Phospholipase D participates in H₂O₂-induced A549 alveolar epithelial cell migration

ABSTRACT

To investigate the effects of phospholipase D (PLD) on low-concentration hydrogen peroxide (H₂O₂)-induced growth and migration in alveolar epithelial A549 cells, the cells were exposed to H₂O₂ (3–100 μM) for 12–48 hours, cell proliferation was determined by MTT assay and cell migration was tested by a modified epithelial wound healing assay. We found that one bolus of H₂O₂ (10–100 μM) did not affect proliferation, but significantly stimulated migration (143–161% of control) after a 12-hour exposure. Pretreatment with the antioxidants catalase (1000 U/ml), N-acetyl-cysteine (2 mM), or edaravone (10 μM) abolished the migration induced by 30 μM H₂O₂; the PLD inhibitor 1-butanol (0.5%) also attenuated H₂O₂-induced migration to the control level; while exogenous phosphatidic acid (PA) (10⁻⁷–10⁻⁴ M) mimicked the effects of PLD activation and induced migration in a dose-dependent manner. We suggest that the alveolar epithelial cell migration induced by exposure to low concentrations of H₂O₂ benefits tissue repair during acute lung injury (ALI) and PLD is involved in the underlying mechanism.

KEYWORDS :

• A549 cell
• acute lung injury
• hydrogen peroxide
• migration
• phospholipase D