Simvastatin treatment improves functional recovery after experimental spinal cord injury by upregulating the expression of BDNF and GDNF

The aim of this study was to determine the therapeutic efficacy of simvastatin treatment starting 1 day after spinal cord injury (SCI) in rat and to investigate the underlying mechanism. Spinal cord injury was induced in adult female Sprague–Dawley rats after laminectomy at T9-T10. Then additionally with sham group (laminectomy only) the SCI animals were randomly divided into 3 groups: vehicle-treated group; 5-mg/kg simvastatin-treated group; and 10-mg/kg simvastatin-treated group. Simvastatin or vehicle was administered orally at 1 day after SCI and then daily for 5 weeks. Locomotor functional recovery was assessed during 8 weeks postoperation by performing open-field locomotor test and inclined-plane test. At the end of study, motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) were assessed to evaluate the integrity of spinal cord pathways. Then, the animals were killed, and 1-cm segments of spinal cord encompassing the injury site were removed for histopathological analysis. Immunohistochemistry was performed to observe the expression of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) in the spinal cord. Results show that the simvastatin-treated animals showed significantly better locomotor function recovery, better electrophysiological outcome, less myelin loss, and higher expression of BDNF and GDNF. These findings suggest that simvastatin treatment starting 1 day after SCI can significantly improve locomotor recovery, and this neuroprotective effect may be related to the upregulation of BDNF and GDNF. Therefore, simvastatin may be useful as a promising therapeutic agent for SCI.     

Effects of methylprednisolone and ganglioside GM-1 on a spinal lesion: a functional analysis

OBJECTIVES: The pharmacological effects of methylprednisolone (MP) and ganglioside GM-1 on spinal injuries have been thoroughly investigated, but only a few studies have evaluated the interaction between these two drugs. METHODS: Twenty-four Wistar rats were subjected to contusive injury of the spinal cord produced by the NYU system. These animals were divided into four groups: group I was injected with MP; group II was injected with GM-1; group III was injected with MP together with GM-1; and group control received physiological serum. The animals were evaluated with regard to their recovery of locomotive function by means of the BBB test on the second, seventh and fourteenth days after receiving the contusive injury to the spinal cord. They were sacrificed on the fourteenth day. RESULTS: This study demonstrated that the MP and GM-1 groups presented functional results that were better than those of the control group, although the enhanced recovery of group II (GM-1) relative to the control group was not statistically significant (p>0.05). The most notable recovery of locomotive function was observed in the group that received MP alone (p<0.05). The group that received MP together with GM-1 presented results that were better than those of the control group (p<0.05). CONCLUSION: Administration of methylprednisolone alone or with GM-1 was shown to be effective for recovery of locomotive function. Combined administration of these drugs resulted in better outcomes than administration of methylprednisolone alone.     

Human mesenchymal stem cell transplantation promotes functional recovery following acute spinal cord injury in rats

Many attempts have been made in animals to produce cellular regeneration in the spinal cord using a variety of transplanted cell types. The present study was to investigate whether transplantation of human mesenchymal stem cells (hMSCs) into the spinal cord after contusion injury promotes a functional outcome. Spinal cord injury (SCI) was induced using an NYU impactor and hMSCs were transplanted 1 week after SCI. Behavioral testing was performed weekly for 2 months. Somatosensory (SSEPs) and motor evoked potentials (MEPs) were recorded to determine functional recovery. Hindlimb performance was modestly improved in the transplanted group based on BBB scaling and pain tests. SSEP latencies in the transplanted group were significantly shorter than in the media-treated group. Pathologically, LacZ and hTau positive cells were located at the injury and adjacent sites. The data indicate improvement in functional outcome in animals treated with hMSC transplantation compared to media-treated animals.     

Continuous brain-derived neurotrophic factor (BDNF) infusion after methylprednisolone treatment in severe spinal cord injury

Although methylprednisolone (MP) is the standard of care in acute spinal cord injury (SCI), its functional outcome varies in clinical situation. Recent report demonstrated that MP depresses the expression of growth-promoting neurotrophic factors after acute SCI. The present study was designed to investigate whether continuous infusion of brain-derived neurotrophic factor (BDNF) after MP treatment promotes functional recovery in severe SCI. Contusion injury was produced at the T10 vertebral level of the spinal cord in adult rats. The rats received MP intravenously immediately after the injury and BDNF was infused intrathecally using an osmotic mini-pump for six weeks. Immunohistochemical methods were used to detect ED-1, Growth associated protein-43 (GAP-43), neurofilament (NF), and choline acethyl transferase (ChAT) levels. BDNF did not alter the effect of MP on hematogenous inflammatory cellular infiltration. MP treatment with BDNF infusion resulted in greater axonal survival and regeneration compared to MP treatment alone, as indicated by increases in NF and GAP-43 gene expression. Adjunctive BDNF infusion resulted in better locomotor test scores using the Basso-Beattie-Bresnahan (BBB) test. This study demonstrated that continuous infusion of BDNF after initial MP treatment improved functional recovery after severe spinal cord injury without dampening the acute effect of MP.     

Tissue engineered regeneration of completely transected spinal cord using human mesenchymal stem cells

The present study employed a combinatorial strategy using poly(D,L-lactide-co-glycolide) (PLGA) scaffolds seeded with human mesenchymal stem cells (hMSCs) to promote cell survival, differentiation, and neurological function in a completely transected spinal cord injury (SCI) model. The SCI model was prepared by complete removal of a 2-mm length of spinal cord in the eighth-to-ninth spinal vertebra, a procedure that resulted in bilateral hindlimb paralysis. PLGA scaffolds 2 mm in length without hMSCs (control) or with different numbers of hMSCs (1 × 10(5), 2 × 10(4), and 4 × 10(3)) were fitted into the completely transected spinal cord. Rats implanted with hMSCs received Basso-Beattie-Bresnahan scores for hindlimb locomotion of about 5, compared with ~2 for animals in the control group. The amplitude of motor-evoked potentials (MEPs) averaged 200-300 μV in all hMSC-implanted SCR model rats. In contrast, the amplitude of MEPs in control group animals averaged 135 μV at 4 weeks and then declined to 100 μV at 8 weeks. These results demonstrate functional recovery in a completely transected SCI model under conditions that exclude self-recovery. hMSCs were detected at the implanted site 4 and 8 weeks after transplantation, indicating in vivo survival of implanted hMSCs. Immunohistochemical staining revealed differentiation of implanted hMSCs into nerve cells, and immunostained images showed clear evidence for axonal regeneration only in hMSC-seeded PLGA scaffolds. Collectively, our results indicate that hMSC-seeded PLGA scaffolds induced nerve regeneration in a completely transected SCI model, a finding that should have significant implications for the feasibility of therapeutic and clinical hMSC-delivery using three-dimensional scaffolds, especially in the context of complete spinal cord transection.     

蛛网膜下腔置管灌注rhNCAM1促损伤脊髓再生修复的实验研究

目的:探讨神经细胞粘附分子1(neural cell adhesion molecule 1,NCAM1)灌注治疗小鼠脊髓撞击伤后对脊髓修复及神经功能恢复的影响。方法:采用改良NYU(纽约大学)Weight-Drop Impactor打击装置,以25 gcf(l0 g重量从25 mm高度自由落下)制备脊髓损伤模型(打击面积为2 mm×2 mm)。将SA小鼠30只随机分为3组:实验组(rhNCAM1组,n=10)于损伤即刻经蛛网膜下腔注入rhNCAM1蛋白2μl(约100μg),隔日1次,共5次;对照组(生理盐水组,n=10)于损伤即刻经蛛网膜下腔注入生理盐水2μl,隔日1次,共5次;假手术组仅做椎板切除术,术后缝合切口。观察各组小鼠1~8周行为学改变,行BBB评分。第8周灌注固定、取材,采用神经纤维200(NF200)免疫荧光检测,进行图像分析及统计处理。结果:(1)行为学评估:实验组BBB评分在各时间点均显著高于对照组(P<0.01);(2)NF200免疫荧光染色:实验组阳性着色明显多于、并强于对照组;实验组无组织瘢痕结构面积明显小于对照组。结论:蛛网膜下腔应用rhNCAM1后可能改善SCI后损伤区及两端的神经细胞之间的功能,促进轴突再生,促进双下肢运动功能的恢复。     

Simvastatin mobilizes bone marrow stromal cells migrating to injured areas and promotes functional recovery after spinal cord injury in the rat

This study investigated the therapeutic effects of simvastatin administered by subarachnoid injection after spinal cord injury (SCI) in rats; explored the underlying mechanism from the perspective of mobilization, migration and homing of bone marrow stromal cells (BMSCs) to the injured area induced by simvastatin. Green fluorescence protein labeled-bone marrow stromal cells (GFP-BMSCs) were transplanted into rats through the tail vein for stem cell tracing. Twenty-four hours after transplantation, spinal cord injury (SCI) was produced using weight-drop method (10g 4cm) at the T10 level. Simvastatin (5mg/kg) or vehicle was administered by subarachnoid injection at lumbar level 4 after SCI. Locomotor functional recovery was assessed in the 4 weeks following surgery using the open-field test and inclined-plane test. At the end of the study, MRI was used to evaluate the reparation of the injured spinal cord. Animals were then euthanized, histological evaluation was used to measure lesion cavity volumes. Immunofluorescence for GFP and cell lineage markers (NeuN and GFAP) was used to evaluate simvastatin-mediated mobilization and differentiation of transplanted BMSCs. Western blot and immunohistochemistry were used to assess the expression of vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF). Simvastatin-treated animals showed significantly better locomotor recovery, less signal abnormality in MRI and a smaller cavity volume compared to the control group. Immunofluorescence revealed that simvastatin increased the number of GFP-positive cells in the injured spinal cord, and the number of cells double positive for GFP/NeuN or GFP/GFAP was larger in the simvastatin treated group than the control group. Western blot and immunohistochemistry showed higher expression of BDNF and VEGF in the simvastatin treated group than the control group. In conclusion, simvastatin can help to repair spinal cord injury in rat, where the underlying mechanism appears to involve the mobilization of bone marrow stromal cells to the injured area and higher expression of BNDF and VEGF.     

Nanoparticle-mediated local delivery of methylprednisolone after spinal cord injury

Systemic administration of a high-dose of Methylprednisolone (MP) can reduce neurological deficits after acute spinal cord injury (SCI). However, the use of high-dose MP in treating acute SCI is controversial due to significant dose related side effects and relatively modest improvements in neurological function. Here, using a rat model of SCI, we compare the efficacy of controlled, nanoparticle-enabled local delivery of MP to the injured spinal cord with systemic delivery of MP, and a single local injection of MP without nanoparticles. Based on histological and behavioral data, we report that local, sustained delivery of MP via nanoparticles is significantly more effective than systemic delivery. Relative to systemic delivery, MP-nanoparticle therapy significantly reduced lesion volume and improved behavioral outcomes. Nanoparticle-enabled delivery of MP presents an effective method for introducing MP locally after SCI and significantly enhances therapeutic effectiveness compared to bare MP administered either systemically or locally.     

Transplantation of neurospheres derived from bone marrow stromal cells promotes neurological recovery in rats with spinal cord injury

Previous studies have revealed that cell therapy using bone marrow stromal cells (BMSCs) could promote motor functional recovery in animals with spinal cord injury (SCI). We describe here the development of cell biology technique and the experimental study of regeneration in SCI. The aim of this study was to investigate the potential for neurological recovery by transplantation neurospheres (NS) derived from BMSCs into thoracic SCI. Adult Fisher rats were used: 45 were subjected to complete thoracic SCI performed by the balloon compression method. BMSCs were cultured in vitro to obtain NS. Seven days after thoracic SCI, groups of 15 rats each received transplants of BMSCs-NS (group A), BMSCs (group B), or injection of medium only (group C) into the SCI lesion. Rats from each group were evaluated and compared longitudinally for motor function recovery. The spinal cords (SC) of injured rats were harvested at day 21 or day 42 and prepared for histological analysis. Five weeks after transplantation, many neuronal or axonal sproutings were observed and replaced by host cells in the SCI lesion of group A. Also, transplanted BMSCs-NS expressed neuronal lineage markers. Transplanted rats could walk with weight bearing and showed recovered motor evoked potentials (MEPs).     

丙戊酸钠联合甲强龙对大鼠脊髓损伤的影响及其机制

目的 探讨丙戊酸钠(VAP)联合甲强龙(MP)在大鼠脊髓损伤(SCI)后神经功能恢复中的作用及其机制。方法 选取8～10周龄雄性健康SD大鼠60只,按照数字表法随机分为假手术组、SCI组、VAP组、MP组和VAP+MP组,每组12只;各组大鼠再按照数字表法随机分为A组、B组2个亚组,每组6只。假手术组仅暴露脊髓、不做SCI处理,其余4组均采用改良Allen法进行大鼠SCI模型制备。假手术组、SCI组术后30 min、6 h、8 h和24 h腹腔注入生理盐水(剂量为30 mg/kg),24 h后每天腹腔注入相同剂量生理盐水,持续28 d;VAP组:分别于术后于30 min、6 h和24 h腹腔注入生理盐水(30 mg/kg),术后8 h腹腔注入VAP(30 mg/kg),24 h后每天腹腔注入相同剂量VAP,持续28 d;MP组:分别于术后30 min、6 h和24 h腹腔注入MP(30 mg/kg),术后8 h腹腔注入生理盐水(30 mg/kg),24 h后每天腹腔注入相同剂量生理盐水,持续28 d;VAP+MP组:分别于术后30 min、6 h和24 h腹腔注入MP(30 mg/kg),术后8 h腹腔注入VAP(30 mg/kg),24 h后每天腹腔注入相同剂量VAP,持续28 d。选取各组A亚组大鼠:术后第1、3、7、14、28天,分别采用脊髓损伤行为学运动功能(BBB)评分标准和改良Rivlin斜板试验评价SCI后各组大鼠肢体运动功能的恢复情况。选取各组B亚组大鼠:术后第7天手术切取SCI区域脊髓组织,HE染色观察各组大鼠脊髓组织形态变化,Nissl染色观察脊髓运动神经元情况并计算凋亡运动神经元数目,免疫组织化学染色半定量分析肿瘤坏死因子(TNF-α)、白细胞介素-1β(IL-1β)蛋白的相对表达情况,Western blot法检测凋亡相关蛋白B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关的X因子(Bax)、caspase-3的相对表达情况。结果 (1)组内比较:与术前相比,假手术组术后第1、3、7、14、28天BBB评分和Rivlin斜板试验结果差异均无统计学意义(P值均＞0.05);SCI组、VAP组、MP组、VAP +MP组术后不同时间点BBB评分和Rivlin斜板试验结果均明显降低,但随着时间延长,BBB评分和Rivlin斜板试验结果逐渐升高,差异均有统计学意义(P值均＜0.05)。组间比较:SCI组、VAP组、MP组、VAP+MP组SCI后BBB评分和Rivlin斜板试验结果均显著低于假手术组,VAP组、MP组、VAP+MP组的BBB评分和Rivlin斜板试验结果均高于SCI组,VAP+MP组BBB评分和Rivlin斜板试验结果均高于VAP组、MP组,差异均有统计学意义(P值均＜0.05)。(2)假手术及造模后第7天,HE染色观察组织学特征:假手术组脊髓组织形态正常;SCI组脊髓组织可见脊髓灰质出现大量炎性细胞因子浸润,细胞出血、水肿, 运动神经元坏死、凋亡明显;VAP组、MP组、VAP+MP组较SCI组大鼠脊髓组织可见出血水肿显著减轻,炎性细胞因子浸润显著减少,运动神经元溶解、凋亡减轻,其中VAP+MP组效果更加显著。SCI组、VAP组、MP组、VAP+MP组脊髓空洞面积均明显大于假手术组,VAP组、MP组、VAP+MP组脊髓空洞面积均明显小于SCI组,VAP+MP组脊髓空洞面积均小于VAP组和MP组,差异均有统计学意义(P值均＜0.05)。(3)假手术及造模后第7天,Nissl染色观察脊髓运动神经元数目:SCI组、VAP组、MP组、VAP+MP组大鼠脊髓组织正常运动神经元数目明显少于假手术组,VAP组、MP组、VAP+MP组正常运动神经元数目均高于SCI组,VAP+MP组正常运动神经元数目均高于VAP组、MP组,差异均有统计学意义(P值均＜0.05)。(4)假手术及造模后第7天,免疫组织化学检测TNF-α、IL-1β表达情况:SCI组、VAP组、MP组、VAP+M组TNF-α、IL-1β表达明显高于假手术组,VAP组、MP组、VAP+MP组TNF-α、IL-1β表达水平显著低于SCI组,VAP+MP组TNF-α、IL-1β表达明显低于VAP组和MP组,差异均有统计学意义 (P值均＜0.05)。(5)假手术及造模后第7天,Western blot法测试大鼠脊髓组织中凋亡蛋白表达情况:与假手术组比较,SCI组、VAP组、MP组、VAP+MP组凋亡相关蛋白Bcl-2、Bax和caspase-3的相对表达量明显增加;与SCI组比较,VAP组、MP组、VAP+MP组Bcl-2的相对表达量明显增加,Bax、caspase-3的相对表达量明显减少;VAP+MP组Bcl-2的相对表达量明显高于VAP组、MP组,Bax、caspase-3的相对表达量明显低于VAP组、MP组:差异均有统计学意义 (P值均＜0.05)。结论 VAP联合MP能够显著改善大鼠SCI后神经运动功能,其机制可能与抑制局部炎性反应、促进抗凋亡蛋白Bcl-2的表达和减少凋亡蛋白Bax、caspase-3的表达有关。     

Neuroprotective effect of methylprednisolone combined with placenta-derived mesenchymal stem cell in rabbit model of spinal cord injury

The aim of this study was to assess the ability of the combination treatment of methylprednisolone (MP) and placenta-derived mesenchymal stem cells (PDMSCs) in a rabbit model of spinal cord injury (SCI). Rabbits were randomly divided into four groups: group 1 (control), group 2 (MP), group 3 (PDMSCs) and group 4 (MP + PDMSCs). In all groups, the spinal cord injury model was created by the weight drop method. Levels of malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined by kit. Histopathological examination was also performed. Neurological evaluation was carried out with the Tarlov scoring system. The results showed both MP and PDMSCs had neuroprotective effects, and combining the administration of MP with PDMSCs was shown a significant effect on the recovery of neurological function. Therefore, the combined use of MP and PDMSCs can be used as a potential therapeutic method for SCI.     

Transplantation of undifferentiated and induced human exfoliated deciduous teeth-derived stem cells promote functional recovery of rat spinal cord contusion injury model

Regarding both the neural crest origin and neuronal potential of stem cells from human exfoliated deciduous teeth (SHED), here, we assessed their potential in addition to neural induced SHED (iSHED) for functional recovery when transplanted in a rat model for acute contused spinal cord injury (SCI). Following transplantation, a significant functional recovery was observed in both groups relative to the vehicle and control groups as determined by the open field locomotor functional test. We also observed that animals that received iSHED were in a better state as compared with the SHED group. Immunohistofluorescence evaluation 5 weeks after transplantation showed neuronal and glial differentiation and limited proliferation in both groups. However, myelin basic protein and chondroitin sulfate proteoglycan NG2-oligodendrocyte markers-were increased and glial fibrillary acidic protein-astrocyte marker-was decreased in the iSHED group in comparison with the SHED group. These findings have demonstrated that transplantation of SHED or its derivatives could be a suitable candidate for the treatment of SCI as well as other neuronal degenerative diseases.     

Implanted electro-acupuncture electric stimulation improves outcome of stem cells' transplantation in spinal cord injury

Abstract Spinal cord injury (SCI) is one of the most serious disorders in clinics, and the high disability rate and functional deficits are common issues in patients. Transplantation of bone-marrow-derived mesenchymal stromal cells (BMSCs) into the injured spinal cord is emerging as a novel method in the therapeutics of SCI; however, its application is limited by the poor survival rate of the transplanted cells and low differentiation rate into neurons. Our laboratory recently reported that electrical stimulation (ES) dramatically improves the survival rate of transplanted BMSCs and increases spinal cord functions in animals with spinal cord injury. In this paper, we asked whether implanted electro-acupuncture (iEA) can advance the beneficial effects from the ES treatment in animals with spinal cord injury. We showed that BMSCs transplantation alone resulted in significant functional recovery in animals. Interestingly, iEA with BMSCs treatment induced a significantly higher functional improvement in locomotor functions and SSEP compared to the BMSCs treatment alone. Additionally, we used molecular biology techniques and showed that BMSCs transplantation with iEA treatment significantly increased the number of surviving BMSCs compared to the BMSCs alone group. In conclusion, our experiment showed that the approach of coupling iEA electric stimulation and BMSCs transplantation remarkably promotes functional improvements in animals with spinal cord injury and holds promising potential to treat spinal cord injury in humans.     

骨形成蛋白4对脊髓损伤后大鼠功能和神经干细胞的影响

目的　观察骨形成蛋白 4对脊髓损伤后大鼠功能和神经干细胞的影响。方法　应用改良Allen脊髓损伤模型 ,将成年SD大鼠 6 0只随机分为BMP 4组、脊髓损伤组。分别于术后 1d、7d、14d、2 1d、2 8d处死动物 ,并且对大鼠进行Tarlov评分和斜板试验检查后肢功能。应用免疫组织化学技术检测巢蛋白 (nestin)的表达 ,观察BMP4对脊髓损伤后nestin表达的影响。结果　第 2 1d时BMP4组大鼠功能改善明显与损伤组比较差异有显著性意义 (P <0 0 5 ) ;脊髓损伤后第 1天 ,在BMP4组和脊髓损伤组的室管膜、室管膜下区、损伤脊髓灰质中都可见到nestin的表达。于损伤后迅速增加 ,第 14天时达到高峰。BMP4组灰质nestin表达为 15 35± 3 83,脊髓损伤组灰质为 8 4 8± 3 5 3,两者差异有显著性 (P <0 0 1)。BMP4组可使损伤的脊髓中nestin持续高表达至术后第 2 8天 ,而脊髓损伤组仅持续表达至术后 2 1d。增加的nestin阳性细胞数与神经功能的改善平行。结论　提示BMP4可减轻神经损伤症状和对脊髓损伤后神经干细胞有促进增殖作用。     

龟板对脊髓损伤后大鼠功能和骨形态发生蛋白4表达的影响

目的　观察龟板对大鼠损伤脊髓骨形态发生蛋白 4 (BMP4 )表达和后肢功能恢复的影响。方法　应用改良Allen脊髓损伤模型 ,于术后 1、7、14、2 1、2 8d分别对大鼠进行Tarlov评分和斜板试验检查后肢功能。应用免疫组织化学技术检测BMP4的表达 ,观察龟板对脊髓损伤后BMP4的影响。结果　脊髓损伤后第 1d ,在两组受损伤脊髓灰质中都可见到BMP4的表达。第 14d时达到高峰 ,龟板组为 37 2 4± 5 73,损伤组 2 1 4 8± 6 83(P <0 0 5 )。龟板组可使损伤的脊髓BMP4持续高表达至术后第 2 8d ,而损伤组仅持续表达至术后 2 1d。增加的BMP4阳性细胞数与神经功能的改善平行。结论　龟板可减轻神经损伤症状和促进脊髓损伤后BMP4表达     

Repair of thoracic spinal cord injury by chitosan tube implantation in adult rats

Spinal cord injury (SCI) is a common outcome of traffic accidents and trauma with severe consequences. There has been no cure for such a condition. We performed experiments to evaluate the feasibility of implanting a chitosan tube filled with semifluid type I collagen into the site of surgically induced SCI to facilitate functional recovery. After a segment of the spinal cord, 4 mm in length and 2/3 of the spinal cord across its width, at the ninth thoracic level of an adult rat was dissected and removed, the biodegradable chitosan tube was implanted into the lesioned site. One year later, we found that axons from the proximal spinal cord regenerated, traversed the dissected area inside the tube and reentered the distal spinal cord, leading to functional restoration of the essentially paralyzed hind limbs. The nerve regeneration and functional recovery were confirmed by immunohistochemistry, electron microscopy, nerve tracing and Basso–Beattie–Bresnahan behavioral evaluation. Such beneficial outcomes were not observed in the control groups, in which either no tube was implanted or the implanted tube had no collagen filling. We conclude that the newly designed tube implant promotes both axon regeneration and functional recovery following SCI. A similar approach may have clinical implications in humans.     

脐带间充质干细胞移植对脊髓损伤小鼠运动功能的修复和镇痛作用

目的：探讨人脐带间充质干细胞（ hUC-MSCs）移植缓解脊髓损伤神经病理性痛,并促进功能恢复的效果及 其与脊髓损伤小鼠胶质细胞活化及炎症因子水平的调控关系。方法：建立ICR 小鼠脊髓损伤模型,同时构建慢病毒 载体介导绿色荧光蛋白（ GFP）标记体外培养的 hUC-MSCs ;将模型小鼠分为模型组和治疗组,治疗组于脊髓损 伤1 周后采用局部注射 hUC-MSCs 移植到脊髓中,每周进行运动功能（ BBB）评分及机械性痛觉过敏检测,持续8 周后行组织学评价与炎症因子检测。结果：治疗组脊髓组织中 GFP 荧光有表达。BBB检测结果显示,治疗组和模 型组小鼠随时间延长运动功能均逐渐恢复,其中治疗组运动功能恢复速度要显著快于模型组;机械触诱发痛检测显 示,小鼠脊髓损伤后痛阈值降低,随着时间延长痛阈值逐渐升高。同一个时间点治疗组的痛阈值显著高于模型组。 与模型组相比,治疗组小鼠脊髓组织的白细胞介素-6（ IL-6）、肿瘤坏死因子-α（ TNF-α）表达下降,胶质细胞源 性神经营养因子（ GDNF）表达升高,同时脊髓组织巨噬细胞激活抗原1（ ED1/CD68） 荧光表达显著降低。结论： 脊髓损伤小鼠中hUC-MSCs 移植可能通过降低炎症因子 IL-6 和TNF-α 的分泌,提高 GDNF 的表达水平来促进受损 脊髓组织的修复,并发挥镇痛效应。     

MnTBAP对脊髓损伤大鼠脂质过氧化和运动功能的影响

目的观察脊髓损伤(SCI)后锰卟啉(MnTBAP)对损伤早期脂质过氧化反应、活性氧水平和伤后4W内运动功能的影响,探讨MnTBAP对脊髓继发性损伤的保护作用。方法用钳夹法制备大鼠SCI模型,分为假手术组、损伤组、MnTBAP治疗组和甲基强的松龙(MP)治疗组。损伤组术后立即腹腔注射生理盐水,MnTBAP组伤后立即腹腔注射MnTBAP(10mg/kg体重),MP组伤后立即腹腔注射MP(100mg/kg)。经1、6、12、24h,取SCI段标本,用于测定损伤段脊髓超氧化物歧化酶(SOD)、脂质过氧化产物丙二醛(MDA)和活性氧水平(ROS),经1、7、14、21、28d,进行斜板试验,评价运动功能。结果与假手术组相比,损伤组伤段脊髓组织SOD显著减少(均<0.01),MDA和ROS显著增加(均<0.01);与损伤组相比,MnTBAP治疗组伤段脊髓组织SOD水平显著增加(均<0.01),相反,MDA和ROS水平显著减少(均<0.01),其作用和MP相当;斜板试验结果观察,除1d组外,MnTBAP治疗组斜板角度与损伤组相比明显增加(均<0.01)。结论 MnTBAP有效抑制SCI早期受损脊髓脂质过氧化反应和活性氧水平,改善SCI大鼠运动功能,对继发性SCI具有保护作用。     

高压氧联合神经干细胞移植治疗大鼠脊髓损伤

背景：单纯神经干细胞移植已应用于对受损脊髓组织的修复。 目的：以神经干细胞移植同时应用高压氧治疗大鼠脊髓损伤,观察联合作用对脊髓损伤大鼠运动功能恢复的影响。 方法：雌性SD大鼠60只,以半切法制成胸段脊髓半横断大鼠模型。随机分成单纯损伤组、神经干细胞移植组及高压氧治疗组,每组20只。伤后第4周取材行病理切片苏木精-伊红染色及BrdU免疫组织化学染色,第8周取材行辣根过氧化物酶示踪,透射电镜观察轴突的再生情况,通过体感诱发电位观察神经电生理恢复情况。造模后1,2,4,6,8周进行BBB评分和斜板实验等运动功能检测。  结果与结论：观察伤后4周病理切片,单纯损伤组未见神经轴索通过,神经干细胞移植组可见少量神经轴索样结构,高压氧治疗组可见较多神经轴索样结构。BrdU的阳性细胞数及辣根过氧化物酶阳性神经纤维数,高压氧治疗组最多,神经干细胞移植组次之,单纯损伤组最少,且各组之间差异有显著性意义(P < 0.05)。透射电镜下神经干细胞移植组、高压氧治疗组正中横断面可见新生的无髓及有髓神经纤维。高压氧治疗组大鼠体感诱发电位的潜伏期短于神经干细胞移植组,波幅高于神经干细胞移植组(P < 0.05),明显优于单纯损伤组(P < 0.01)。伤后4周神经干细胞移植组、高压氧治疗组大鼠后肢运动功能均有较明显恢复,高压氧治疗组较神经干细胞移植组恢复快(P < 0.05);单纯损伤组亦有所恢复,但程度较轻。提示神经干细胞移植对于脊髓损伤大鼠后肢功能的恢复有促进作用,联合应用高压氧有协同效果。     

GAP-43治疗大鼠脊髓横断后神经中丝NF200表达的变化

通过制备成年SD大鼠完全性脊髓损伤模型,研究生长相关蛋白(GAP-43)治疗大鼠脊髓损伤后神经中丝(NF200)表达的变化,探讨GAP-43在再生修复中的作用,为临床治疗提供实验依据。实验采用雌性8周龄SD大鼠75只,制成脊髓损伤模型后随机分为三组:GAP-43抗体组、GAP-43抗原组和对照组,每组25只。使用直接注射法将GAP-43抗原和GAP-43多克隆抗体分别注入抗原组和抗体组的大鼠脊髓的断端,对照组仅切断脊髓而不给药,最后观察各组大鼠肢体功能的恢复情况。用BBB评分法对不同时段大鼠的行为学表现进行评分,用HE染色及免疫组化染色观察NF200的表达,并对其进行相关性分析。结果发现对照组在不同的时间段行为学评分最低和抗原组评分最高,脊髓损伤区病理改变明显好转,NF200的表达呈进行性增高,且前角神经元NF200的表达早于后角神经元。抗体组早期恢复出现明显的停滞状态,但停药后能很快恢复。说明GAP-43能促进损伤脊髓的恢复,而抗体对损伤脊髓恢复的影响是可逆的,这对于脊髓再生的研究是一种值得探讨的新方法,对进一步探索脊髓损伤的治疗具有重要的意义。