Mobilization and homing of hematopoietic stem cells.

摘要: Hematopoietic stem cells (HSC) are a population of precursor that posses the capacity for self-renewal and multilineage differentiation. In bone marrow (BM), HSCs warrant blood cell homeostasis, but at same time stable pool functional must be constantly maintained. For this, constitute model in which subpopulations quiescent active adult co-exist tissue, specific microenvironment called stem-cell “niches.” These microenvironments keep (osteoblastic niche) its activate (vascular proliferation and/or injury repair, maintaining dynamic balance between HSC reside can forces into blood, process termed mobilization used clinically to harvest large number transplantation. At time, homing BM is necessary optimize engraftment. Here, we summarize current understanding niche characteristics, physiological pathological mechanisms guide both within distant niches periphery. Mobilization Homing mirror depending on an interplay chemokines, chemokine receptors, intracellular signaling, adhesion moleculas proteases. The interaction SDF-1/CXCL12 receptor CXCR4 critical retain marrow. Current strategies clinic, mainly G-CSF cytokine, well tolerated often produce suboptimal collected HSCs. Novel agents (AMD3100, factor, GROsT.) being developed enhance modify signaling boost harvest, increasing available transplant.