Safeguards for Cell Cooperation in Mouse Embryogenesis Shown by Genome-Wide Cheater Screen Using a genome-wide screen in murine induced pluripotent stem cells, scientists identified a network of genes (centered on p53, topoisomerase 1, and olfactory receptors) whose down-regulation caused the cells to replace wild-type cells in vitro and in the mouse embryo-without perturbing normal development. [Science] Abstract | Press Release Enhanced Survival of Transplanted Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes by the Combination of Cell Sheets with the Pedicled Omental Flap Technique in a Porcine Heart The cell-sheet method has been used to transplant many functional cells; however, potential ischemia might limit cell survival. The omentum, which is known to have rich vasculature, is expected to be a source of blood supply. Researchers hypothesized that transplantation of human induced pluripotent stem cell-derived cardiomyocyte (hiPS-CM) cell sheets combined with an omentum flap may deliver a large number of functional hiPS-CMs with enhanced blood supply. [Circulation] Abstract Regulation of Pluripotency in Male Germline Stem Cells by Dmrt1 Researchers report that induction of global DNA hypomethylation in germline stem (GS) cells (cultured spermatogonial stem cells) induces pluripotent cell derivation. When DNA demethylation was triggered by Dnmt1 depletion, GS cells underwent apoptosis. [Genes Dev] Abstract MicroRNA-Based Discovery of Barriers to Dedifferentiation of Fibroblasts to Pluripotent Stem Cells Individual microRNAs (miRNAs) can target hundreds of mRNAs forming networks of presumably cooperating genes. To test this presumption, scientists functionally screened miRNAs and their targets in the context of dedifferentiation of mouse fibroblasts to induced pluripotent stem cells. [Nat Struct Mol Biol] Abstract Driving Vascular Endothelial Cell Fate of Human Multipotent Isl1+ Heart Progenitors with VEGF Modified mRNA Investigators identified a family of human cardiac endothelial intermediates located in outflow tract of the early human fetal hearts (OFT-ECs), characterized by coexpression of Isl1 and CD144/vWF. By comparing angiocrine factors expressed by the human OFT-ECs and non-cardiac ECs, vascular endothelial growth factor (VEGF)-A was identified as the most abundantly expressed factor, and clonal assays documented its ability to drive endothelial specification of human embryonic stem cell-derived Isl1+ progenitors in a VEGF receptor-dependent manner. [Cell Res] Full Article Spheroid Culture for Enhanced Differentiation of Human Embryonic Stem Cells to Hepatocyte-Like Cells Researchers report cultivation of human embryonic stem cells as three-dimensional aggregates that enhances their differentiation to hepatocyte-like cells. [Stem Cell Dev] Abstract Functional Analysis in Mouse Embryonic Stem Cells Reveals Wild-Type Activity for Three Msh6 Variants Found in Suspected Lynch Syndrome Patients The authors previously developed a method for functional characterization of MSH2 missense mutations of unknown significance. This method is based on endogenous gene modification in mouse embryonic stem cells using oligonucleotide-directed gene targeting, followed by a series of functional assays addressing the mutations in mismatch repair functions. They have adapted this method for the characterization of MSH6 missense mutations. [PLoS One] Full Article CHIR99021 Promotes Self-Renewal of Mouse Embryonic Stem Cells by Modulation of Protein-Encoding Gene and Long Intergenic Non-Coding RNA Expression Scientists identified CHIR99021 (CHIR)-regulated genes in mouse embryonic stem cells using microarray analysis. Their microarray data demonstrated that CHIR not only influenced the Wnt/β-catenin pathway by stabilizing β-catenin, but also modulated several other pluripotency-related signaling pathways such as TGF-β, Notch and MAPK signaling pathways. [Exp Cell Res] Abstract Tracking Induced Pluripotent Stem Cell-Derived Neural Stem Cells in the Central Nervous System of Rats and Monkeys Investigators attempted to track induced pluripotent stem cell-derived neural stem cells in the rodent and primate central nervous system and explore their therapeutic viability for stem cell replacement in traumatic brain injury rats and monkeys with spinal cord injury. [Cell Reprogram] Abstract Slow Turning Lateral Vessel Bioreactor Improves Embryoid Body Formation and Cardiogenic Differentiation of Mouse Embryonic Stem Cells Scientists describe a method of embryoid body (EB) formation in hydrodynamic conditions using a slow-turning lateral vessel bioreactor and the subsequent differentiation of EBs into cardiomyocytes. [Cell Reprogram] Abstract |