Phospholipase A2 stimulation of rat intestinal epithelial cell (IEC-6) migration

The effect of phospholipase A2 (PLA2) on intestinal epithelial cell migration was investigated using an in vitro wounding model of confluent monolayers of IEC-6. PLA2 (0.001-2 U/ml) enhanced IEC-6 cell migration in a dose dependent manner. Addition of 4-bromophenacyl bromide (BPB) (a PLA2 inhibitor) to PLA2 completely blocked the migration-promoting effect. However, addition of piroxicam (a cyclooxygenase inhibitor) or nordihydroguaiaretic acid (a lipoxygenase inhibitor) had no influence on the effect. Lysophosphatidylcholine (lysoPC) (0.01-5,000 ng/ml), one of the products of phosphatidylcholine by PLA2, dose-dependently enhanced IEC-6 cell migration as well. A combination of PsLA2 (1 U/ml) and lysoPC (1,000 ng/ml) had no additive effect or migration. Moreover, the migration-promoting effect of PLA2 that was blocked by BPB was recovered by lysoPC. After pretreatment of IEC-6 cells with replication-inhibiting doses of mitomycin C, the enhanced migration induced by PLA2 or lysoPC was still observed. These observations suggest that PLA2 may, independently of proliferation, enhance intestinal epithelial cell migration mainly via lysoPC.