Fig. 5.
Effect of rolipram/forskolin in CLL heavy-membrane fractions.
Rolipram/forskolin treatment reduces Bad Ser112 phosphorylation and association with 14-3-3 and augments Bad levels in CLL heavy-membrane fractions. (A) CLL cells were incubated with 10 μM rolipram and 40 μM forskolin (R/F) for the indicated period of time, followed by isolation of membrane-rich fractions (heavy-membrane) and immunoblotting for Bcl-2, Bcl-XL, Bax, or Bad as indicated. The “0” time point refers to culture for 18 hours in media with vehicle control alone. (B) CLL cells were cultured for 18 hours either with media (0) or 40 μM forskolin combined with the indicated concentration of rolipram, followed by analysis as for panel A. (C) CLL cells were cultured in media (CT) or 10 μM rolipram and 40 μM forskolin (R/F) for 18 hours. (Top) Whole-cell lysates (WCL)or Bad immunoprecipitates were immunoblotted with an antibody specific for phospho-Bad Ser112. (Middle) Treated as for top panel, but immunoblotted for 14-3-3. (Bottom) Treated as for top panel, but immunoblotted for Bad. Similar results were obtained in 3 of 5 CLL patients. At least 2 experiments were performed for each patient.