The present invention relates to a novel method for multi-target-directed inducing direct differentiation of human stem cells, such as human embryonic stem cells (ES cells) or induced pluripotent stem cells (iPS cells), into hepatocytes using combinations of small molecules. The present invention discloses a medium and a culturing method for inducing directed differentiation of human stem cells into hepatocytes directly. In the method of the present invention, no exogenous genes are need to be introduced into stem cells, no stepwise induction is needed, various cell growth factors are not needed, and directed differentiation of human stem cells into hepatocytes directly can be achieved using only small chemical molecules. The differentiated human hepatocytes obtained have the typical characteristics of human hepatocytes, the differentiated liver precursor cells can be passaged for a long period of time, and the differentiated liver mature cells can be passaged for a limited number of times. Moreover, the method uses a conventional culturing procedure with simple operation, low cost, safety and stability.

The present invention provides embryonic stem cells obtained from an embryo of a mouse engineered to replace all or some of domains in the mouse MHC class I molecule H2-D with domains from the human MHC class I molecule HLA-A by culture in the presence of a GSK3 inhibitor and an MEK inhibitor, as well as a mouse which is created with the use of these embryonic stem cells.

Human pluripotent stem cells (hPSCs) are a concrete source of hepatic cells for regenerative medicine applications and are largely contributing to the study of liver diseases, toxicity, and drug efficacy. However, hP SC-derived hepatocyte-like cells possess morphological and functional features typical of foetal hepatocytes rather than post-natal or adult hepatocytes. By self-assembling hepatic progenitors into spheroids and by refining the maturation step of their differentiation protocol, the inventors aim at generating hPSC-derived hepatocyte-like cells with an improved maturation degree, showing morphological and functional features of adult hepatocytes. More particularly, they adjusted the morphogen cocktail used for the maturation step by the regular administration of vitamin Kl, a daily regulation of glucocorticoid supply, and a progressive decrease of Oncostatin M (OSM) supply in the last days. They demonstrated that the hepatocytes produced with their protocol have reached the highly functional ability of primary human hepatocytes, an improved maturation stage compared to previously reported data on hPSC-derived hepatocytes. Thus the invention relates to a new method for improving the differentiation of hepatoblasts into hepatocytes.

Provided is an isolated population of human pluripotent stem cells comprising at least 50% human pluripotent stem cells characterized by an OCT4+/TRA1-60?/TRA1-81?/SSEA1+/SSEA4? expression signature, and novel methods of generating and maintaining same in a pluripotent, undifferentiated state a suspension culture devoid of cell clumps. Also provided are novel culture media, cell cultures and methods for culturing pluripotent stem cells in a suspension culture or a two-dimensional culture system while maintaining the cells in a proliferative, pluripotent and undifferentiated state. The novel culture media comprise interleukin 11 (IL11) and Ciliary Neurotrophic Factor (CNTF); bFGF at a concentration of at least 50 ng/ml and an IL6RIL6 chimera; or an animal contaminant-free serum replacement and an IL6RIL6 chimera. Also provided are methods for generating lineage-specific cells from the pluripotent stem cells.

Provided is a selective method for inducing differentiation from pluripotent stem cells to enterocyte-like cells. Also provided is an excellent enterocyte-like cell expressing drug-metabolizing enzymes and drug transporters. More specifically, provided is an enterocyte-like cell having properties closer to those of primary enterocytes, which are difficult to acquire. The foregoing is achieved by adding an ALK5 inhibitor (SB431542), Wnt3a, and EGF to a culture system of definitive endoderm cells obtained by differentiation induction from pluripotent stem cells and extending a culture time. The foregoing is also achieved by introducing CDX2 gene and/or FOXA2 gene into the pluripotent stem cells or the definitive endoderm cells. The foregoing is also achieved by overlaying a basement membrane matrix on the enterocyte-like cells.

Provided herein are methods of producing three-dimensional (3-D) microtissue from a starting cell suspension of pluripotent stem cell (PSC)-derived hepatocytes. Such a method may comprise supplementing the cell suspension with cell adhesion-promoting components and culturing the PSC-derived hepatocytes on a non-adhesive surface to produce the microtissue.

This disclosure provides an improved system for culturing human pluripotent stem cells. Traditionally, pluripotent stem cells are cultured on a layer of feeder cells (such as mouse embryonic fibroblasts) to prevent them from differentiating. In the system described here, the role of feeder cells is replaced by components added to the culture environment that support rapid proliferation without differentiation. Effective features are a suitable support structure for the cells, and an effective medium that can be added fresh to the culture without being preconditioned by another cell type. Culturing human embryonic stem cells in fresh medium according to this invention causes the cells to expand surprisingly rapidly, while retaining the ability to differentiate into cells representing all three embryonic germ layers. This new culture system allows for bulk proliferation of pPS cells for commercial production of important products for use in drug screening and human therapy.

Methods for producing hepatocyte and/or cholangiocyte lineage cells from pluripotent stem cells, the method comprising (a) specifying the extended nodal agonist treated induced endodermal cell population to obtain a cell population comprising hepatocyte and/or cholangiocyte progenitors by contacting the extended nodal agonist treated induced endodermal cell population with specification media comprising a FGF agonist and a BMP4 agonist and/or active conjugates and/or fragments thereof; (b) inducing maturation, and optionally further lineage specification and/or expansion of the hepatocyte and/or cholangiocyte progenitors of the cell population to obtain a population comprising hepatocyte lineage cells such as hepatoblasts, hepatocytes and/or cholangiocytes, the inducing maturation step comprising generating aggregates of the cell population. Optionally, the method also comprises activating the cAMP pathway within the aggregates and forming co-aggregates.

Factors for extending the ability of isolated pluripotent stem cells to generate extraembryonic lineages in vivo, following in vitro culture, herein, chemical extenders of pluripotency (CEP). Methods of extending the ability of a pluripotent cell to generate embryonic and extraembryonic lineages. The cell to be reprogrammed is contacted with effective amounts of the CEPs for a sufficient period of time to reprogram the cell into a chemically induced extended pluripotent cell (ciEPSC). ciEPSC are identified as an extended pluripotent cell based on properties including: (i) morphologically and (ii) functionally for example, based on their ability contribute to both TE and ICM, in vivo. The ciEPSCs can be cultured or induced to differentiate into cells of a desired type, and used in a number of applications, including but not limited to cell therapy and tissue engineering.

Methods are provided for producing a population of hepatocyte-like cells (iHeps) from a population of adipocyte-derived stem cells (ASCs). Aspects of the methods include placing a population of ASCs into a three dimensional culture (e.g., hanging drop suspension culture, high density culture, spinner flask culture, microcarrier culture, etc.), and contacting the cells with a first and second culture medium. Also provided are methods of treating an individual, which include producing a population of iHeps from a population of ASCs, and administering an effective number of iHeps into the individual. Kits for practicing the methods are also described herein.