Characterization of mechanism for anti-apoptotic effect against Jo2 by phospholipase D2 in A20 murine B lymphoma cell lines

초록

The effect of anti-Fas mAb on phospholipase D activities in wild type A20 cells, PLD2 transfectant and Fas-resistant cell clones were tested. Basal PLD activities of Fas-resistant clone and PLD2 transfectant were about 2-3 times higher than that of wild type A20 cells. PLD2 was overexpressed in Fas-resistant clone and PLD2 transfectant cells compared to wild type cells but the expression level of PLD1 was not different between Fas-resistant clone and wild type cells, suggesting that PLD2 overexpression is responsible for the increase of basal PLD activity observed in Fas-resistant clone. The Bcl-2 expression in wild type A20 cells was not detectable, where as the expression level of Bcl-2 in Fas-resistant clone, PLD2 transfectant and PA pretreated A20 cells were shown to be very high. When the PLD2 cDNA was transfected into wild type A20 cells, we found increased PLD2 activation and Bcl-2 expression as well as suppressed Fas-induced apoptosis. Exogenous pretreatment of PA to wild type cells showed increased Bcl-2 expression and attenuated Fas-induced apoptosis. Therefore, PA production induced by PLD2 might affect both in Bcl-2 expression and apoptosis induced by Fas activation.