffusing capacity of the lungs for carbon monoxide (r'= -0.63, p=0.03 and r'= -0.66, p=0.01). Further, N-cadherin positively correlated with arterial thickness (r'=0.58, p=0.03)., Conclusion: This is the first study to demonstrate active EndMT in size-based classified pulmonary arteries from IPF patients and potential role in driving remodelling changes. The mesenchymal markers had a negative impact on the diffusing capacity of the lungs for carbon monoxide. This work also informs early origins of pulmonary hypertension in patients with IPF., Competing Interests: Conflict of interest: S.S. Sohal reports personal fees for lectures from Chiesi, travel support from Chiesi and AstraZeneca, and a research grant from Boehringer Ingelheim outside the submitted work. S.S. Sohal is on the Small Airway Advisory Board for Chiesi Australia. Conflict of interest: All the other authors have no conflict of interest to declare., (Copyright ©The authors 2023.)

Background: COPD is the third leading cause of death worldwide. Cigarette smoke (CS)-induced chronic inflammation inducing airway remodelling, emphysema and impaired lung function is the primary cause. Effective therapies are urgently needed. Human chymase (hCMA)1 and its orthologue mCMA1/mouse mast cell protease (mMCP)5 are exocytosed from activated mast cells and have adverse roles in numerous disorders, but their role in COPD is unknown., Methods: We evaluated hCMA1 levels in lung tissues of COPD patients. We used mmcp5 -deficient ( -/- ) mice to evaluate this protease's role and potential for therapeutic targeting in CS-induced experimental COPD. In addition, we used ex vivo/in vitro studies to define mechanisms., Results: The levels of hCMA1 mRNA and CMA1 + mast cells were increased in lung tissues from severe compared to early/mild COPD patients, non-COPD smokers and healthy controls. Degranulated mast cell numbers and mMCP5 protein were increased in lung tissues of wild-type mice with experimental COPD. mmcp5 -/- mice were protected against CS-induced inflammation and macrophage accumulation, airway remodelling, emphysema and impaired lung function in experimental COPD. CS extract challenge of co-cultures of mast cells from wild-type, but not mmcp5 -/- mice with wild-type lung macrophages increased in tumour necrosis factor (TNF)-α release. It also caused the release of CMA1 from human mast cells, and recombinant hCMA-1 induced TNF-α release from human macrophages. Treatment with CMA1 inhibitor potently suppressed these hallmark features of experimental COPD., Conclusion: CMA1/mMCP5 promotes the pathogenesis of COPD, in part, by inducing TNF-α expression and release from lung macrophages. Inhibiting hCMA1 may be a novel treatment for COPD., Competing Interests: Conflict of interest: M. Fricker reports grants from GlaxoSmithKline, outside the submitted work. P.M. Hansbro reports grants from National Health and Medical Research Council, grants from Australian Research Council, during the conduct of the study. The remaining authors disclose no potential conflicts of interest., (Copyright ©The authors 2022. For reproduction rights and permissions contact permissions@ersnet.org.)

Introduction: Pulmonary vascular remodelling in chronic obstructive pulmonary disease (COPD) has detrimental consequences for lung physiology. The aim of our study was to provide a comprehensive size-based morphometric quantification of pulmonary arterial remodelling in smokers and in patients with small airway disease (SAD) or COPD., Method: Movat's pentachrome staining was performed on lung resections for 46 subjects: 12 never-smoker normal controls (NC), six normal lung function smokers (NLFS), nine patients with SAD, nine patients with mild-to-moderate COPD who were current smokers (COPD-CS) and 10 patients with mild-to-moderate COPD who were ex-smokers (COPD-ES). Following a size-based classification of pulmonary arteries, image analysis software was used to measure their number, total wall thickness, individual layer thickness and elastin percentage., Results: All pathological groups showed decreased numbers of pulmonary arteries compared with the NC group in all artery sizes. Arterial wall thickness was greater in NLFS and COPD-CS than in NC. Thickness in COPD-ES was decreased compared with COPD-CS. Intimal thickness was greater in all pathological groups in all arterial sizes than in the NC group. Medial thickness was also greater in small and medium arteries. Intimal thickness of larger arteries in COPD-CS correlated negatively to forced expiratory volume in 1 s/forced vital capacity (FVC) % and forced expiratory flow at 25-75% of FVC. Elastin deposition in small arteries was greatest in COPD-CS. Intimal elastin deposition had a more negative correlation with intimal thickness in NLFS and SAD than in COPD-CS., Conclusion: Smoking, SAD and mild-to-moderate COPD are associated with pruning and a decrease in the number of pulmonary arteries, increased wall thickness and variable elastin deposition. These changes were associated with worse airway obstruction., Competing Interests: Conflict of interest: S.S. Sohal reports personal fees for lectures from Chiesi outside the submitted work. The other authors do not have any conflict of interest to declare., (Copyright ©The authors 2022.)

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible fibrotic interstitial lung disease. We performed size-based quantitation of pulmonary arterial remodelling in IPF and examined the role of endothelial-to-mesenchymal transition (EndMT) and effects on lung physiology., Methods: Resected lung tissues from 11 normal controls (NCs), and 13 IPF patients were differentially stained using the Movat Pentachrome technique. Size-based classification for pulmonary arteries was conducted in NC and IPF tissues. For each pulmonary artery, arterial size, luminal diameter, thickness of the intima, media and adventitia, and elastin deposition were quantified using Image ProPlus7.0 software. In addition, immunohistochemical staining was performed for EndMT markers and collagen., Results: Large and medium-size arterial numbers were significantly reduced in IPF compared to NCs (p<0.0001). Intima thickness was highest in the arterial range of 200-399 μm and 600-1000 μm (p<0.0001), while medial and adventitial thickness was significant across 200-1000 μm (p<0.05) compared to NC. Medial thickness was found to significantly affect the diffusing capacity of the lungs for carbon monoxide ( D LCO ) (r=-0.8, p=0.01). Total arterial elastin in IPF was higher across all arterial ranges except 100-199 μm in IPF than in NC, with the greatest differences in 200-399 μm (p<0.001) and 600-1000 μm (p<0.001). Total elastin also negatively correlated with D LCO (r'=-0.63, p=0.04) in IPF. An increase in EndMT markers and collagen type I/ IV was observed., Conclusions: This is the first study demonstrating size-based differences in pulmonary arteries in IPF and its detrimental effect on lung physiology. The process of EndMT might be central to these vascular remodelling changes and could be a potential novel therapeutic target., Competing Interests: Conflict of interest: S.S. Sohal reports personal fees for lectures from Chiesi outside the submitted work. All the other authors do not have any conflict of interest to declare., (Copyright ©The authors 2022.)

Introduction: Previous reports have shown epithelial-mesenchymal transition (EMT) as an active process that contributes to small airway fibrotic pathology. Myofibroblasts are highly active pro-fibrotic cells that secrete excessive and altered extracellular matrix (ECM). Here we relate small airway myofibroblast presence with airway remodelling, physiology and EMT activity in smokers and COPD patients., Methods: Lung resections from nonsmoker controls, normal lung function smokers and COPD current and ex-smokers were stained with anti-human α-smooth muscle actin (SMA), collagen 1 and fibronectin. αSMA + cells were computed in reticular basement membrane (Rbm), lamina propria and adventitia and presented per mm of Rbm and mm 2 of lamina propria. Collagen-1 and fibronectin are presented as a percentage change from normal. All analyses including airway thickness were measured using Image-pro-plus 7.0., Results: We found an increase in subepithelial lamina propria (especially) and adventitia thickness in all pathological groups compared to nonsmoker controls. Increases in αSMA + myofibroblasts were observed in subepithelial Rbm, lamina propria and adventitia in both the smoker and COPD groups compared to nonsmoker controls. Furthermore, the increase in the myofibroblast population in the lamina propria was strongly associated with decrease in lung function, lamina propria thickening, increase in ECM protein deposition, and finally EMT activity in epithelial cells., Conclusions: This is the first systematic characterisation of small airway myofibroblasts in COPD based on their localisation, with statistically significant correlations between them and other pan-airway structural, lung function and ECM protein changes. Finally, we suggest that EMT may be involved in such changes., Competing Interests: Conflict of interest: M.S. Eapen has nothing to disclose. Conflict of interest: W. Lu has nothing to disclose. Conflict of interest: T.L. Hackett has nothing to disclose. Conflict of interest: G.K. Singhera has nothing to disclose. Conflict of interest: M.Q. Mahmood has nothing to disclose. Conflict of interest: A. Hardikar has nothing to disclose. Conflict of interest: C. Ward has nothing to disclose. Conflict of interest: E.H. Walters has nothing to disclose. Conflict of interest: S.S. Sohal reports personal fees from Chiesi outside the submitted work., (Copyright ©The authors 2021.)

Heat-not-burn (HNB) devices can alter vital physiological functions in the lung. HNB devices may not be a safer option than cigarette smoking or eCig vaping; this does not support the recommendation of their use over other nicotine delivery products. http://ow.ly/wZ5P30ng8bU., Competing Interests: Conflict of interest: S.S. Sohal has nothing to disclose. Conflict of interest: M.S. Eapen has nothing to disclose. Conflict of interest: V.G.M. Naidu has nothing to disclose. Conflict of interest: P. Sharma has nothing to disclose.

We have investigated whether mast cells are associated with bronchodilator responsiveness and airway vascular changes in chronic obstructive pulmonary disease (COPD) airways. We have previously shown that the reticular basement membrane is hypervascular and the lamina propria is hypovascular in COPD. Bronchial biopsies from 32 COPD subjects, 15 smokers with normal lung function and 17 controls, were immunostained for factor VIII, mast cell tryptase and chymase antibodies. Mast cells in the airway smooth muscle, the reticular basement membrane and the underlying lamina propria were quantitated. 41% of COPD subjects had significant bronchodilator responsiveness, but this was not related to smooth muscle mast cell numbers. The reticular basement membrane had greater mast cell density in all groups compared with controls (p<0.01). In this compartment, perivascular mast cell density was related to hypervascularity. Lamina propria mast cell density was increased only in COPD (p<0.05). Perivascular mast cell density in the lamina propria was not related to its decreased vessel density. Bronchodilator responsiveness in COPD is not related to large airway smooth muscle mast cells of either type; both reticular basement membrane and lamina propria mast cells are increased in COPD patients, and perivascular mast cells may be involved in increased angiogenesis in the reticular basement membrane.