TY - JOUR T1 - Epithelial mesenchymal transition (EMT) is present in both large and small airways of smokers JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P841 AU - Malik Mahmood AU - Sukhwinder Singh Sohal AU - Ashutosh Hardikar AU - David Reid AU - Cameron Hunter AU - Darryl Knight AU - Konard Muller AU - Eugene Haydn Walters Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P841.abstract N2 - Introduction:Airway remodelling is seen in COPD in both small and large airways. Small airway fibrosis is the main contributor in airflow obstruction in COPD; EMT has been implicated in this. In large airways we have shown active EMT to be associated with angiogenesis i.e, malignancy-associated Type-3 EMT.Objective:In this study we have investigated whether EMT biomarkers are expressed in small airways compared to large airways, and what type of EMT is present on the basis on vascularity of airway epithelium and Reticular basement membrane (Rbm).Methods:Cross-sectionally we evaluated Rbm fragmentation (core structural marker of EMT) and EMT-related mesenchymal bio-markers in small and large airways from resected lung tissue from 24 COPD lung cancer patients and, 9 normal controls using immunohistochemistry. Tissues were immunostained using antibodies against Vimentin (mesenchymal marker) and S100-A4 (fibroblast epitope).Type-IV collagen was stained to demonstrate vessels.Results:There was significantly increased expression of EMT-related markers in small airways compared to control tissue: Vimentin(p <0.001), S100-A4(p<0.001) and fragmentation(p<0.001). However, levels of EMT expression were less than in large airways. Notably there was no hyper vascularity in small airway Rbm as there was in large airways (p<0.001 against large airways; p=1 against normal).Conclusion:EMT is active in small airway in COPD suggesting a potential role in small airway fibrosis, i.e, EMT-Type 2; in contrast to Type-3 EMT in large airways where it could be important in promoting cancer formation. ER -