Essential Roles of PKA, iNOS, CD95/CD95L, and Terminal Caspases in Suppression of Eosinopoiesis by PGE2 and Other cAMP-Elevating Agents
Figure 3
Isoproterenol duplicates the effects of PGE2 by acting at different receptors in a caspase-dependent, flt3L/SCF-sensitive way. (a)–(c) Bone-marrow cultures were established in the presence of IL-5, alone or associated with PGE2, isoproterenol (Iso), caspase inhibitor zVAD-fmk (ZVAD), EP2 antagonist H6809, EP4 antagonist SC19220, or the indicated combinations of these agents, which were all present from the beginning of culture for a 7-day period. (d) Bone-marrow cultures were primed with flt3L-SCF [22] for 4 days and further cultured for 4 days with IL-5 alone or associated with PGE2 and Iso. Data (mean + SEM; in (a), remaining panels) are the numbers of EPO+ cells recovered at the end of the culture ((a), (c), and (d)) or the % eosinophilopoiesis suppression in the indicated conditions, where inhibitors were used to prevent this suppression (b). Significant differences relative to the respective IL-5 controls: , , , .
