ESC & iPSC News Volume 9.05 | Feb 12 2014

The Two Active X Chromosomes in Female ESCs Block Exit from the Pluripotent State by Modulating the ESC Signaling Network
Using embryonic stem cells with distinct sex chromosome compositions as a model system, scientists showed that two X chromosomes stabilize the naive pluripotent state by inhibiting MAPK and Gsk3 signaling and stimulating the Akt pathway. [Cell Stem Cell] Abstract | Graphical Abstract

Isolation of Single-Base Genome-Edited Human iPS Cells without Antibiotic Selection
Researchers developed an efficient method to capture rare mutational events, enabling isolation of mutant lines with single-base substitutions without antibiotic selection. This method facilitates efficient induction or reversion of mutations associated with human disease in isogenic human induced pluripotent stem cells. [Nat Methods] Abstract

Derivation and Characterization of Mouse Embryonic Stem Cells from Permissive and Nonpermissive Strains
The authors describe a protocol for efficient derivation of germline-competent mouse embryonic stem cells from any mouse strain, including strains previously deemed nonpermissive. They provide a protocol that is generally applicable to most inbred strains, as well as a variant for nonpermissive strains. [Nat Protoc] Abstract

Oct4 Is Required for Lineage Priming in the Developing Inner Cell Mass of the Mouse Blastocyst
Investigators explored the role of Oct4 in blastocyst formation and specification of epiblast versus primitive endoderm lineages using conditional genetic deletion. Experiments involving mouse embryos deficient for both maternal and zygotic Oct4 suggest that it is dispensable for zygote formation, early cleavage and activation of Nanog expression. [Development] Abstract | Full Article

Growth and Proliferation of Human Embryonic Stem Cells on Fully Synthetic Scaffolds Based on Carbon Nanotubes
Scientists showed an industrially scalable and inexpensive method of fabricating entirely synthetic, non-xenogeneic carbon nanotube-based scaffolds by vacuum filtration for the culture of human embryonic stem cells. [ACS Appl Mater Interfaces] Abstract | Press Release

ONSL and OSKM Cocktails Act Synergistically in Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells
Researchers compared the reprogramming efficiency of two different polycistronic genes, OCT4, NANOG, SOX2 and LIN28 (ONSL) and OCT4, SOX2, KLF4 and cMYC (OSKM) placed in the same retrovector backbone. [Mol Hum Reprod] Abstract

A Single-Cell and Feeder-Free Culture System for Monkey Embryonic Stem Cells
Researchers report a new single-cell and feeder-free culture system for primate pluripotent stem cells, the key feature of which is an originally formulated serum-free medium containing FGF and activin. [PLoS One]
Full Article

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JDRF to Provide Additional Support for Upcoming Clinical Trial of ViaCyte’s Encapsulated Cell Therapy for Type 1 Diabetes
JDRF and ViaCyte, Inc. jointly announced that JDRF is providing additional milestone-based funding for the continued development of ViaCyte’s VC-01™ encapsulated cell therapy product candidate for the treatment of type 1 diabetes. [ViaCyte, Inc.] Press Release

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Stem Cell Lines Not Fit for Clinic
Many of the stem cell lines used by academics and registered with the U.S. National Institutes of Health would not be eligible for commercialization because they don’t pass muster with the Food and Drug Administration, according to a report published in Cell Stem Cell. The lack of harmonization between the agencies’ standards throws up a potential roadblock on the path from the laboratory to the clinic. [The Scientist] Editorial | Report

UK Politicians Demand Action over Dearth of Female Scientists
An influential group of UK politicians has demanded that more be done to increase the number of women in scientific careers. The House of Commons Science and Technology Select Committee points the finger at universities. [Nature News] Editorial

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Postdoctoral Scholar – Cell-Cell Interactions in Mammalian Development (University of California, San Francisco)

Postdoctoral Fellow – Human Induced Pluripotent Stem Cell Initiative (European Bioinformatics Institute)

Senior Research Scientist – Immunogenicity and Epigenetic Regulation of hiPSC-Derived Endothelial Cells (Magdi Yacoub Institute)

Postdoctoral Position – Stem Cell Signaling and Epigenetics (Fondazione Istituto Nazionale Genetica Molecolare)

Postdoctoral Position – Systems Biology of Cellular Reprogramming (University of California, San Diego)

Postdoctoral Position – Stem Cells and Epigenetics (Mount-Sinai)

Postdoctoral Fellow – Morphogenetic Signaling Pathways in Development and Disease (University of Rochester Medical Center)

Postdoctoral Position – Epigenetic Regulation of Heart Formation Using Human ES & iPS Cells (University of Pittsburgh)

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