Figure 2

Intestinal development and directed differentiation of human pluripotent stem cells into intestinal tissue in vitro. (a) Schematic representation of embryonic development of endodermal organs. Top panels: central events in intestinal development; arrows point to stages of neural crest development including migration to the gut, proliferation and differentiation into enteric nerves. (b) Comparison of mouse embryonic intestinal development in vivo (top) and human intestinal organoid development (bottom). To induce differentiation, pluripotent stem cells (PSCs) were cultured for 3 days in ActivinA (ActA) to form definitive endoderm (DE) co-expressing SOX17 and FOXA2. Fibroblast growth factor 4 (FGF4) and Wnt3a were used to direct the formation of three-dimensional (3D) hindgut spheroids expressing the posterior marker CDX2. Continued growth in a 3D matrix in epidermal growth factor (EGF), R-spondin and Noggin promoted the growth of intestinal progenitors into differentiated intestinal tissues expressing SOX9, KLF5, CDX2, and goblet cell markers (mucin). Human intestinal organoids had a well-formed brush border (villin) and microvilli similar to the adult mouse intestine. Figure adapted from Spence and colleagues [5]. E, epithelium; EM, electron micrograph; ICM, inner cell mass; M, mesenchyme.