The PI3K/AKT/mTOR pathway regulates autophagy to induce apoptosis of alveolar epithelial cells in chronic obstructive pulmonary disease caused by PM2.5 particulate matter.

OBJECTIVE

Many lung diseases are associated with changes in autophagic activity. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway plays a key regulatory role in autophagy. Our aim was to explore the function of PI3K/AKT/mTOR pathway on autophagy in chronic obstructive pulmonary disease (COPD) caused by particulate matter with a diameter <2.5 µm (PM2.5).

METHODS

Male C57BL/6 mice were randomly divided into sham, model, and PI3K inhibitor groups. Mice were exposed to PM2.5 for 4 weeks to establish an COPD model. Alveolar epithelial cells were stimulated with PM2.5 to establish an COPD model.

RESULTS

In mice with COPD induced by PM2.5, the PI3K inhibitor PF-04979064 suppressed protein expression of PI3K, p-AKT, and p-mTOR to increase apoptosis of alveolar epithelial cells and reduce autophagy. Short interfering PI3K suppressed the PI3K/AKT/mTOR pathway to induce apoptosis and reduce autophagy of alveolar epithelial cells in an model of COPD. Activation of PI3K induced the PI3K/AKT/mTOR pathway to reduce apoptosis of alveolar epithelial cells in the model of COPD by promoting autophagy.

CONCLUSIONS

These data demonstrate that PI3K/AKT/mTOR pathway regulates autophagy to induce apoptosis of alveolar epithelial cells in COPD.