Fig. 3.
Expression and localization of GREM1 and GREM2 by myofibroblast cells and smooth muscle cells at colon crypt. (A and B) In situ hybridization (ISH) for GREM1 (A) and GREM2 (B). Dark brown dots indicate positive staining. (C and D) Immunohistochemical staining of fibronectin (C) and α-smooth muscle actin (D) as markers for intestinal myofibroblasts as well as smooth muscle cells. Dark brown staining indicates positive staining. (E and F) Double labeling for GREM1 mRNA (E, red) and myofibroblast marker vimentin (F, green) at colon basal crypt region. (G) Combined image showing coexpression of GREM1 and vimentin (yellow dots indicated by white arrows) at scattered pericryptal mesenchymal cells corresponding to myofibroblasts. See SI Fig. 10 for the enlarged version of fluorescent ISH/immunostaining. (H) RT-PCR analysis of BMP antagonists expression in four intestinal myofibroblast isolates (CMF11, CMF7B, IMF11B, and 18Co) as well as three colon cancer cell lines (Caco-2, DLD-1, and HT29).