Malfunction of airway basal stem cells plays a crucial role in pathophysiology of tracheobronchopathia osteoplastica

Tracheobronchopathia osteoplastica (TO), is an underreported affliction characterized by squamous metaplasia and heterotopic bone formation in trachea and bronchi. Here the authors apply functional, as well as genome-wide transcriptional and epigenetic profiling to identify airway basal cells dysfunction underlying TO. Understanding disease-associated stem cell abnormality has major clinical implications for prevention and treatment of human disorders, as well as for regenerative medicine. Here we report a multifaceted study on airway epithelial stem cells in Tracheobronchopathia Osteochondroplastica (TO), an under-detected tracheobronchial disorder of unknown etiology and lack of specific treatment. Epithelial squamous metaplasia and heterotopic bone formation with abnormal cartilage proliferation and calcium deposits are key pathological hallmarks of this disorder, but it is unknown whether they are coincident or share certain pathogenic mechanisms in common. By functional evaluation and genome-wide profiling at both transcriptional and epigenetic levels, we reveal a role of airway basal cells in TO progression by acting as a repository of inflammatory and TGF beta-BMP signals, which contributes to both epithelial metaplasia and mesenchymal osteo-chondrogenesis via extracellular signaling and matrix remodeling. Restoration of microenvironment by cell correction or local pathway intervention may provide therapeutic benefits.