Objective To investigate the experimental condition and mechanism of differentiation of human umbilical cord blood derived mesenchymal stem cells（hUCB-MSC）into neuron-like cells induced by recombined human epidermal growth factor （rhEGF） and taurine in vitro.Methods hUCB-MSC were primary cultured in Dulbeccoprime;s modified Eagle's medium/F12 （DMEM/F-12）which supplemented with 105U/L penicillin G, 100 mg/L streptomycin sulfate, 10% fetal bovine serum (FBS),5% autologous plasma,4 mmol Lglutamine, 30 ng/ml rhEGF.The DMEM/F-12 medium was replaced by taurine medium after 3 passages.The expression of surface antigen CD90,CD29,CD34,CD44 and CD45 were detected by flow cytometry；the expression of neuron specific enolase,rhodopsin and nestin were investigated by immunocytochemistry. The statistical method was chi square test.Results Morphologically similar to bonemarrow MSC,hUCB-MSC became attached cells after the first 5 to 7 days in culture，and reached 80% to 90% confluent after 3 to 4 weeks. Growth accelerated after passage. hUCB-MSC were positive for CD29,CD44 and CD90 but negative for CD34 and CD45. After taurine induction, 2515/3120 cells expressed NSE, 1168/3175 cells expressed rhodopsin and 903/3050 cells expressed nestin while only 234/2965 cells expressed NSE in the control group(P＜0.01).Conclusion rhEGF and taurine can induce hUCB-MSC differentiating into neuronlike or rhodopsin positive cells.
Objective To isolate neural stem cells (NSCs) from rabbit retina and brain, and induce differentiation of those NSCs using different culture media. Methods Single-cell suspensions of retina and cerebral cortex were prepared from rabbit embryo, cultured in 5 types of different media to isolate the NSCs by continual passages. After 3 passages, NSCs were induced to differentiation in 2 types of different media for 8 to 10 days. NSCs and inducedretinal cells were examined by immunofluorescence and flow cytometry for the expression pattern of some specific antigens.Results Immunofluorescence showed that NSCs from retina and brain, cultured in serumfree media, both expressed Nestin partially. Flow cytometry showed that Nestin positive cells were significantly decreased while the Rhodopsin and Thy1.1 positive cells were increased after induction. Compared with the combined induction of alltrans retinoid acid (ATRA) and serum, 5%FBS (fetal bovine serum) led to higher expression of Rhodopsin（P＜0.01），but lower expression of Thy1.1（P=0.01）.Conclusion Serumfree media with N2, EGF, bFGF, LIF is the best for NSCs purification. Both induciton media can induce NSCs to differentiate.Retina NSCs have higher potentials to differentiate into retinal neuroepithelial cells than brain NSCs.
Objective To investigate the feasibility of differentiation of invitro induced rat bone marrowderived mesenchymal stem cells（rMSCs） into retinal pigment epithelial （RPE） cells.Methods The rMSCs from BrwonNorway (BN) rats were isolated and cultured by adherent screening method. RPE cells lysate made by repeated freezethawing was put into the rMSCs culture system to identify whether the induced cells could express characteristic label cytokeratin（CK）and S-100 simultaneously or not.Results The growth rate of rMSCs induced by RPE cells lysate was slower and protuberant burr surrounded the fusiform cells. The results of immunoblotting and double immunofluorescence showed that partial induced cells expressed CK and S-100 simultaneously. The result of flow cytometry indicated that 14.1% induced cells expressed CK and S-100 simultaneously.Conclusion Induced by RPE cells lysate, rMSCs can differentiate into RPE cells.