Using ex vivo bioengineered lungs to model pathologies and screening therapeutics: A proof-of-concept study.

Respiratory diseases, claim over eight million lives annually. However, the transition from preclinical to clinical phases in research studies is often hindered, partly due to inadequate representation of preclinical models in clinical trials. To address this, we conducted a proof-of-concept study using an ex vivo model to identify lung pathologies and to screen therapeutics in a humanized rodent model. We extracted and decellularized mouse heart-lung tissues using a detergent-based technique. The lungs were then seeded and cultured with human cell lines (BEAS-2B, A549, and Calu3) for 6-10 days, representing healthy lungs, cancerous states, and congenital pathologies, respectively. By manipulating cultural conditions and leveraging the unique characteristics of the cell lines, we successfully modeled various pathologies, including advanced-stage solid tumors and the primary phase of SARS-CoV-2 infection. Validation was conducted through histology, immunofluorescence staining, and pathology analysis. Additionally, our study involved pathological screening of the efficacy and impact of key anti-neoplastic therapeutics (Cisplatin and Wogonin) in cancer models. The results highlight the versatility and strength of the ex vivo model in representing crucial lung pathologies and screening therapeutics during the preclinical phase. This approach holds promise for bridging the gap between preclinical and clinical research, aiding in the development of effective treatments for respiratory diseases, including lung cancer.

A systematic review of the clinical characteristics of influenza-COVID-19 co-infection.

COVID-19 has impacted populations across the globe and has been a major cause of morbidity and mortality. Influenza is another potentially deadly respiratory infection that affects people worldwide. While both of these infections pose major health threats, little is currently understood regarding the clinical aspects of influenza and COVID-19 co-infection. Our objective was to therefore provide a systematic review of the clinical characteristics, treatments, and outcomes for patients who are co-infected with influenza and COVID-19. Our review, which was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, involved searching for literature in seven different databases. Studies were eligible for inclusion if they included at least one co-infected patient, were available in English, and described clinical characteristics for the patients. Data were pooled after extraction. Study quality was assessed using the Joanna Brigg's Institute Checklists. Searches produced a total of 5096 studies, and of those, 64 were eligible for inclusion. A total of 6086 co-infected patients were included, 54.1% of whom were male; the mean age of patients was 55.9 years (SD = 12.3). 73.6% of cases were of influenza A and 25.1% were influenza B. 15.7% of co-infected patients had a poor outcome (death/deterioration). The most common symptoms were fever, cough, and dyspnea, with the most frequent complications being pneumonia, linear atelectasis, and acute respiratory distress syndrome. Oseltamivir, supplemental oxygen, arbidol, and vasopressors were the most common treatments provided to patients. Having comorbidities, and being unvaccinated for influenza, were shown to be important risk factors. Co-infected patients show symptoms that are similar to those who are infected with COVID-19 or influenza only. However, co-infected patients have been shown to be at an elevated risk for poor outcomes compared to mono-infected COVID-19 patients. Screening for influenza in high-risk COVID-19 patients is recommended. There is also a clear need to improve patient outcomes with more effective treatment regimens, better testing, and higher rates of vaccination.

The Underappreciated Role of Epithelial Mesenchymal Transition in Chronic Obstructive Pulmonary Disease and Its Strong Link to Lung Cancer.

The World Health Organisation reported COPD to be the third leading cause of death globally in 2019, and in 2020, the most common cause of cancer death was lung cancer; when these linked conditions are added together they come near the top of the leading causes of mortality. The cell-biological program termed epithelial-to-mesenchymal transition (EMT) plays an important role in organ development, fibrosis and cancer progression. Over the past decade there has emerged a substantial literature that also links EMT specifically to the pathophysiology of chronic obstructive pulmonary disease (COPD) as primarily an airway fibrosis disease; COPD is a recognised strong independent risk factor for the development of lung cancer, over and above the risks associated with smoking. In this review, our primary focus is to highlight these linkages and alert both the COPD and lung cancer fields to these complex interactions. We emphasise the need for inter-disciplinary attention and research focused on the likely crucial roles of EMT (and potential for its inhibition) with recognition of its strategic place mechanistically in both COPD and lung cancer. As part of this we discuss the future potential directions for novel therapeutic opportunities, including evidence-based strategic repurposing of currently used familiar/approved medications.

Microbiome-focused asthma management strategies.

Asthma is a common, heterogeneous and serious disease with high prevalence globally. Poorly controlled, steroid-resistant asthma is particularly important as there are no effective therapies and it exerts substantial healthcare and societal burden. The role of microbiomes, particularly in chronic diseases has generated considerable interest in recent times. Existing evidence clearly demonstrates an association between asthma initiation and the microbiome, both respiratory and gastro-intestinal, although its' roles are poorly understood when assessing the asthma progression or heterogeneity (i.e. phenotypes/endotypes) across different geographical locations. Moreover, modulating microbiomes could be preventive and/or therapeutic in patients with asthma warrants urgent attention. Here, we review recent advances in assessing the role of microbiomes in asthma and present the challenges associated with the potential therapeutic utility of modifying microbiomes in management.

ß-catenin, Twist and Snail: Transcriptional regulation of EMT in smokers and COPD, and relation to airflow obstruction.

COPD is characterised by poorly reversible airflow obstruction usually due to cigarette smoking. The transcription factor clusters of ß-catenin/Snail1/Twist has been implicated in the process of epithelial mesenchymal transition (EMT), an intermediate between smoking and airway fibrosis, and indeed lung cancer. We have investigated expression of these transcription factors and their "cellular localization" in bronchoscopic airway biopsies from patients with COPD, and in smoking and non-smoking controls. An immune-histochemical study compared cellular protein expression of ß-catenin, Snail1 and Twist, in these subject groups in 3 large airways compartment: epithelium (basal region), reticular basement membrane (Rbm) and underlying lamina propria (LP). ß-catenin and Snail1 expression was generally high in all subjects throughout the airway wall with marked cytoplasmic to nuclear shift in COPD (P < 0.01). Twist expression was generalised in the epithelium in normal but become more basal and nuclear with smoking (P < 0.05). In addition, ß-catenin and Snail1 expression, and to lesser extent of Twist, was related to airflow obstruction and to expression of a canonical EMT biomarker (S100A4). The ß-catenin-Snail1-Twist transcription factor cluster is up-regulated and nuclear translocated in smokers and COPD, and their expression is closely related to both EMT activity and airway obstruction.

Epithelial mesenchymal transition (EMT) and non-small cell lung cancer (NSCLC): a mutual association with airway disease.

NSCLC is a leading cause of morbidity and mortality worldwide. It includes adeno- and squamous cell carcinoma. In the background, COPD and smoking play a vital role in development of NSCLC. Local progression and metastasis of NSCLC has been associated with various mechanisms, but in particular by a process called epithelial mesenchymal transition (EMT), which is implicated in COPD pathogenesis. In this study, we have investigated whether expression of EGFR (activation marker) and S100A4, vimentin and N-cadherin (as EMT) is different both in central and leading edge of NSCLC and to what extent related to EMT activity of both small and large airways, stage and differentiation of NSCLC. We have investigated EMT biomarkers (S100A4, vimentin, and N-cadherin), an epithelial activation marker (EGFR) and a vascularity marker (Type-IV collagen) in surgically resected tissue from patients with NSCLC (adeno- and squamous cell carcinoma), and compared them with expression in the corresponding non-tumorous airways. EGFR, S100A4, vimentin, N-cadherin expression was higher in tumor cells located at the peripheral leading edge of NSCLC when compared with centrally located tumor cells of same subjects (P < 0.01). Type-IV collagen-expressing blood vessels were also more at the leading edge in comparison with central parts of NSCLC. EGFR and S100A4 expression was related to differentiation status (P < 0.05) and TNM stage (P < 0.05) of NSCLC. Moreover, EMT markers in the leading edge were significantly related to airway EMT activity, while peripheral edge vascularity of squamous cell carcinoma only was significantly related to large airway Rbm vascularity (P < 0.05). EGFR- and EMT-related protein expression was markedly high in the peripheral leading edge of NSCLCs and related to tumor characteristics associated with poor prognosis. The relationships between EMT-related tumor biomarker expression and those in the airway epithelium and Rbm provide a background for utility of airway changes in clinical settings.

The Role of Epidermal Growth Factor Receptor in the Management of Gastrointestinal Carcinomas: Present Status and Future Perspectives.

BACKGROUND: The global burden of gastrointestinal cancers, including colorectal, stomach, and esophageal cancers is rising steadily. Several therapeutic approaches have been considered for the treatment of GI carcinomas. However, none showed to halt or cure the disease. There is a need to develop effective targeted molecular therapies; mainly to overcome the adverse effects of currently used treatment regimens, as well as, to benefit a large proportion of cancer patients who do not respond well to chemotherapeutics. METHODS: Epidermal growth factor receptor (EGFR) is one of the promising targets for cancer therapy. Through a cascade of events, activation of EGFR plays an important role in the homeostasis and pathogenesis of various disorders, including carcinomas of the gastrointestinal (GI) tract, ranging from oesophagitis to complex colon carcinoma. RESULTS: The GI carcinomas are associated with aberrant EGFR expression. In this review, emphasis was made on various EFGR-associated signalling pathways, their mechanisms and role in the formation of gastrointestinal lesions. CONCLUSION: The current EGFR-targeting therapeutics and an outline of various novel drug delivery systems that could potentially be employed for targeting EGFR during cancer treatment were discussed. This would help medical, pharmaceutical and other life science researchers in providing broad understanding of the work previously conducted in this field.

The main rhinovirus respiratory tract adhesion site (ICAM-1) is upregulated in smokers and patients with chronic airflow limitation (CAL).

BACKGROUND: ICAM-1 is a major receptor for ~60% of human rhinoviruses, and non-typeable Haemophilus influenzae, two major pathogens in COPD. Increased cell-surface expression of ICAM-1 in response to tobacco smoke exposure has been suggested. We have investigated epithelial ICAM-1 expression in both the large and small airways, and lung parenchyma in smoking-related chronic airflow limitation (CAL) patients. METHODS: We evaluated epithelial ICAM-1 expression in resected lung tissue: 8 smokers with normal spirometry (NLFS); 29 CAL patients (10 small-airway disease; 9 COPD-smokers; 10 COPD ex-smokers); Controls (NC): 15 normal airway/lung tissues. Immunostaining with anti-ICAM-1 monoclonal antibody was quantified with computerized image analysis. The percent and type of cells expressing ICAM-1 in large and small airway epithelium and parenchyma were enumerated, plus percentage of epithelial goblet and submucosal glands positive for ICAM- 1. RESULTS: A major increase in ICAM-1 expression in epithelial cells was found in both large (p < 0.006) and small airways (p < 0.004) of CAL subjects compared to NC, with NLFS being intermediate. In the CAL group, both basal and luminal areas stained heavily for ICAM-1, so did goblet cells and sub-mucosal glands, however in either NC or NLFS subjects, only epithelial cell luminal surfaces stained. ICAM-1 expression on alveolar pneumocytes (mainly type II) was slightly increased in CAL and NLFS (p < 0.01). Pack-years of smoking correlated with ICAM-1 expression (r = 0.49; p < 0.03). CONCLUSION: Airway ICAM-1 expression is markedly upregulated in CAL group, which could be crucial in rhinoviral and NTHi infections. The parenchymal ICAM-1 is affected by smoking, with no further enhancement in CAL subjects.

Epithelial mesenchymal transition in smokers: large versus small airways and relation to airflow obstruction.

BACKGROUND: Small airway fibrosis is the main contributor in airflow obstruction in chronic obstructive pulmonary disease. Epithelial mesenchymal transition (EMT) has been implicated in this process, and in large airways, is associated with angiogenesis, ie, Type-3, which is classically promalignant. OBJECTIVE: In this study we have investigated whether EMT biomarkers are expressed in small airways compared to large airways in subjects with chronic airflow limitation (CAL) and what type of EMT is present on the basis of vascularity. METHODS: We evaluated epithelial activation, reticular basement membrane fragmentation (core structural EMT marker) and EMT-related mesenchymal biomarkers in small and large airways from resected lung tissue from 18 lung cancer patients with CAL and 9 normal controls. Tissues were immunostained for epidermal growth factor receptor (EGFR; epithelial activation marker), vimentin (mesenchymal marker), and S100A4 (fibroblast epitope). Type-IV collagen was stained to demonstrate vessels. RESULTS: There was increased expression of EMT-related markers in CAL small airways compared to controls: EGFR (P<0.001), vimentin (P<0.001), S100A4 (P<0.001), and fragmentation (P<0.001), but this was less than that in large airways. Notably, there was no hypervascularity in small airway reticular basement membrane as in large airways. Epithelial activation and S100A4 expression were related to airflow obstruction. CONCLUSION: EMT is active in small airways, but less so than in large airways in CAL, and may be relevant to the key pathologies of chronic obstructive pulmonary disease, small airway fibrosis, and airway cancers.

Airway epithelial platelet-activating factor receptor expression is markedly upregulated in chronic obstructive pulmonary disease.

BACKGROUND: We recently published that platelet-activating factor receptor (PAFr) is upregulated on the epithelium of the proximal airways of current smokers and also in bronchial epithelial cells exposed to cigarette smoke extract. These treated cells also showed upregulation of Streptococcus pneumoniae adhesion. Bacterial wall phosphorylcholine specifically binds to PAFr expressed on airway epithelium, thus facilitating adherence and tissue invasion, which may be relevant to chronic obstructive pulmonary disease (COPD). Moreover, the use of inhaled corticosteroids (ICS) in COPD patients is associated with an increased risk of invasive respiratory pneumococcal infections. OBJECTIVE: In this study, we have investigated whether PAFr expression is especially upregulated in airway epithelium in COPD patients and whether this expression may be modulated by ICS therapy. METHODS: We cross-sectionally evaluated PAFr expression in bronchial biopsies from 15 COPD patients who were current smokers (COPD-smokers) and 12 COPD-ex-smokers, and we compared these to biopsies from 16 smokers with normal lung function. We assessed immunostaining with anti-PAFr monoclonal antibody. We also used material from a previous double-blinded randomized placebo-controlled 6-month ICS intervention study in COPD patients to explore the effect of ICS on PAFr expression. We employed computer-aided image analysis to quantify the percentage of epithelium stained for PAFr. RESULTS: Markedly enhanced expression of PAFr was found in both COPD-smokers (P<0.005) and COPD-ex-smokers (P<0.002) compared to smokers with normal lung function. There was little evidence that PAFr expression was affected by ICS therapy over 6 months. CONCLUSION: Epithelial PAFr expression is upregulated in smokers, especially in those with COPD, and is not obviously affected by ICS therapy.

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.