Mitomycin induces alveolar epithelial cell senescence by down-regulating GSK3β signaling
Xiafang Xu1, Xionghua Sun2, Xuelei Wan2
1College of Pharmaceutical Sciences, Soochow University, China; Shaoxing Maternity and Child Health Care Hospital, China.
Abstract:
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 GSK3β (S9). The GSK3β (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 GSK3β (S9), suppressed mitomycin-induced alveolar epithelial cell senescence. The knockdown of p53, a downstream effector of GSK3β and an important regulator of cell senescence, repressed mitomycin-induced alveolar epithelial cell senescence. Treatment with baicalein weakened the phosphorylation of GSK3β (S9) and alleviated the senescence of alveolar epithelial cells brought about by mitomycin treatment. GSK3β (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.
Insights
Mitomycin treatment causes lung damage by inducing alveolar epithelial cell senescence. Glycogen synthase kinase 3 beta (GSK3β) phosphorylation is identified as a key early step in this process.
Area of Science:
- Cellular Biology
- Toxicology
- Pulmonary Medicine
Background:
- Mitomycin treatment is known to cause pulmonary toxicity.
- Alveolar epithelial cell senescence plays a critical role in the development of this toxicity.
- The precise mechanisms underlying mitomycin-induced senescence remain unclear.
Purpose of the Study:
- To elucidate the mechanism by which mitomycin induces alveolar epithelial cell senescence.
- To investigate the role of Glycogen synthase kinase 3 beta (GSK3β) phosphorylation in this process.
- To identify potential therapeutic targets for mitigating mitomycin-induced pulmonary toxicity.
Main Methods:
- Human alveolar type II-like epithelial cells were treated with varying doses of mitomycin (37.5-300 nM).
- Investigated the phosphorylation status of GSK3β (S9) and utilized a GSK3β (S9A) mutant.
- Employed pharmacological inhibition and gene deletion of Akt1, and knockdown of p53.
- Assessed the effects of baicalein treatment on GSK3β phosphorylation and cell senescence.
Main Results:
- Mitomycin treatment induced senescence in alveolar epithelial cells and increased GSK3β (S9) phosphorylation.
- The GSK3β (S9A) mutant reversed mitomycin-induced senescence.
- Inhibition or deletion of Akt1, and knockdown of p53, suppressed mitomycin-induced senescence.
- Baicalein treatment reduced GSK3β (S9) phosphorylation and alleviated mitomycin-induced senescence.
Conclusions:
- GSK3β (S9) phosphorylation is an early signaling event in mitomycin-induced alveolar epithelial cell senescence.
- The Akt1/GSK3β/p53 pathway is implicated in this process.
- Targeting GSK3β phosphorylation may offer a strategy to attenuate mitomycin-induced pulmonary toxicity.
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