Impact of rs16969968 polymorphism (SNPα5) on epithelial differentiation in COPD patients
Résumé
Background
Genome-wide association studies unveiled the association of rs16969968 present on the α5 subunit of nicotinic receptors with nicotine addiction, cancer, and chronic obstructive pulmonary disease independently, but no biological data is available in humans.
Aims and Objectives
We previously demonstrated that rs16969968 impaired ciliogenesis and cytokine production in respiratory epithelia. Here, we investigated the role of rs16969968 in the context of COPD. We suggest it is involved in bronchial and bronchiolar remodeling and differentiation and therefore participates in COPD pathogenesis.
Methods
Lung tissues from COPD patients (n=23) were genotyped to identify the rs16969968 polymorphism. Immunostainings on bronchial and bronchiolar sections were performed to analyze histological features. Air-liquid interface cultures from bronchial brushings of COPD patients (n=8) were analyzed after 15 days of differentiation to assess ciliogenesis.
Results
Bronchiolar SNPα5 COPD sections presented a 23% increase of basal cells (p<0.05), and a 122% increase of Muc5ac secretory cells (p<0.001), without affecting cilia. The bronchial SNPα5 COPD tissues did not differ compared to wild-type α5. However, in vitro analysis, revealed a 33% increase of primary cilia (p<0.01) in differentiated epithelia of SNPα5 COPD patients.
Conclusions
These results highlighted the participation of SNPα5 in the remodeling of bronchial and bronchiolar epithelium, affecting the basal cells, primary cilia, and the secretion of Muc5ac in COPD patients.