Fig. 4.
PKC does not regulate in vitro nSMase2 activity in A549 cells. A, A549 cells with (■) and without (○) nSMase2 overexpression were stimulated with PMA (100 nM) for 0 to 60 min (*, P < 0.05, n = 5). B, A549 cells were transfected with negative control (Scr), PKC-δ or -ε siRNA (20 nM) for 48 to 60 h before stimulation with TNF for 5 min (*, P < 0.05, n = 4). In vitro N-SMase activity was measured as described under Materials and Methods.