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Transforming growth factor (TGF) β1 and Smad signalling pathways: A likely key to EMT-associated COPD pathogenesis


Mahmood, MQ and Reid, D and Ward, C and Muller, HK and Knight, DA and Sohal, SS and Walters, EH, Transforming growth factor (TGF) β1 and Smad signalling pathways: A likely key to EMT-associated COPD pathogenesis, Respirology, 22, (1) pp. 133-140. ISSN 1323-7799 (2017) [Refereed Article]

Copyright Statement

© 2016 Asian Pacific Society of Respirology

DOI: doi:10.1111/resp.12882


Background and objective: COPD is characterized by poorly reversible airflow obstruction usually due to cigarette smoking. Transforming growth factor (TGF)-β1 has been implicated in the pathogenesis of COPD, and in particular a process called epithelial mesenchymal transition (EMT), which may well be an intermediatory between smoking and both airway fibrosis and lung cancer. The downstream classical or ‘canonical’ TGF-β1 pathway is via the phosphorylated (p) Smad transcription factor system.

Methods: We have investigated TGF-β1 expression and its ‘pSmad fingerprint’ in bronchoscopic airway biopsies from patients with COPD, and in smoking and non-smoking controls. A cross-sectional immunohistochemical study compared TGF-β1 and pSmad 2, 3 (excitatory) and 7 (inhibitory) expression in cells and blood vessels of three compartments of large airways: epithelium (especially the basal region), reticular basement membrane (Rbm) and underlying lamina propria (LP).

Results: TGF-β1 expression was generally higher in COPD subjects throughout the airway wall (P < 0.01), while pSmad 2/3 expression was associated with smoking especially in current smoking COPD (P < 0.05). Expression of inhibitory pSmad 7 was also prominently reduced in patients with COPD in contrast to smokers and controls (P < 0.01). In addition, pSmad, but not TGF-β1 expression, was related to airflow obstruction and a canonical EMT biomarker (S100 A4) expression.

Conclusion: Activation of the Smad pathway in the airways is linked to EMT activity and loss of lung function. The disconnection between TGF-β1 and pSmad in terms of relationships to EMT activity and lung function suggests that factors other than or in addition to TGF-β1 are driving the process.

Item Details

Item Type:Refereed Article
Keywords:chronic obstructive pulmonary disease, epithelial mesenchymal transition, Smad 2/3, Smad 7, transforming growth factor &#946;1
Research Division:Biomedical and Clinical Sciences
Research Group:Cardiovascular medicine and haematology
Research Field:Respiratory diseases
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Mahmood, MQ (Mr Malik Mahmood)
UTAS Author:Reid, D (Dr David Reid)
UTAS Author:Muller, HK (Professor Konrad Muller)
UTAS Author:Sohal, SS (Dr Sukhwinder Sohal)
UTAS Author:Walters, EH (Professor Haydn Walters)
ID Code:120632
Year Published:2017
Web of Science® Times Cited:55
Deposited By:Health Sciences
Deposited On:2017-08-29
Last Modified:2022-08-25

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