Fig. 4.
Expression analysis of Wnt/β-catenin target genes, CD44 and EphB2, in the gastrointestinal tract of Ad Dkk1- or Ad Fc-treated adult C57BL/6 mice (12–16 weeks old). Organs were harvested 2 days after Ad Dkk1 i.v injection (109 pfu). (Left) Ad Dkk1 repression of CD44 expression in proliferative zones of all levels of the gastrointestinal epithelium. Arrowheads indicate the absence of CD44 immunoreactivity in proliferative compartments of the intestinal epithelium in Ad Dkk1 animals. *, residual CD44 staining in nonepithelial lamina propria. (Right) Ad Dkk1 repression of EphB2 in small intestine and colon. Repression was weaker in ascending colon and no repression was observed in stomach. EphB2 immunofluorescence was performed with Alexa 488 detection of EphB2 immunoreactivity (green) and Hoechst 33342 nuclear counterstain (blue). Stomach (st), duodenum (du), jejunum (je), ileum (il), cecum (ce), ascending colon (ac), and descending colon (dc) are shown.