Hematopoiesis News Volume 4.39 | Oct 8 2013

Induction of Multipotential Hematopoietic Progenitors from Human Pluripotent Stem Cells via Respecification of Lineage-Restricted Precursors
Researchers report a strategy to respecify lineage-restricted CD34⁺CD45⁺ myeloid precursors derived from human pluripotent stem cells into multilineage progenitors that can be expanded in vitro and engrafted in vivo. [Cell Stem Cell] Abstract | Graphical Abstract

RhoA GTPase Controls Cytokinesis and Programmed Necrosis of Hematopoietic Progenitors
By using a RhoA conditional knockout mouse model, scientists showed that RhoA deficiency causes a multilineage hematopoietic failure that is associated with defective multipotent hematopoietic progenitor cells. [J Exp Med] Abstract

TRIM28 Is Essential for Erythroblast Differentiation in the Mouse
The authors tested the contribution of TRIM28 to globin gene regulation and erythropoiesis using a conditional loss of function in vivo model. They discovered that Trim28 genetic loss in the adult mouse leads to defective immature erythropoiesis in the bone marrow and consequently to anemia. [Blood] Abstract

Osteoclasts Are Not Crucial for Hematopoietic Stem Cell Maintenance in Adult Mice
Researchers transplanted hematopoietic stem cells from two osteopetrotic mouse models, with lack of osteoclasts or defective osteoclast function, to normal adult mice and examined the bone phenotype and hematopoiesis in the recipients. [Haematologica] Abstract | Full Article

Cited2 Is Required for the Maintenance of Glycolytic Metabolism in Adult Hematopoietic Stem Cells
Scientists showed that conditional deletion of Cited2 in murine hematopoietic stem cells results in elevated levels of reactive oxygen species, decreased cellular glutathione content, increased mitochondrial activity, and decreased glycolysis. [Stem Cell Dev] Abstract

Adipocytic Cells Augment the Support of Primitive Hematopoietic Cells In Vitro, but Have No Effect in the Bone Marrow Niche under Homeostatic Conditions
Researchers compared the ability of adipocytic and non-adipocytic cell lines to support primitive hematopoietic cells in vitro. Pre-adipocytic cell lines demonstrated enhanced support of hematopoietic cells. [Stem Cell Dev] Abstract

Rapamycin Enhances Long-Term Hematopoietic Reconstitution of Ex Vivo Expanded Mouse Hematopoietic Stem Cells by Inhibiting Senescence
A well-established ex vivo expansion system for mouse bone marrow hematopoietic stem cells (HSCs) was used to investigate whether inhibition of overactivated mammalian target of rapamycin with rapamycin can promote long-term hematopoiesis of ex vivo expanded HSCs and to elucidate the mechanisms of action of rapamycin. [Transplantation] Abstract

Hematopoietic Stem Cell Expansion Caused by a Synthetic Fragment of Leptin
Mice were treated with 1 mg/kg LEP5 for three days. The mature and primitive hematopoietic populations were quantified. Investigators observed that the mature populations from the bone marrow and spleen were not affected by LEP5. However, the peptide caused at least a two-fold increase in the number of hematopoietic stem cells, the most primitive population of the bone marrow. [Peptides] Abstract

CLINICAL RESEARCH

Efficacy of Deferred Dosing of Granulocyte Colony-Stimulating Factor in Autologous Hematopoietic Transplantation for Multiple Myeloma
To determine whether delayed G-CSF dosage could result in equivalent ANC recovery and thereby improve cost effectiveness, researchers deferred the administration of G-CSF until WBC recovery had begun. There was no difference between groups in the incidence or duration of febrile neutropenia, duration of greater than or equal to grade III mucositis, weight gain, rash, engraftment syndrome or early death (100 days). [Bone Marrow Transpl] Full Article

Outcome and Prognostic Factors for Patients Who Relapse after Allogeneic Stem Cell Transplantation
Scientists studied 1080 patients that received hematopoietic stem cell transplantation between 2004 and 2008, among whom 351 relapsed. The 3-year post-relapse overall survival was 19%. Risk factors for mortality after relapse included shorter time to relapse, higher disease risk index at hematopoietic stem cell transplantation, myeloablative conditioning, high pre-transplantation co-morbidity index, and graft-versus-host disease occurring prior to relapse. [Biol Blood Marrow Transpl] Abstract

Hematopoietic SCT with Cryopreserved Grafts: Adverse Reactions after Transplantation and Cryoprotectant Removal before Infusion
The authors review the history of hematopoietic stem cell cryopreservation, the side effects reported after transplantation, along with advances in strategies for reducing the adverse reactions, including methods and devices for removal of dimethyl sulfoxide. [Bone Marrow Transpl] Abstract

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Canadian Blood Services’ and The Ottawa Hospital Celebrate First Step Towards Building Canada’s First National Public Cord Blood Bank
Mothers delivering at The Ottawa Hospital’s General and Civic Campuses, will have an opportunity to donate their babies’ umbilical cord blood as part of Canadian Blood Services’ initial step in building Canada’s first national public cord blood bank. [The Ottawa Hospital] Press Release

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Postdoctoral Research Fellow – Human Induced Pluripotent Stem Cell Research (Bioprocessing Technology Institute)

Faculty Positions – Stem Cells and Regenerative Medicine (Baylor College of Medicine)

Postdoctoral Position – Cellular and Genetic Therapies for Hemoglobinopathies (Blood Systems Research Institute)

Research Associate – Leukemia & Stem Cell Biology (King’s College London)

Postdoctoral Fellow – Mechanisms that Regulate Stem Cell Self-Renewal Using Mouse Blood-Forming Stem Cells (Columbia University)

Postdoctoral Researcher – Hematopoietic and Malignant Stem Cells (Istanbul University Institute of Experimental Medicine)

Scientist – Particle Chemistry (STEMCELL Technologies Inc.)

Research Technologist – Human Pluripotent Stem Cell Products (STEMCELL Technologies Inc.)

Research Technologist – Mesenchymal Cell Research (STEMCELL Technologies Inc.)

Research Technologist – Cell Culture Media & Matrices (STEMCELL Technologies Inc.)

Research Associate/Scientist – Antibodies Group (STEMCELL Technologies Inc.)

Research Associate – Particle Chemistry (STEMCELL Technologies Inc.)

Quality Control Analyst – Media (STEMCELL Technologies Inc.)

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