Generation of gastrointestinal organoids derived from human pluripotent stem cells

Abstract

Over the past two decades, the stem cell field has developed methods to differentiate human pluripotent stem cells (hPSCs) into specific tissue types. These studies have been largely driven by developmental biologists who have identified pathways and tissue-specific markers that can be used to direct the differentiation of hPSCs. Furthermore, the identification of Lgr5+ adult stem cells in the mouse small intestine led to the development of protocols to grow these stem cells into self-organizing, self-renewing, multicellular “organoids." PSC-derived and adult organoids derived from human samples now allow researchers to study cell lineage processes and model complex cell-cell interactions. Both PSC-derived gastrointestinal organoids and those generated from freshly excised tissue have many properties of gastrointestinal physiology. However, PSC-derived gastrointestinal organoids are generated through a stepwise differentiation that largely mimics gastrointestinal development and is therefore a good system to study congenital defects of the human GI tract. Moreover, PSC-derived organoids are complex and contain mesodermal cell types comprising smooth muscle and subepithelial myofibroblasts. Lastly, developmentally inspired approaches have been used to tissue engineer human PSC-derived organoids with a functional enteric nervous system. In this chapter we describe the development of both the intestine and stomach. We then describe how pathways identified by developmental studies can be used to direct the differentiation of pluripotent stem cells into human intestinal organoids (HIOs) and human gastric organoids (HGOs). In addition, we discuss potential applications of these systems for studying human gastrointestinal development and disease and in engineering GI tissues for eventual transplantation-based therapies.