Paracrine signals regulate human liver organoid maturation from iPSC

Abstract

A self-organizing organoid model provides a new approach to study the mechanism of human liver organogenesis. Previous animal models documented that simultaneous paracrine signaling and cell-to-cell surface contact regulate hepatocyte differentiation. To dissect the relative contributions of the paracrine effects, we first established a liver organoid using human induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs) and human umbilical vein endothelial cells (HUVECs) as previously reported. Time-lapse imaging showed that hepatic-specified endoderm iPSCs (HE-iPSCs) self-assembled into three-dimensional organoids, resulting in hepatic gene induction. Progressive differentiation was demonstrated by hepatic protein production after organoid transplantation. To assess the paracrine contributions, we employed a Transwell system in which HE-iPSCs were separately co-cultured with MSCs and/or HUVECs. Although the three-dimensional structure did not form, their soluble factors induced a hepatocyte-like phenotype in HE-iPSCs, resulting in the expression of bile salt export pump. In conclusion, the mesoderm-derived paracrine signals promote hepatocyte maturation in liver organoids, but organoid self-organization requires cell-to-cell surface contact. Our model demonstrates a novel approach to identify developmental paracrine signals regulating the differentiation of human hepatocytes.

Generating Embryonic Salivary Gland Organoids

“…Mixed cell populations from multiple tissue sources formed organoids capable of self-organizing and differentiating in culture and during in vivo implantation. It has also been shown that many organoids contain mesenchyme, particularly embryonic and induced pluripotent stem cell-derived organoids (Asai et al, 2017;Dye et al, 2015;Hegab et al, 2015;McQualter, Yuen, Williams, & Bertoncello, 2010;Mondrinos, Koutzaki, Lelkes, & Finck, 2007;Nikolić & Rawlins, 2017;Shamir & Ewald, 2014;Spence et al, 2011;Takebe et al, 2013Takebe et al, , 2017Tan, Choi, Sicard, & Tschumperlin, 2017;Teisanu et al, 2011). Fibroblasts have been shown to be critical in providing niche factors for stem cells and organoid survival in the intestine (Pastuła et al, 2016).…”

Biliary Atresia: Clinical and Research Challenges for the Twenty‐First Century

“…reconstruction. Finally, cutting-edge technologies to craft organoids from hepatocytes, cholangiocytes, and various stromal cells may be powerful future strategies to model human disease, develop cell-based therapies, and test therapeutic agents (54)(55)(56)(57). …”

Organoid Medicine in Hepatology

“…The details of hepatic differentiation protocols were reviewed recently . We reported a complex method to generate liver organoids from iPSCs by coculturing with vascular stem cells and mesenchymal stem cells . In this method, iPSCs were separately differentiated into the endoderm, endothelial cells, and mesenchymal cells in 2D culture dish, followed by dissociation and mix‐culture.…”

“…The mesenchymal cells (fibroblasts and vascular endothelial cells) dynamically interact with differentiating hepatocyte‐like cells by supplying potent growth factors to promote further differentiation and provide an extracellular microenvironment to support the integrity of organoids . These minor populations of mesenchymal cells are essential for creating a differentiating niche and are important in mimicking the complexity of the liver.…”