Figure 6.

Csf1r is a downstream target of C/EBPβ. (A) Schematic illustration of the Csf1r reporter vector containing the promoter region and FIRE. Open circles indicate the consensus binding sites for C/EBPβ. (B) Activity of the luciferase reporter gene under the control of a combination of the promoter and FIRE of the Csf1r gene in response to different amounts of the C/EBPβ expression vector (0, 1, 5, and 10 ng) (n = 4). Open circles indicate the consensus binding sites for C/EBPβ, and closed circles indicate sites that were mutated to disrupt the binding of C/EBPβ. Data are representative of 2 independent experiments. (C-D) mRNA (C) and surface (D) expression of Csf1r (CD115) in EML cells that were engineered to express ER alone or ER fused to C/EBPβ. 4-OHT, 4-hydroxytamoxifen. Shaded histograms indicate isotype controls. Data are representative of 3 independent experiments. (E) ChIP-PCR to analyze the direct binding of C/EBPβ to the promoter and FIRE region in the Csf1r locus (n = 2). EML cells expressing C/EBPβ-ER were used for this analysis. Data are representative of 2 independent experiments and are presented as mean ± SD. (F) ChIP analysis showing binding of C/EBPβ to the mouse Csf1r locus in monocyte-derived cells. Data were taken from a study by Bornstein et al.⁴⁰ Red arrows indicate promoter (Prom) and FIRE regions. IgG, immunoglobulin G.