Figure 1.

Schematic representation of the double-dish culture system. A: Control culture. The epithelial cells are cultured on cell-free type I collagen gels. B: Reconstruction culture for gastric surface mucosa. Isolated gastric epithelial cells are maintained on fibroblast-containing collagen gel layer under immersion conditions. C: Effects of fibroblast-derived soluble factors on epithelial differentiation. Isolated epithelial cells are cultured on the cell-free collagen gel layer with conditioned medium elaborated by monolayer-cultured fibroblasts in the outer dish. D: Air-liquid interface (ALI) culture. The reconstructed gastric mucosa was treated with an ALI environment.