E‑Cigarette Aerosols Trigger Mitochondrial Dysfunction-Associated Ferroptosis in Human Primary ATII Cells.

BACKGROUND

E‑cigarettes contain nicotine and flavoring compounds. They can disrupt mitochondrial homeostasis, injure the alveolar epithelium, and ultimately contribute to lung dysfunction.

METHODS

To investigate the systemic response, plasma was obtained from e-cigarette users. Mitochondrial DNA damage was detected, suggesting that vaping alters cell physiology. ATII cells are highly abundant in mitochondria and dependent on their integrity for surfactant production and alveolar epithelial regeneration. ATII cells and PCLS were obtained from organ donors to examine the effects of cinnamon roll-flavored e-cigarette aerosols with nicotine.

RESULTS

E-cigarette aerosols induced mitochondrial DNA damage and lipid peroxidation, as indicated by elevated MitoCLox levels. Additionally, reduced levels of mitochondrial respiratory chain subunits NDUFS1 and UQCRC2 were detected in ATII cells, suggesting disruption of complexes I and III, respectively. A similar decrease was observed in ATII cells in wild-type mice after treatment with cinnamon roll-flavored e-cigarette aerosols with nicotine. Furthermore, increased LAMP2 and LC3B levels were found, indicating autophagy. This response was accompanied by decreased GPX4 and increased ACSL4 protein expression, a molecular signature characteristic of ferroptosis. The role of DJ-1 was analyzed following this exposure, as it is localized in mitochondria. ATII cells in DJ-1 KO mice had reduced SP-C expression. Also, DJ-1 deficiency in cells led to increased mitochondrial superoxide production, suggesting a cytoprotective function for DJ-1.

CONCLUSIONS

These findings demonstrate that cinnamon roll-flavored e-cigarette aerosols with nicotine disrupt mitochondrial function, alter cytosol-mitochondria crosstalk, and induce ATII cell ferroptosis as a mechanism of vaping-associated lung injury.