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BACKGROUND:Chitosan biological materials can induce bone marrow mesenchymal stem cells to differentiate toward neurons. As a derivative of chitosan, carboxymethyl chitosan has a series of excelent properties. However, whether carboxymethyl chitosan can induce the neuronal differentiation of bone marrow mesenchymal stem cells remains unclear.OBJECTIVE:To investigate the effect of carboxymethyl chitosan thermosensitive hydrogel on the differentiation of bone marrow mesenchymal stem cells into neurons and the possible mechanism.METHODS:Passage 3 bone marrow mesenchymal stem cells from rats were selected and cultured in carboxymethyl chitosan thermosensitive hydrogel extracts in different concentrations (0, 50, 100, 150, 200, 500 g/L). Control cells were cultured in culture medium with no addition of carboxymethyl chitosan thermosensitive hydrogel extracts. MTT assay was performed to investigate the effects of different concentrations of carboxymethyl chitosan thermosensitive hydrogel extracts on bone marrow mesenchymal stem cell proliferation. Western blot assay was used to explore the effect of 150 g/L carboxymethyl chitosan thermosensitive hydrogel extracts on the expression of neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, β3-tubulin, Notch1 and Jag1 protein.RESULTS AND CONCLUSION:MTT assay showed that carboxymethyl chitosan thermosensitive hydrogel promoted the cell proliferation, and the proliferation rate reached the peak at the concentration of 150 g/L. Western blot assay showed that the cells induced by 150 g/L carboxymethyl chitosan thermosensitive hydrogel extract had significant increases in neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, and β3-tubulin protein expression, and obvious decreases in Notch1 and Jag1 protein expression in comparison with the control group. These results indicate that the carboxymethyl chitosan thermosensitive hydrogel induces rat bone marrow mesenchymal stem cells to differentiate toward neurons, and suppresses the activity of Notch signal pathway in the process of differentiation.
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BACKGROUND:Bone marrow stromal cel s can differentiate into nerve cel s to promote nerve tissue repair, but the exact mechanism has not been ful y elucidated. OBJECTIVE:To explore the influence of adenovirus-mediatedβnerve growth factor transfection on bone marrow stromal stem cel transplantation fighting against brain injury in rats. METHODS:(1) Rat bone marrow stromal stem cel s were cultured in vitro, transfected with the adenovirus-mediatedβnerve growth factor and directional y induced usingβ-mercaptoethanol. (2) A total of 210 Sprague-Dawley rats were randomized into induction+tranfection group, induction+non-transfection group, induction+medium group, model group, and sham group (n=42 per group). Rat skul injury models were made, and given corresponding treatments at different time points (12, 24, 36, 48, 72 hours). Neurological function of rats was evaluated based on neurological severity scores on the day that the rats were given transplantation, and 1, 2, 3, 4 weeks after transplantation. (3) Another 75 Sprague-Dawley rats were also divided into five groups (n=15 per group) as above, fol owed by model establishment and corresponding treatments at 24 hours after modeling. Neurological severity scores were recorded at the same day, 1, 2, 3, 4 weeks after transplantation. Five rats from each group were sacrificed to detect levels of malondialdehyde and superoxide dismutase in the rat brain at the same day, 2 and 4 weeks after transplantation, respectively. RESULTS AND CONCLUSION:If the cel s were transplanted within 48 hours after modeling, the neurological severity scores in the induction+transfection group decreased significantly compared with the induction+non-transfection group and model group at 1 and 2 weeks after transplantation (P<0.05). If the cel s were transplanted at different time, the neurological severity scores in the induction+transfection group were decreased significantly compared with the induction+non-transfection group and model group at 3 and 4 weeks after transplantation (P<0.05). If the cel s were transplanted within 24 hours after modeling, the neurological severity scores in the induction+transfection group decreased significantly compared with the model group at 1 week after transplantation (P<0.05), and the neurological severity scores in the induction+transfection group and induction+non-transfection group both were significantly lower than those in the model group (P<0.05). Two weeks after cel transplantation, the level of superoxide dismutase was significantly higher in the induction+transfection group than the induction+medium group and model group (P<0.05), but the level of malondialdehyde was significantly lower (P<0.05). Al these findings indicate that adenovirus-mediatedβnerve growth factor transfer plays a certain neuroprotective role in bone marrow stromal stem cel transplantation for brain injury in rats.
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BACKGROUND:Choosing an effective means to label and trace the distribution, differentiation and migration of celsin vivo help to further explore the specific mechanism of cels that exert a therapeutic effect. OBJECTIVE:To understand the migration and localization of BrdU-labeled human umbilical cord mesenchymal stem cels in brain injury model rats. METHODS:Human umbilical cord blood samples were obtained, and the isolation of human umbilical cord mesenchymal stem cels was carried out. The primary and passage culture were performed. The phenotype of cels was detected by flow cytometry. Passage 3 human umbilical cord mesenchymal stem cels were labeled using BrdU, and the cel proliferation was detected using MTT method. BrdU-labeled cels were injected into brain injury ratsvia the tail vein. At 14 days after transplantation, brain tissues in the injury region were cut into sections and the migration and location of the umbilical cord mesenchymal stem cels were observed under inverted fluorescence microscope. RESULTS AND CONCLUSION: Cel surface specific markers CD45 and CD34 were detected by flow cytometry, but the cels could not express CD44, CD105 and CD29. Based on the cel growth curve, the cels came into a conditioning period at 1-3 days of seeding and came into a logarithmic phase at 3-5 days. BrdU-positive cels were visible at the injury region after 14 days, indicating that in the rats, transplanted human umbilical cord mesenchymal stem cels migrated from the peripheral blood to the site of brain injury to achieve the effective repair of injured parts. Cite this article:Liu HL, Liu ZJ, Chen XB, Hu WZ, Ding BQ. Migration and localization of umbilical cord mesenchymal stem cels implanted into brain injury model rats. Zhongguo Zuzhi Gongcheng Yanjiu. 2016;20(1):31-35.