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.
ObjectiveTo investigate the effect of intravitreal injection of neural stem cells (NSC) derived from human umbilical cord mesenchymal stem cells (hUCMSC) on the expression of brain-derived neurotrophic factor (BDNF) and the number of retinal ganglion cells (RGC).
MethodsFifty-two adult male Sprague-Dawley rats were randomly divided into normal group (group A) and diabetes mellitus group which received intraperitoneal injection of streptozocin to make diabetic rat models. One month after the diabetic rat models were confirmed successfully, diabetic rats were randomly divided into diabetic group (group B), hUCMSC group (group C) and hUCMSC-induced NSC group (group D). And thirteen diabetic rats were included in each group. Immuno-cytochemistry was applied to observe BDNF and thymosin-1(Thy-1) staining in the retina. Then mean integrated absorbance of the staining region on the retina slices were analyzed by Image-Pro Plus 6.0. The number of Thy-1 labeled RGC was record.
ResultsBDNF and Thy-1 were positive on the retina slices from group A. The staining intensity from group B became weak and the expression of BDNF and Thy-1 gradually decrease with time (P < 0.05), and those from group C and group D were positively (P < 0.05), especially in group D (P < 0.05). The BDNF expression and Thy-1 labeled RGC were the same between group B and C (P > 0.05) at 2 weeks after injection, but were significant different for other time points (P < 0.05).Significant positive correlation between the expression of BDNF and the number of RGC were found by the Pearson correlation analysis (r=0.964, P < 0.05).
ConclusionIntravitreal injection of hUCMSC-derived NSC to diabetic rat may protect the retina by promoting the expression of BDNF and increasing the number of RGC.
ObjectiveTo establish the system of isolation, cultivation, and identification of the neural stem cells (NSCs) from subventricular zone (SVZ) of neonatal mice so as to seek for the appropriate seed cells for potential therapeutic interventions of neurological disorders.
MethodsNSCs were isolated enzymatically and mechanically from SVZ of neonatal mice and cultured. The cellular morphology was observed by inverted microscopy. Immunocytochemical stainings of anti-Nestin and anti-SOX-2 were used to identify NSCs of passage 3. To study the differentiation of NSCs, NSCs were plated into 24-wells in the medium supplemented without epidermal growth factor (EGF) and basic fibroblastic growth factor (bFGF) for 3 or 7 days. To compare the differentiation and proliferation potential of NSCs with different cultivation time, the BrdU pulse-labeling method and MTT test were used. To identify neurons and astrocytes, the anti-β-tubulin Ⅲ (Tuj-1) and anti-glial fibrillary acidic protein (GFAP) staining were used.
ResultsThe cells of the SVZ can be isolated and cultured in vitro, and these cells began to form neurospheres after cultured for 3 days at primary passage. While cultured for 7 days, these cells formed more neurospheres, and the volume of the neurospheres became bigger than neurospheres cultured for 3 days. In addition, after cultured for 7 days, the phenomena of fusion of neurospheres and adherent differentiation of neurospheres were observed under inverted microscope. These cells were provided with the typical phenotype of NSCs. The immunofluorescence staining results revealed that these cells showed positive immunoreactivity to Nestin and SOX-2. During the 4 hours BrdU pulse, the number of proliferated NSCs cultured for 3 days (75.817±2.961) was significantly higher than that of NSCs cultured for 7 days (56.600±4.881) (t=3.366, P=0.028). The results of MTT assay revealed that the absorbance (A) value of NSCs cultured for 3 days (0.478±0.025) was significantly higher than that of NSCs which were cultured for 7 days (0.366±0.032)(t=2.752, P=0.011). After cultivated without EGF and bFGF, the percentage of Tuj-1 and GFAP positive cells in NSCs was 23.1%±3.7% and 23.7%±3.8% for 3 days and was 40.1%±3.6% and 37.1%±4.5% for 7 days, respectively, all showing significant differences (t=3.285, P=0.030; t=3.930, P=0.017).
ConclusionThe NSCs from SVZ of neonatal mice have potentials of self-renewal and multipotential differentiation in vitro. With different cultivation time, the potentials of proliferation and differentiation of NSCs are different.
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.
Objective To investigate the division, prol iferation and differentiation abil ities of nestin+/GFAP+cell after spinal cord injury and to identify whether it has the characteristic of neural stem cells (NSCs). Methods Twelvemale SD rats, aged 8 weeks and weighing 200-250 g, were randomized into 2 groups (n=6 per group): model group inwhich the spinal cord injury model was establ ished by aneurysm cl ip compression method, and control group in which no processing was conducted. At 5 days after model ing, T8 spinal cord segment of rats in each group were obtained and the gray and the white substance of spinal cord outside the ependymal region around central tube were isolated to prepare single cellsuspension. Serum-free NSCs culture medium was adopted to culture and serum NSCs culture medium was appl ied to induce differentiation. Immunohistochemistry detection and flow cytometry were appl ied to observe and analyze the type of cells and their capabil ity of division, prol iferation and differentiation. Results At 3-7 days after injury, the model group witnessed a plenty of nestin+/GFAP+ cells in the single cell suspension, while the control group witnessed few. Cell count of the model and the control group was 5.15 ± 0.71 and 1.12 ± 0.38, respectively, indicating there was a significant difference between two groups (P lt; 0.01). Concerning cell cycle, the proportion of S-phase cell and prol iferation index of the model group (15.49% ± 3.04%, 15.88% ± 2.56%) were obviously higher than those of the control group (5.84% ± 0.28%, 6.47% ± 0.61%), indicating there were significant differences between two groups (P lt; 0.01). In the model group, primary cells gradually formed threedimensional cell clone spheres, which were small in size, smooth in margin, protruding in center and positive for nestin immunofluorescence staining, and large amounts of cell clone spheres were harvested after multi ple passages. While in the control group, no obvious cell clone spheres was observed in the primary and passage culture of single cell suspension. At 5 days after induced differentiation of cloned spheres in the model group, immunofluorescence staining showed there were a number of galactocerebroside (GaLC) -nestin+ cells; at 5-7 days, there were abundance of β-tubul in III-nestin+ and GFAP-nestin+ cells; and at 5-14 days, GaLC+ ol igodendrocyte, β-tubul in II+ neuron and GalC+ cell body and protruding were observed. Conclusion Nestin+/GFAP+ cells obtained by isolating the gray and the white substance of spinal cord outside the ependymal region around central tube after compressive spinal cord injury in adult rat has the abil ity of self-renewal and the potential of multi-polarization and may be a renewable source of NSCs in the central nervous system.
ObjectiveTo prepare bionic spinal cord scaffold of collagen-heparin sulfate by three-dimensional (3-D) printing, and provide a cell carrier for tissue engineering in the treatment of spinal cord injury.
MethodsCollagen-heparin sulfate hydrogel was prepared firstly, and 3-D printer was used to make bionic spinal cord scaffold. The structure was observed to measure its porosity. The scaffold was immersed in simulated body fluid to observe the quality change. The neural stem cells (NSCs) were isolated from fetal rat brain cortex of 14 days pregnant Sprague-Dawley rats and cultured. The experiment was divided into 2 groups: in group A, the scaffold was co-cultured with rat NSCs for 7 days to observe cell adhesion and morphological changes;in group B, the NSCs were cultured in 24 wells culture plate precoating with poly lysine. MTT assay was used to detect the cell viability, and immunofluorescence staining was used to identify the differentiation of NSCs.
ResultsBionic spinal cord scaffold was fabricated by 3-D printer successfully. Scanning electron microscope (SEM) observation revealed the micro porous structure with parallel and longitudinal arrangements and with the porosity of 90.25%±2.15%. in vitro, the value of pH was not changed obviously. After 8 weeks, the scaffold was completely degraded, and it met the requirements of tissue engineering scaffolds. MTT results showed that there was no significant difference in absorbence (A) value between 2 groups at 1, 3, and 7 days after culture (P>0.05). There were a lot of NSCs with reticular nerve fiber under light microscope in 2 groups;the cells adhered to the scaffold, and axons growth and neurosphere formation were observed in group A under SEM at 7 days after culture. The immunofluorescence staining observation showed that NSCs could differentiated into neurons and glial cells in 2 groups;the differentiation rate was 29.60%±2.68% in group A and was 10.90%±2.13% in group B, showing significant difference (t=17.30, P=0.01).
ConclusionThe collagen-heparin sulfate scaffold by 3-D-printed has good biocompatibility and biological properties. It can promote the proliferation and differentiation of NSCs, and can used as a neural tissue engineered scaffold with great value of research and application.
Objective To observe the biocompatibil ity of self-assembled FGL peptide nano-fibers scaffold with neural stem cells (NSCs). Methods FGL peptide-amphiphile (FGL-PA) was synthesized by sol id-phase peptide synthesistechnique and thereafter It was analyzed and determined by high-performance l iquid chromatography (HPLC) and massspectrometry (MS). The diluted hydrochloric acid was added into FGL-PA solution to reduce the pH value and accordinglyinduce self-assembly. The morphological features of the assembled material were studied by transmission electron microscope (TEM). NSCs were cultured and different concentrations of FGL-PA assembled material were added with the terminal concentrations of 0, 50, 100, 200, 400 mg/L, respectively. CCK-8 kit was used to test the effect of FGL assembled material on prol iferation of NSCs. NSCs were added into differentiation mediums (control group: DMEM/F12 medium containing 2% B27 supplement and 10% FBS; experimental group: DMEM/F12 medium containing 2% B27 supplement, 10% FBS and 100 mg/L FGL-PA, respectively). Immunofluorescence was appl ied to test the effect of FGL-PA assembled material on differentiation of NSCs. Results FGL-PA could be self-assembled to form a gel. TEM showed the self-assembled gel was nano-fibers with diameter of 10-20 nm and length of hundreds nanometers. After NSCs were incubated for 48 hours with different concentrations of FGL-PA assembled material, the result of CCK-8 assay showed that FGL-PA with concentrations of 50, 100 or 200 mg/L could promote the prol iferation of NSCs and absorbance of them was increased (P lt; 0.05). Immunofluorescence analysis notified that the differentiation ratio of neurons from NSCs in control group and experimental group were 46.35% ± 1.27% and 72.85% ± 1.35%, respectively, when NSCs were induced to differentiation for 14 days, showing significant difference between 2 groups (P lt; 0.05). Conclusion FGL-PA can self-assemble to nano-fiber gel, which has good biocompatibil ity and neural bioactivity.
【Abstract】 Objective To investigate the effectiveness of all-trans-retinoic acid (ATRA) at different concentrationson prol iferation and differentiation of the rat embryonic neural stem cells (NSCs), and to find the optimal concentration of ATRA that promoting the differentiation of NSCs into neurons. Methods NSCs were isolated from cerebral cortex of rat embryos (embryonic day 12-16, average 15 days), and were cultured in serum-free medium (DMEM/F12 medium containing 20 ng/mL bFGF and 20 ng/mL EGF) at the concentration of 1×106 cells/mL. Subcultures were performed 7 days after the primary culture. The cell clusters of the 3rd passage were centrifuged and divided into 5 groups. In the experimental groups (groups A, B, C, D), the ATRA concentration was 0.5, 1.0, 5.0, 10.0 μmol/L in DMEM/F12 complete medium respectively, while in control group (group E), the ATRA concentration was 0 in DMEM/F12 complete medium. The prol iferation rate of each group was analyzedby cell counting day by day till 7th day, and BrdU positive cell counting 1, 3, 5, 7, 9 days after culture. In addition, collecting the 3rd passage NSCs and divided into 5 groups. In the experimental groups (groups A, B, C, D), the ATRA concentration was 0.5, 1.0, 5.0, 10.0 μmol/L in DMEM/F12 medium containing 5% FBS respectively, while in control group (group E), the ATRA concentration was 0 in DMEM/F12 medium containing 5% FBS. The capacity of NSCs differentiation toward neurons was determined by immunofluorescence double-labell ing and flow cytometry. Results Cell counting 1-7 days after culture in each experimental group (groups A, B, C, D) showed no significant differences (P gt; 0.05). Cell counting at each time point of all the experimental groups were less than those of control group (P lt; 0.05). BrdU positive cells were increased 1, 3, 5, 7, 9 days after culture in each experimental group (groups A, B, C, D), but there was no significant difference between each experimental group(P gt; 0.05). BrdU positive cells at each time point of control groups were more than those of all the experimental groups (P lt;0.05). The differentiation ratio of neurons was enhanced in experimental groups and the optimal ATRA treatment concentration was 1.0 μmol/ L (experimental group B). The differentiation ratio of neurons induced by ATRA in group B was 29.46% ± 0.47%, 47.25% ± 0.46% and 66.81% ± 0.57% respectively after cultured 3, 5 and 7 days, whereas the differentiation ratio of neurons was 11.11% ± 0.59%, 14.10% ± 0.32% and 15.92% ± 0.70% respectively in control group. The majority of NSCs differentiated into astrogl ial phenotypes in control group. By flow cytometry detection, the differentiation ratio of neurons after cultured 3 days and 7 days in experimental groups were more than those in control group (P lt; 0.05). Conclusion ATRA treatment remarkably promoted the differentiation of NSCs into neurons and the optimal concentration was 1.0 μmol/L.
Objective To compare single cell suspension of neural stem cells (NSCs) with neurospheres transplantation for spinal cord injury (SCI) so as to explore the therapeutic effectiveness of two NSCs transplantation methods for SCI. Methods The NSCs were isolated from the spinal cord of adult Sprague Dawley (SD) rats, purified and cultured. At passage 3, the cells were identified by Hoechst33342, Nestin staining, and gl ial fibrillary acidic protein staining for differentiated cells. Sixty adult SD rats (weighing 230-250 g) were made the SCI models at T10 level with modified Allen method and randomlydivided into 3 groups (20 rats in each). The injury sites were treated by injecting 5 μL sal ine (group A), 5 μL single cellssuspensions of NSCs at passage 3 (group B), and 5 μL neurospheres cell suspensions at passage 3 (group C). At preoperation and 3, 7, 14, 21, and 28 days after operation, the locomotor functions of each group were assessed using the Basso, Beattie, and Bresnahan (BBB) rating scale. HE staining was applied to observe the morphology of spinal cord. Subsequently immunofluorescence staining was used to observe microtubule-associated protein 2 (MAP-2). Results The cells cultured were NSCs by morphological observation and immunofluorescence staining. After 3 days of modeling surgery, BBB score significantly decreased when compared with preoperative score, and there was no significant difference among 3 groups at 3 and 7 days (P gt; 0.05). BBB score increased in different degrees with time; at 14, 21, and 28 days, BBB score of groups B and C was better than that of group A, and group C was better than group B, showing significant differences (P lt; 0.05). HE staining showed that spinal cord structure of group C was more clear than that of groups A and B, and had less scar. There was no significant difference in the number of MAP-2 positive cells among 3 groups at 3 and 7 days (P gt; 0.05). At 14, 21, and 28 days, the number of MAP-2 positive cells of groups B and C was significantly more than that of group A, and group C was more than group B, showing significant differences (P lt; 0.05). Conclusion Transplantation of neurospheres suspension compared with single cell can significantly promote NSCsto differentiate into neurons and is conducive to recover the lower extremity function after SCI.
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.
