Ex vivo culture of hematopoietic stem and progenitor cells with platelet lysate: Investigating proliferation and erythroid-megakaryocytic lineage effects.

The role of chemokine activation of Rac GTPases in hematopoietic stem cell marrow homing, retention, and peripheral mobilization

Transcriptome Analysis Identifies Regulators of Hematopoietic Stem and Progenitor Cells

On the symmetry of siblings: automated single-cell tracking to quantify the behavior of hematopoietic stem cells in a biomimetic setup

Mechanisms of hematopoietic stem cell mobilization: When innate immunity assails the cells that make blood and bone

Differential effects of mixed lymphocyte reaction supernatant on human mesenchymal stromal cells

MYC Promotes Bone Marrow Stem Cell Dysfunction in Fanconi Anemia.

Roles for Heme Synthesis in the Maintenance of Hematopoietic Stem and Progenitor Cells

Polycom Group Protein Mel18 Inhibits Hematopoietic Stem Cell Self-Renewal through Repressing the Expression of Genes Important for Cellular Senescence and Proliferation

Hematopoietic Stem Cells and Their BM Stromal Microenvironment Share a Dynamic Inverse Metabolic State During Quiescence and Proliferation Via ROS Transfer Between The Two Populations

1004 – FROM SINGLE-CELL TECHNOLOGIES TO UNEXPECTED FINDINGS: STEM CELLS AS ANTIGEN PRESENTING CELLS

Blood Cell Replenishment and Bone Marrow Stem Cell Pool Renewal Are Regulated By Different Circadian Peaks Via Norepinephrine and TNFα/S1P Signaling

Endothelial cells (ECs) line blood vessels and serve as a niche for hematopoietic stem and progenitor cells (HSPCs). Recent data point to tissue-specific EC specialization as well as heterogeneity; however, it remains unclear how ECs acquire these properties. Here, by combining live-imaging-based lineage-tracing and single-cell transcriptomics in zebrafish embryos, we identify an unexpected origin for part of the vascular HSPC niche. We find that islet1 (isl1)-expressing cells are the progenitors of the venous ECs that constitute the majority of the HSPC niche. These isl1-expressing cells surprisingly originate from the endoderm and differentiate into ECs in a process dependent on Bmp-Smad signaling and subsequently requiring npas4l (cloche) function. Single-cell RNA sequencing analyses show that isl1-derived ECs express a set of genes that reflect their distinct origin. This study demonstrates that endothelial specialization in the HSPC niche is determined at least in part by the origin of the ECs.

Germline DDX41 mutations cause ineffective hematopoiesis and myelodysplasia.

CD45 regulates homing and engraftment of immature normal and leukemic human cells in transplanted immunodeficient mice

Hematopoietic stem and progenitor cells (HSPCs) hold significant promise for various diseases and gene therapy, highlighting the need for improved in vitro expansion while maintaining their properties. Efficient HSPC expansion requires an environment that preserves self-renewal and homing capabilities. Human Platelet Lysates (HPL) contain bioactive molecules and growth factors that may enhance HSPC functionality. This study investigates the effects of HPL on peripheral blood HSPC proliferation, self-renewal capacity, and homing. We observed that HPL significantly promoted HSPC proliferation, resulting in a 1.7-fold increase in final cell count and reduced doubling time, without affecting colony-forming capacity. Flow cytometry analysis revealed no significant changes in the percentages of CD34+, CD34−CD38+, CD34+CD38+, and CD34+CD38− cells, though CXCR4 marker expression was notably higher in the HPL-treated group. Furthermore, real-time analysis of self-renewal genes (GFI1, HOXB4, and TAL1) indicated a significant increase in GFI1 expression, while HOXB4 and TAL1 remained unchanged. Among homing-related genes (CXCR4, VLA-4, and LFA-1), CXCR4 expression increased significantly, while VLA-4 and LFA-1 levels showed no significant alterations. These findings suggest that HPL enhances HSPC proliferation while preserving their self-renewal and homing abilities, providing a promising approach for optimizing HSPC culture conditions for both research and clinical use.