G-CSF delays G6pc3^−/− neutrophil apoptosis by modulating apoptotic mediators. The annexin V–depleted BM neutrophils were isolated from 6- to 8-week-old unaffected (+/+, ○, ●) and G6pc3^−/− (−/−, Δ, ▴) littermates as described in “Neutrophil isolation.” (A) Western blot analysis of protein extracts of neutrophils using antibodies against Mcl-1, Bax, cleaved PARP, total GSK-3β, p-GSK-3β (Ser9), or β-actin. Each lane contains 50 μg protein. The relative protein levels of Mcl-1, Bax, cleaved PARP, total GSK-3β, or p-GSK-3β (Ser9) were quantified by densitometry of 3 or 4 separate pairs of Western blots. (B) Representative confocal microscopic analysis of Bax (green fluorescence), COX IV (red fluorescence, mitochondria), and DAPI nuclei (blue fluorescence) staining (original magnification ×1000). (C) Quantitative flow cytometric analysis of active caspase-9 and caspase-3 in neutrophils of untreated wild-type (○, ●) and G6pc3^−/− (Δ, ▴) mice in the absence (○, Δ) or presence (●, ▴) of G-CSF. Data are the mean ± SEM of 3 independent experiments. **P < .005. *P < .05.