Mitomycin induces alveolar epithelial cell senescence by down-regulating GSK3β signaling

Mitomycin treatment induces pulmonary toxicity, and alveolar epithelial cell senescence is crucial in the pathogenesis of the latter. However, the mechanism by which mitomycin induces alveolar epithelial cell senescence has yet to be elucidated. In this work, different doses (37.5-300 nM) of mitomycin induced the senescence of human alveolar type II-like epithelial cells and enhanced the phosphorylation of GSK3 beta (S9). The GSK3 beta (S9A) mutant reversed the senescence of mitomycin-treated alveolar epithelial cells. Pharmacological inhibition and gene deletion of Akt1, a kinase that regulates the phosphorylation of GSK3 beta (S9), suppressed mitomycin-induced alveolar epithelial cell senescence. The knockdown of p53, a downstream effector of GSK3 beta and an important regulator of cell senescence, repressed mitomycin-induced alveolar epithelial cell senescence. Treatment with baicalein weakened the phosphorylation of GSK3 beta (S9) and alleviated the senescence of alveolar epithelial cells brought about by mitomycin treatment. GSK3 beta (S9) phosphorylation appears to be the first signal involved in the mitomycin-induced senescence of alveolar epithelial cells and may present a potential target for attenuating mitomycin-induced pulmonary toxicity. (C) 2021 Elsevier B.V. All rights reserved.