Provided herein are compositions and methods for generation of naive human pluripotent stem cells. The method comprises incubation of iPSCs under 5% O.sub.2 in a medium comprising 5% glucose, an MEK inhibitor, a GSK3β inhibitor, human leukemia inhibitory factor (LIF), human insulin and Torin 1. The method does not need any other inhibitors or transgene expression. The naive human pluripotent cells can be used to generate a large amount of mature human cells from all three germ layers in host non-human animals.

The invention relates to a method for differentiating human pluripotent stem cells into fibroblasts, characterized in that the human pluripotent stem cells are cultured on an adherent system in the presence of a medium that is suitable for culturing fibroblasts and in the absence of feeder cells.

Well-defined, xeno-free culture media which comprise a TGF-beta isoform or the chimera formed between IL6 and the soluble IL6 receptor (IL6RIL6), which are capable of maintaining stem cells, and particularly, human embryonic stem cells, in an undifferentiated state are provided. Also provided are cell cultures comprising the culture media and the stem cells and methods of expanding and deriving embryonic stem cells in such well-defined, xeno-free culture media. In addition, the present invention provides methods of differentiating ESCs or EBs formed therefrom for the generation of lineage specific cells.

The present invention relates to a method to differentiate pluripotent stem cells to a primitive streak cell population, in a stepwise manner for further maturation to definitive endoderm.

The present invention relates to a cryopreserved in vitro cell culture comprising human pancreatic progenitor cells that co-express pancreatic-duodenal homeobox factor-1 (PDX1) and NK6 homeobox 1 (NKX6.1) and are chromogranin negative. The present invention also relates to a method for cryopreserving an in vitro population of human pancreatic progenitor cells that co-express PDX1 and NKX6.1 and are chromogranin negative.

The electrical pacemakers currently being used for the therapeutic approaches for treatment of “sick sinus syndrome” are not hormonally regulatable and entail risks through infections or premature battery discharge. These problems could be overcome by means of “biological cardiac pacemakers” obtained from pluripotent stem cells (PSCs). It has been shown that the controlled differentiation of stem cells with TBX, inductors of sinoatrial node cells, and an additional Myh6 promoter-specific antibiotic selection can give cardiomyocyte aggregates consisting to an extent of more than 80% of physiologically functional pacemaker cells. These induced sinoatrial bodies (“iSABs”) for the first time exhibited very high beat frequencies (300-400 bpm), similar to those in a murine heart, and were able to stably rhythmically stimulate heart muscle cells ex vivo. In the iSAB transcriptome decoded by means of RNA-seq, it was possible to assign almost all the genes to the ontologies of heart function/heart development and the structures of contractile cells. Overall, this is the first example of a high-purity functional sinoatrial tissue derived from stem cells, which means that a crucial step for future cell therapy and the testing of medicaments in vitro is being implemented.

Provided are assay systems for determining the therapeutic or toxic effect of a putative drug based on assaying its activity in cells which have been differentiated in vitro from stem cells, and induced to display a phenotype that resembles a disease to be treated.

The present invention provides a composition for treating ischemic diseases or neuroinflammatory diseases. PSA-NCAM-positive neural progenitor cells used in the present invention promote angiogenesis in injected tissue and inhibit an inflammatory response. The PSA-NCAM-positive neural progenitor cells can be simply isolated by using an anti-PSA-NCAM-antibody, and exhibit excellent angiogenic and anti-inflammatory activities compared with mesenchymal stem cells, and thus can be useful as a composition for effectively treating ischemic diseases caused by a vascular injury and nerve damage diseases caused by inflammation. In addition, a secretome of the neural progenitor cells of the present invention reduces the ischemic injury site and allows a neurological function to recover, and thus can be used as an agent for treating ischemic diseases and degenerative nervous system disorders such as nerve damage diseases caused by inflammation.

The present description provides improved methods for generating thymic epithelial progenitor (TEP) cells from pluripotent stem (PS) cells in vitro. Also provided are isolated invitro cell populations, compositions, and systems comprising TEP cells produced in vitro. Compositions and systems of cell populations of thymic epithelial cells and subpopulations thereof, as well as cells formed during different stages of differentiation of PS cells into thymic epithelial cells and subpopulations thereof are provided.

A genetically modified glial cells, and use of such cells for rejuvenating glial cell population or treating glial cell-related disorders are disclosed. A method of treating a disorder of the brain and/or brain stem in a subject by introducing a population of genetically modified glial progenitor cells into the brain and/or brain stem of the subject, wherein the genetically modified glial progenitor cells have increased expression of one or more genes compared to the same type of glial progenitor cells that have not been genetically modified, wherein said increased expression of the one or more genes in the genetically modified glial progenitor cells confer competitive advantage over native or already resident glial progenitor cells in the subject.