Phospholipase D is important in Der f 2 induced expression of IL-8 and IL-13 in human bronchial epithelial cells

초록

The purpose of this study was to identify the role of PLD in Der f 2 induced IL-8 and IL-13 expression. The major house dust mite allergen, Der f 2, stimulates the PLD in human bronchial epithelial cell line (BEAS-2B). PLD activity was increased within 5 min after exposure of Der f 2. The well-known PLD activator PKC-α was found to be translocated to membrane from cytosol in Der f 2 treated BEAS-2B cells. To determine whether the effects of Der f 2 on PLD occurred as a consequence of PKC activation, BEAS-2B cells were pretreated for 30 min with PKC inhibitor (RO320432). RO320432 reduced the effects of Der f 2 induced PLD activation suggesting that PKC-α acts as upstream activator of PLD in Der f 2 treated BEAS-2B cells. Also, the p38 MAPK inhibitor (SB203580) prevented PLD activation. Der f 2 enhanced IL-8 and IL-13 expressions in BEAS-2B cells. We found that the expressions of IL-8 and IL-13 were increased when PLDs were activated with Der f 2 in BEAS-2B cells. To confirm the role of PLD in IL-8 and IL-13 expression, we transfected the PLD1 and PLD2, and their dominant negative forms. Interestingly, we found that only PLD1, not PLD2, overexpressed IL-8 and IL-13. These results indicate that Der f 2 might activate PLD through PKC-α activation and p38 MAPK phosphorylation which induces IL-8 and IL-13 expression in BEAS-2B cells