Mechanisms that govern hematopoietic lineage specification, as opposed to the expansion of committed hematopoietic progenitors, from human pluripotent stem cells (hPSCs) have yet to be fully defined. Here, we show that within the family of genes called inhibitors of differentiation (ID), ID1 and ID3 negatively regulate the transition from lineage-specified hemogenic cells to committed hematopoi...

Several major vascular tissues, such as the aorta-gonad-mesonephros region (AGM), yolk sac, and fetal liver have been confirmed to possess hematopoietic function. Recently, the placenta has been demonstrated as another hematopoietic organ. However, it is not conclusive whether the placenta possesses hematopoietic ability. Therefore, we undertook a series of experiments to study the hematopoieti...

Current induction schemes directing hematopoietic differentiation of human embryonic stem cells (hESCs) are not well defined to mimic the sequential stages of hematopoietic development in vivo. Here, we report a 3-stage method to direct differentiation of hESCs toward hematopoietic progenitors in chemically defined mediums. In the first 2 stages, we efficiently generated T-positive primitive st...

Although hematopoietic precursor activity can be generated in vitro from human embryonic stem cells, there is no solid evidence for the appearance of multipotent, self-renewing and transplantable hematopoietic stem cells. This could be due to short half-life of hematopoietic stem cells in culture or, alternatively, human embryonic stem cell-initiated hematopoiesis may be hematopoietic stem cell...

The molecular determinants regulating the specification of human embryonic stem cells (hESCs) into hematopoietic cells remain elusive. HOXA9 plays a relevant role in leukemogenesis and hematopoiesis. It is highly expressed in hematopoietic stem and progenitor cells (HSPCs) and is downregulated upon differentiation. Hoxa9-deficient mice display impaired hematopoietic development, and deregulatio...

The development and emergence of the hematopoietic stem cell involves a series of tightly regulated molecular events that are not well characterized. The hematopoietically expressed homeobox (Hhex) gene, a member of the homeobox gene family, is an essential regulator of embryogenesis and hematopoietic progenitor development. To investigate the role of Hhex in hematopoiesis we adapted a murine e...

BACKGROUND Mobilization of hematopoietic stem/progenitor cells from the bone marrow to the peripheral blood by granulocyte colony-stimulating factor is the primary means to acquire stem cell grafts for hematopoietic cell transplantation. Since hematopoietic stem/progenitor cells represent a minority of all blood cells mobilized by granulocyte colony-stimulating factor, the underlying mechanisms...

background: myeloablative-allogeneic stem cell transplantation is a common way of treating various malignant and nonma-lignant diseases; but, it is associated with hazardous immediate and late complications. the majority of patients are not good candidates for high dose therapy because of old age, medical co-morbidities or previous heavy treatments. the donor stem cells can engraft in the recip...

BACKGROUND Hematopoietic stem and progenitor cells can interact with their microenvironment via integrins which are adhesion receptors consisting of alpha and beta subunits. Current knowledge suggests that the integrin subunits alpha4 and alpha6 expressed on hematopoietic stem and progenitor cells have distinct roles in retaining stem cells in the bone marrow. The aim of our study was to gain i...

Hematopoiesis is the process of blood cell production, which involves the maintenance and proliferation of hematopoietic progenitor cells and their differentiation into mature, functional erythrocytes, leukocytes, and platelets. Normal hematopoiesis depends on the presence of (1) normal pluripotent hematopoietic stem cells, which are capable of maintaining differentiated hematopoietic cell prod...