MicroRNA-125b (miR-125b) is up-regulated in patients with leukemia. Overexpression of miR-125b alone in mice causes a very aggressive, transplantable myeloid leukemia. Before leukemia, these mice do not display elevation of white blood cells in the spleen or bone marrow; rather, the hematopoietic compartment shows lineage-skewing, with myeloid cell numbers dramatically increased and B-cell numb...

Impaired hematopoiesis is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Bone marrow aplasia and peripheral cytopenias arise from primary secondary graft failure or poor function. Chimerism analysis useful to discriminate these conditions. By determining the pathogenesis of impaired hematopoiesis, timely appropriate treatment can be performed. Hemat...

The development of the hematopoietic system during early embryonic stages occurs in spatially and temporally distinct waves. Hematopoietic stem cells (HSC), the most potent and self-renewing cells of this system, are produced in the final 'definitive' wave of hematopoietic cell generation. In contrast to HSCs in the adult, which differentiate via intermediate progenitor populations to produce f...

In the human hematopoietic system, aging is associated with decreased bone marrow cellularity, decreased adaptive immune system function, and increased incidence of anemia and other hematological disorders and malignancies. Recent studies in mice suggest that changes within the hematopoietic stem cell (HSC) population during aging contribute significantly to the manifestation of these age-assoc...

Every day, billions of new blood cells are produced in the body, each one derived from a hematopoietic stem cell (HSC). Because most mature blood stem cells have a limited life span, the ability of HSCs to perpetuate themselves through self-renewal and generate new blood cells for the lifetime of an organism is critical to sustaining life. A key problem in hematopoietic stem cell biology is how...

many investigators have used xenogeneic, especially murine stromal cells and fetal calf serum to maintain and expand human stem cells. the proliferation and expansion of human hematopoietic stem cells in ex vivo culture were examined with the goal of generating a suitable protocol for expanding hematopoietic stem cells for patient transplantation. using primary fetal liver cells, we established...

the aim of this study was to isolate mouse embryonic stem cells from late blastocyst stage embryos and to use them as a model system for the study of hematopoietic induction outside the embryo by coculturing of embryonic stem cells with bone marrow stromal cells. blastocyst stage embryos from pregnant nmri mice were obtained and cultured for 1-2 days in dmem medium. the inner cell masses formed...

Understanding how the blood system is formed is an ongoing fundamental research challenge. Developmental biology has provided many insights into the molecules and processes that affect the formation of the blood tissues, both in health and disease. It is of particular interest for clinical transplantation therapies to understand how hematopoietic stem cells (HSCs)-the self-renewing purveyors of...

Enormous numbers of adult blood cells are constantly regenerated throughout life from hematopoietic stem cells through a series of progenitor stages. Accessibility, robust functional assays, well-established prospective isolation, and successful clinical application made hematopoiesis the classical mammalian stem cell system. Most of the basic concepts of stem cell biology have been defined in ...

Cellular and tissue activities highly depend on environmental pH. Murine lung tissue, when cultured properly in-vitro, is a potent producer of hematopoietic growth factors. We have studied the effect of pH on the production of hematopoietic growth factors and protein synthesis by the murine lung in-vitro. Various concentrations of NaHC03 were used to adjust the pH of the culture medium unde...