SPAK-p38 MAPK signal pathway modulates claudin-18 and barrier function of alveolar epithelium after hyperoxic exposure

Hyperoxia downregulates the tight junction (TJ) proteins of the alveolar epithelium and leads to bar‑ rier dysfunction. Previous study has showed that STE20/SPS1-related proline/alanine-rich kinase (SPAK) interferes with the intestinal barrier function in mice.