Fig. 5

Characterization of murine and porcine SMIS. A Analysis of the surface of the murine SMIS, implementing embryonic fibroblasts (3T3) and epithelial cells (CMT-93) by scanning electron microscopy at two different magnifications. Higher magnification images identify membrane protrusions. Scale bar of the upper image indicates 2 µm while the lower displays 200 nm. B Immunostaining of superior and medial z-stack projections of murine spheroids consisting of a primary colonic myofibroblast (pMF) core (vimentin, green) and intestinal epithelial cells (CMT-93, CTNNB1, red). Nuclei are stained blue. C TEMs display the surface of the spheroids consisting of murine primary intestinal myofibroblasts (pMF) and epithelial cells (CMT-93) to identify membrane protrusions proving ordered microvilli formation. Scale bars of the upper image indicate 500 nm and of the lower image 200 nm. D Representative images of superior and medial z-stack projections of porcine SMIS. Localization of primary colonic fibroblasts is shown by immunostaining using vimentin (green) whereas epithelial cells by adherens junctions (IPEC-J2, CTNNB1, red). Scale bars indicate 100 µm. For green immunostaining DyLight 488 and for red staining DyLight 594 was used, whereas cell-nuclei were stained blue by DAPI in all IFs. Exposure time was identical for all spheroids and presented images are representative for three biological replicates tested