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

Figure 1

PGE2 suppresses eosinophilopoiesis by activating a caspase-dependent mechanism. Bone-marrow cultures were established in the presence of IL-5, alone or associated with PGE2, caspase inhibitor zVAD-fmk, or both. All cultures were maintained for 7 days, except for (b). All agents were added at the beginning of the culture, except for (c). Data (mean + SEM; 𝑛=3) are the numbers of EPO+ cells recovered at the end of the culture ((a)–(c)) or the % eosinophilopoiesis suppression in the indicated conditions, where inhibitors were used to prevent this suppression (d). Significant differences relative to the respective IL-5 controls: ^∗𝑃≤0.05, ^∗∗𝑃≤0.01, ^§𝑃≤0.005, ^#𝑃≤0.0025.

(a)

(b)

(c)

(d)