Project description:The International Stem Cell Initiative compared three common approaches for assessing pluripotent stem cells (PSC). The formation of teratomas in vivo, or embryoid bodies (EB) in vitro, provide direct tests of differentiation, whereas PluriTest predicts pluripotency through bioinformatic analysis of transcriptomes of undifferentiated cells. Here we studied the starting poulations of pluripotent stem cells using an Illumina HumanHT-12 V4.0 expression beadchip assays
Project description:Background and aim: Human Induced pluripotent stem (iPS) cells have been derived from dermal fibroblasts, keratinocytes and blood cells by ectopic expression of defined transcription factors.1–5 Application of this approach in human cells would have enormous potential and generate patient-specific pluripotent stem cells to accelerate the implementation of stem cells for clinical treatment of degenerative diseases. In the present study, we investigated whether genetically marked human mesenchymal cells of gut mesentery may give rise to iPS cells. Methods: We used lentiviruses to express Oct4, Sox2, Nanog in mesenchymal cells of gut mesentery, then generated iPS cells were identified in many aspects including morphology, pluripotent markers, global gene expression profile, DNA methylation status at pluripotent cell-specific genes, embryoid bodies and terotomas formation. Results: The resulting iPS cells from mesenchymal cells of gut mesentery were similar to human embryonic stem (ES) cells in morphology, proliferation, surface antigens, gene expression, and epigenetic status of pluripotent cell-specific genes. Furthermore, these cells could differentiate into cell types of the three germ layers in vitro and in teratomas. DNA fingerprinting showed that the human iPS cells were derived from the donor cells and are not a result of contamination. one sample/variable
Project description:Background and aim: Human Induced pluripotent stem (iPS) cells have been derived from dermal fibroblasts, keratinocytes and blood cells by ectopic expression of defined transcription factors.1–5 Application of this approach in human cells would have enormous potential and generate patient-specific pluripotent stem cells to accelerate the implementation of stem cells for clinical treatment of degenerative diseases. In the present study, we investigated whether genetically marked human mesenchymal cells of gut mesentery may give rise to iPS cells. Methods: We used lentiviruses to express Oct4, Sox2, Nanog in mesenchymal cells of gut mesentery, then generated iPS cells were identified in many aspects including morphology, pluripotent markers, global gene expression profile, DNA methylation status at pluripotent cell-specific genes, embryoid bodies and terotomas formation. Results: The resulting iPS cells from mesenchymal cells of gut mesentery were similar to human embryonic stem (ES) cells in morphology, proliferation, surface antigens, gene expression, and epigenetic status of pluripotent cell-specific genes. Furthermore, these cells could differentiate into cell types of the three germ layers in vitro and in teratomas. DNA fingerprinting showed that the human iPS cells were derived from the donor cells and are not a result of contamination.
Project description:Expression data from diploid and aneuoploid human pluripotent stem cells, teratomas derived from them, and pluripotent-like cells recovered from these teratomas
Project description:Induced pluripotent stem cells (iPSCs) with potential for therapeutic applications can be derived from somatic cells via ectopic expression of a set of limited and defined transcription factors. However, due to risks of random integration of the reprogramming transgenes into the host genome, the low efficiency of the process, and the potential risk of virally induced tumorigenicity, alternative methods have been developed to generate pluripotent cells using nonintegrating systems, albeit with limited success. Here, we show that c-KIT+ human first-trimester amniotic fluid stem cells (AFSCs) can be fully reprogrammed to pluripotency without ectopic factors, by culture on Matrigel in human embryonic stem cell (hESC) medium supplemented with the histone deacetylase inhibitor (HDACi) valproic acid (VPA). The cells share 82% transcriptome identity with hESCs and are capable of forming embryoid bodies (EBs) in vitro and teratomas in vivo. After long-term expansion, they maintain genetic stability, protein level expression of key pluripotency factors, high cell-division kinetics, telomerase activity, repression of X-inactivation, and capacity to differentiate into lineages of the three germ layers, such as definitive endoderm, hepatocytes, bone, fat, cartilage, neurons, and oligodendrocytes. We conclude that AFSC can be utilized for cell banking of patient-specific pluripotent cells for potential applications in allogeneic cellular replacement therapies, pharmaceutical screening, and disease modeling. Total RNA obtained from mid gestation human amniotic fluid cells (AFSCs/2nd trimester AFSCs), early gestation human amniotic fluid cells (eAFSCs/1st trimester AFSCs) and human embryonic stem cells (hESCs) as described in the corresponding Materials and Methods sections.
Project description:The tumorigenicity of human pluripotent stem cells (hPSCs) is a major safety concern for their application in regenerative medicine. Here we identify the tight-junction protein Claudin-6 as a specific cell surface marker of hPSCs that can be used to selectively remove Claudin-6-positive cells from mixed cultures. We show that Claudin-6 is absent in adult tissues but highly expressed in undifferentiated cells, where it is dispensable for hPSC survival and self-renewal. We use three different strategies to remove Claudin-6-positive cells from mixed populations: an antibody against Claudin-6; a cytotoxin-conjugated antibody that selectively targets undifferentiated cells; and clostridium perfringens enterotoxin, a toxin that binds several Claudins, including Claudin-6, and efficiently kills undifferentiated cells, thus eliminating the tumorigenic potential of hPSC-containing cultures. This work provides a proof of concept for the use of Claudin-6 to eliminate residual undifferentiated hPSCs from culture, highlighting a strategy that may increase the safety of hPSC-based cell therapies. total RNA was isolated from teratomas or from embryoid bodies differentiated from human induced pluripotent stem cells
Project description:Induced pluripotent stem cells (iPSCs) with potential for therapeutic applications can be derived from somatic cells via ectopic expression of a set of limited and defined transcription factors. However, due to risks of random integration of the reprogramming transgenes into the host genome, the low efficiency of the process, and the potential risk of virally induced tumorigenicity, alternative methods have been developed to generate pluripotent cells using nonintegrating systems, albeit with limited success. Here, we show that c-KIT+ human first-trimester amniotic fluid stem cells (AFSCs) can be fully reprogrammed to pluripotency without ectopic factors, by culture on Matrigel in human embryonic stem cell (hESC) medium supplemented with the histone deacetylase inhibitor (HDACi) valproic acid (VPA). The cells share 82% transcriptome identity with hESCs and are capable of forming embryoid bodies (EBs) in vitro and teratomas in vivo. After long-term expansion, they maintain genetic stability, protein level expression of key pluripotency factors, high cell-division kinetics, telomerase activity, repression of X-inactivation, and capacity to differentiate into lineages of the three germ layers, such as definitive endoderm, hepatocytes, bone, fat, cartilage, neurons, and oligodendrocytes. We conclude that AFSC can be utilized for cell banking of patient-specific pluripotent cells for potential applications in allogeneic cellular replacement therapies, pharmaceutical screening, and disease modeling.