OBJECTIVETo explore the feasibility of in vitro differentiation of human umbilical cord blood cells (HUCBC) into neural cells induced by receptor activator of NF-KappaB ligand (RANKL) and brain-derived neurotrophic factor (BDNF).

METHODSNormal fresh HUCBC were cultured as the following: (1) Control group cultured by differentiation medium only; (2) BDNF group, cultured by differentiation medium + BDNF; (3) RANKL group, cultured by differentiation medium + human soluble RANKL (sRANKL); (4) BDNF + RANKL group, cultured by differentiation medium + BDNF and sRANKL. Cultured cells were observed with invert microscope. After ten-days culture, the expression of glial fibrillary acidic protein (GFAP) and neuron-specific nuclear protein (NeuN) of the cultured cells were detected by immunocytochemical staining.

RESULTSAfter 10 day's culture, the NeuN positive cells were (97.0 +/- 13.5), (85.0 +/- 5.6), (167.0 +/- 19.7) in RANKL, BDNF and BDNF + RANKL groups, respectively, with 1.7, 1.5, 3.0 fold in crease than that of control (55.7 +/- 8.5), the GFAP positive cells were (114.7 +/- 18.0), (233.3 +/- 21.7), (289.0 +/- 24.7), respectively, with 1.4, 2.9, 3.6 fold increase compared with the control group. The differentiation ratio of neurons in RANKL group was similar to that of the BDNF group, but the differentiation ratio of glial cells was lower than that in the BDNF group. In the RANKL + BDNF group, the differentiation of HUCBC into neurons and glial cells were enhanced obviously, the differentiated neural cells were typical with longer axons and dendrites.

CONCLUSIONRANKL and BDNF could induce HUCBC into neurons and glial cells, and they have synergistic effect on the induced differentiation. It is hopeful that HUCBC might be an source of stem cells for the treatment of central nervous system injury.