Essential Roles of PKA, iNOS, CD95/CD95L, and Terminal Caspases in Suppression of Eosinopoiesis by PGE2 and Other cAMP-Elevating Agents

Figure 4

Isoproterenol and PGE2 share intracellular signaling mechanisms. Bone-marrow cultures were established in the presence of IL-5, alone or associated with adenylate cyclase inhibitor SQ22536 (a), PKA selective inhibitor H89 (b), PKC/PKA dual inhibitor Bis (c), or the indicated combinations of these agents, which were all present from the beginning of culture for a 7-day period. Data (mean + SEM; 𝑛=4) are the numbers of EPO+ cells recovered at the end of the culture (a) or the % eosinophilopoiesis suppression in the indicated conditions, where inhibitors were used to prevent this suppression ((b) and (c)). Significant differences relative to the respective IL-5 controls: ^∗𝑃≤0.05, ^∗∗𝑃≤0.01, ^§𝑃≤0.005, ^#𝑃≤0.0025.

(a)

(b)

(c)