Figure 1: C/EBPδ promotes HIF-1α expression in macrophages through inhibition of FBXW7α.

(a) RT–PCR analysis of FBXW7 isoform expression from different sources as follows. (1) primary peritoneal macrophages (PPMs); (2) RAW 264.7 cells; (3) MMTV-Neu mammary tumour tissue; (4) primary mouse embryo fibroblasts. Numbers indicate the position of size markers in base pairs. (b) RT–qPCR analysis of Fbxw7 transcript levels in PPMs from WT and Cebpd^−/− mice, cultured +/− LPS (100 ng ml⁻¹, 24 h), compared with WT untreated (n=4, *P<0.05; **P<0.001). (c) Western analysis of nuclear extract (NE) from primary human monocytes nucleofected with siRNA oligos (C, control; D, CEBPD; F, FBXW7) and treated with LPS (100 ng ml⁻¹) and 1%O₂ (16 h) as indicated. SE, short exposure; LE, long exposure. (d) RT–qPCR analysis of FBXW7 and CEBPD transcripts in primary human monocytes as in panel (c) (n=3, *P<0.05; **P<0.001). (e) Western analysis of NE from PPMs nucelofected with siRNA oligos and treated with LPS (100 ng ml⁻¹) and 1% O₂ for 16 h as indicated. SE, short exposure; LE, long exposure. Where applicable, data are mean±s.e.m., evaluated by two-tailed unequal variance t-test.