Epithelial-to-mesenchymal and mesenchymal-to-epithelial transitions in the colon

Figure 1 Schematic view of the effector pathways associated with epithelial-to-mesenchymal transition and mesenchymal-to-epithelial transition. EMT: Epithelial-to-mesenchymal transition; MET: Mesenchymal-to-epithelial transition; TGF-β: Transforming growth factor-β; MAPK: Mitogen-activated protein kinase; ERK: Extracellular signal-regulated kinase; MEK: MAPK/ERK kinase; MLCK: Myosin light chain kinase; ROCK: Rho-dependent protein kinase.

Figure 2 Chronic, fibrotizing phase of inflammatory bowel disease. The arrowed cytokeratin (CK) positive epithelial cells in a colonic crypt show α-smooth muscle actin (α-SMA) positivity. The initiation of the epithelial-to-mesenchymal transition is possible. (α-SMA: Red; CK: Green; nuclear counter-staining: Blue; fluorescence immunohistochemistry, taken by virtual microscope). DAPI: 4′,6′-diamidino-2-phenylindole hydrochloride.

Figure 3 Regenerative phase of ulcerative colitis. The arrowed α-SMA positive pericryptic cell shows cytokeratin (CK) expression. The presence of the mesenchymal-to-epithelial transition is possible. (α-SMA: Red; CK: Green; nuclear counter-staining: Blue; fluorescence immunohistochemistry, taken by virtual microscope). DAPI: 4′,6′-diamidino-2-phenylindole hydrochloride.