丙戊酸对脊髓损伤大鼠内源性神经干细胞增殖的影响

BACKGROUND： Valproic acid has been reported to decrease apoptosis, promote neuronal differentiation of brain-derived neural stem cells, and inhibit glial differentiation of brain-derived neural stem cells.
OBJECTIVE： To investigate the effects of valproic acid on proliferation of endogenous neural stem cells in a rat model of spinal cord injury.
DESIGN, TIME AND SETTING： A randomized, controlled, neuropathological study was performed at Key Laboratory of Trauma, Buming, and Combined Injury, Research Institute of Surgery, Daping Hospital, the Third Military Medical University of Chinese PLA between November 2005 and February 2007.
MATERIALS： A total of 45 adult, Wistar rats were randomly divided into sham surgery （n = 5）, injury （n = 20）, and valproic acid （n = 20） groups. Valproic acid was provided by Sigma, USA. METHODS： Injury was induced to the T10 segment in the injury and valproic acid groups using the metal weight-dropping method. The spinal cord was exposed without contusion in the sham surgery group. Rats in the valproic acid group were intraperitoneally injected with 150 mg/kg valproic acid every 12 hours （twice in total）.
MAIN OUTCOME MEASURES： Nestin expression （5 mm from injured center） was detected using immunohistochemistry at 1,3 days, 1, 4, and 8 weeks post-injury.
RESULTS： Low expression of nestin was observed in the cytoplasm, but rarely in the white matter of the spinal cord in the sham surgery group. In the injury group, nestin expression was observed in the ependyma and pia mater one day after injury, and expression reached a peak at 1 week （P 〈 0.05）. Expression was primarily observed in the ependymal cells, which expanded towards the white and gray matter of the spinal cord. Nestin expression rapidly decreased by 4 weeks post-injury, and had almost completely disappeared by 8 weeks. At 24 hours after spinal cord injury, there was no significant difference in nestin expression between the valproic acid and injury groups. At 1 week, there was a significant increase in the number of nestin-positive cells surrounding the central canal in valproic acid group compared with the injury group （P 〈 0.05）. Expression reached a peak by 4 weeks, and it was still present at 8 weeks.
CONCLUSION： Valproic acid promoted endogenous neural stem cell proliferation following spinal cord injury in rats.     

丹参酮对大鼠脊髓缺血再灌注损伤NMDAR1蛋白表达的影响

BACKGROUND： Tanshinone has been previously shown to be involved in the prevention and treatment of cerebral ischemia/reperfusion injury. In addition, excitatory amino acid-mediated neu- rotoxicity may induce neuronal damage following spinal cord ischemia/reperfusion injury.
OBJECTIVE： To explore the interventional effect of tanshinone on N-methyl-D-aspartate receptor 1 （NMDAR1） protein expression in a rat model of spinal cord ischemia/reperfusion injury.
DESIGN, TIME AND SETTING： A randomized molecular biology experiment was conducted at the Traumatology ＆ Orthopedics Laboratory of Fujian Hospital of Traditional Chinese Medicine （Key Laboratory of State Administration of Traditional Chinese Medicine） between September 2007 and May 2008. MATERIALS： A total of 88 Sprague Dawley rats were randomly divided into a sham operation （n = 8）, model （n = 40）, and tanshinone （n = 40） groups. Thirty minutes after ischemia, rats in the model and tanshinone groups were observed at hour 0.5, 1, 4, 8, and 12 following perfusion, with eight rats for each time point. METHODS： Abdominal aorta occlusion was performed along the right renal arterial root using a Scoville-Lewis clamp to induce spinal cord ischemia. Blood flow was recovered 30 minutes following occlusion to establish models of spinal cord ischemia/reperfusion injury. Abdominal aorta occlusion was not performed in the sham operation group. An intraperitoneal injection of tanshinone ⅡA sulfonic sodium solution （0.2 L/g） was administered to rats in the tanshinone group, preoperatively. In addition, rats in the sham operation and model groups were treated with an intraperitoneal injection of the same concentration of saline, preoperatively.
MAIN OUTCOME MEASURES： NMDAR1 protein expression in the anterior horn of the spinal cord, accumulative absorbance, average absorbance, and area of positive cells were detected in the three groups through immunohistochemistry.
RESULTS： All 88 rats were included in the final analysis. （1） NMDAR1 protein expression increased following 30-minute ischemia/1-hour reperfusion injury to the spinal cord, and reached a peak 4 hours after reperfusion. （2） Accumulative absorbance and average absorbance of NMDAR1, as well as area of positive cells in the model group, were significantly greater than the sham operation group at each time point （P 〈 0.05）. However, values in the tanshinone group were significantly less than the model group （P 〈 0.05）.
CONCLUSION： NMDAR1 protein expression was rapidly increased following spinal cord ischemia/reperfusion injury and reached a peak 4 hours following reperfusion. In addition, tanshinone downregulated NMDAR1 protein expression in the anterior horn of the spinal cord.     

Differentiation of endogenous neural precursors following spinal cord injury in adult rats☆

BACKGROUND： Studies have shown that cell death can activate proliferation of endogenous neural stem cells and promote newly generated cells to migrate to a lesion site.
OBJECTIVE： To observe regeneration and differentiation of neural cells following spinal cord injury in adult rats and to quantitatively analyze the newly differentiated cells.
DESIGN, TIME AND SETTING： A cell biology experiment was performed at the Institute of Orthopedics and Medical Experimental Center, Lanzhou University, between August 2005 and October 2007.
MATERIALS： Fifty adult, Wistar rats of both sexes; 5-bromodeoxyuridine （BrdU, Sigma, USA）; antibodies against neuron-specific enolase, glial fibrillary acidic protein, and myelin basic protein （Chemicon, USA）.
METHODS： Twenty-five rats were assigned to the spinal cord injury group and received a spinal cord contusion injury. Materials were obtained at day 1, 3, 7, 15, and 29 after injury, with 5 rats for each time point. Twenty-five rats were sham-treated by removing the lamina of the vertebral arch without performing a contusion.
MAIN OUTCOME MEASURES： The phenotype of BrdU-labeled cells, i.e., expression and distribution of surface markers for neurons （neuron-specific enolase）, astrocytes （glial fibrillary acidic protein）, and oligodendrocytes （myelin basic protein）, were identified with immunofluorescence double-labeling. Confocal microscopy was used to detect double-labeled cells by immunofluorescence. Quantitative analysis of newly generated cells was performed with stereological counting methods.
RESULTS： There was significant cell production and differentiation after adult rat spinal cord injury. The quantity of newly-generated BrdU-labeled cells in the spinal cord lesion was 75-fold greater than in the corresponding area of control animals. Endogenous neural precursor cells differentiated into astrocytes and oligodendrocytes, however spontaneous neuronal differentiation was not detected. Between 7 and 29 d after spinal cord injury, newl     

Transplantation of Nogo-66 receptor gene-silenced cells in a poly(D,L-lactic-co-glycolic acid) scaffold for the treatment of spinal cord injury

Inhibition of neurite growth,which is in large part mediated by the Nogo-66 receptor,affects neural regeneration following bone marrow mesenchymal stem cell transplantation.The tissue engineering scaffold poly(D,L-lactide-co-glycolic acid) has good histocompatibility and can promote the growth of regenerating nerve fibers.The present study used small interfering RNA to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells and Schwann cells,which were subsequently transplanted with poly(D,L-lactide-co-glycolic acid) into the spinal cord lesion regions in rats.Simultaneously,rats treated with scaffold only were taken as the control group.Hematoxylin-eosin staining and immunohistochemistry revealed that at 4 weeks after transplantation,rats had good motor function of the hind limb after treatment with Nogo-66 receptor gene-silenced cells plus the poly(D,L-lactide-co-glycolic acid) scaffold compared with rats treated with scaffold only,and the number of bone marrow mesenchymal stem cells and neuron-like cells was also increased.At 8 weeks after transplantation,horseradish peroxidase tracing and transmission electron microscopy showed a large number of unmyelinated and myelinated nerve fibers,as well as intact regenerating axonal myelin sheath following spinal cord hemisection injury.These experimental findings indicate that transplantation of Nogo-66 receptor gene-silenced bone marrow mesenchymal stem cells and Schwann cells plus a poly(D,L-lactide-co-glycolic acid) scaffold can significantly enhance axonal regeneration of spinal cord neurons and improve motor function of the extremities in rats following spinal cord injury.     

.：pendymal cell proliferation and apoptosis following acute spinal cord injury in the adult rat

BACKGROUND： Studies have reported that spinal cord injury can induce the reactive proliferation of ependymal cells and secondarily cause the apoptosis of nerve cells. However, there is no generally accepted theory on the apoptotic characteristics of ependymal cells in the injured spinal cord. OBJECTIVE： To observe the reactive proliferation and apoptosis of ependymal cells in adult rats following acute spinal cord injury. DESIGN, TIME AND SETTING： A randomized control study based on neuropathology was performed in the Third Military Medical University of Chinese PLA between 2005 and 2007. MATERIALS： Forty healthy, adult, Wistar rats were included in the present study. METHODS： Moderate spinal cord injury was established in twenty rats using Feeney＇s method, while the remaining 20 rats served as controls and were only treated with laminectomy. All rats were injected intraperitoneally with 1.25 mL of BrdU solution （10 mg BrdU/mL saline） 3 times at 4 hours intervals during the 12 hours prior to sacrifice. MAIN OUTCOME MEASURES： Ependymal cell proliferation and apoptosis in the rat spinal cord were determined by BrdU and nestin immunofluorescence double-labeling, as well as the TUNEL method, at 1, 3, 7, and 14 days after operation. RESULTS： In the moderate spinal cord injury rats, nestin expression was observed in the cytoplasm of ependymal cells. One day immediately following surgery, ependymal cells were BrdU-labeled. The number of BrdU-positive cells increased at 3 days, reached a peak at 7 days, and gradually reduced thereafter. The ependyma developed from a constitutive monolayer cells to a multi-layer cell complex. Some BrdU/Nestin double-positive ependymal cells migrated out from the ependyma. TUNEL-positive cells were also detected in the ependyma in the central region, as well as ischemic regions of the injured spinal cord. In addition, TUNEL-positive cells were visible in the ependyma. No TUNEL-positive ependymal cells were observed in the normal spinal cord. CONCLUSION： Proliferating     

Neurotoxicity of intrathecal injections of dexmedetomidine into the rat spinal dorsal horn

To investigate the neurotoxicity of intrathecal injections of dexmedetomidine,Sprague-Dawley rats were intrathecally injected with dexmedetomidine at doses of 0.75,1.50 and 3.00μg/kg into the spinal dorsal horn.We found that c-Fos expression in the rat spinal dorsal horn peaked at 7 hours following the 3.00μg/kg dexmedetomidine injection,while the levels of c-Fos expression following 0.75 and 1.50μg/kg dexmedetomidine were similar to those in the spinal dorsal horn of normal rats. At 48 hours following administration,the level of c-Fos expression was similar to normal levels.In addition,the intrathecal injections of dexmedetomidine increased paw withdrawal mechanical thresholds and prolonged thermal tail flick latencies.These results indicate that dexmedetomidine has pronounced antinociceptive effects.However,dexmedetomidine appears to have neurotoxic effects in the spinal cord because it increased c-Fos expression in the spinal dorsal horn within 7 hours following administration.     

Expression of nitric oxide synthase in the spinal cord after selective brachial plexus injury

BACKGROUND: Some researches showed that motoneurons in spinal cord anterior horn wound die following brachial plexus injury, but the concrete mechanism of motoneurons death remains unclear. OBJECTIVE: To observe the expression of nitric oxide synthase (NOS) and survival of C7 motoneurons in spinal cord of rats after selective brachial plexus injury. DESIGN: A randomized controlled animal experiment. SETTING:Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University. MATERIALS: Totally 35 adult healthy male Sprague-Dawley rats with the body mass of 200-300 g were provided by Experimental Animal Center, Sun Yet-sen Medical College, Sun Yat-sen University. The rats were divided into control group (n =5) and experimental group(n =30) by random number table method, and the experimental group was divided into three injury subgroups: anterior root avulsion group, dorsal root transection group and spinal cord hemisection group, 10 rats in each group. There were horse anti-neuronal NOS (nNOS) polycolonal antibody (Sigma company) and nicotina mideadeninedinucleotide phosphate (NADPH-d) (Sigma Company). METHODS: The experiment was performed at Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University between September 2004 and April 2005. ①After anesthetizing the rats, the spinous process of second thoracic vertebra as a marker, the vertebra was exposed from C5 to T1 and the lamina of vertebra was unclenched, and spinal dura mater was carved to expose the spinal nerve dorsal roots of C5-T1. The right ventral root of C7 was avulsed, and the residual root was removed in anterior root avulsion group. The right ventral root of C7 was avulsed and the right dorsal roots of brachial plexus (C5-T1) were cut off in dorsal root transection group. In spinal cord hemisection group, the hemisection between the C5 and C6 spinal segment on right side and avulsion of right ventral root of C7 were made. In the control group, the vertebra from C5 to T1 was unclenched and the skin of wound was sutured. ②Three weeks after operation, behavior of rats was observed. The rats were killed after anesthesia. The C7 segment of spinal cord was removed and treated with NADPH-d staining, neutral red counterstaining and NOS immunohistochemistry staining to detect the expression of NOS. MAIN OUTCOME MEASURES: The expression of NOS and survival of C7 motoneurons in spinal cord of rats 3 weeks after operation. RESULTS: Among the 35 included rats, 3 rats died 2 weeks following operation, so totally 32 rats were involved in the result analysis. ①NADPH-d positive neurons of in anterior horn of C7 in the three groups: The NADPH-d positive neurons could be found in anterior horn of C7 in the three groups. The percentage of that in anterior root avulsion group to that of non-injury side of spinal cord was(20.98±2.65)%, (29.43±6.81)% in dorsal root transection group and (31.74±6.80)% in spinal cord hemisection group. There was significant difference among the three injury groups(F =5.135，P =0.016). There was significant difference in anterior root avulsion group with dorsal root transection group and spinal cord hemisection group (t =2.562，3.167，P < 0.05). There was no significant difference between the dorsal root transection group and spinal cord hemisection group (P =0.534). ②survival rate of motoneurons in anterior horn of C7: There were dead motoneurons in the three injury groups, the percentages of surviving motoneurons to that of non-injured side of spinal cord were (69.22±4.04)%，(62.01±3.82)% and (56.74±6.86)%, respectively. There were significant differences among the three groups (F =9.508，P =0.002). The anterior root avulsion group was significantly different from the other two groups(t =2.764，4.587，P < 0.05). There was no significant difference between the dorsal root transection group and spinal cord hemisection group(P =0.073). CONCLUSION: The selective brachial plexus injury can induce the up-regulation of NOS expression in motorneurons of spinal cord anterior horn and block descending pathway of cortex to cause the more significant up-regulation of NOS and low survival rate in motoneurons. It indicates that descending pathway of cortex can inhibit the NOS expression in motorneurons of spinal cord anterior horn, and the high NOS expression might induce the death of motorneurons in spinal cord anterior horn.     

p75 neurotrophin receptor signal pathway influence on apoptosis in anterior horn neurons of the spinal cord in a rat model of cauda equina compression injury

BACKGROUND： Studies have demonstrated that cauda equina compression results in apoptosis of motor neurons in the spinal cord. The combination of p75 neurotrophin receptor （p75NTR） and precursor of nerve growth factor （pro-NGF） expression initiates the apoptotic pathway and induces neuronal apoptosis. However, few reports have focused on the p75-mediated mechanism of neuronal apoptosis following cauda equine compression injury OBJECTIVE： To determine apoptosis of spinal cord neurons and activation of the pro-NGF-p75NTR-JNK（c-Jun N-terminal kinase） signal pathway in rats following cauda equina compression, and to verify experimental outcomes. DESIGN, TIME AND SETTING： A randomized, controlled, in vivo experiment was performed at the Medical Experimental Center of Xi＇an Jiaotong University between April and November in 2008. MATERIALS： Streptavidin-perosidase kit was purchased from Wuhan Boster, China; in situ end labeling detection kit was provided by Promega, USA; type AEG-220G electron microscope was purchased from Hitachi, Japan. METHODS： A total of 48 healthy, adult, female, Sprague Dawley rats were randomly assigned to three groups： normal （n = 6）, sham-surgery （n = 6）, and compression （n = 36）. The compression group was randomly assigned to six subsets at 1,3, 5, 7, 14, and 28 days, respectively, with 6 rats in each subset. A cylindrical silica gel stick was implanted into the rats to compress 75% of the vertebral canal in the compression group; in the sham-surgery group, only vertebral resection was performed; and no procedures were performed in the normal group. MAIN OUTCOME MEASURES： At 1,3, 5, 7, 14, and 28 days following compression, L2-3 spinal cord segments were processed for immunohistochemistry, in situ cell apoptosis detection, and transmission electron microscopy observation. Nissl staining was used to observe neuronal survival in the L2 spinal cord segment. Immunohistochemistry was applied to detect expressions of pro-NGF, p75NTR, and JNK in the L2 segment. TUNEL fluorometric method was used to observe apoptosis of neurons in the L2 segment. RESULTS： In the normal and sham-surgery groups, little neuronal apoptosis was observed in the L2-3 spinal cord segment. At 3 days after compression injury, pro-NGF, p75NTR and JNK expression was observed in the spinal cord. Expression levels reached a peak at 7 days, and then gradually decreased. In the compression and sham-surgery groups, neurons primarily expressed pro-NGF and p75NTR. The number of JNK-positive neurons in the compression group was dramatically increased compared with the sham-surgery group （P〈 0.05）. A few neurons were apoptotic in the spinal cord 1 day after compression injury. The number of apoptotic neurons gradually increased and reached a peak at 7 days, and subsequently decreased. Apoptosis was still detectable at 28 days. There was a positive correlation between p75NTR expression and neuronal apoptosis （r= 0.75, P〈 0.05）. CONCLUSION： Following cauda equina compression injury, apoptosis of spinal cord neurons was observed. The compression-induced neuronal apoptosis was associated with p75NTR expression in the L2-3 spinal cord segment.     

Effect of intravenous transplantation of bone marrow mesenchymal stem cells on neurotransmitters and synapsins in rats with spinal cord injury

Bone marrow mesenchymal stem cells were isolated, purified and cultured in vitro by Percoll density gradient centrifugation combined with the cell adherence method. Passages 3-5 bone marrow mesenchymal stem cells were transplanted into rats with traumatic spinal cord injury via the caudal vein. Basso-Beattie-Bresnahan scores indicate that neurological function of experimental rats was significantly improved over transplantation time (1-5 weeks). Expressions of choline acetyltransferase, glutamic acid decarboxylase and synapsins in the damaged spinal cord of rats was significantly increased after transplantation, determined by immunofluorescence staining and laser confocal scanning microscopy. Bone marrow mesenchymal stem cells that had migrated into the damaged area of rats in the experimental group began to express choline acetyltransferase, glutamic acid decarboxylase and synapsins, 3 weeks after transplantation. The Basso-Beattie- Bresnahan scores positively correlated with expression of choline acetyltransferase and synapsins. Experimental findings indicate that intravenously transplanted bone marrow mesenchymal stem cells traverse into the damaged spinal cord of rats, promote expression of choline acetyltransferase, glutamic acid decarboxylase and synapsins, and improve nerve function in rats with spinal cord injury.     

NT-3 gene delivery elicits growth of chronically injured corticospinal axons and modestly improves functional deficits after chronic scar resection

Nervous system growth factors promote axonal growth following acute spinal cord injury. In the present experiment, we examined whether delivery of neurotrophic factors after chronic spinal cord injury would also promote axonal growth and influence functional outcomes. Adult Fischer 344 rats underwent mid-thoracic spinal cord dorsal hemisection lesions. Three months later, primary fibroblasts genetically modified to express human neurotrophin-3 (NT-3) were placed in, and distal to, the lesion cavity. Upon sacrifice 3 months later (6 months following the initial lesion), NT-3-grafted animals exhibited significant growth of corticospinal axons up to 15 mm distal to the lesion site and showed a modest but significant 1.5-point improvement in locomotor scores (P < 0.05) on the BBB scale, compared to control-grafted animals. Thus, growth factor gene delivery can elicit growth of corticospinal axons in chronic stages of injury and improves functional outcomes compared to non-growth-factor-treated animals.     

Stem cell transplantation for treatment of cerebral ischemia in rats Effects of human umbilical cord blood stem cells and human neural stem cells

BACKGROUND:Exogenous neural stem cell transplantation promotes neural regeneration. However, various types of stem cells transplantation outcomes remain controversial. OBJECTIVE:To explore distribution, proliferation and differentiation of human neural stem cells (hNSCs) and human umbilical cord blood stem cells (hUCBSCs) following transplantation in ischemic brain tissue of rats, and to compare therapeutic outcomes between hNSCs and hUCBSCs. DESIGN, TIME AND SETTING:Randomized controlled animal studies were performed at the Experimental Animal Center of Nanjing Medical University and Central Laboratory of Second Affiliated Hospital of Nanjing Medical University of China from September 2008 to April 2009. MATERIALS:hNSCs were harvested from brain tissue of 10-13 week old fetuses following spontaneous abortion, and hUCBSCs were collected from umbilical cord blood of full-term newborns at the Second Affiliated Hospital of Nanjing Medical University of China. hNSCs and hUCBSCs were labeled by 5-bromodeoxyuridine (BrdU) prior to transplantation. METHODS:Rat models of cerebral ischemia were established by the suture method. A total of 60 healthy male Sprague Dawley rats aged 7-9 weeks were randomly assigned to hNSC transplantation, hUCBSC transplantation and control groups. The rat models in the hNSC transplantation, hUCBSC transplantation and control groups were infused with hNSC suspension, hUCBSC suspension and saline via the caudal vein, respectively. MAIN OUTCOME MEASURES:The distribution, proliferation and differentiation of hNSCs and hUCBSCs in ischemic brain tissue were observed using immunohistochemical methods. Neurological function in rats was assessed using the neurological severity score. RESULTS:The number of BrdU-positive cells was significantly greater in the hNSC transplantation group compared with hUCBSC transplantation group at 14 days following transplantation (P < 0.05). The number of BrdU-positive cells reached a peak at 28 days following transplantation. Nestin-positive, glial fibrillary acidic protein-positive, cyclic nucleotide 3' phosphohydrolase-positive and neuron specific enolase-positive cells were visible following transplantation. No significant difference was determined in the constituent ratio of various cells between hNSC and hUCBSC transplantation groups (P > 0.05). The neurological severity score was significantly decreased in rats at 21 days following transplantation (P < 0.05). No significant difference was detected in neurological severity score between hNSC and hUCBSC transplantation groups at various time points (P > 0.05). CONCLUSION:The transplanted hNSCs and hUCBSCs can migrate into ischemic brain tissue, proliferate and differentiate into neuron-like, astrocyte-like and oligodendrocyte-like cells, and improve neurological function in rats with cerebral ischemia.     

Human fetal neural stem cells grafted into contusion-injured rat spinal cords improve behavior

Grafted human neural stem cells (hNSCs) may help to alleviate functional deficits resulting from spinal cord injury by bridging gaps, replacing lost neurons or oligodendrocytes, and providing neurotrophic factors. Previously, we showed that primed hNSCs differentiated into cholinergic neurons in an intact spinal cord. In this study, we tested the fate of hNSCs transplanted into a spinal cord T10 contusion injury model. When grafted into injured spinal cords of adult male rats on either the same day or 3 or 9 days after a moderate contusion injury, both primed and unprimed hNSCs survived for 3 months postengraftment only in animals that received grafts at 9 days postinjury. Histological analyses revealed that primed hNSCs tended to survive better and differentiated at higher rates into neurons and oligodendrocytes than did unprimed counterparts. Furthermore, only primed cells gave rise to cholinergic neurons. Animals receiving primed hNSC grafts on the ninth day postcontusion improved trunk stability, as determined by rearing activity measurements 3 months after grafting. This study indicates that human neural stem cell fate determination in vivo is influenced by the predifferentiation stage of stem cells prior to grafting. Furthermore, stem cell-mediated facilitation of functional improvement depends on the timing of transplantation after injury, the grafting sites, and the survival of newly differentiated neurons and oligodendrocytes.     

人脐带间充质干细胞移植对大鼠脊髓损伤神经功能恢复的评价

目的 观察人脐带间充质干细胞（human umbilical cordmesenchymal stem cell，hUCMSC）移植对大鼠脊髓损伤神经功能恢复的影响。方法 SD大鼠70只，随机分为3组：脊髓半切＋hUCMSC组（n=30）、脊髓半切＋PBS组（n=30）和假手术组（n=10）。脊髓半切＋hUCMSC组和PBS组又分为头侧注射、尾侧注射和头尾两侧注射三个亚组。移植后1、7、14、21、28d观察大鼠神经功能恢复情况，应用免疫组化检测移植到脊髓的hUCMSC胶质纤维酸性蛋白（GFAP）和神经元特异性烯醇化酶（NSE）表达情况。结果 大鼠脊髓半切损害后，hUCMSC组动物较PBS组有明显的神经功能恢复。植入后28d在宿主脊髓中存活的hUCMSC细胞MABl281（mouse antiuman nuclei monoclonal antibody）染色阳性，免疫组化双标染色显示MABl28l阳性细胞亦分别有NSE或GFAP表达并向损伤部位迁移，hUCMSC来源的GFAP阳性细胞可见明显的树突生长。结论 hUCMSC移植到宿主损伤脊髓后可以存活、向损伤部位迁移，并向神经元样和星形胶质细胞分化，且可促进大鼠脊髓损伤后神经功能恢复。hUCMSC作为一种来源广泛的干细胞用于治疗脊髓损伤可能具有重要的价值。     

骨髓间质干细胞移植对大鼠脊髓损伤神经功能恢复的影响

目的：观察成人骨髓间质干细胞（hBMSCs)移植对大鼠脊髓损伤神经功能恢复的影响.方法：Wistar大鼠90只，随机分为脊髓半切＋hBMSCs组、脊髓半切＋PBS组、单纯脊髓半切组和假手术组。脊髓半切＋hBMSCs组和PBS组又分别分为头侧注射、尾侧注射和头尾两侧注射三个亚组。移植后1、7、14、21、28d观察大鼠神经功能恢复情况，应用免疫组化和免疫荧光技术检测BrdU标记hBMSCs的胶质纤维酸性蛋白（GFAP）和神经元特异性核蛋白（NeuN)表达情况。结果：大鼠脊髓半切损害后，hBMSCs组动物较PBS组死亡率下降并有明显的神经功能恢复。移植的hBMSCs 在宿主脊髓中存活，从第7天开始即有NeuN和GFAP表达并向损伤部位及对侧迁移，第28天hBMSCs来源GFAP阳性细胞可见明显的树突生长。结论：hBMSCs可在宿主损伤脊髓中存活、向损伤部位迁移并向神经元和星形胶质细胞分化，并促进神经功能恢复，降低死亡率，成人骨髓间质干细胞作为一种独特的干细胞来源用于治疗脊髓损伤可能具有非常重要的价值。     

驽药针刺对大鼠脊髓损伤后运动功能及BDNF表达的影响

目的研究驽药针刺在大鼠脊髓损伤后运动功能变化以及BDNF表达的变化。方法采用脊髓半横断损伤模型。100只SD大鼠随机分为对照组、假手术组、脊髓损伤组、单纯针刺组、驽药针刺组,每组分为3天、7天、14天、21天共4个亚组,每组5只。BBB法评定大鼠后肢运动功能变化,免疫组化法检测大鼠脊髓中BDNF的表达变化。结果 BBB评分显示驽药针刺组的各时间点评分均高于脊髓损伤组(P0.05),驽药针刺组7、14、21d的BDNF表达均高于脊髓损伤组(P0.05),且与BBB评分呈正相关(r=0.717,P0.05)。结论驽药针刺可明显改善脊髓损伤大鼠的运动功能,并可明显促进大鼠脊髓损伤后BDNF的表达。     

再程序化脂肪干细胞移植治疗大鼠脊髓损伤的机制

目的制备再程序化脂肪干细胞(ADSCs),并在体研究再程序化ADSCs移植入大鼠脊髓损伤模型后促进损伤脊髓神经功能恢复的作用和机制。方法体外培养、纯化和鉴定大鼠ADSCs,并利用慢病毒包装神经元生成素2(Ngn2)基因转染ADSCs制备再程序化干细胞。体内实验将48只雌性SD大鼠随机分成3组:SCI对照(A)组、单纯ADSCs移植(B)组和Ngn2-ADSCs移植(C)组。采用BBB评分评价大鼠运动功能,并通过HE染色、免疫组化和免疫荧光等方法检测脊髓组织学改变和相关蛋白的表达水平,进而观察实验动物脊髓功能恢复情况。结果 Ngn2-ADSCs移植组在运动功能评分、胶质瘢痕的形成、脊髓损伤后病理变化和分泌神经营养因子BDNF和VEGF蛋白含量明显优于其他组。结论 Ngn2-ADSCs移植后能有效地存活,并分化为神经细胞,抑制胶质瘢痕形成,减小脊髓损伤空洞,增加BDNF和VEGF表达,最终促进SCI大鼠的运动功能恢复,较单纯应用ADSCs能更好地促进SCI修复。     

许旺细胞-海藻酸钠凝胶移植修复大鼠脊髓损伤*

目的：观察许旺细胞-海藻酸钠凝胶移植对大鼠脊髓损伤后细胞凋亡、Bcl-2表达及下肢运动功能恢复的影响。 方法：清洁级SD大鼠随机分为4组：正常对照组、单纯损伤组、许旺细胞组、许旺细胞-海藻酸钠凝胶组。后3组制作脊髓全横断损伤模型。正常对照组、单纯损伤组不进行移植处理,许旺细胞组植入吸附许旺细胞悬液的明胶海绵块、许旺细胞-海藻酸钠凝胶组植入许旺细胞-海藻酸钠凝胶。分别于 12 h,1,3,7,21 d对动物进行BBB评分后处死,取损伤区脊髓节段制成石蜡切片进行TUNEL、Bcl-2染色,观察脊髓内凋亡细胞、Bcl-2细胞的数量及分布变化。 结果：正常对照组仅有少量淡染Bcl-2阳性细胞;单纯损伤组神经元Bcl-2免疫反应阳性细胞表达的高峰在第3天,14 d时Bcl-2免疫反应阳性细胞表达接近正常水平。许旺细胞-海藻酸钠凝胶移植后损伤脊髓细胞Bcl-2免疫反应阳性细胞表达具有显著增高(P < 0.05),7 d高度表达并持续2周以上。单纯损伤组脊髓内细胞凋亡最多,并于损伤后1,7 d形成两个高峰,多分布于白质中。许旺细胞-海藻酸钠凝胶组BBB评分较单纯损伤组及许旺细胞组明显提高(P < 0.05)。 结论：许旺细胞-海藻酸钠凝胶移植能抑制大鼠脊髓损伤后脊髓细胞凋亡、促进Bcl-2的表达,提高了脊髓运动功能的恢复,但未达到正常水平。 关键词：脊髓损伤;细胞凋亡;许旺细胞;Bcl-2     

微囊化兔坐骨神经组织细胞移植对大鼠损伤脊髓核因子κB表达的影响

BACKGROUND： It has been reported that nuclear factor-kappa B （NF- κB）, activated after spinal cord injury in rats, plays a key role in inflammatory responses in the central nervous system. OBJECTIVE： To investigate the effects of transplantation of microencapsulated rabbit sciatic nerve on NF- κB expression and motor function after spinal cord injury in rats, and to compare the results with the transplantation of rabbit sciatic nerve alone. DESIGN, TIME AND SETTING： This completely randomized, controlled study was performed at the Department of Neurobiology, Medical College of Nanchang University between December 2007 and July 2008. MATERIALS： A rabbit anti-NF- κB P65 monoclonal antibody was made by the Santa Cruz Company, USA and a streptavidin peroxidase immunohistochemical kit was provided by the Sequoia Company, China. METHODS： Eight rabbits were used to prepare a sciatic nerve cell suspension that was divided into two parts： one stored for transplantation, and the other mixed with a 1.5% sodium alginate solution. One hundred and twenty adult Sprague Dawley rats weighing 220-250 g were randomly divided into four groups： the microencapsulated cell group （n = 36）, the non-encapsulated cell group （n = 36）, the saline group （n = 36） and the sham operation group （n = 12）. The first three groups underwent a right hemisection injury of the spinal cord at the T10 level, into which was transplanted a gelatin sponge soaked with 10 μL of a microencapsulated nerve tissue/cell suspension （microencapsulated cell group）, a tissue/cell suspension （non-encapsulated cell group） or physiological saline （saline group）. In the sham operation group the vertebrae were exposed, but the spinal cord was not injured, and no implantation was given. MAIN OUTCOME MEASURES： Pathological changes were detected using hematoxylin-eosin staining; NF- κB expression was quantified using immunohistochemical staining; motor function was assessed using the Basso, Beattie and Bresnahan （BBB） scale. RESULTS： Spinal cord injuries, such as neuronal death and inflammatory cell infiltration, were found in the microencapsulated cell group, the non-encapsulated cell group and the saline group. However, the damage in the microencapsulated cell group was milder than in the non-encapsulated cell or saline groups. NF- κB expression in the microencapsulated cell group, the non-encapsulated cell group and the saline group was increased after spinal cord injury; it reached a peak after 24 hours, gradually decreased after 3 days, and was close to normal levels after 7 days. NF- κB expression in the microencapsulated cell group was significantly lower than in the saline group and the non-encapsulated cell group （P 〈 0.05）. With time, the motor function of the animals in each group improved to a certain extent, but did not reach normal levels. There were no significant differences in BBB scores between the different groups on post-operative day 3; however, the BBB scores for the microencapsulated cell group and the non-encapsulated cell group were significantly higher than the saline group on post-operative day 7 （P 〈 0.05）. In addition, the motor function recovered better in the microencapsulated cell group than in the non-encapsulated cell group （P 〈 0.05）. CONCLUSION： The transplantation of microencapsulated rabbit sciatic nerve can inhibit NF- κB expression and inflammatory reactions and promote recovery of motor function after spinal cord injury in rats. The effects of microencapsulated cell transplantation are superior to those of transplantation of cells alone.