Mitomycin induced the senescence of alveolar epithelial cells by targeting peroxiredoxin I

The senescence of alveolar epithelial cells is one of the characteristics of mitomycin pulmonary toxicity, but the direct target of mitomycin-induced alveolar epithelial cell senescence remains unclear. In this study, a method of small-molecule ligand–protein interaction by pulldown/mass spectrometry identified peroxiredoxin I (Prdx I) as the target of mitomycin-induced alveolar epithelial cell senescence, and mitomycin was shown to significantly inhibit the peroxidase activity of Prdx I. Consequently, the levels of cellular reactive oxygen species (ROS) increased, leading to the activation of mitogen-activated protein kinase kinase 1/2 (MEK1/2)-extracellular signal-regulated protein kinases 1/2 (ERK 1/2) and, accordingly, to the increased expression of p53. Both a Prdx I activator and Prdx I overexpression alleviated mitomycin-induced alveolar cell senescence. A ROS scavenger inhibited MEK1/2-ERK1/2-p53 activation and then attenuated the senescence of alveolar epithelial cells triggered by mitomycin. Thus, Prdx I can serve as the first target of mitomycin-induced alveolar epithelial cell senescence, which might represent a promising approach to reduce mitomycin-induced lung toxicity.