Project description:The concept of dedifferentiation of somatic cells into pluripotent stem cells has opened a new era in regenerative medicine. Viral transduction of defined factors has successfully achieved pluripotency derived from somatic cells. However, during the generation process of induced pluripotent stem (iPS) cells, genetic integration of certain factors may cause mutagenesis or tumorigenicity, which limits further application. Therefore, there is currently ongoing an extensive search for new methods such as transient gene delivery and oocyte-free and non-viral inducers like small molecules. Here we show that the transient delivery of embryonic stem (ES) cell-derived soluble proteins enables dedifferentiation of mouse adult somatic cells converting them into pluripotent stem cells without the introduction of certain transcription factors or genetic manipulation. During the dedifferentiation, global gene expression patterns and epigenetic status were converted from the somatic to the ES-equivalent status. Dedifferentiated somatic cells were morphologically, biologically and functionally indistinguishable from ES cells. Furthermore, the dedifferentiated cells possessed in vivo differentiation and development potential. Our results provide an alternative and safe strategy for dedifferentiation of somatic cells that can be used to facilitate pluripotent stem cell-based cell therapy. Total RNA from mES cell (triplicate), adult fibroblast (triplicate), or dedifferentiated adult fibroblast was isolated. Samples were hybridized to a Affymetrix Mouse Gene 1.0 ST Array according to the manufacturer's protocol. After hybridization, the chips were stained and washed in a Genechip Fluidics Station 450(Affymetrix) and scanned by using a Genechip Array scanner 3000 7G (Affymetrix).
Project description:The concept of dedifferentiation of somatic cells into pluripotent stem cells has opened a new era in regenerative medicine. Viral transduction of defined factors has successfully achieved pluripotency derived from somatic cells. However, during the generation process of induced pluripotent stem (iPS) cells, genetic integration of certain factors may cause mutagenesis or tumorigenicity, which limits further application. Therefore, there is currently ongoing an extensive search for new methods such as transient gene delivery and oocyte-free and non-viral inducers like small molecules. Here we show that the transient delivery of embryonic stem (ES) cell-derived soluble proteins enables dedifferentiation of mouse adult somatic cells converting them into pluripotent stem cells without the introduction of certain transcription factors or genetic manipulation. During the dedifferentiation, global gene expression patterns and epigenetic status were converted from the somatic to the ES-equivalent status. Dedifferentiated somatic cells were morphologically, biologically and functionally indistinguishable from ES cells. Furthermore, the dedifferentiated cells possessed in vivo differentiation and development potential. Our results provide an alternative and safe strategy for dedifferentiation of somatic cells that can be used to facilitate pluripotent stem cell-based cell therapy.
Project description:Human primordial germ cells and mouse neonatal and adult germline stem cells are pluripotent and derive embryonic stem cell properties. Here we report the successful establishment of stable pluripotent human adult germline stem cells (haGSCs) derived from spermatogonial cells of adult human testis. Cellular and molecular characterization of haGSCs revealed many similarities to human embryonic stem (hES) cells and haGSCs produced teratomas after subcutaneous transplantation into immunodeficient mice. The haGSCs differentiated into various types of somatic cells of all three germ layers when grown under conditions used to induce the differentiation of hES cells. We conclude that the generation of haGSCs from testicular biopsies may provide simple and non-controversial access to individual cell-based therapy without the ethical and immunological problems associated with hES cells. Keywords: pluripotent stem cells characterisation
Project description:Somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by Oct4, Sox2, Klf4, plus c-Myc. Recently, Sox2 plus Oct4 were shown to reprogram fibroblasts and Oct4 alone to reprogram mouse and human neural stem cells (NSCs) into iPS cells. Here we report that Bmi1 leads to dedifferentiation of mouse fibroblasts into NSC-like cells and, in combination with Oct4, replaces Sox2, Klf4 and c-Myc during reprogramming fibroblasts to iPS cells. Furthermore, activation of sonic hedgehog signalling (by Shh, purmorphamine, or oxysterol) replaces the effects of Bmi1, and, in combination with Oct4, reprograms mouse embryonic and adult fibroblasts into iPS cells. One-and two-factor iPS cells are similar to mouse embryonic and adult fibroblasts into iPS cells in global gene expression profile, epigenetic status, in vitro and in bibo differentiation into all three ferm layers, as well as teratoma formation and germline transmission in vivo. These data support that fibroblasts can be reprogrammed into iPS cells by Oct4 alone. Total RNAs were isolated from indicated cells and labeled with Cy3. Hybridization was performed once for each sample.