Increase of Cxcr4 Expression on Expanded Tton-Enriched Cord Blood C034+ Cells (Ising Mscs

Introduction: a number of potential cell adhesion molecules, whichmediate essential cell-to-cell or cell-to-matrix interactions, areexpressed on the surface of cd34+ hematopoietic progenitor cells(hpcs), including integrins, cd44, and cxcr4. these moleculesare essential for homing process. in this study, we compared thechanges of expression of cd44 and cxcr4 on the cd34+hematopoietic progenitor cells expanded on mscs in the presence ofcytokines.material and methods: cord blood cd34+ cells were expandedusing human bone marrow mesenchymal stem cells and cytokines(tpo, scf, flt-3, il-6, and il-3), and then expression of cd44 andcxcr4 on cd34+ cells were evaluated by flow cytometric analysis.results: after 2 weeks of serum free culture of cd34+ cells in thepresence of cytokines, the expression of cxcr4 on cd34+ cellswas decreased 3.4 fold (p(less than)o.05). in contrast, the expression ofcxcr4 on cd34+ cells expanded on hmscs was increased(p(less than)o.05). the expression of cd44 on expanded cd34+ cells in bothmethods did not differ significantly.conclusions: our results indicated that co-culture of cord bloodstem cells on hmscs significantly increased cxcr4 expression oncord blood cd34+ cells.