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 summarize the role of N-myc downstream regulated gene 1 (NDRG1) and the advancement of it in tumor research. Methods Publications on line at home and abroad involving the roles of NDRG1 and the correlation between it and tumor were collected and reviewed. Results NDRG-1, has a number of important functions such as in organism responses in hypoxia, histological differentiation, and so on, especially plays a significant role in generation, metastasis, and invasion of cancer. Conclusion NDRG1 may be a candidate of metastasis relevant gene for cancer and may serve as a useful prognostic marker of carcinoma.
Objective To investigate the possibility of commitment differentiation of embryonic stem cells induced by the medium of cultured retinal neurons of SD rats. Methods The medium from cultured retinal neurons of SD rats were collected, sterilized and mixed with DMEM medium according to 2∶3 proportion, ES cells were cultured with these mixed medium and were observed under the phase contrast microscope daily, the induced cells were identified by NF immunohistochemistry methods. Results The ES cells cultured with these mixed medium can differentiate into neuron-like structure, and the induced cells were positive in NF immunofluorescence staining. Conclusion The medium from cultured retinal neurons of SD rats can induce ES cells commitment differentiation into neuron-like structure. (Chin J Ocul Fundus Dis, 2002, 18: 134-136)
Objective To introduce the basic research and cl inical potential of the hair foll icle stem cells related signal transduction in prol iferation and differentiation. Methods The recent original articles about the hair foll icle stem cells were extensively reviewed. Results Many different signal pathways had been involved in the skin development and self-newals.The hair foll icle stem cells could play an important role in the skin self-renewal and regeneration which were modulated by several different signal pathways, which included bone morphogenetic protein/transforming growth factor β, Wnt, Notch and ectodysplasin A genes. Conclusion The hair foll icle stem cells may be a future approach to repair cutaneous wounds as a cell therapy．
Objective To investigate the feasibility of Y27632 to induce transdifferentiation from human retinal pigment epithelial (hRPE) cells into neuron-like cells in vitro. Methods The third to sixth generation of primary hRPE cells were cultured with 2% fetal bovine serum + Dulbecco's modified eagle medium/F12 culture solution, with (experimental group) or without (control group) 10 mu;mol/L Y27632. At 3, 6 hours and 1, 3, 5, 7 days after induction, the morphologic changes of RPE cells were observed by inverted microscope. The expression rate of CK18, Map2, NF200 and Pax6 at 3 days after induction in the experimental and control group were detected by immunofluorescent staining. chi;2 test was employed for comparison between the two groups. Results 50.1% cells of the experimental group formed axon-like processes and interconnected each other with typical neuron-like appearance. The expression rates of CK18, Map2, NF200 and Pax6 in the experimental group were 43.88%, 31.90%, 57.45% and 65.79%, while the above indexes in the control group were 93.97%, 4.49%, 22.37% and 8.33% respectively. Compared the expression rate of CK18 (chi;2=64.763), Map2 (chi;2=23.634), NF200 (chi;2=21.261) and Pax6 (chi;2=25.946) between the two groups, the differences were significant (P＜0.01). Conclusion The hRPE cells can be trans-differentiated into neuron-like cells in vitro by Y27632.
ObjectiveTo study the effects of leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF) on the proliferation and differentiation of human bone marrow mesenchymal stem cells (hBMSCs). MethodshBMSCs at passage 4 were divided into 4 groups according to different culture conditions:cells were treated with complete medium (α-MEM containing 10%FBS, group A), with complete medium containing 10 ng/mL LIF (group B), with complete medium containing 10 ng/mL bFGF (group C), and with complete medium containing 10 ng/mL LIF and 10 ng/mL bFGF (group D). The growth curves of hBMSCs at passage 4 in different groups were assayed by cell counting kit 8; cellular morphologic changes were observed under inverted phase contrast microscope; the surface markers of hBMSCs at passage 8 including CD44, CD90, CD19, and CD34 were detected by flow cytometry. ResultsThe cell growth curves of each group were similar to the S-shape; the cell proliferation rates in 4 groups were in sequence of group D > group C > group B > group A. Obvious senescence and differentiation were observed very early in group A, cells in group B maintained good cellular morphology at the early stage, with slow proliferation and late senescence; a few cells in group C differentiated into nerve-like cells, with quick proliferation; and the cells in group D grew quickly and maintained cellular morphology of hBMSCs. The expressions of CD44 and CD90 in groups A and C at passage 8 cells were lower than those of groups B and D; the expressions of CD19 and CD34 were negative in 4 groups, exhibiting no obvious difference between groups. ConclusionLIF combined with bFGF can not only maintain multiple differentiation potential of hBMSCs, but also promote proliferation of hBMSCs.
Objective To analyze MC3T3E1 cell morphology, prol iferation, and osteogenic differentiation in fibrin gel (FG) so as to lay a fundament for use of FG in tissue engneering. Methods MC3T3E1 cells were incubated in three concentrations (20, 10 and 5 mg/mL)of FG as the experimental groups (groups A, B and C) and in the common medium culture as the control group (group D). The cell morphology and distribution in FG were observed by inverted phase contrast microscope and confocal laser scanning microscope at different time. The cell prol iferation was assessed by fluorospectrophotometer. The alkal ine phosphatase (ALP) activity was detected by automatic biochemistry analyses and von Kossa staining was used to analyze calcium salts mineralization. RT-PCR was used to analyze the ALP and bone sialoprotein (BSP)mRNA expression at 14 and 21 days. Results In groups A, B and C, the MC3T3E1 cells had long processes which connected each other and formed network; but fusiform or cube cells were observed in group D at 21 days. The fluorescence intensity was increased gradually with time, was the highest at 14 days and the lowest at 28 days in group D; it was highest in groups A, B and C at 28 days, there were statistically significant differences when compared with group D (P lt; 0.05). The ALP activity was increased gradually with time, and it was the highest at 28 days in group D and at 21 days in groups A and B, there were significant differences (P lt; 0.05), no statistically significant differences compared with group D at other time points (P gt; 0.05). The mineral ization nodus were seen at 21 and 28 days in group A, but no mineral ization nodus was seen in group D at 28 days. The RT-PCR results showed the mRNA expressions of ALP and BSP were enhanced in group A when compared with group D (P lt; 0.05). Conclusion The osteogenic differentiation was most obvious and cell prol iferation was most active after 21 days of incubation in FG.
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.
ObjectiveTo investigate the feasibility of small molecule compound XAV939 to induce mouse embryonic stem cells (mESC) to differentiate into cardiac myocytes. MethodsWe revived and cultured undifferentiated mESC growing confluently on trophoderm made of mouse embryonic inoblast cell. The mESCs were digested by trypsin to form embryoid bodies (EBs) by handing drop method. After plated, EBs were induced by XAV939 to differentiate into cardiac myocytes. We observed the cardiac myocytes with lightmicroscopy and identified it with immunofluorescence method. Result The XAV939 can effectively induce mESC into cardiac myocytes with the mean efficiency rate of 71.85%±1.05%. The differentiated cardiac myocytes shrinked spanteously and rhythmicly. The cardiac troponin T as the special marker of cardiac myocyte was positive. ConclusionThe small molecule compound XAV939 could effectively induce mES cells into cardiac myocytes.
Previous studies have shown that growth arrest, dedifferentiation, and loss of original function occur in cells after multiple generations of culture, which are attributed to the lack of stress stimulation. To investigate the effects of multi-modal biomimetic stress (MMBS) on the biological function of human bladder smooth muscle cells (HBSMCs), a MMBS culture system was established to simulate the stress environment suffered by the bladder, and HBSMCs were loaded with different biomimetic stress for 24 h. Then, cell growth, proliferation and functional differentiation were detected. The results showed that MMBS promoted the growth and proliferation of HBSMCs, and 80 cm H2O pressure with 4% stretch stress were the most effective in promoting the growth and proliferation of HBSMCs and the expression level of α-smooth muscle actin and smooth muscle protein 22-α. These results suggest that the MMBS culture system will be beneficial in regulating the growth and functional differentiation of HBSMCs in the construction of tissue engineered bladder.