Modeling Hepatitis C Virus Infection Using Human Induced Pluripotent Stem Cells Here researchers report that hepatocyte-like cells derived from induced pluripotent stem cells support the entire life cycle of hepatitis C virus, including inflammatory responses to infection, enabling studies of how host genetics impact viral pathogenesis. [Proc Natl Acad Sci USA] Abstract | Press Release Direct Conversion of Mouse Fibroblasts to Self-Renewing, Tripotent Neural Precursor Cells Researchers hypothesized that neural precursor cell (NPC)-like cells may be induced using the same principal approach used for generating “induced neuronal” cells. Toward this goal, the researchers infected mouse embryonic fibroblasts derived from Sox2-EGFP mice with a set of 11 transcription factors highly expressed in NPCs. [Proc Natl Acad Sci USA] Abstract | Press Release SFRP1 and 2 Dose-Dependently Regulate Midbrain Dopamine Neuron Development In Vivo and in Embryonic Stem Cells Secreted Frizzled related proteins (sFRPs) are a family of proteins that modulate Wnt signaling, which in its turn regulates multiple aspects of ventral midbrain and dopaminergic (DA) neuron development. Here, researchers show that sFRP1 and sFRP2 activate the Wnt/PCP/Rac1 pathway in DA cells. [Stem Cells] Abstract Concentration-Dependent Requirement for Local Protein Synthesis in Motor Neuron Subtype-Specific Response to Axon Guidance Cues Using a growth cone collapse assay, researchers demonstrate that mouse embryonic stem cell-derived spinal motor neurons respond to ephrin-A5, Sema3f, and Sema3a in a concentration-dependent manner. [J Neurosci] Abstract The Roles of FGF and MAP Kinase Signaling in the Segregation of the Epiblast and Hypoblast Cell Lineages in Bovine and Human Embryos The inability to derive embryonic stem cell lines in a variety of species suggests divergence between species in the cell signaling pathways involved in early lineage specification. Here researchers examined segregation of the hypoblast and epiblast lineages in bovine and human embryos through modulation of FGF/MAP kinase signaling pathways in cultured embryos. [Development] Abstract Ribosomal Stress Induces L11- and p53-Dependent Apoptosis in Mouse Pluripotent Stem Cells Here, researchers show that treatment with low doses of Actinomycin D or depletion of ribosomal protein L37, two well-established inducers of ribosomal stress, activate p53 in an L11-dependent manner in mouse embryonic stem cells and in induced pluripotent stem cells. [Cell Cycle] Abstract MicroRNA-125b/Lin28 Pathway Contributes to the Mesendodermal Fate Decision of Embryonic Stem Cells Here researchers report novel functions of microRNA-125b/Lin28 axis in the regulation of mouse embryonic stem cell lineage specification and cardiomyocyte differentiation. [Stem Cells Dev] Abstract TGFß1 Inhibits Lymphatic Endothelial Cell Differentiation from Mouse Embryonic Stem Cells In this work, researchers identified Transforming Growth Factor-ß1 (TGFß1) as a negative regulator of lymphvasculogenesis from embryonic stem cell-derived vascular progenitors. [J Cell Physiol] Abstract Directed Differentiation of Embryonic Stem Cells Allows Exploration of Novel Transcription Factor Genes for Pancreas Development Researchers hypothesize that, if directed differentiation in vitro recapitulates the developmental process in vivo, embryonic stem cells provide a powerful model to discover novel pancreatic transcription factor genes. [Stem Cell Rev Rep] Abstract |