Commentary: A Breath of Fresh Air on the Mesenchyme: Impact of Impaired Mesenchymal Development on the Pathogenesis of Bronchopulmonary Dysplasia

摘要

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of prematurity that is only now beginning to be understood at the molecular level. The review by Chao et al. (1) elegantly takes us through mouse and human lung development to identify possible mediators of the abnormal mesenchymal response characteristic of the disease. However, it quickly becomes clear that many aspects of BPD development seem to mimic chronic lung disease in adults. For example, secondary septa formation is a critical step in alveologenesis, with alveolar simplification in BPD thought to result from disordered septation. In the emphysematous adult lung, enlarged airspaces reminiscent of alveolar simplification are also seen; importantly, evidence suggests that many mediators thought to be important in BPD development are also important in COPD pathogenesis, such as wingless and int (Wnt) (2, 3), fibroblast growth factor (FGF) (4, 5), and sonic hedgehog (Shh) (6). Similarly, exuberant collagen and elastin deposition during alveologenesis bears remarkable similarity to the deposition of extracellular matrix proteins during adult lung fibrogenesis (7), although it is unclear whether the pattern and relative quantities of proteins are also similar. These observations, plus others, suggest a potential stereotypic lung injury response resulting in disrepair in adult lung and abnormal development in the neonate.