Neurotrophin-3 promotes the recovery of neurological function after cerebral ischemia-reperfusion injury in rats / 神经解剖学杂志

Objective:To explore the role and mechanism of neurotrophin-3(NT-3)in promoting neurological func-tion recovery after cerebral ischemia-reperfusion injury in rats.Methods:Twenty-four SD rats were randomly divided into sham operation group(Sham),middle cerebral artery occlusion/reperfusion(MCAO/R)group,and MCAO/R+NT-3 group.The neurological function scores of rats in each group were evaluated using the modified Garcia score.Western Blot was used to detect the expression of NT-3 and LC3B in brain tissues of rats.Culture dishes with the same density of neurons were randomly divided into normal group(Normal),oxygen-glucose deprivation(OGD)group,OGD+NT-3 group,OGD+NT-3+PF-06273340(TrkC inhibitor)group,OGD+NT-3+ZSTK474(PI3K inhibitor)group,and OGD+NT-3+CCT128930(AKT inhibitor)group.Western Blot was used to detect the expression of TrkC,the phosphorylation of PI3K/AKT,and LC3B in neurons.The morphological changes of neurons and the phenomenon of neuronal autophagy were observed using autophagy-specific fluorescent staining.Results:The animal experiment found that the expression of NT-3 increased in the brain tissue with ischemia-reperfusion injury(P＜0.05),and after the treatment with exogenous NT-3,the modified Garcia score increased(P＜0.05),and the level of autophagy weakened(P＜0.05).The cell experiment found that NT-3 can inhibit neuronal autophagy under ischemic hypoxia and maintain the neuronal morphology to the maximum extent.After using PF-06273340,the expression of p-PI3K and p-AKT de-creased(P＜0.05).After using ZSTK474 and CCT128930,the autophagy-inhibiting effect of NT-3 weakened(P＜0.05).Conclusion:NT-3 inhibits autophagy via the PI3K/AKT signaling pathway to maintain neuronal survival,thereby promoting the recovery of neurological function after cerebral ischemia-reperfusion injury in rats.

Effect of medium frequency electrical stimulation on expression of neurotrophin-3 in rat masseter muscle / 上海交通大学学报（医学版）

Objective • To investigate the effect of medium frequency electrical stimulation on the expression of neurotrophin-3(NT-3) in the mandibular protrusion of SD rats. Methods • Sixty male SD rats were randomly divided into three groups (n=20): blank control group, conditioned control group (treated with functional appliance, but without medium frequency electrical stimulation) and experimental group (treated with functional appliance and medium frequency electrical stimulation). Five rats in each group were sacrificed on the 3rd, 7th, 14th and 21st day to prepare the samples of masseter muscle. Immunohistochemistry and quantitative real-time PCR methods were used to detect the protein and mRNA expressions of NT-3 in the masseter muscle of rats. Results • The protein and mRNA expressions of NT-3 were increased firstly and then decreased in the conditioned control group and the experimental group, compared with those in the blank control group. Moreover, the protein and mRNA expressions of NT-3 in the conditioned control group were still higher than those in the blank control group on the 21st day (both P<0.05), while the protein and mRNA expressions of NT-3 in the experimental group almost returned to the normal level on the 21st day. Conclusion • Medium frequency electrical stimulation may accelerate the rate of neuromuscular reconstruction and shorten the time of functional orthopedic therapy in rats.

Electrical stimulation combined with neurotrophin 3 promotes proliferation and differentiation of endogenous neural stem cells after spinal cord injury in rats / 中国组织工程研究

BACKGROUND: Due to limited access to exogenous neural stem cells, immune rejection and ethical problems, how to activate endogenous neural stem cells and promote their growth, proliferation and differentiation has become an issue of concern. OBJECTIVE: To investigate the effects of electrical stimulation combined with neurotrophin 3 on the proliferation and differentiation of endogenous neural stem cells into neurons after spinal cord injury in rats. METHODS: Ninety-six rats were randomly divided into sham operation (spinal cord exposed only), spinal cord injury, electrical stimulation, and electrical stimulation+neurotrophin groups, 24 rats in each group. A rat model of spinal cord injury was established by modified Allen method in the latter three groups. After the model was established, the rats in the four groups were given corresponding treatments. At 7, 14, 21, and 28 days after modeling, the motor function of hind limbs was evaluated by Basso-Beattie-Bresnahan score. The latency of motor evoked potential was examined by electrophysiology. At 28 days after modeling, samples of the spinal cord were taken for hematoxylin-eosin staining to observe the pathological changes and for immunohistochemical staining to observe the the proliferation and differentiation of endogenous neural stem cells. The study was approved by the Ethics Committee of the Second Hospital of Lanzhou University. RESULTS AND CONCLUSION: (1) Compared with the sham operation group, the Basso-Beattie-Bresnahan score in the spinal cord injury group was significantly decreased (P electrical stimulation group > spinal cord injury group. The expression level of glial fibrillary acidic protein was highest in the spinal cord injury group, followed by electrical stimulation group, and lowest in the electrical stimulation+neurotrophin group. These results show that after electrical stimulation plus neurotrophin 3 intervention, endogenous neural stem cells can proliferate and differentiate into neurons. Pathological damage is significantly alleviated and motor function of hind limbs is significantly improved.

Neurotrophin-3 modified hyaluronan-methylcellulose hydrogel promotes neurological function in rats with spinal cord injury / 中国组织工程研究

BACKGROUND: Hyaluronan-methylcellulose hydrogel cannot only be conjugated with short peptide sequences and growth factors to achieve sustained release, but also has a role in blocking dural defects and reducing inflammation. It is an ideal biomaterial for the treatment of spinal cord injury. OBJECTIVE: To investigate the effect of neurotrophin-3 modified hyaluronan-methylcellulose (HAMC-NT-3) hydrogel on the recovery of neurological function in rats with spinal cord injury. METHODS: Fifty-four female Sprague-Dawley rats (provided by the Experimental Animal Center of the Academy of Military Medical Sciences in China) were randomly divided into three groups (n=18 per group) . The sham group only underwent T10 laminectomy. In the model group and the experimental group, an aneurysm clip was used to establish spinal cord injury models after T10 laminectomy. The experimental group was locally injected with HAMC-NT-3 hydrogel. The Basso Beattie Bresnahan function scoring was performed at 1 day, 1, 2, 3, 4, 5, 6, 7, and 8 weeks after surgery. The inclined plane test was performed at 4, 6 and 8 weeks after surgery to evaluate the recovery of hindlimb motor function. ELISA was used to detect the concentrations of inflammatory factors in the spinal cord at 1 week after surgery. Immunohistochemical staining was used to observe the area of syringomyelia, glial fibrillary acidic protein expression and nerve regeneration at 8 weeks after surgery. RESULTS AND CONCLUSION: (1) The Basso Beattie Bresnahan scores of the model group and the experimental group were lower than those of the sham group at various time points after surgery (P < 0.05) . The Basso Beattie Bresnahan scores of the experimental group were higher than those of the model group at 4-8 weeks after surgery (P < 0.05) . (2) In the inclined plane test, the maximum inclined angles of the model group and the experimental group at each time point after surgery were lower than that of the sham group (P < 0.05) . The maximum inclined angles of the experimental group at 6 and 8 weeks after surgery were higher than those of the sham group (P < 0.05) . (3) The concentrations of tumor necrosis factor-α, interleukin-1β, interleukin-6 and interleukin-10 in the experimental group and the model group were higher than those in the sham group (P < 0.05) . The concentrations of tumor necrosis factor-α, interleukin-1β and interleukin-6 in the experimental group were lower than those in the model group (P < 0.05) . The concentration of interleukin-10 in the experimental group was higher than that in the model group (P < 0.05) . (4) Immunohistochemical staining showed that the expression levels of glial fibrillary acidic protein in the experimental group and the model group were higher than those in the sham group, while the expression of glial fibrillary acidic protein in the experimental group was lower than that in the model group. The area of syringomyelia in the experimental group was smaller than that in the model group (P < 0.05) . These results indicate that local injection of HAMC-NT-3 hydrogel can effectively inhibit inflammation as well as astrocyte activation and proliferation, reduce fibrous scar formation, and promote the protection of nerve tissue and the recovery of hindlimb motor function after spinal cord injury.

Construction of adipose-derived stem cells line that can stably express brain-derived neurotrophic factor and neurotrophin-3 genes and its significance / 西安交通大学学报(医学版)

Objective: To construct adipose-derived stem cells (ADSCs) line that can stably express brain-derived neurotrophic factor (BDNF) and neurotrophin-3(NT-3) genes and elucidate its significance. Methods: ADSCs were obtained by collagenase digestion along with differential adhesion method. After 2 and 4 weeks of osteogenic induction, alkaline phosphatase staining and alizarin red staining were performed. The third generation of ADSCs were transfected with Lenti-BDNF-GFP and Lenti-NT-3-RFP recombinant lentivirus solution. The ADSCs line that stably expressed BDNF and NT-3 genes were obtained by the optimal infection value determined before. Results: The ADSCs isolated and cultured successfully had the potential to differentiate in varous directions. After being induced to osteogenesis, alkaline phosphatase and alizarin red staining both showed positive. The best infection value for Lenti-BDNF-GFP and Lenti-NT-3-RFP recombinant lentivirus transfection was 100 while the infection duration was 72 hours. Expressions of BDNF and NT-3 in co-transfection group remained stable and high at both gene and protein levels. Conclusion: Establishment of ADSCs with stable and over-expressed BDNF and NT-3 genes is of great significance for treatment of spinal cord injury (SCI). It can solve the problem of low amount of neurotrophin secreted and short half-life during the treatment of SCI by ADSCs transplantation, which has great significance for further studies on the repair mechanism of SCI.

Differential Clinical Significance of Neurotrophin-3 Expression according to MYCN Amplification and TrkC Expression in Neuroblastoma

BACKGROUND: Neurotrophin-3 (NT-3), a member of the NT family, has only been considered an ancillary compound that provides anti-apoptotic benefits by inactivating tropomyosin receptor kinase C (TrkC)-induced apoptotic signals. However, little is known about the clinical relevance of NT-3 expression itself in neuroblastoma. The purpose of this study was to assess NT-3 expression in patients with neuroblastoma and its relevance to clinicopathologic findings and treatment outcomes. METHODS: In this study, expression of NT-3 and TrkC was analyzed using immunohistochemistry in 240 patients with newly diagnosed neuroblastoma. RESULTS: The results of the study revealed that NT-3 expression was associated with older age at diagnosis, localized tumors, and more differentiated tumors but was not associated with early treatment response (degree of residual tumor volume after three cycles of chemotherapy) and progression-free survival (PFS). However, when analysis was confined to patients with MYCN amplified tumors, NT-3 expression was associated with better early treatment response with borderline significance (P = 0.092) and higher PFS (86.9% vs. 58.2%; P = 0.044). In multivariate analysis in patients with MYCN amplified tumors, NT-3 was independent prognostic factor (hazard ratio, 0.246; 95% confidence interval, 0.061–0.997; P = 0.050). In another subgroup analysis, the early treatment response was better if NT-3 was expressed in patients without TrkC expression (P = 0.053) while it was poorer in patients with TrkC expression (P = 0.023). CONCLUSION: This study suggests that NT-3 expression in neuroblastoma has its own clinical significance independent of TrkC expression, and its prognostic significance differs depending on the status of MYCN amplification and/or TrkC expression.

Experimental study of lentivirus-mediated Nogo extracellular peptide residues 1-40 gene and neurotrophin 3 gene co-transduction in neural stem cells / 中国修复重建外科杂志

Objective: To explore the feasibility of co-transduction and co-expression of Nogo extracellular peptide residues 1-40 (NEP1-40) gene and neurotrophin 3 (NT-3) gene into neural stem cells (NSCs).

Effects of aripiprazole on clinical symptoms and serum neurotrophic factor levels in patients with schizophrenia / 中国神经精神疾病杂志

Objective To explore the effects of aripiprazole on clinical symptoms and neurotrophic factor levels in patients with schizophrenia. Methods Forty patients with schizophrenia and 40 normal controls were included in the study. The clinical symptoms of patients receiving aripiprazole only for 12 weeks were evaluated by using the Positive and Negative Syndrome Scale (PANSS). Stroop Color-Word Test (SCWT), Continuous Performance Test, Digit-Symbol Coding Test and Trail Making Test-A were used to evaluate the cognitive function both in patients and controls. Serum levels of Nerve Growth Factor (NGF), Brain Derived Neurotrophic Factor (BDNF) and Neurotrophin 3 (NT-3) were measured using enzyme linked immunosorbent assay. Results The clinical scores, cognitive function and levels of neurotrophic factors were different before and after treatment (P<0.01). And those were significantly lower in patients than in control group (P<0.05). Before treatment, BDNF was negatively correlated with PANSS negative symptom score (r=-0.362, P=0.022);NGF was related to the total score of PANSS (r=0.332, P=0.037) and positive symptoms (r=0.401, P=0.010); NT-3 was associated with negative symptom scores (r=-0.376, P=0.017) and SCWT-color words (r=0.332, P=0.037) in patient group. After treatment, the increase in BDNF was correlated with the reduction in PANSS total score (r=0.371, P=0.018), negative symptom score (r=0.345, P=0.029) and general pathology score (r=0.342, P=0.031). There was a correlation of the increase of NGF with the decrease of PANSS total scores (r=0.437, P=0.005) and with positive symptom scores (r=0.357, P=0.024). Conclusion Treatment with Aripiprazole can improve the clinical symptoms and cognitive functiona impairments in patients with schizophrenia, which may be related to the increase in serum levels of BDNF, NGF and NT-3.

Effect of neurotrophic factor-3 on the proliferation and apoptosis of bone marrow mesenchymal stem cells and mechanisms / 中华行为医学与脑科学杂志

Objective To investigate the effect of neurotrophin-3(NT-3)on the proliferation and apoptosis of bone marrow mesenchymal stem cells(BMSCs)in rats and possible mechanisms. Methods The NT-3 overexpression and lentiviral transfection of BMSCs were co-cultured with neuronal cells respectively and then they were divided into overexpression control group,NT-3 transfection group and shRNA-NT-3 transfection group(NT-3 silencing group).MTT assay was used to detect the cell culture for 24 h,48 h and 72 h. Cell cycle and apoptosis were detected by flow cytometry for 48 h. Real-time quantitative PCR was used to detect the expression of C/EBPβmRNA.The expression of C/EBPβprotein was detected by Western blot. Results MTT results showed that the proliferation ability of BMSCs in the NT-3 overexpres-sion group was significantly higher than that in the control group(0.650±0.042,0.826±0.074)at 48 h and 72 h(P<0.05).Compared with the control group(P<0.05),the cell cycle and apoptosis of BMSCs in NT-3 silencing group were significantly decreased at 48 h and 72 h(P<0.05). The results of 48 h cell cycle and apoptosis showed that the percentage of G1 phase in BMSCs was decreased,G2 and S were increased and the apoptosis was decreased. The percentage of G1 phase in G2-S phase and the increase of apoptosis were in-creased in NT-3 silencing group. The results of Western Blot showed that C/EBPβ mRNA and protein levels were significantly up-regulated in BMSCs of NT-3 overexpression group and significantly decreased in NT-3 silencing group(P<0.05).Conclusion NT-3 may promote the expression of C/EBP beta and affect the ex-pression of its downstream target genes,which can inhibit the apoptosis of BMSCs cells.

Neurotrophin 3 promotes osteogenic differentiation of human dental follicle cells / 华西口腔医学杂志

OBJECTIVE@#This study aims to investigate the effect of neurotrophin 3 (NT-3) on the osteogenic differentiation of human dental follicle cells (hDFCs).@*METHODS@#hDFCs were isolated and cultured in vitro. Immunocytochemical staining was used to identify the origin of hDFCs. The effects of different NT-3 concentrations on hDFCs proliferation were detected by using CCK-8 assay. The alkaline phosphatase (ALP) activities and mRNA expression levels of bone morphogenetic protein-2 (BMP-2) and osteocalcin (OCN) were determined to investigate the effects of NT-3 on hDFCs osteogenesis. The difference in the number of mineralized nodules was detected using alizarin red staining.@*RESULTS@#Vimentin and cytokeratin staining results showed that hDFCs originated from the mesenchymal cells. NT-3 exerted no evident effect on hDFCs proliferation. The ALP activity and the BMP-2 and OCN mRNA expression levels of hDFCs were significantly improved under treatment with different NT-3 concentrations (25, 50, and 100 ng·mL ⁻¹) compared with those in the control group. BMP-2 and OCN mRNA relative expression levels of hDFCs reached the highest when the NT-3 concentration was 100 ng·mL ⁻¹. The number of mineralized nodules reached the maximum when the hDFCs were treated with 50 and 100 ng·mL ⁻¹ NT-3.@*CONCLUSIONS@#Appropriate mass concentration of NT-3 can promote the osteogenic differentiation of hDFCs.

The expression of NT-3 and TrkC in prefrontal cortex of the post-stroke depression model rats / 中华行为医学与脑科学杂志

Objective To explore the expression of NT-3 and high-affinity receptors TrkC at mRNA and protein level in the prefrontal cortex of the post stroke depression(PSD)model rats.Methods Open-field method was used to evaluate the behavior.Focal cerebral ischemic rat models were made with thread em-bolization method.PSD rat models were established with comprehensive separately breeding and chronic un-predicted mild stress(CUMS)on this basis.Normal control group,depression group and stroke group were used to compare with PSD group.13 rats were used in each group.At 29th day after the CUMS RT-PCR was employed to detect gene expression of NT-3 and TrkC.The expression of NT-3 and TrkC in positive cells was detected by immunohistochemistry.Results The immunohistochemistry results showed that the number of NT-3 immunopositive cells in PSD group(10.11± 2.89)was lower than that of the normal group(19.00 ± 12.41)(P<0.05).Whereas there was no statistical difference in the other groups(P>0.05).The number of TrkC immunopositive cells in PSD group(19.56±5.66)was less than that of the normal group(25.11±3.95) and stroke group(29.67±7.38).The number of TrkC immunopositive cells in depression group(19.00±5.61)also was lower than that of the normal group(25.11±3.95)and stroke group(29.67±7.38).There was no sta-tistical difference among other groups(P>0.05).RT-PCR results showed that the GAPDH,NT-3 and TrkC mRNA in all of the groups could be detected in the prefrontal cortex of rats.The expression of NT-3 in the prefrontal cortex in the PSD group decreased significantly compared with that of normal control rats(P<0.05).There was no statistical difference in the other groups(P>0.05).The expression of TrkC in the pre-frontal cortex had no statistical difference in all of the groups(P>0.05).Conclusion The down-regulation of NT-3 and TrkC both at mRNA and protein levels in the prefrontal cortex maybe responsible for the pathogen-esis of PSD.

Study on Combination Strategy of Governor Vessel Acupoints Electroacupuncture and Adult Stem Cell Transplantation in Repaired Spinal Cord Injury / 中山大学学报(医学科学版)

On the basis of an outline on Governor Vessel acupoints electroacupuncture ,endogenous neurotrophic factor expres?sion,grafted adult stem cell-derived neurons integrating to spinal host neuron circuit for repairing spinal cord injury ,it is summa?rized that mechanism of a combination of Governor Vessel acupoints electroacupuncture and grafted adult stem cells improving the tis?sue microenvironment of spinal cord injury to reestablish neuron conduction pathway. Governor Vessel acupoints electroacupuncture stimulate meningeal branch of spinal nerve in rat spinal cord transected or demyelinated. The stimulation message is input into spinal cord through afferent nerve,which activates spinal cord cells synthesizing and secreting neurotrophin-3(NT-3). The NT-3 can pro?mote the survival,differentiation and migration of exogenous neural stem cells(NSC)and bone marrow mesenchymal stem cells (MSC)expressing tyrosine kinase receptor C(TrkC)at the injury/graft site or demyelination/graft site in the spinal cord transected or demyelinated. The combined therapeutic strategy may replace and protect host neurons injured ,perfect tissue microenvironment in?jured,promote nerve fiber regenerating,and improve motor evoked potential of cerebral cortex and motor function of paralysis limbs.

Hippocampus-dependent Task Improves the Cognitive Function after Ovariectomy in Rats

OBJECTIVES: Estrogen is an important hormone for cell growth, development, and differentiation by transcriptional regulation and modulation of intracellular signaling via second messengers. The reduction in the estrogen level after ovariectomy may lead to cognitive impairments associated with morphological changes in areas of the brain mediate memory. The aim of the present study was to find out the effect of tasks on the cognitive function after ovariectomy in rats. METHODS: The animals used in the experiment were 50 Sprague-Dawley female rats. This study applied a hippocampus-independent task (wheel running) and a hippocampus-dependent task (Morris water maze) after ovariectomy in rats and measured the cognitive performance (object-recognition and object-location test) and growth-associated protein 43 (GAP-43) and neurotrophin 3 (NT-3) expression in the hippocampus, which is an important center for memory and learning. RESULTS: There were meaningful differences between the hippocampus-independent and hippocampus-dependent task groups for the object-location test and GAP-43 and NT-3 expression in the hippocampus, but not the object-recognition test. However, the hippocampus-independent task group showed a significant improvement in the object-recognition test, compared to the control group. CONCLUSION: These results suggest that hippocampus-dependent task training after ovariectomy enhances the hippocampus-related memory and cognitive function that are associated with morphological and functional changes in the cells of the hippocampus.

Effect of Neurotrophin 3-chitosan on Endogenous Neurogenesis and Motor Function after Motor Cortex Injury in Rats / 中国康复理论与实践

Objective To observe the effects of neurotrophin 3 (NT3)-chitosan on motor function, and proliferation and differentiation of the neural stem cells (NSCs) in the injury area and subventricular zone (SVZ) in rats with motor cortex injury. Methods Sixty-five Wistar rats were divided into control group (n=7), injury group (n=29) and NT3-chitosan group (n=29). The motor cortex was aspirated and re-moved as cerebral injury model. NT3-chitosan was immediately implanted into the injured area after operation, and the control group re-ceived no intervention. Pellet reaching test was performed to detect the recovery of the forelimb function, HE staining was used to observe the lesion cavity size, and immunofluorescence staining was used to observe the proliferation and differentiation of NSCs 3 days, 7 days, 14 days, 1 month, 2 months and 3 months after operation. Results The grasp success rate was higher (F>6.00, P≤0.05), and the lesion cavity size was significantly smaller (F>629.5, P171.43, P155.06, P<0.001), the number of Dcx positive cells was significantly higher in the NT3-chitosan group than in the injury group (F=62.367, P<0.001), and the number of BrdU/Dcx positive cells was significantly higher in the NT3-chitosan group than in the control group (F=33.527, P<0.001). Conclusion NT3-chitosan could activate NSCs in the SVZ, and pro-mote endogenous neurogenesis and forelimb function recovery in rats after motor cortex injury.

Role of NT-3 gene modified mesenchymal stem cells and its mechanism in treatment of acute cerebral infarction / 中华神经医学杂志

Objective To investigate the role of neurotrophin-3 (NT-3) gene modified bone marrow mesenchymal stem cells (BMSCs) in treatment of acute cerebral infarction and its underlying mechanism.Methods Seventy-two SD male rats were randomly divided into model group,BMSCs group,and BMSCs+NT-3 group (n=24).Focal cerebral ischemia rat models were established by middle cerebral artery occlusion (MCAO);24 h after MCAO,rats in the BMSCs group and BMSCs+NT-3 group were given BMSCs and NT-3 gene modified BMSCs via tail intravenous injection,respectively.Modified neurological severity scale (mNSS) was performed one,6,12 and 24 d after MCAO;infarct sizes were measured by TTC staining one,12 and 24 d after MCAO;expressions of neuronspecific enolase (NSE) and nestin in the surrounding areas of infarction were detected by Western blotting 6 d after MCAO.Results As compared with those in the BMSCs group,significantly decreased mNSS scores in BMSCs+NT-3 group were noted 6,12 and 24 d after MCAO (P＜0.05).Rats in the BMSCs+NT-3 group had significantly smaller brain infarct sizes than the BMSCs group 12 and 24 d after MCAO (P＜0.05).Expressions of NSE and nestin in the BMSCs+NT-3 group were significantly higher than those in the BMSCs group 6 d after MCAO (P＜0.05).Conclusion Transplantation of NT-3 gene modified BMSCs can further improve neurological functions and reduce brain infarct sizes as compared with BMSCs transplantation,whose mechanism might be related to promote the differentiation of BMSCs into neurons.

Expression of neurotrophic factors in injured spinal cord after transplantation of human-umbilical cord blood stem cells in rats

We induced percutaneous spinal cord injuries (SCI) using a balloon catheter in 45 rats and transplanted human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) at the injury site. Locomotor function was significantly improved in hUCB-MSCs transplanted groups. Quantitative ELISA of extract from entire injured spinal cord showed increased expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and neurotrophin-3 (NT-3). Our results show that treatment of SCI with hUCB-MSCs can improve locomotor functions, and suggest that increased levels of BDNF, NGF and NT-3 in the injured spinal cord were the main therapeutic effect.

The role of bone marrow mesenchymal stem cells transfected with neurotrophin-3 in treatment of spinal cord ischemia-reperfusion injury / 实用医学杂志

Objective To observe the mechanisms of bone marrow mesenchymal stem cells (BMSCs) transfected with neurotrophin-3 in treating nanoparticle repaired spinal cord ischemia-reperfusion (I/R) injury of adult rat. Methods BMSCs were transfected into NT-3 with nanoparticle carrier and transplanted into 80 adult rats on the spinal cord I/R injury model. Then the rats were divided into four groups: sham group, NS group, BMSCs and BMSCs+NT-3. The BBB scoring system, the neurons cell apoptosis, levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were observed and compared between the four groups. Results The BBB score of the BMSCs+NT-3 group was significantly higher than those of BMSCs and NS group , but was lower obviously than the Sham group. TUNEL-apoptosis cells were significantly decreased in the BMSCs + NT-3 group compared to BMSCs and NS groups, but was more significantly lower than the Sham group. The contents of MDA and MPO of the NS group were significantly higher than the BMSCs group. The contents of the BMSCs + NT-3 group were lower than those of the BMSCs group, but lower significantly than the Sham group (P < 0.05). Conclusion BMSCs transfected with NT-3 with nanoparticle carrier could be induced each other. When transplanted into SCI , they can repair spinal cord by alleviating neuron cells apoptosis and inhibiting the lipid peroxidation of free radicals.

Construction and identification of the recombinant retroviral vector to carry out hypoxia-regulated expression of neurotrophin-3 / 西安交通大学学报(医学版)

Objective To construct and identify the recombinant retroviral vector containing five copies of hypoxia responsive elements (5HRE)and neurotrophin-3 (NT-3 ).Methods Using PCR,enzyme digestion and DNA ligase,5HRE and human derived NT-3 were cloned into the retroviral vector plasmid (pLNCX)to construct the recombinant retroviral vector plasmid pLNCX-5HRE-SV40-NT3-IRES-EGFP.The retrovirus RV-5HRE-NT3 was packaged in the PT67 cells,and then it was purified and concentrated by high-speed centrifugation.After infected for 48 h with the concentrated retrovirus,the number of the EGFP positive cells in the NIH 3T3 cells was counted by fluorescence activated cells and sorted to calculate the retrovirus titer.Results The retroviral vector plasmid,pLNCX-5HRE-SV40-NT3-IRES-EGFP,was successfully constructed,and the retrovirus was packaged and defined as RV-5HRE-NT3.After purification and concentration,the retrovirus titer reached 9.1 × 10 6 cfu/mL. Conclusion The recombinant retroviral vector which carried out hypoxia-regulated expression of NT-3 was successfully constructed.It may provide basis for studies on hypoxia-regulated expression of the exogenous genes.

Neurotrophin 3 gene overexpression promotes cholinergic differentiation in neural stem cells / 中国药理学通报

Aim To investigate the effects of neurotro-phin-3 ( NT-3 ) gene overexpression on the differentia-tion into cholinergic neuron of neural stem cells ( NSCs) in vitro and its underlying mechanism. Meth-ods Brain-derived NSCs from newborn mice were iso-lated and cultured in vitro and determined by immuno-fluorescence. The NSCs were divided into three groups: NSCs, GFP-NSCs and NT-3-NSCs groups. The expression of NT-3 was detected by immunofluo-rescence and ELISA. Then, the ability of NSCs on dif-ferentiation into cholinergic neuron was detected by im-munofluorescence and RT-PCR, and the Acetylcholine Assay Kit was used for acetylcholine ( ACh) , and the expression of Hes1 , Mash1 and Ngn1 mRNA was de-termined by RT-PCR. Results The neurosphere dis-played Nestin and Sox 2-postive by immunofluores-cence, suggesting that the cultured cells were NSCs. The proportion of ChAT immunopositive cells was sig-nificantly higher in the NT-3-NSCs group than that in the other two groups ( P <0. 01 ) . Ach secretion in NT-3-NSCs was significantly elevated compared with the other two groups ( P <0. 01 ) . NSCs transfected with NT-3 increased the levels of Mash1 and Ngn1 mR-NA, and decreased the level of Hes1 mRNA ( P <0. 05 ) . Conclusion NT-3 can significantly promote the in vitro differentiation of NSCs into cholinergic neu-rons via probablly inhibiting Notch signaling pathway.

Effect of neurotrophin-3 on Akt expression during ropivacaine-induced neurotoxicity to spinal cord of rats / 中华麻醉学杂志

Objective To evaluate the effect of neurotrophin-3 (NT-3) on the expression of serine/threonine protein kinase (Akt) during ropivacaine-induced neurotoxicity to the spinal cord of rats.Methods Healthy adult male Sprague-Dawley rats,aged 1-2 months,weighing 280-320 g,were used in the study.A catheter was inserted at L5,6 interspace into the epidural space of rats.A total of 108 rats,in which intrathecal catheters were successfully implanted,were randomly divided into 3 groups (n =36each):control group (group C),1％ ropivacaine group (group R),and 1％ ropivacaine + NT-3 group (group NT).The equal volume of normal saline was given in group C,1％ ropivacaine 0.12 ml/kg was injected via the intrathecal catheter once every 1.5 h for 8 times in total in R and NT groups.In addition,NT-3 0.1 mg/kg was simultanenously injected via the intrathecal catheter in group NT.On days 1,3,5,7,14 and 28 after the end of administration (T1-6),6 rats were sacrificed in each group.Their lumbar enlargements were removed for determination of neuronal apoptosis (using TUNEL) and Akt expression (by immuno-histochemistry).The apoptotic rate was calculated.Results Compared with group C,the apoptotic rate was significantly increased at T1-4,and Akt expression was significantly up-regulated at T1-3 in group R,and the apoptotic rate were significantly increased,and Akt expression was significantly up-regulated at T1-3 in group NT (P＜0.05).Compared with group R,the apoptotic rate was significantly decreased at T3,4,and Akt expression was significantly down-regulated at T2.3 in group NT (P＜0.05).Conclusion The mechanism by which NT-3 reduces ropivacaine-induced neurotoxicity to the spinal cord may be related to down-regulation of the expression of Akt in rats.