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.
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.