Role of Phospholipase D1 in production of IL-13 through PLC γ/PKC α/p38 MAPK pathway induced by Der f 2 in BEAS-2B cells

초록

The purpose of this study was to identify the role of PLD1 in Der f 2-induced IL-13 production. PLD activity was increased within 30 min after exposure of Der f 2, the major house dust mite allergen, in a human bronchial epithelial cell line (BEAS-2B). Der f 2 treatment activated phospholipase Cγ (PLCγ) / protein kinase Cα (PKCα) / p38 MAPK pathway. Der f 2-induced PLD activation was attenuated by PLCγ inhibitor (U73122), PKCα inhibitor (Ro320432), and p38 MAPK inhibitor (SB203580). These results indicated that PLCγ, PKCα, and p38 MAPK act as upstream activators of PLD in Der f 2-treated BEAS-2B cells. Furthermore, expression and production of IL-13 increased by Der f 2 were blocked by inhibition of PLCγ, PKCα, and p38 MAPK, respectively. The results suggest that IL-13 expression and production were related to a PLCγ / PKCα / p38 MAPK pathway. When we blocked PLD1 activity with PLD1 siRNA, Der f 2-induced IL-13 expression and production were decreased, suggesting that PLD1 was also involved in the production of IL-13. Moreover, we detected activation of ATF-2 in Der f 2 treated BEAS-2B cells. To confirm the involvement of ATF-2 in IL-13 expression and production, cells were transfected with ATF-2 siRNA. Knockdown of ATF-2 blocked the expression and production of IL-13 induced by Der f 2 treatment. Thus, ATF-2 might be one of the transcriptional factors for the expression of IL-13 in Der f 2 treated BEAS-2B cells. Taken together, PLD1 acts as an important regulator in Der f 2-induced expression and production of IL-13 through a PLCγ / PKCα / p38 MAPK pathway.