Directed differentiation of human embryonic stem cells to colon organoids as a model of development in an obesogenic environment

Early life exposures play a significant role in shaping health and disease susceptibility. Maternal obesity influences the offspring’s long-term risk of colorectal cancer, yet our understanding of the impact on developmental programming of intestinal stem cells and later risk of colorectal cancer remains limited. This has highlighted the growing need for a model that studies the influence of the maternal environment on the developing colon. Our goal is to optimize a platform that generates human colon organoids (HCOs) from embryonic stem cells (hESCs) reliably and reproducibly and use it as a model to study colonic developmental patterning in an obesogenic environment. The organoids are derived by multi-step directed differentiation trajectory of embryonic stem cells, definitive endoderm, mid/hind gut, to fetal colon. We optimized the protocol to ensure consistent production of colonic organoids in contrast to small intestinal or urothelial cells which follow similar differentiation paths. To model an obesogenic environment on our platform, we are leveraging both intrinsic and extrinsic properties of the developing colon: 1) pharmacologically activating the transcription factor Peroxisome Proliferator-Activated Receptors Delta (PPARd) to mimic the cell-autonomous response to a pro-obesity maternal high fat diet, and 2) exposing the developing colon organoids to pro-inflammatory cytokine IL-17 to mimic the pre-pathological inflammatory state. With administration of PPARd agonist GW501516, we observe an increase in all differentiated cell types and intestinal stem cells, thereby stimulating maturation of the organoids. Additionally, IL-17 administration induced a significant increase in the secretory cell populations with concomitant upregulation of secretory lineage master regulator Atoh1, indicating that IL-17 signaling promotes a lineage bias in human colon organoids, altering cell fate. Thus far, our hESC-to-HCO model demonstrates the utility of ESC-derived organoids in studying the impact of maternal environmental factors on colonic development, generating a platform to explore factors that affect human development and maturation.