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Nanog is a well-known transcription factor that plays a fundamental role in stem cell self-renewal and the maintenance of their pluripotent cell identity. There remains a large data gap with respect to the spectrum of the key pluripotency transcription factors' interaction partners. Limited information is available concerning Nanog-associated RNA-binding proteins (RBPs), and the intrinsic protein-RNA interactions characteristic of the regulatory activities of Nanog. Herein, we used an improved affinity protocol to purify Nanog-interacting RBPs from mouse embryonic stem cells (ESCs), and 49 RBPs of Nanog were identified. Among them, the interaction of YBX1 and ILF3 with Nanog mRNA was further confirmed by in vitro assays, such as Western blot, RNA immunoprecipitation (RIP), and ex vivo methods, such as immunofluorescence staining and fluorescent in situ hybridization (FISH), MS2 in vivo biotin-tagged RNA affinity purification (MS2-BioTRAP). Interestingly, RNAi studies revealed that YBX1 and ILF3 positively affected the expression of Nanog and other pluripotency-related genes. Particularly, downregulation of YBX1 or ILF3 resulted in high expression of mesoderm markers. Thus, a reduction in the expression of YBX1 and ILF3 controls the expression of pluripotency-related genes in ESCs, suggesting their roles in further regulation of the pluripotent state of ESCs., (© 2015 International Federation for Cell Biology.)

Data sharing is an essential element of research; however, recent scientific and social developments have challenged conventional methods for protecting privacy. Here we provide guidance for determining data sharing thresholds for human pluripotent stem cell research aimed at a wide range of stakeholders, including research consortia, biorepositories, policy-makers, and funders., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Human induced pluripotent stem (iPS) cells have the ability to differentiate into all somatic cells and to maintain unlimited self-renewal. Therefore, they have great potential in both basic research and clinical therapy for many diseases. To identify potentially universal mechanisms of human somatic cell reprogramming, we studied gene expression changes in three types of cells undergoing reprogramming. The set of 570 genes commonly regulated during induction of iPS cells includes known embryonic stem (ES) cell markers and pluripotency related genes. We also identified novel genes and biological categories which may be related to somatic cell reprogramming. For example, some of the down-regulated genes are predicted targets of the pluripotency microRNA cluster miR302/367, and the proteins from these putative target genes interact with the stem cell pluripotency factor POU5F1 according to our network analysis. Our results identified candidate gene sets to guide research on the mechanisms operating during somatic cell reprogramming., (Copyright © 2012. Published by Elsevier Ltd.)

Since the initial description of induced pluripotent stem (iPS) cells created by forced expression of four transcription factors in mouse fibroblasts, the technique has been used to generate embryonic stem (ES)-cell-like pluripotent cells from a variety of cell types in other species, including primates and rat. It has become a popular means to reprogram somatic genomes into an embryonic-like pluripotent state, and a preferred alternative to somatic-cell nuclear transfer and somatic-cell fusion with ES cells. However, iPS cell reprogramming remains slow and inefficient. Notably, no live animals have been produced by the most stringent tetraploid complementation assay, indicative of a failure to create fully pluripotent cells. Here we report the generation of several iPS cell lines that are capable of generating viable, fertile live-born progeny by tetraploid complementation. These iPS cells maintain a pluripotent potential that is very close to ES cells generated from in vivo or nuclear transfer embryos. We demonstrate the practicality of using iPS cells as useful tools for the characterization of cellular reprogramming and developmental potency, and confirm that iPS cells can attain true pluripotency that is similar to that of ES cells.

Mental retardation is the main clinical manifestation of Down syndrome (DS), and neural abnormalities occur during the early embryonic period and continue throughout life. Tc1, a model mouse for DS, carries the majority part of the human chromosome 21 and has multiple neuropathy phenotypes similar to patients with DS. To explore the mechanism of early neural abnormalities of Tc1 mouse, induced pluripotent stem (iPS) cells from Tc1 mice were obtained, and genome‐wide gene expression and methylation analysis were performed for Tc1 and wild‐type iPS cells. Our results showed hypermethylation profiles for Tc1 iPS cells, and the abnormal genes were shown to be related to neurodevelopment and distributed on multiple chromosomes. In addition, important genes involved in neurogenesis and neurodevelopment were shown to be downregulated in Tc1 iPS cells. In short, our study indicated that genome‐wide hypermethylation leads to the disordered expression of genes associated with neurodevelopment in Tc1 mice during early development. Overall, our work provided a useful reference for the study of the molecular mechanism of nervous system abnormalities in DS. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to an article related to the mice generated from tetraploid complementation competent Induced pluripotent stem (iPS) cells, was similar to that from Embryonic stem (ES) cells.