Progressive Airway Disease Research Articles

Pulmonary Computed Tomography Screening Frequency in Primary Antibody Deficiency

BackgroundPatients with primary antibody deficiency (PAD) frequently suffer from pulmonary complications, associated with severe morbidity and mortality. Hence, regular pulmonary screening by computed tomography (CT) scanning is advised. However, predictive risk factors for pulmonary morbidity are lacking. ObjectiveTo identify PAD patients at risk for pulmonary complications necessitating regular CT screening. MethodsA retrospective longitudinal cohort study of PAD patients (median follow-up 7.4 (2.3 – 14.8) years). CTs were scored using the modified Brody-II scoring system. Clinical and laboratory parameters were retrospectively collected. Potential risk factors were identified by univariate analysis when p<0.2 and confirmed by multivariable logistic regression when p<0.05. ResultsThe following independent risk factors for progression of airway disease (AD) were identified: 1) diagnosis of X-linked agammaglobulinemia (XLA), 2) recurrent airway infections (2.5/year), 3) presence of AD at baseline. Signs of AD progression were detected in 5/11 XLA patients and in 17/80 of the other PAD patients. Of the patients who progressed, 17/22 had preexistent AD scores ≥7.0%. Increased AD scores were related to poorer FEV1 values and chronic cough. CVID and increased CD4 effector/memory cells were risk factors for an interstitial lung disease (ILD) score ≥13.0%. ILD ≥13.0% occurred in 12/80 patients. Signs of ILD progression were detected in 8/80 patients and 4/8 patients showing progression had preexistent ILD scores ≥13.0%. ConclusionWe identified risk factors that distinguished PAD patients at risk for airway disease and interstitial lung disease presence and progression which could guide future screening frequency, however independent and preferably prospective validation is needed.

CME exam: Prevention Is Better Than Cure: Impact of Allergen Immunotherapy on the Progression of Airway Disease

CME exam: Prevention Is Better Than Cure: Impact of Allergen Immunotherapy on the Progression of Airway Disease

Prevention Is Better than Cure: Impact of Allergen Immunotherapy on the Progression of Airway Disease

Allergen immunotherapy is highly effective for seasonal pollinosis. Three years of treatment results in long-term efficacy. This disease modification is accompanied by downregulation of allergen-specific Th2 responses and the induction of persistent specific IgG- and IgA-associated IgE-blocking activity. In children with seasonal rhinitis, both subcutaneous and sublingual pollen immunotherapy have been shown to reduce the development of asthma symptoms and asthma medication requirements. House dust mite tabletallergen immunotherapy has been shown to be effective for perennial mite-driven rhinitis in adults and children and may suppress asthma exacerbations, whereas its long-term efficacy has yet to be explored. The success of primary prevention of peanut allergy in childhood by introduction of peanut into the diet during infancy provides a strong rationale to explore whether primary prevention of inhalant allergies and asthma may also be possible. House dust mite allergy is a major risk factor for developing asthma. Preliminary data in at-risk children suggest that sublingual house dust mite immunotherapy initiated during infancy could reduce the onset of multiple allergen sensitizations and prevent the development of asthma at age 6 years. This possibility should now be explored in an adequately powered, prospectively randomized controlled trial.

Outcomes of lung transplantation for chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease is a progressive airway disease that can progress to the terminal stage requiring oxygen supply. In this period, lung volume reduction therapies and/or lung transplantation may be considered. Morbidity and mortality risks due to transplant surgery and posttransplant immunosuppressive therapy show the importance of selecting the best candidates who will benefit from transplantation. In this context, BODE index criteria serve as important markers. This study aimed to analyze the outcomes of lung transplantation in patients with chronic obstructive pulmonary disease and to identify variables that may affect post-transplant clinical outcomes. Lung transplants diagnosed with chronic obstructive pulmonary disease performed in our center between March 2013 and January 2023 were included in the study. Demographic information and both pre-op and post-op clinical data of the transplant patients were collected. The effect of BODE index criteria and other pre-transplant clinical data on short- and long-term outcomes after transplantation were investigated. During the study period, 34 lung transplants were performed for chronic obstructive pulmonary disease. One patient died during the operation, three patients received single transplants, and 30 received double transplants. Post-operative primary graft dysfunction was more common in single transplant recipients. The results were comparable between single and double transplants in terms of post-transplant pulmonary function and the development of chronic lung allograft dysfunction. BODE index criteria had no effect on early and late post-operative clinical data, however intra-operative use of extracorporeal membrane oxygenation, primary graft dysfunction, and prolonged extubation were significantly higher in recipients younger than 60 years. Our study suggests that prelisting demographic and clinical data of chronic obstructive pulmonary disease patients had no significant effect on post-operative outcomes, however, intra-operative ECMO use, prolonged extubation, primary graft dysfunction (p< 0.05 for each) and chronic rejection (p> 0.05) were more common in patients who are <60 years of age. These data need to be confirmed by larger studies.

Study of Psychiatric Morbidity among Patients with Chronic Obstructive Pulmonary Disease in a Tertiary Health Care Institute

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a lung disease characterized by chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible. COPD is a progressive airway disease associated with psychological distress Screening the psychiatric disorders in COPD patients will be helpful in better management of the disease by assuring compliance as well as will help to improve quality of life of these patients leading to overall improvement in patients’ health, by helping in starting early psychiatry management whenever necessary. Methods: A single-center, cross-sectional, observational study performed at a tertiary care hospital between august 2016 and June 2018 to study psychiatric morbidity among patients with chronic obstructive pulmonary disease in a tertiary health care institute. A total of 68 clinically stable patients with COPD were screened for psychiatric morbidity by using Mini International Neuropsychiatric Interview (MINI) version 6.0.0. The clinical diagnosis was confirmed using DSM-5 and by qualified psychiatrist of the Department of Psychiatry. Result: Generalized anxiety disorder, Major depressive disorder, major depressive disorder with Anxiety, Panic attack, Phobia and Substance Abuse Disorder was present in 8.8%, 13.2%, 5.9%, 7.4%, 1.5% and 7.4% of study population respectively. Conclusions: We found that patients with COPD had high prevalence of depressive and anxious symptoms. Therefore, screening and treatment of these psychiatric comorbidities in patients with COPD may lead to significant improvements in patients’ quality of life.

EPS1.04 Change in lung clearance index in adolescents with cystic fibrosis treated with elexacaftor/tezacaftor/ivacaftor: results from 12 months follow-up in the Danish cystic fibrosis cohort

Objectives: The efficacy of elexacaftor/tezacaftor/ivacaftor (ETI) on cystic fibrosis (CF) lung disease as measured by percent predicted forced expiratory volume in 1 second (ppFEV1) has been well-established in adults. However, ppFEV1 is not sensitive enough to detect small airway disease progression at early stages of lung disease in children. In the eligible Danish pediatric cohort, we aimed to assess the real-world effectiveness of ETI on small airway disease using multiple breath washout (MBW).

Airway Findings in Patients with Hunter Syndrome Treated with Intravenous Idursulfase.

People with Hunter syndrome are known to be affected by a variety of airway pathologies. Treatment of Hunter syndrome with the enzyme replacement therapy (ERT) idursulfase is now the standard of care. However, it is not known how ERT changes the progression of airway involvement. To evaluate this, we performed a retrospective analysis of bronchoscopies performed on children with Hunter syndrome who were part of intrathecal ERT trials. Findings for airway pathology were extracted from bronchoscopy reports and analyses were performed for cross-sectional and longitudinal changes in airway disease. One-hundred and thirty bronchoscopies from 23 subjects were analyzed. Upper airway disease (adenoid hypertrophy and/or pharyngomalacia) was reported in 93% and 87% of bronchoscopies, respectively. Laryngeal abnormalities were recognized in 46% of cases. There were lower airway (tracheal and or bronchial) findings in 64% of all bronchoscopies and prevalence increased with age. Evaluations over time adjusted for repeat evaluations showed that increasing airway involvement was associated with older age (p = 0.0007) despite ongoing ERT. No association was discovered between age of intravenous ERT initiation and progression of airway disease. Individuals with Hunter syndrome who are receiving intravenous enzyme replacement therapy showed the progression of airways disease supporting the need for regular airway monitoring and intervention.

Diversity of cystic fibrosis chronic rhinosinusitis microbiota correlates with different pathogen dominance

Chronic rhinosinusitis (CRS) affects nearly all individuals with cystic fibrosis (CF) and is thought to serve as a reservoir for microbiota that subsequently colonize the lung. To better understand the microbial ecology of CRS, we generated a 16S rRNA gene sequencing profile of sinus mucus from CF-CRS patients. We show that CF-CRS sinuses harbor bacterial diversity not entirely captured by clinical culture. Culture data consistently identified the dominant organism in most patients, though lower abundance bacteria were not always identified. We also demonstrate that bacterial communities dominated by Staphylococcus spp. were significantly more diverse compared to those dominated by Pseudomonas spp. Diversity was not significantly associated with clinical factors or patient age, however, younger subjects yielded a much wider range of bacterial diversity. These data mirror bacterial community dynamics in the lung and provide additional insight into the role of sinus microbiota in chronic airway disease progression.

Role of Collagen in Airway Mechanics.

Collagen is the most abundant airway extracellular matrix component and is the primary determinant of mechanical airway properties. Abnormal airway collagen deposition is associated with the pathogenesis and progression of airway disease. Thus, understanding how collagen affects healthy airway tissue mechanics is essential. The impact of abnormal collagen deposition and tissue stiffness has been an area of interest in pulmonary diseases such as cystic fibrosis, asthma, and chronic obstructive pulmonary disease. In this review, we discuss (1) the role of collagen in airway mechanics, (2) macro- and micro-scale approaches to quantify airway mechanics, and (3) pathologic changes associated with collagen deposition in airway diseases. These studies provide important insights into the role of collagen in airway mechanics. We summarize their achievements and seek to provide biomechanical clues for targeted therapies and regenerative medicine to treat airway pathology and address airway defects.

EFFECT OF PULMONARY REHABILITATION IN PATIENTS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE: A HOSPITAL BASED CROSS SECTIONAL STUDY

BACKGROUND: Chronic obstructive pulmonary disease(COPD) is an obstructive and progressive airway disease associated with reduction in daily physical activity and psychological problems related to patient's disability and poor quality of life. Pulmonary rehabilitation(PR) plays an essential role in the management of COPD, by breaking the vicious circle of dyspnea–decreased activity–deconditioning–isolation. AIM: This study aimed to highlight the impact of PR on COPD patients while focusing on the clinical usefulness of PR. MATERIALS &amp; METHODS: This study was done over a period of 1.5 years including all the diagnosed cases of COPD (both OPD and IPD) who did not have any acute exacerbation requiring oxygen, not associated with other medical conditions such as heart disease, neurological disease, lumbar spondylitis or osteoarthritis or those unable to perform PFT after taking proper consent. The study was completed with a follow up schedule, monthly, for 3 months. Proforma for the study included demographics, history, examination, dyspnea grading using modied Borg scale as well as CAT questionnaire along with a six-minute walk test and spirometry. Statistical analysis was done using SPSS Version 20 (Chicago Inc., USA). Data comparison was done by applying specic statistical tests to nd out the statistical signicance of the comparisons. Quantitative variables were compared using mean values and qualitative variables using proportions. Signicance level was xed at P &lt; 0.05. RESULTS: Out of total 227 cases, only 71 completed the 3-month monthly follow up and hence were used for the statistical analysis. The results showed male:female ratio 80.3:19.7. As per Borg scale, mean fever, chest pain, cough, expectoration and dyspnea score decreased over subsequent follow-up. Rate of hospitalisation was seen more in 61-70 year age group. Mean sixminute walk test value increased continuously during the duration of follow up. CONCLUSION: Effective pulmonary rehabilitation that incorporates exercise schedules and patient education compreh ensively can encompass treatment and improve the quality of life of patients suffering with COPD.

Altered Stool Microbiota of Infants with Cystic Fibrosis Shows a Reduction in Genera Associated with Immune Programming from Birth

Previous work from our group indicated an association between the gastrointestinal microbiota of infants with cystic fibrosis (CF) and airway disease in this population. Here we report that stool microbiota of infants with CF demonstrates an altered but largely unchanging within-individual bacterial diversity (alpha diversity) over the first year of life, in contrast to the infants without CF (control cohort), which showed the expected increase in alpha diversity over the first year. The beta diversity, or between-sample diversity, of these two cohorts was significantly different over the first year of life and was statistically significantly associated with airway exacerbations, confirming our earlier findings. Compared with control infants, infants with CF had reduced levels of Bacteroides, a bacterial genus associated with immune modulation, as early as 6 weeks of life, and this significant reduction of Bacteroides spp. in the cohort with CF persisted over the entire first year of life. Only two other genera were significantly different across the first year of life: Roseburia was significantly reduced and Veillonella was significantly increased. Other genera showed differences between the two cohorts but only at selected time points. In vitro studies demonstrated that exposure of the apical face of polarized intestinal cell lines to Bacteroides species supernatants significantly reduced production of interleukin 8 (IL-8), suggesting a mechanism whereby changes in the intestinal microbiota could impact inflammation in CF. This work further establishes an association between gastrointestinal microbiota, inflammation, and airway disease in infants with CF and presents a potential opportunity for therapeutic interventions beginning in early life.IMPORTANCE There is growing evidence for a link between gastrointestinal bacterial communities and airway disease progression in CF. We demonstrate that infants with CF ≤1 year of age show a distinct stool microbiota versus that of control infants of a comparable age. We detected associations between the gut microbiome and airway exacerbation events in the cohort of infants with CF, and in vitro studies provided one possible mechanism for this observation. These data clarify that current therapeutics do not establish in infants with CF a gastrointestinal microbiota like that in healthy infants, and we suggest that interventions that direct the gastrointestinal microbiota closer to a healthy state may provide systemic benefits to these patients during a critical window of immune programming that might have implications for lifelong health.

A Neutralizing Aptamer to TGFBR2 and miR-145 Antagonism Rescue Cigarette Smoke- and TGF-β-Mediated CFTR Expression.

Transforming growth factor β (TGF-β), signaling induced by cigarette smoke (CS), plays an important role in the progression of airway diseases, like chronic bronchitis associated with chronic obstructive pulmonary disease (COPD), and in smokers. Chronic bronchitis is characterized by reduced mucociliary clearance (MCC). Cystic fibrosis transmembrane conductance regulator (CFTR) plays an important role in normal MCC. TGF-β and CS (via TGF-β) promote acquired CFTR dysfunction by suppressing CFTR biogenesis and function. Understanding the mechanism by which CS promotes CFTR dysfunction can identify therapeutic leads to reverse CFTR suppression and rescue MCC. TGF-β alters the microRNAome of primary human bronchial epithelium. TGF-β and CS upregulate miR-145-5p expression to suppress CFTR and the CFTR modifier, SLC26A9. miR-145-5p upregulation with a concomitant CFTR and SLC26A9 suppression was validated in CS-exposed mouse models. While miR-145-5p antagonism rescued the effects of TGF-β in bronchial epithelial cells following transfection, an aptamer to block TGF-β signaling rescues CS- and TGF-β-mediated suppression of CFTR biogenesis and function in the absence of any transfection reagent. These results demonstrate that miR-145-5p plays a significant role in acquired CFTR dysfunction by CS, and they validate a clinically feasible strategy for delivery by inhalation to locally modulate TGF-β signaling in the airway and rescue CFTR biogenesis and function.

Epithelial-Immune Cell Interactions for Drug Discovery in Chronic Obstructive Pulmonary Disease.

New studies of chronic obstructive pulmonary disease (COPD) are revealing the key role of airway epithelial cells and innate immune cells in the initiation, exacerbation, and progression of airway disease. An emerging scheme focuses on expansion of airway progenitor epithelial cells that feed forward for a type 2 immune response and consequent IL-13-driven mucus production that is linked to the morbidity and mortality of COPD. Analysis of human airway progenitor epithelial cells and airway tissue shows that IL-13 signaling to MUC5AC mucin gene expression relies on specific activation of mitogen-activated protein kinase 13, providing a druggable target for attenuating mucus production in the setting of viral infection and other inhaled stimuli of airway inflammation. Moreover, structure-based drug design is delivering highly potent, selective, and nontoxic small-molecule kinase inhibitors of mitogen-activated protein kinase 13 that offer a therapeutic strategy to downregulate excess mucus production to a physiological level and thereby achieve a precision medicine solution to the major health care problem of COPD and related airway diseases.

Impact of CFTR modulation with Ivacaftor on Gut Microbiota and Intestinal Inflammation

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Next to progressive airway disease, CF is also associated with intestinal inflammation and dysbiosis. Ivacaftor, a CFTR potentiator, has improved pulmonary and nutritional status but its effects on the intestinal microbiota and inflammation are unclear. Hence, we assessed the changes on the intestinal microbial communities (16S rRNA variable 3 gene region) and inflammatory markers (calprotectin and M2-pyruvate kinase [M2-PK]) in 16 CF individuals (8 children and 8 adults) before and after (median 6.1 months) ivacaftor. Stool calprotectin significantly decreased following ivacaftor (median [IQR]: 154.4 [102.1–284.2] vs. 87.5 [19.5–190.2] mg/kg, P = 0.03). There was a significant increase in Akkermansia with ivacaftor. Increased abundance of Akkermansia was associated with normal stool M2-PK concentrations, and decreased abundances of Enterobacteriaceae correlated with decreased stool calprotectin concentrations. In summary, changes in the gut microbiome and decrease in intestinal inflammation was associated with Ivacaftor treatment among individuals with CF carrying at least one gating CFTR mutation. Thus, CFTR-modifying therapy may adequately improve the aberrant pathophysiology and milieu of the CF gut to favor a more healthy microbiota, which in turn reduces intestinal inflammation.

Slowing Progression of Airway Diseases by Smoking Cessation and Reducing Infections

The prevalence of respiratory diseases, including asthma and chronic obstructive pulmonary disease, has increased in recent decades, placing a significant burden on healthcare systems and economies around the world. As these diseases are largely incurable, the aim of treatment is to control symptoms and improve quality of life. Aside from stopping smoking and reducing biomass fuel exposure, arguably the most effective strategy in the long-term management of chronic respiratory diseases is the prevention or control of respiratory infections via vaccines and antimicrobial agents. By preventing these infections or reducing exposure to some of the major risk factors, we can reduce further lung damage in these patients, thereby slowing disease progression. This review looks at maintaining long-term respiratory health in patients with asthma and chronic obstructive pulmonary disease, primarily through smoking cessation, reducing exposure to allergens and air pollutants, and infection control.

Increasing awareness of sex differences in airway diseases.

There is growing epidemiologic data demonstrating sex differences with respect to prevalence and progression of airway diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF) and non-CF-related bronchiectasis. In asthma, for example, young boys have increased exacerbations and higher morbidity than girls which distinctly reverses after adolescence and into adulthood. In COPD, a disease that was historically considered an illness of men, the number of women dying per year is now greater than in men. Finally, women with CF-related bronchiectasis have a decreased median life expectancy relative to men and a higher risk of respiratory infections despite equal prevalence of the disease. A number of studies now exist demonstrating mechanisms behind these sex differences, including influences of genetic predisposition, sex hormones and comorbidities. The notable sex disparity has potential diagnostic, therapeutic and prognostic implications and for the practicing respiratory or general physician, a familiarity with these distinctions may augment effective management of patients with airway diseases. This review seeks to concisely summarize the data regarding gender-based differences in airway diseases, outline the current understanding of contributing factors and discuss therapeutic implications for clinicians.

WS10.5 Pseudomonas aeruginosa adaptation as a potential risk factor to the progression of cystic fibrosis airway disease in mice and humans

Objectives CF is characterized by loss of pulmonary function and tissue injury. As the disease progresses, P. aeruginosa adapts to the host and dramatically modifies its phenotype; however, it is still unclear if and how bacterial adaptation influences pathogenesis and disease development. Methods Initially-acquired and CF-adapted P. aeruginosa clonal variants were challenged in C57Bl/6 and CF ko mice after their inclusion in agar beads. Mice were evaluated for bacterial count, lung histopathology, markers of inflammation and tissue damage. Patho-adaptive traits of P. aeruginosa isolated from CF patients airways were correlated with clinical scores. Results Different to P. aeruginosa initially-acquired strains, CF-adapted variants caused long-term chronic infection in mice by shaping the immune response and activating pathways relevant to tissue damage and remodelling. At an advanced stage of a P. aeruginosa infection, murine airways displayed hallmarks of remodelling and fibrosis, including epithelial hyperplasia and structure degeneration, goblet cell metaplasia, collagen deposition, elastin degradation and several markers of tissue damage. In mice, these pathologic traits are only partially dependent on the CFTR genetic background. In CF patients, we observed correlation between P. aeruginosa patho-adaptive traits and inflammation, remodelling processes and lung functions suggesting exploitable disease markers. Conclusion We conclude that bacterial adaptation may be a potential risk factor in the progression of airway disease and a critical success determinant for reproducing the human disease in mice. Supported by Italian CF Research Foundation.

Clinical significance of epithelial mesenchymal transition (EMT) in chronic obstructive pulmonary disease (COPD): potential target for prevention of airway fibrosis and lung cancer.

Unfortunately, the research effort directed into chronic obstructive pulmonary disease (COPD) has been disproportionately weak compared to its social importance, and indeed it is the least researched of all common chronic conditions. Tobacco smoking is the major etiological factor. Only 25% of smokers will develop “classic” COPD; in these vulnerable individuals the progression of airways disease to symptomatic COPD occurs over two or more decades. We know surprisingly little about the pathobiology of COPD airway disease, though small airway fibrosis and obliteration are likely to be the main contributors to physiological airway dysfunction and these features occur earlier than any subsequent development of emphysema. One potential mechanism contributing to small airway fibrosis/obliteration and change in extracellular matrix (ECM) is epithelial mesenchymal transition (EMT), so called Type-II EMT. When associated with angiogenesis (Type-III EMT) it may well also be a link with the development of lung (airway) cancer which is closely associated with COPD. Active EMT in COPD may help to explain why lung cancer is so common in smokers and also the core pathophysiology of small airway fibrosis. Better understanding may lead to new markers for incipient neoplasia, and better preventive management of patients. There is serious need to understand key components of airway EMT in smokers and COPD, and to demarcate novel drug targets for the prevention of lung cancer and airway fibrosis, as well as better secondary management of COPD. Since over 90% of human cancer arises in epithelia and the involvement of EMT in all of these may be a central paradigm, insights gained in COPD may have important generalizable value.

The effect of azithromycin in adults with stable neutrophilic COPD: a double blind randomised, placebo controlled trial.

BackgroundChronic Obstructive Pulmonary Disease (COPD) is a progressive airway disease characterised by neutrophilic airway inflammation or bronchitis. Neutrophilic bronchitis is associated with both bacterial colonisation and lung function decline and is common in exacerbations of COPD. Despite current available therapies to control inflammation, neutrophilic bronchitis remains common. This study tested the hypothesis that azithromycin treatment, as an add-on to standard medication, would significantly reduce airway neutrophil and neutrophils chemokine (CXCL8) levels, as well as bacterial load. We conducted a randomised, double-blind, placebo-controlled study in COPD participants with stable neutrophilic bronchitis.MethodsEligible participants (n = 30) were randomised to azithromycin 250 mg daily or placebo for 12 weeks in addition to their standard respiratory medications. Sputum was induced at screening, randomisation and monthly for a 12 week treatment period and processed for differential cell counts, CXCL8 and neutrophil elastase assessment. Quantitative bacteriology was assessed in sputum samples at randomisation and the end of treatment visit. Severe exacerbations where symptoms increased requiring unscheduled treatment were recorded during the 12 week treatment period and for 14 weeks following treatment. A sub-group of participants underwent chest computed tomography scans (n = 15).ResultsNine participants with neutrophilic bronchitis had a potentially pathogenic bacteria isolated and the median total bacterial load of all participants was 5.22×107 cfu/mL. Azithromycin treatment resulted in a non-significant reduction in sputum neutrophil proportion, CXCL8 levels and bacterial load. The mean severe exacerbation rate was 0.33 per person per 26 weeks in the azithromycin group compared to 0.93 exacerbations per person in the placebo group (incidence rate ratio (95%CI): 0.37 (0.11,1.21), p = 0.062). For participants who underwent chest CT scans, no alterations were observed.ConclusionsIn stable COPD with neutrophilic bronchitis, add-on azithromycin therapy showed a trend to reduced severe exacerbations sputum neutrophils, CXCL8 levels and bacterial load. Future studies with a larger sample size are warranted.Trial RegistrationAustralian New Zealand Clinical Trials Registry ACTRN12609000259246

MAChRs activation induces epithelial-mesenchymal transition on lung epithelial cells

BackgroundEpithelial-mesenchymal transition (EMT) has been proposed as a mechanism in the progression of airway diseases and cancer. Here, we explored the role of acetylcholine (ACh) and the pathway involved in the process of EMT, as well as the effects of mAChRs antagonist.MethodsHuman lung epithelial cells were stimulated with carbachol, an analogue of ACh, and epithelial and mesenchymal marker proteins were evaluated using western blot and immunofluorescence analyses.ResultsDecreased E-cadherin expression and increased vimentin and α-SMA expression induced by TGF-β1 in alveolar epithelial cell (A549) were significantly abrogated by the non-selective mAChR antagonist atropine and enhanced by the acetylcholinesterase inhibitor physostigmine. An EMT event also occurred in response to physostigmine alone. Furthermore, ChAT express and ACh release by A549 cells were enhanced by TGF-β1. Interestingly, ACh analogue carbachol also induced EMT in A549 cells as well as in bronchial epithelial cells (16HBE) in a time- and concentration-dependent manner, the induction of carbachol was abrogated by selective antagonist of M1 (pirenzepine) and M3 (4-DAMP) mAChRs, but not by M2 (methoctramine) antagonist. Moreover, carbachol induced TGF-β1 production from A549 cells concomitantly with the EMT process. Carbachol-induced EMT occurred through phosphorylation of Smad2/3 and ERK, which was inhibited by pirenzepine and 4-DAMP.ConclusionsOur findings for the first time indicated that mAChR activation, perhaps via M1 and M3 mAChR, induced lung epithelial cells to undergo EMT and provided insights into novel therapeutic strategies for airway diseases in which lung remodeling occurs.