Osteoblasts Induced From Human Marrow Mesenchymal Stem Cells Support Hematopoietic Stem/Progenitor Cells From Umbilical Cord Blood

ObjectiveHematopoietic stem cells niches are subsets of tissues and extracellular subsets that can indefinitely house one or more Hematopoietic stem cells and control their self-renewal and progeny production in vivo. Recent studies prove that osteoblasts and their precursors derived from a common mesenchymal stem cell play a critical role in the creation of a stem cell niche and thereby regulate HSCs maintenance, proliferation, and maturation. It is the demonstration that osteoblast-expressed regulatory components that influence Hematopoietic stem cell function are likely to include cell-cell receptors, soluble and cell surface-associated cytokines, and growth factors. Each of these factors—those known and those yet to be determined—are likely influenced by mechanical, systemic (eg, PTH), and local (eg, BMPs, Ang-1) signals that regulate osteoblastic function. Furthermore, reciprocal cooperation between HSCs and osteoblasts play a profound and central role in the establishment and maintenance of the stem cell niche in the bone marrow. The Osteoblasts are a heterogeneous population, which includes...