Peroxiredoxin 6 enhances PINK1 phosphorylation to activate mitophagy to protect acute lung injury.

<bold>Introduction</bold>: Repairing damaged epithelial cells is crucial in treating acute lung injury (ALI). Mitochondria play a significant role in protecting against ALI. Peroxiredoxin 6 (PRDX6) is involved in regulating mitochondrial function. <bold>Aims and objectives</bold>: This study aimed to define the role and mechanism of PRDX6 in protecting against ALI. <bold>Methods:</bold> In wild-type and alveolar type II epithelial cell-specific Prdx6 knockout (Prdx6 cKO) mice, an ALI model was induced via intratracheal administration of LPS. The severity of ALI, PRDX6 expression levels and localization were assessed. Cell lines with PRDX6 knockdown, mutation and reconstitution were utilized to investigate changes in mitophagy. Seahorse analysis was performed to assess the impact of PRDX6 on mitochondrial energy metabolism. <bold>Results:</bold> Prdx6 cKO mice show a severe ALI compared to WT mice, with a higher mortality. There is a notable reduction in autophagosome formation and inhibition of mitophagy in Prdx6 cKO mice. In vitro experiments demonstrate that cell viability and mitochondrial energy metabolism decreases after PRDX6 knockdown, accompanied by decreased expression of PINK1, p-Ub, and LC3II/I. However, these effects are reversed upon reconstitution of PRDX6 in cells. Finally, we find that PRDX6 phosphorylation activity is a crucial regulatory point for mitophagy and energy metabolism, as evidenced by significantly reduced levels of PINK1 phosphorylation and impaired mitochondrial oxidative phosphorylation capacity in PRDX6 T177A cells. <bold>Conclusions:</bold>PRDX6 can activate mitophagy by enhancing PINK1 phosphorylation and simultaneously enhance mitochondrial oxidative phosphorylation to protect against ALI.