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BACKGROUND:Our previous studies confirmed that NGF-PEG-PLGA-NPs has good sustained release effect and biological activity in vitro, and can induce the differentiation of PC12 cel s into neuron-like cel s. OBJECTIVE:To investigate the feasibility of neuronal differentiation of neural stem cel s from septal area of fetal brain induced by NGF-PEG-PLGA-NPs and its influence on PI3K/Akt signaling pathway. METHODS:According to optimization prescription, NGF-PEG-PLGA-NPs were prepared by multiple emulsion solvent diffusion method. Neural stem cel s were induced to neuronal differentiation in six groups, including control group, NGF group, NGF-PEG-PLGA-NPs group, LY294002 group, LY294002+NGF group and LY294002+NGF-PEG-PLGA-NPs group. Neurons were identified by immunofluorescence, while phosphorylation levels of Akt in PI3K/Akt signaling pathway were detected by western blotting. RESULTS AND CONCLUSION:The proportions ofβ-Tubulin III-positive neurons in control group, NGF group, NGF-PEG-PLGA-NPs group, LY294002 group, LY294002+NGF group and LY294002+NGF-PEG-PLGA-NPs group were (22.80±2.58)%, (35.80±3.98)%, (35.40±5.77)%, (26.60±3.87)%, (21.20±2.59)%and (25.80±7.22)%, respectively. There were no statistical differences in neuronal differentiation between NGF group and NGF-PEG-PLGA-NPs group (P>0.05), but the ratios of neural differentiation in the two groups were both higher than that in the other four groups (P0.05), but the phosphorylation levels of Akt were both higher than other four groups (P0.05), but the phosphorylation levels of Akt were higher than LY294002 group (P<0.05). Results suggest that NGF-PEG-PLGA-NPs promoted neural differentiation of neural stem cel s. The role might be related to increasing phosphorylation levels of Akt in PI3K/Akt signaling pathway.
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BACKGROUND:Nerve growth factor (NGF) belongs to a biological macromolecule that is difficult to pass through the blood-brain barrier. However, a retroviral vector carrying exogenous gene can be stably inserted and integrated into the host cellgenome, which is suitable for gene therapy. OBJECTIVE:To study the gene expression of recombinant retroviral vector carrying rat NGF gene in neural stem cels. METHODS: The rat NGF gene was inserted into a retroviral vector pLEGFP-N1, which was transferred into packaging cels PT67 by Lipofectamine 2000. The positive clones in virus supernatant were colected by G418 selection and used to infect neural stem cels. After that, the NGF expression was tested by enzyme linked immunosorbent assay and the biological competence by PC12 cels, and then morphological change of neural stem cels and celltyping were examined by fluorescent microscope. RESULTS AND CONCLUSION:The neural stem cels could express extrinsic source NGF protein after the recombinant plasmid was infected into neural stem cels. The PC12 cels increased in the experimental group and stretched out long neurites. And the NGF protein could maintain the neural stem cellsurvival and stimulate their differentiation. These findings suggest that the neural stem cels carrying extrinsic source NGF gene could express NGF successfuly, and the NGF protein induced the survival and differentiation of neural stem cels.
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There was no subspecialties differentiation such as physical therapy and occupational therapy of the rehabilitation therapy in most of institutions in China. The outstanding issues included teacher shortage, technological backwardness and imperfect practice educa-tion conditions of occupational therapy. The experience of cooperation was also introduced.
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BACKGROUND: Lot of researches has been made on investigating the influence of neurturin(NTN) on dopaminergic neurons,motor neurons,sensory neurons and sympathetic neurons in respect of its enhancing survival and neuroprotective potential. But reports about its influence on cholinergic neurons still remained less.OBJECTIVE: To study the influence of NTN combined with nerve growth factor(NGF) on the survival of NGF receptor positive neurons in vitro.DESIGN: A repeated measurement and experimental study. based on cell model.SETTING: Department of anatomy in a university.MATERIALS: This study was carried out at the Human Anatomical Department of Guangzhou Medical College between September 2001 and June2002. Neonatal SD rats were adopted,DMEM/F12 culture medium supplemented with 20 g/L additive without serum were filtered and sterilized for cell culture.METHODS: Rats were divided into four groups: NGF group,NTN group,NGF + NTN group and control group. Cells of the former three groups were cultured with NGF,NTN and NGF + NTN of 100 μg/L respectively,which were replaced by culture medium in control group. Cholinergic neurons derived from neonatal rat basal forebrain were primary cultured for observing the influence of NTN,NGF on their survival by using immunohistochemical combined imaging analysis method.MAIN OUTCOME MEASURES: The survival rate and growing state of NGFR positive neurons derived from forebrain of neonatal rats when cultured for 4 days and 8 days in vitro.RESULTS: In 4-day culture,indexes of NTN group were significantly different from control group( P ＜ 0. 05 ),and indexes of NGF + NTN group were better than those of NGF group or NTN group( P ＜ 0. 05); in 8-day culture,all indexes except the number of neuronal processes in NTN group were similar to control group( P ＞ 0.05),and indexes of NGF + NTN group were still better than that of NGF group or NTN group( P ＜ 0. 05); but the number of NGF-R positive neuronal processes in NTN group was more that that in NGF group ( P ＜ 0. 05).CONCLUSION: NTN has neurotrophic effect on NGF-R positive neurons of neonatal rat basal forebrain in vitro by relatively shorter acting time,and the number of neuronal processes induced by NTN is stronger than NGF; Moreover NTN combined with NGF exerts better effect than NTN or NGF alone in vitro.
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Objective To investigate the effects of combined neural stem cells(NSCs) and brain-derived neurotrophic factor(BDNF) on NOS-positive neurons of basal forebrain of rats with Alzheimer disease(AD). Methods Adult SD rats with left fimbria-fornix(FF) transection received neural stem cells transplanted in the basal forebrain.Then BDNF was continuous injected into lateral ventricle.After 4 weeks,morphologic data and percentages of NOS-positive neurons were measured in basal forebrain by using histochemical method combined with technique of micromeasure and image analysis. Results About 1 month after FF lesion,35.5% and 55.8% of NOS-positive neurons were survived in medial septum(MS) and vertical diagonal band(VDB) of the lesion side of basal forebrain,(P