PAR2 Overexpression is Involved in the Occurrence of Hyperoxygen-Induced Bronchopulmonary Dysplasia in Rats.

BACKGROUND

Bronchopulmonary dysplasia is a chronic lung disease commonly seen in preterm infants. It is characterized by delayed development of the alveoli and lung fibrosis. Protease-activated receptor 2 (PAR2) is an inflammatory driver that plays a proinflammatory role mainly through the P38 MAPK/NF-κB signaling pathway.

METHODS

Newborn rat pups were kept under air or oxygen at >60% concentration. Lung tissues were collected at postnatal days (P) 1, 4, 7, and 10 to observe pathological changes and take measurements.

RESULTS

In the hyperoxic group, P4 and P7 rats showed delayed alveolar development, septal thickening, and disturbances in alveolar structure.PAR2, P38 MAPK, NF-κB, and IL-18 expression at P4, P7, and P10 was significantly higher than in the air group.

CONCLUSION

PAR2 is involved in lung injury induced by persistent hyperoxia. Activated PAR2 promotes IL-18 overexpression through the P38 MAPK/NF-κB signaling pathway, which may be an important mechanism of PAR2-mediated lung injury in bronchopulmonary dysplasia.