LABORATORY RESEARCH Gata2 cis-Element Is Required for Hematopoietic Stem Cell Generation in the Mammalian Embryo Scientists describe a deletion of a Gata2 cis-element that depletes fetal liver hematopoietic stem cells, is lethal at E13-14 of embryogenesis, and is mutated in an immunodeficiency that progresses to myelodysplasia/leukemia. [J Exp Med] Abstract | Press Release Aggf1 Acts at the Top of the Genetic Regulatory Hierarchy in Specification of Hemangioblasts in Zebrafish Scientists showed that aggf1 acts at the top of the genetic regulatory hierarchy in the specification of hemangioblasts in zebrafish. Knockdown of aggf1 expression decreases expression of endothelial cell-specific markers (cdh5, admr), and disrupts primitive hematopoiesis as shown by a decreased number of erythroid cells and reduced expression of gata1 (marker for erythroid progenitors) and pu.1 (myeloid progenitors). [Blood] Abstract CXCR7 Participates in CXCL12-Induced CD34+ Cell Cycling through β-Arrestin-Dependent Akt Activation Blocking CXCR7 inhibited CXCL12-induced Akt activation as well as the percentage of CD34+ cells in cycle, colony formation and survival, demonstrating its participation in CXCL12-induced functional effects in hematopoietic stem/progenitor cells. [Blood] Abstract Mitigation of Radiation Induced Hematopoietic Injury via Regulation of Cellular MAPK/Phosphatase Levels and Increasing Hematopoietic Stem Cells Scientists describe a novel strategy for mitigation of ionizing radiation induced hematopoietic syndrome by suppressing the activity of MKP3 resulting in ERK activation and enhanced abundance of hematopoietic stem cells using an antioxidant flavonoid baicalein (5,6,7 trihydroxyflavone). [Free Radic Biol Med] Abstract Hematopoietic Stem and Progenitor Cell Activation during Chronic Dermatitis Provoked by Constitutively Active Aryl-Hydrocarbon Receptor Driven by Keratin 14 Promoter To clarify how the Keratin 14 promoter-driven aryl-hydrocarbon receptor (AhR) activation influences hematopoiesis, investigators analyzed bone marrow and spleen of constitutively active AhR mice. [Toxicol Sci] Abstract Canonical Wnt Signaling Promotes Early Hematopoietic Progenitor Formation and Erythroid Specification during Embryonic Stem Cell Differentiation Scientists investigated the effects of canonical Wnt/β-catenin signaling during early embryonic differentiation and hematopoietic specification using an embryonic stem cell system. [PLoS One] Full Article Hematopoietic Stem and Progenitor Cells Acquire Distinct DNA-Hypermethylation during In Vitro Culture Researchers compared DNA-methylation (DNAm) profiles of freshly isolated and culture-expanded hematopoietic stem and progenitor cells. Culture conditions of CD34+ cells – either with or without mesenchymal stromal cells – had relatively little impact on DNAm, although proliferation is greatly increased by stromal support. [Sci Rep] Full Article CLINICAL RESEARCH Autoimmune Hematological Diseases after Allogeneic Hematopoietic Stem Cell Transplantation in Children. An Italian Multi-Center Experience Between 1998 and 2011, 1,574 consecutive children underwent allogeneic hematopoietic stem cell transplantation in nine Italian centers. Thirty-three children (2.1%) developed autoimmune hematological diseases: 15 autoimmune hemolytic anemia, 10 immune thrombocytopenia, five Evans’ syndrome, two pure red cell aplasia, and one immune neutropenia. [Biol Bone Marrow Transplant] Abstract Influence of Two Different Doses of Antithymocyte Globulin in Patients with Standard-Risk Disease following Haploidentical Transplantation: A Randomized Trial To evaluate the effect of the different doses of antithymocyte globulin on the incidence of acute GVHD among patients receiving hematopoietic SCT without ex vivo T-cell-depletion from haploidentical donors, 224 patients with standard-risk hematological malignancy were randomized in this study. [Bone Marrow Transplant] Abstract |