C/EBPs induce clusterin.

<p><b>A</b>) C/EBPβ is up-regulated in the αGSU.<i>PTTG</i> pituitary. Confocal image showing C/EBPβ co-localization with αGSU-positive, GH-positive and PRL-positive cells in WT and pre-tumorous αGSU.<i>PTTG</i> pituitary glands. (Hormones-green, cytoplsmic, C/EBPβ–red, intranuclear); <b>B</b>) Western blot analysis of C/EBPβ and δ isoforms induced in LβT2 cells stably transfected with m<i>Pttg</i>; <b>C</b>) Effects of C/EBPs on the clusterin promoter in LβT2 and αT3 cells 24 h after transfection. Cells were co-transfected with 200 ng murine pGL3-luc-m<i>Clu</i> reporter plasmid and 800 ng murine pCDNA3-C/EBPα, β or δ. The ratio of luciferase to co-trasfected β-galactosidase control reporter vector was normalized to pCDNA3-null expression vector. SEM was calculated from triplicate assays, and experiments repeated three times with similar results. Results of a representative experiment are shown.*, p<0.05, **,p<0.01; <b>D</b>) Western blot analysis of clusterin expression in gonadotroph-derived αT3 cells 24 hours after transfection with pCDNA3-C/EBPβ or <b>E</b>) pCDNA3-C/EBPδ; <b>F</b>) Western blot analysis of clusterin expression in LβT2 mPttg cells 48 hours after simultaneous transfection with siC/EBPβ and siC/EBPδ (3 nM each). Two different combinations of siRNAs were used.