Phospholipase A2 stimulates rat gastric epithelial cell line (RGM-1) migration

Abstract.

Objective and Methods: The effect of phospholipase A₂ (PLA₂) and its phospholipid metabolites on gastric epithelial migration was examined using an in vitro wounding model of confluent monolayers of rat gastric epithelial cell line RGM-1. ¶Results: Lysophosphatidylcholine (lysoPC) (0.01–100 ng/ml) as well as PLA₂ (0.01–100 mU/ml) dose-dependently increased the cell migration. Lysophosphatidic acid (10 ng/ml) also increased the migration, but no significant increase in migration was observed when stimulated by lysophosphatidylethanolamine (10 ng/ml) or lysophosphatidylserine (10 ng/ml). Addition of 4-bromophenacyl bromide (BPB), a PLA₂ inhibitor, completely blocked the effect of PLA₂. However, addition of piroxicam (a cyclooxygenase inhibitor) or nordihydroguaiaretic acid (a lipoxygenase inhibitor) had no significant effect. Combination of PLA₂ (10 mU/ml) with lysoPC (10 ng/ml) had no additive effect on migration. Moreover, lysoPC levels were increased in the cells after incubation with PLA₂ (10 mU/ml). After pretreatment of RGM-1 cells with replication-inhibiting doses of mitomycin C, PLA₂ and lysoPC still increased the cell migration. ¶Conclusions: These data suggest that PLA₂ may, independently of proliferation, increase gastric epithelial migration mainly via lysoPC production.