【Abstract】 Objective To review the progress in the treatment of spinal cord injury (SCI) by graft of neuralstem cells (NSCs) or bone marrow mesenchymal stem cells (BMSCs) as well as immune characteristics of two stemcells. Methods Different kinds of documents were widely collected, and then immunologic characteristics of NSCs andBMSCs were summarized. The therapy of SCI by stem cell transplantation was reviewed. Additionally, some problems intreatment were analyzed. Results Experimental study showed that graft of NSCs and BMSCs can promote the functionalrecovery of the injured spinal cord in animals. Due to immunologic properties of two stem cells, rejection reaction oftransplantation could produce a harmful effect on SCI treatment. Conclusion Transplantation of NSCs or BMSCs might bean effective measure for SCI treatment, but immunologic rejection reaction must be considered.
ObjectiveTo investigate the behavioral recovery of spinal cord injury (SCI) rats that received transplantation of NEP1-40 gene-modified neural stem cells. MethodsNeural stem cells (NSCs) were derived from the cortex tissue of rat embryo at the age of 18 days and identified by Nestin immunofluorescence. The lentiviruses were transduced to NSCs to construct NEP1-40 gene modified NSCs. Spinal cords of 30 Sprague-Dawley rats were hemisected at the nineth thoracic vertebrae level. The rats were randomly assigned to three groups. Cell culture medium, NSCs and NEP1-40 gene-modified NSCs were transplanted into the lesion site of rats of SCI group, NSCs group and NEP1-40-NSCs group respectively 7 days after injury. Additional 10 rats served as blank control group (sham group), which only received laminectomy. Following transplantation, behavior tests including Basso, Beattie, Bresnahan (BBB) Locomotor Rating Scale and grid test were utilized to evaluate spinal cord functional recovery. ResultsBehavior tests 8 weeks after cells transplantation showed that the rats in SCI group got worst results, the BBB scores improved and the grid drop times reduced significantly in NSCs transplantation group (P<0.01) and behavioral test outcomes were best in the NEP1-40 gene-modified NSCs group (P<0.01). ConclusionNEP1-40 gene modification can significantly improve the behavioral recovery of SCI rats that received transplantation of pure neural stem cells. It can provide a new idea and reliable experimental base for the study of NSCs transplantation for spinal cord injury.
ObjectiveTo investigate the effect of serum on the differentiation of neural stem cells.MethodsThe neural stem cells were isolated from the embryonic hippocampus tissues of Sprague Dawley rats at 14 day of pregnancy. After culturing and passaging, the 3rd generation cells were identified by immunocytochemical staining. Then, the cells were divided into 3 groups according to the concentrations of fetal bovine serum (FBS) used in the differentiation cell culture medium: 5% (group A), 1% (group B), 0 (group C), respectively. The other components of the culture media in 3 groups were the same. Cell viability was determined by using the Live/Dead cell staining at 8 days; the expressions of glial cell marker [glial fibrillary acidic protein (GFAP)] and neuronal marker (β-Ⅲ Tubulin) were determined and analyzed by immunocytochemical staining and real-time fluorescent PCR at 4 and 8 days of culture.ResultsBased on cell morphology and immunocytochemical staining, neural stem cells were identified. Cells were growing well with no death in all groups. With decreasing FBS concentration, the expression of GFAP was significantly decreased on both protein and mRNA level, whereas the expression of β-Ⅲ Tubulin was evidently increased. The staining of each group at 8 days was more obvious than that at 4 days. There were significant differences in mRNA expressions of GFAP and β-Ⅲ Tubulin at 4 and 8 days between groups (P<0.05).ConclusionSerum can promote the differentiation of neural stem cells into glial cells. At the same time, it inhibits the differentiation of neural stem cells into neurons, the lower the serum concentration, the smaller the effect.
Objective To observe the effects of neural stem cells(NSCs) transplantation on the glial cell line-derived neurotrophic factor (GDNF) and growth associated protein 43(GAP-43) after the spinal cord injury(SCI), and to investigate the mechanism of repairing the SCI by NSCs transplantation. Methods The neural stem cells from the hippocampus of rats’ embryo were cultured and identified by immunocytochemistry. The SCI model was made by the modified Allen device. Sixty adult Wistar rats were randomly divided into three groups: spinal cord injury was treated with transplantation of NSCs (group A, n=24), with DMEM solution(group B, n=24) and normal control group without being injured(group C, n=12). Seven days after the operation of SCI, the NSCs were transplanted into the injured site. Then GAP-43 and GDNF expressions were tested by RT-PCR and immunohistochemistry. Results Compared with group B, the GDNF mRNA expression of group A increased by 23.3％ on the 1st day, by 26.8% on the 3rd day and by 32.7% on the 7th day; the GAP-43 mRNA expression increased by 19.5% on the 1st day, 21.6% on the 3rd day and 23.1% on the 7th day. There were statistically significant differences(Plt;0.05). Conclusion The transplantation of NSCs can change the microenvironment injured site and promote the regeneration of axon by enhancing the expressions of GDNF mRNA and GAP-43 mRNA. It is one of the mechanisms of repairing the SCI by NSCs transplantation.
ObjectiveTo study the possibility of the C17.2 neural stem cells (NSCs) differentiating into neural cells induced by serum-free condition medium of olfactory ensheathing cells (OECs) and to detect the cell viability of the differentiated cells. MethodsOECs were isloated and cultured from the olfactory bulbs of 3-day-old postnatal mouse to prepare serum-free condition medium of OECs. After C17.2 NSCs were cultured with H-DMEM/F12 medium containing 15% FBS and the cell fusion reached 80%, the 3rd passage cells were induced by serum-free condition medium of OECs in the experimental group, by H-DMEM/F12 in the control group, and non-induced C17.2 NSCs served as the blank control group. The growth condition of cells was observed with inverted microscope. After 5 days, the immunofluorescence staining[microtubule-associated protein 2 (MAP-2) and β-tubulin-Ⅲ] and Western blot (Nestin, β-tubulin-Ⅲ, and MAP-2) were carried out to identify the neural cells derived from NSCs. The cell viabilities were measured by MTT assay and the quantity of lactate dehydrogenase (LDH) release in the medium. ResultsIn the experimental group, the C17.2 NSCs bodies began to contract at 24 hours after induction, and the differentiated cells increased obviously with long synapse at 3 days after induction; in the control group, the cell morphology showed no obvious change at 24 hours, cell body shrinkage, condensation of nuclear chromatin, and lysis were observed at 3 days. The immunofluorescence staining showed that β-tubulin-Ⅲ and MAP-2 of C17.2 NSCs were positive at 5 days after induction, and Western blot suggested that the expression of Nestin protein declined significantly and the expressions of β-tubulin-Ⅲ and MAP-2 protein were increased in the experimental group, showing significant differences when compared with those in the control group and blank control group (P<0.05). The LDH release and the cell viability were 130.60%±6.86% and 62.20%±3.82% in the experimental group, and were 178.20%±5.44% and 18.00%±3.83% in the control group respectively, showing significant differences between 2 groups (P<0.05). The LDH release and the cell viability of experimental group and control group were significantly lower than those of blank control group (100%) (P<0.05). ConclusionNeurotrophic factors from OECs play an important role in inducing C17.2 NSCs differentiation into neural cells and keeping the viability of differentiated cells after induction.
Objective To observe the delaying effect of neural stem cell (NSC) transplantation on denervated muscle atrophy after peri pheral nerve injury, and to investigate its mechanism. Methods NSCs were separated from the spinal cords of green fluorescent protein (GFP) transgenic rats aged 12-14 days mechanically and were cultured and induced to differentiate in vitro. Thirty-two F344 rats, aged 2 months and weighed (180 ± 20) g, were randomized into two groups (n=16 per group). The animal models of denervated musculus triceps surae were establ ished by transecting right tibial nerve and commom peroneal nerve 1.5 cm above the knee joints. In the experimental and the control group, 5 μL of GFP-NSCsuspension and 5 μL of culture supernatant were injected into the distal stump of the tibial nerve, respectivel. The generalcondition of rats after operation was observed. At 4 and 12 weeks postoperatively, the wet weight of right musculus tricepssurae was measured, the HE staining, the Mallory trichrome staining and the postsynaptic membrane staining were adopted for the histological observation. Meanwhile, the section area of gastrocnemius fiber and the area of postsynaptic membrane were detected by image analysis software and statistical analysis. Results The wounds in both groups of animals healed by first intension, no ulcer occurred in the right hind l imbs. At 4 and 12 weeks postoperatively, the wet weight of right musculus triceps surae was (0.849 ± 0.064) g and (0.596 ± 0.047) g in the experimental group, respectively, and was (0.651 ± 0.040) g and (0.298 ± 0.016) g in the control group, respectively, showing a significant difference (P lt; 0.05). The fiber section area of the gastrocnemius was 72.55% ± 8.12% and 58.96% ± 6.07% in the experimental group, respectively, and was 50.23% ± 4.76% and 33.63% ± 4.41% in the control group, respectively. There were significant differences between them (P lt; 0.05). Mallory trichrome staining of muscle notified that there was more collagen fiber hyperplasia of denervated gastrocnemius in the control group than that in the experimental group at 4 and 12 weeks postoperatively. After 12 weeks of operation, the area of postsynaptic membrane in the experimental group was (137.29 ± 29.14) μm2, which doubled that in the control group as (61.03 ± 11.38) μm2 and was closer to that in normal postsynaptic membrane as (198.63 ± 23.11) μm2, showing significant differences (P lt; 0.05). Conclusion The transplantation in vivo of allogenic embryonic spinal cord NSCs is capable of delaying denervated muscle atrophy and maintaining the normal appearance of postsynaptic membrane, providing a new approach to prevent and treat the denervated muscle atrophy cl inically.
ObjectiveTo observe the effects on the function and structure of retina in diabetic rats by intravitreal transplantation of retinal nerve stem cells (NSC) differentiated from human umbilical cord mesenchymal stem cells (hUCMSCs). MethodsFifty clean male Sprague-Dawley rats were randomly divided into normal control with 9 rats (group A) and diabetes mellitus (DM) group with 31 rats. The DM models were induced by intraperitoneal injection of streptozocin. The rats of DM group were randomly divided into four groups after 10 weeks: rats with DM only (group B), diabetic rats with saline intravitreal injection (group C), diabetic rats with NSC intravitreal injection (group D), and 9 rats for each. The rats in the group A and B received no treatment. The retinal function was examined by the flash-electroretinogram on 2, 4, 6 weeks after intervention, the latency and amplitude of a-wave, b-wave of Rod, a-wave, b-wave of Max reactions (Max-R) and the total amplitudes of OPs were recorded. The morphological changes of retina were observed by hematoxylin-eosin staining. ResultsOn 2 and 4 weeks after the intervention, the differences of latency and amplitude of b-wave of Rod, a-wave, b-wave of Max-R and the total amplitudes of OPs among group A-D were significant (P<0.05). Compared group D with group B, C, the amplitude of b-wave of Rod, Max-R and the total amplitudes of OPs were increased (P<0.05); latency of b-wave of Max-R was decreased (P<0.05). On 6 weeks after the intervention, the amplitude of b-wave of Rod and the amplitude of a-wave, b-wave of Max-R and the total amplitudes of OPs in group D were increased compared with group B and C (P<0.05), the latency of b-wave of Rod and Max-R in group D were decreased compared with group C (P<0.05). On 10 weeks after molding, each retinal layers were disordered in diabetes mellitus group. On 2 weeks after the intervention, the number of cells in the retinal layers in group B and C were reduced compared with group A, and the structure was more disorder. On 4 weeks after the intervention, the structure of each retina layer in group D arranged less disordered, and the number of retinal ganglion cells was more than group B and C. It was also found that the retinal vascular endothelial expanded and retinal blood vessels cells proliferated. ConclusionThe function of retina in diabetes mellitus rats is improved by intravitreal injection of retinal NSCs differentiated from hUCMSCs.
Objective To explore the effects of Neurogenesin 1 (Ng1) gene on functional recovery after spinal cord injury (SCI) and its mechanism. Methods Thirty-six rats (aging 4 months, weighing 230 g and being male or female), were randomly divided into two groups: experimental group (n=18) and control group (n=18). After spinal cord contusive injury at T10 level was made in all these rats using modified Allen’s method, Ng1 recombinant plasmid and blank plasmid were transfectedinto the damaged areas of exprimental group and control group respectively by Alzet pumps. At 1 day, 1 week, 2 weeks, 3 weeks, and 4 weeks after SCI, Basso-Beattle-Bresnahan (BBB) Rating Scale was used to observe the recovery of motor function. At 1 week after injury, the expressions of Ng1 mRNA and protein in injured spinal cord were detected by RT-PCR and Western blot techniques. And at 2 and 4 weeks, double immunofluorescence and histopathologic examinations were performed to study the prol iferation of the adult endogenous neural stem cells and pathological change after SCI. Results At 1-4 weeks after SCI, the BBB scores in the exprimental group was significantly higher than that in control group (P lt; 0.05), and at 4 weeks the BBB score of the experimental group (16.80 ± 1.79) was significantly higher than that of the control group (9.60 ± 1.67), (P lt; 0.01). RTPCR and Western blot showed that the mRNA and protein expressions of Ng1 were observed in the exprimental group and no expression was seen in the control group. Histologic observation showed that the morphology of spinal cord and neurons in the exprimental group was better than that in the control group and was close to the normal tissue. The mean number of Nestin+/ BrdU+ newborn endogenous neural stem cells in the exprimental group was significantly more than that in control group (P lt; 0.05). Conclusion Ng1 gene could promote the prol iferation of endogenous neural stem cells and protect the injured neurons, which enhances the repair of the motor function after SCI.
ObjectiveTo observe the morphological and functional changes of retinal degeneration in mice with CLN7 neuronal ceroid-lipofuscinosis, and the therapeutic effects of glial cell derived neurotrophic factor (GDNF) and/or ciliary neurotrophic factor (CNTF) based on neural stem cells (NSC) on mouse photoreceptor cells. MethodsA total of 100 CLN7 mice aged 14 days were randomly divided into the experimental group and the control group, with 80 and 20 mice respectively. Twenty C57BL/6J mice aged 14 days were assigned as wild-type group (WT group). Mice in control group and WT group did not receive any interventions. At 2, 4, and 6 months of age, immunohistochemical staining was conducted to examine alterations in the distribution and quantity of cones, rod-bipolar cells, and cone-bipolar cells within the retinal of mice while electroretinography (ERG) examination was utilized to record scotopic a and b-waves and photopic b-wave amplitudes. At 14 days of age, the mice in the experimental group were intravitreally injected with 2 μl of CNTF-NSC, GDNF-NSC, and a 1:1 cell mixture of CNTF-NSC and GDNF-NSC (GDNF/CNTF-NSC). Those mice were then subdivided into the CNTF-NSC group, the GDNF-NSC group, and the GDNF/CNTF-NSC group accordingly. The contralateral eyes of the mice were injected with 2 μl of control NSC without neurotrophic factor (NTF) as their own control group. At 2 and 4 months of age, the rows of photoreceptor cells in mice was observed by immunohistochemical staining while ERG was performed to record amplitudes. At 4 months of age, the differentiation of grafted NSC and the expression of NTF were observed. Statistical comparisons between the groups were performed using a two-way ANOVA. ResultsCompared with WT group, the density of cones in the peripheral region of the control group at 2, 4 and 6 months of age (F=285.10), rod-bipolar cell density in central and peripheral retina (F=823.20, 346.20), cone-bipolar cell density (F=356.30, 210.60) and the scotopic amplitude of a and b waves (F=1 911.00, 387.10) in central and peripheral retina were significantly decreased, with statistical significance (P＜0.05). At the age of 4 and 6 months, the density of retinal cone cells (F=127.30) and b-wave photopic amplitude (F=51.13) in the control group were significantly decreased, and the difference was statistically significant (P＜0.05). Immunofluorescence microscopy showed that the NSC transplanted in the experimental group preferentially differentiated into astrocytes, and stably expressed CNTF and GDNF at high levels. Comparison of retinal photoreceptor nucleus lines in different treatment subgroups of the experimental group at different ages: CNTF-NSC group, at 2 months of age: the whole, central and peripheral regions were significantly different (F=31.73, 75.06, 75.06; P＜0.05); 4 months of age: The difference between the whole area and the peripheral region was statistically significant (F=12.27, 12.27; P＜0.05). GDNF/CNTF-NSC group, 2 and 4 months of age: the whole (F=27.26, 27.26) and the peripheral area (F=16.01, 13.55) were significantly different (P＜0.05). In GDNF-NSC group, there was no statistical significance at all in the whole, central and peripheral areas at different months of age (F=0.00, 0.01, 0.02; P＞0.05). ConclusionsCLN7 neuronal ceroid-lipofuscinosis mice exhibit progressively increasing degenerative alterations in photoreceptor cells and bipolar cells with age growing, aligning with both morphological and functional observations. Intravitreal administration of stem cell-based CNTF as well as GDNF/CNTF show therapeutic potential in rescuing photoreceptor cells. Nevertheless, the combined application of GDNF/CNTF-NSC do not demonstrate the anticipated synergistic protective effect. GDNF has no therapeutic effect on the retinal morphology and function in CLN7 neuronal ceroid-lipofuscinosis mice.
To explore the expression of Wnt-1 during the process of inducing neural stem cells (NSCs) into neurons by using all-trans-retinoic acid (ATRA) in vitro and the effect of Wnt-1 on NSCs differentiation. Methods NSCs isolated from cerebral cortex of SD rat embryo (12-16 days’ gestation) were cultured. The concentration of cells at passage 3 were adjusted to 1 × 106 cells /mL and treated with ATRA at 0.5, 1.0, 5.0 and 10.0 μmol/L, respectively. Differentiation ratio of NSCsinto neurons in each group was detected by double-labelling immunofluorescence technique and flow cytometry, and 1.0 μmol/ L was selected as the best concentration for ATRA to promote NSCs differentiation. In experimental group, NSCs at passage 3 were cultured with ATRA at 1.0 μmol/L in vitro, and expression of Wnt-1 was detected by immunocytochemistry staining, realtime flurescent quantitive PCR and Western blot at 3, 5, 7 and 9 days after culture, respectively. The cells at passage 3 receiving no ATRA served as control group. Results Immunocytochemistry staining: in the control group, there was l ittle Wnt-1 protein expression; in the experimental group, peak expression of Wnt-1 and numerous positive cells occurred at 3 days after culture, the positive expression of Wnt-1 was still evident at 5 days after culture, and there was significant difference between two groups in integrated absorbance (IA) value at 3 and 5 days after culture(P lt; 0.05), obvious decrease of positive expression of Wnt-1 was evident, and no significant difference was evident between two groups in IA value at 7 and 9 days (P gt; 0.05). Real-time fluorescence quantitative PCR: the relative expression of Wnt-1 mRNA in the control group was 0.021 7 ± 0.072 1; the relative expression of Wnt-1 mRNA in the experimental group at 3, 5, 7 and 9 days was 0.512 2 ± 0.280 0, 0.216 4 ± 0.887 0, 0.038 5 ± 0.299 4 and 0.035 5 ± 0.309 5, respectively, indicating the value decreased over time, and there were significant difference between two groups at 3 and 5 days (P lt; 0.05), and no significant difference at 7 and 9 days (P gt; 0.05) . Western blot detection: specific and visible staining band was noted; in the control group, Wnt-1 protein expression was 0.005 1 ± 0.558 3; in the experimental group, Wnt-1 protein expression at 3, 5, 7 and 9 days was 0.451 7 ± 0.071 3, 0.311 7 ± 0.080 5, 0.007 3 ± 0.052 7 and 0.004 7 ± 0.931 4, respectively, suggesting the value decreased over time; there were significant differences between two groups at 3 and 5 days (P lt; 0.05), and no significant differences at 7 and 9 days (P gt; 0.05). Conclusion With the induction of ATRA at 1.0 μmol/L, Wnt-1 and NSCs differentiation in early stage are positively correlated. Its possible mechanism may rely on the activation of such signals as classic Wnt-1 signal pathway, indicating Wnt-1 relates to the differentation of NSCs into neurons.