GILZ mediates GC-induced B-cell apoptosis. (A) Number of cells in the BM of 8- to 12-week-old WT and gilz KO mice untreated or treated with Dex 3 mg/kg intraperitoneally (i.p.) for 3 days (n = 5/7). (B-D) Frequency of B220⁺ cells (B), B220⁺Ki67⁺ cells (C) and B220⁺AnnexV⁺ cells (D) isolated from the BM of WT and KO mice untreated or treated with Dex 3 mg/kg i.p. for 3 days (n = 5/7). (E) WB analysis of cleaved caspase 3 expression in purified B cells isolated from WT and gilz KO mice treated or not with Dex. The same number of cells was loaded; WB with β-tubulin antibodies served as loading control. (F) qPCR analysis of Bcl2 and Bim mRNA expression in purified B cells isolated from WT and gilz KO mice treated or not with Dex (n = 8/10). (G-K) Frequency of Caspase⁺ cells on PreProB cells (G), ProB cells (H), PreB cells (I), immature B cells (J), and mature B cells (K) isolated from BM of WT and KO mice untreated or treated with Dex (n = 9/12). (L) Chromatin IP assay of NF-κB binding on proximal promoter of Bcl2 in purified B cells of WT and gilz KO mice treated or not with Dex. Cell lysates were immunoprecipitated with anti–NF-κB or control IgG, and the presence of specific regions in the immunoprecipitates was determined by qPCR. CR indicates qPCR in a negative control region 2 kb upstream of the NF-κB binding site. Graphs represent mean ± SEM. Data are from 2 independent experiments. *P < .05, **P < .005, ***P < .0005.