Nuclear reprogramming to a pluripotent state by three approaches.

Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan.
Nature (Impact Factor: 42.35). 06/2010; 465(7299):704-12. DOI: 10.1038/nature09229
Source: PubMed

ABSTRACT The stable states of differentiated cells are now known to be controlled by dynamic mechanisms that can easily be perturbed. An adult cell can therefore be reprogrammed, altering its pattern of gene expression, and hence its fate, to that typical of another cell type. This has been shown by three distinct experimental approaches to nuclear reprogramming: nuclear transfer, cell fusion and transcription-factor transduction. Using these approaches, nuclei from 'terminally differentiated' somatic cells can be induced to express genes that are typical of embryonic stem cells, which can differentiate to form all of the cell types in the body. This remarkable discovery of cellular plasticity has important medical applications.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Human induced pluripotent stem cells (iPSCs) have a wide range of applications throughout the fields of basic research, disease modeling and drug screening. Epigenetic instable iPSCs with aberrant DNA methylation may divide and differentiate into cancer cells. Unfortunately, little effort has been taken to compare the epigenetic variation in iPSCs with that in differentiated cells. Here, we developed an analytical procedure to decipher the DNA methylation heterogeneity of mixed cells and further exploited it to quantitatively assess the DNA methylation variation in the methylomes of adipose-derived stem cells (ADS), mature adipocytes differentiated from ADS cells (ADS-adipose) and iPSCs reprogrammed from ADS cells (ADS-iPSCs). We observed that the degree of DNA methylation variation varies across distinct genomic regions with promoter and 5'UTR regions exhibiting low methylation variation and Satellite showing high methylation variation. Compared with differentiated cells, ADS-iPSCs possess globally decreased methylation variation, in particular in repetitive elements. Interestingly, DNA methylation variation decreases in promoter regions during differentiation but increases during reprogramming. Methylation variation in promoter regions is negatively correlated with gene expression. In addition, genes showing a bipolar methylation pattern, with both completely methylated and completely unmethylated reads, are related to the carbohydrate metabolic process, cellular development, cellular growth, proliferation, etc. This study delivers a way to detect cell-subset specific methylation genes in a mixed cell population and provides a better understanding of methylation dynamics during stem cell differentiation and reprogramming.
    BMC Genomics 01/2014; 15:978. · 4.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Reprogramming of somatic cells has great potential to provide therapeutic treatments for a number of diseases as well as provide insight into mechanisms underlying early embryonic development. Improvement of induced Pluripotent Stem Cells (iPSCs) generation through mRNA-based methods is currently an area of intense research. This approach provides a number of advantages over previously used methods such as DNA integration and insertional mutagenesis. Using transfection of specifically synthesized mRNAs of various pluripotency factors, we generated iPSCs from mouse embryonic fibroblast (MEF) cells. The genetic, epigenetic and functional properties of the iPSCs were evaluated at different times during the reprogramming process. We successfully introduced synthesized mRNAs, which localized correctly inside the cells and exhibited efficient and stable translation into proteins. Our work demonstrated a robust up-regulation and a gradual promoter de-methylation of the pluripotency markers, including non-transfected factors such as Nanog, SSEA-1 (stage-specific embryonic antigen 1) and Rex-1 (ZFP-42, zinc finger protein 42). Using embryonic stem cells (ESCs) conditions to culture the iPS cells resulted in formation of ES-like colonies after approximately 12 days with only five daily repeated transfections. The colonies were positive for alkaline phosphatase and pluripotency-specific markers associated with ESCs. This study revealed the ability of pluripotency induction and generation of mouse mRNA induced pluripotent stem cells (mRNA iPSCs) using transfection of specifically synthesized mRNAs of various pluripotency factors into mouse embryonic fibroblast (MEF) cells. These generated iPSCs exhibited molecular and functional properties similar to ESCs, which indicate that this method is an efficient and viable alternative to ESCs and can be used for further biological, developmental and therapeutic investigations.
    International Journal of Molecular Sciences 12/2014; 15(12):21840-64. · 2.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A common view is that an accidental increase in ploidy contributes to the evolution of neoplastic cells primarily by decreasing the fidelity of mitosis with extra chromosomes and centrosomes. This view implies that how neoplastic cells become polyploid is irrelevant, as it has been widely assumed. If this assumption is correct, then the oncogenic contribution of the pathways to polyploidy and thus their potential as targets for cancer prevention is determined by their incidence in the body. A lesson from plant evolution, in which an accidental increase in ploidy has a prevalent role, suggests that this assumption needs to be reconsidered.
    Cell cycle (Georgetown, Tex.) 08/2014; 13(15):2323-9. · 5.24 Impact Factor


Available from