Migratory capabilities of human umbilical cord blood-derived neural stem cells (HUCB-NSC) in vitro

Many types of neural progenitors from various sources have been evaluated for therapy of CNS disorders. Prerequisite for success in cell therapy is the ability for transplanted cells to reach appropriate target such as stroke lesion. We have established neural stem cell line from human umbilical cord blood neural stem (HUCB-NSC). In the present study we evaluated migratory capabilities of cells (HUCB-NSC) and the presence of various migration-related receptors. Immunocytochemical analysis revealed abundant expression of CXCR4, PDGFRα, PDGFRβ, c-Met, VEGFR, IGF-1R and PSA-NCAM receptors in non-adherent population of HUCB-NSC cultured in serum free (SF) conditions (SF cells). Biological activity of selected receptors was confirmed by HUCB-NSC in vitro migration towards SDF-1 and IGF-1 ligands. Additionally, rat brain-derived homogenates have been assessed for their chemoattractive activity of HUCB-NSC. Our experiments unveiled that brain tissue was more attracted for HUCB-NSC than single ligands with higher potency of injured than intact brain. Moreover, adherent HUCB-NSC cultured in low serum (LS) conditions (LS cells) were employed to investigate an impact of different extracellular matrix (ECM) proteins on cell motility. It turned out that laminin provided most permissive microenvironment for cell migration, followed by fibronectin and gelatin. Unexpected nuclear localization of CXCR4 in SF cells prompted us to characterize intracellular pattern of this expression in relation to developmental stage of cells cultured in different conditions. Continuous culture of LS cells revealed cytoplasmatic pattern of CXCR4 expression while HUCB-NSC cultured in high serum conditions (HS cells) resulted in gradual translocation of CXCR4 from nucleus to cytoplasm and then to arising processes. Terminal differentiation of HUCB-NSC was followed by CXCR4 expression decline.