Endothelial progenitor cell-conditioned medium promotes angiogenesis and is neuroprotective after spinal cord injury

Endothelial progenitor cells secrete a variety of growth factors that inhibit inflammation, promote angiogenesis and exert neuroprotective effects. Therefore, in this study, we investigated whether endothelial progenitor cell-conditioned medium might have therapeutic effectiveness for the treatment of spinal cord injury using both in vitro and in vivo experiments. After primary culture of bone marrow-derived macrophages, lipopolysaccharide stimulation was used to classically activate macrophages to their proinflammatory phenotype. These cells were then treated with endothelial progenitor cell-conditioned medium or control medium. Polymerase chain reaction was used to determine mR NA expression levels of related inflammatory factors. Afterwards, primary cultures of rat spinal cord neuronal cells were prepared and treated with H2O2and either endothelial progenitor cell-conditioned medium or control medium. Hoechst 33258 and propidium iodide staining were used to calculate the proportion of neurons undergoing apoptosis. Aortic ring assay was performed to assess the effect of endothelial progenitor cell-conditioned medium on angiogenesis. Compared with control medium, endothelial progenitor cell-conditioned medium mitigated the macrophage inflammatory response at the spinal cord injury site, suppressed apoptosis, and promoted angiogenesis. Next, we used a rat model of spinal cord injury to examine the effects of the endothelial progenitor cell-conditioned medium in vivo. The rats were randomly administered intraperitoneal injection of PBS, control medium or endothelial progenitor cell-conditioned medium, once a day, for 6 consecutive weeks. Immunohistochemistry was used to observe neuronal morphology. Terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling assay was performed to detect the proportion of apoptotic neurons in the gray matter. The Basso, Beattie and Bresnahan Locomotor Rating Scale was used to evaluate the recovery of motor function of the bilateral hind limbs after spinal cord injury. Compared with the other two groups, the number of axons was increased, cavities in the spinal cord were decreased, the proportion of apoptotic neurons in the gray matter was reduced, and the Basso, Beattie and Bresnahan score was higher in the endothelial progenitor cell-conditioned medium group. Taken together, the in vivo and in vitro results suggest that endothelial progenitor cell-conditioned medium suppresses inflammation, promotes angiogenesis, provides neuroprotection, and promotes functional recovery after spinal cord injury.

Serum and cerebrospinal fluid tau protein level as biomarkers for evaluating acute spinal cord injury severity and motor function outcome

Tau protein, a microtubule-associated protein, has a high specific expression in neurons and axons. Because traumatic spinal cord injury mainly affects neurons and axons, we speculated that tau protein may be a promising biomarker to reflect the degree of spinal cord injury and prognosis of motor function. In this study, 160 female Sprague-Dawley rats were randomly divided into a sham group, and mild, moderate, and severe spinal cord injury groups. A laminectomy was performed at the T8 level to expose the spinal cord in all groups. A contusion lesion was made with the NYU-MASCIS impactor by dropping a 10 g rod from heights of 12.5 mm(mild), 25 mm(moderate) and 50 mm(severe) upon the exposed dorsal surface of the spinal cord. Tau protein levels were measured in serum and cerebrospinal fluid samples at 1, 6, 12, 24 hours, 3, 7, 14 and 28 days after operation. Locomotor function of all rats was assessed using the Basso, Beattie and Bresnahan locomotor rating scale. Tau protein concentration in the three spinal cord injury groups(both in serum and cerebrospinal fluid) rapidly increased and peaked at 12 hours after spinal cord injury. Statistically significant positive linear correlations were found between tau protein level and spinal cord injury severity in the three spinal cord injury groups, and between the tau protein level and Basso, Beattie, and Bresnahan locomotor rating scale scores. The tau protein level at 12 hours in the three spinal cord injury groups was negatively correlated with Basso, Beattie, and Bresnahan locomotor rating scale scores at 28 days(serum: r =-0.94; cerebrospinal fluid: r =-0.95). Our data suggest that tau protein levels in serum and cerebrospinal fluid might be a promising biomarker for predicting the severity and functional outcome of traumatic spinal cord injury.

Therapeutic effect of regulating autophagy in spinal cord injury: a network meta-analysis of direct and indirect comparisons

Objective:An increasing number of studies indicate that autophagy plays an important role in the pathogenesis of spinal cord injury,and that regulating autophagy can enhance recovery from spinal cord injury.However,the effect of regulating autophagy and whether autophagy is detrimental or beneficial after spinal cord injury remain unclear.Therefore,in this study we evaluated the effects of autophagy regulation on spinal cord injury in rats by direct and indirect comparison,in an effort to provide a basis for further research.Data source:Relevant literature published from inception to February 1,2018 were included by searching Wanfang,CNKI,Web of Science,MEDLINE(OvidSP),PubMed and Google Scholar in English and Chinese.The keywords included"autophagy","spinal cord injury",and"rat".Data selection:The literature included in vivo experimental studies on autophagy regulation in the treatment of spinal cord injury(including intervention pre-and post-spinal cord injury).Meta-analyses were conducted at different time points to compare the therapeutic effects of promoting or inhibiting autophagy,and subgroup analyses were also conducted.Outcome measure:Basso,Beattie,and Bresnahan scores.Results:Of the 622 studies,33 studies of median quality were included in the analyses.Basso,Beattie,and Bresnahan scores were higher at 1 day(MD=1.80,95%CI:0.81-2.79,P=0.0004),3 days(MD=0.92,95%CI:0.72-1.13,P<0.00001),1 week(MD=2.39,95%CI:1.85-2.92,P<0.00001),2 weeks(MD=3.26,95%CI:2.40-4.13,P<0.00001),3 weeks(MD=3.13,95%CI:2.51-3.75,P<0.00001)and 4 weeks(MD=3.18,95%CI:2.43-3.92,P<0.00001)after spinal cord injury with upregulation of autophagy compared with the control group(drug solvent control,such as saline group).Basso,Beattie,and Bresnahan scores were higher at 1 day(MD=6.48,95%CI:5.83-7.13,P<0.00001),2 weeks(MD=2.43,95%CI:0.79-4.07,P=0.004),3 weeks(MD=2.96,95%CI:0.09-5.84,P=0.04)and 4 weeks(MD=4.41,95%CI:1.08-7.75,P=0.01)after spinal cord injury with downregulation of autophagy compared with the control group.Indirect comparison of upregulation and downregulation of autophagy showed no differences in Basso,Beattie,and Bresnahan scores at 1 day(MD=-4.68,95%CI:-5.840 to-3.496,P=0.94644),3 days(MD=-0.28,95%CI:-2.231-1.671,P=0.99448),1 week(MD=1.83,95%CI:0.0076-3.584,P=0.94588),2 weeks(MD=0.81,95%CI:-0.850-2.470,P=0.93055),3 weeks(MD=0.17,95%Cl:-2.771-3.111,P=0.99546)or 4 weeks(MD=-1.23,95%Cl:-4.647-2.187,P=0.98264)compared with the control group.Conclusion:Regulation of autophagy improves neurological function,whether it is upregulated or downregulated.There was no difference between upregulation and downregulation of autophagy in the treatment of spinal cord injury.The variability in results among the studies may be associated with differences in research methods,the lack of clearly defined autophagy characteristics after spinal cord injury,and the limited autophagy monitoring techniques.Thus,methods should be standardized,and the dynamic regulation of autophagy should be examined in future studies.

Local injection of bone morphogenetic protein 7 promotes neuronal regeneration and motor function recovery after acute spinal cord injury

After spinal cord injury,the number of glial cells and motor neurons expressing bone morphogenetic protein 7（BMP7）increases,indicating that upregulation of BMP7 can promote nerve repair.We,therefore,tested whether direct injection of BMP7 into acutely injured ratalalo createrywith 50 ng BMP7（BMP7 group）or physiological saline（control group）for 7 consecutive days.Electrophysiological examination showed that the amplitude of N1 in motor evoked potentials（MEP）decreased after spinal cord injury.At 8 weeks post-operation,the amplitude of N1 in the BMP7 group was remarkably higher than that at 1 week post-operation and was higher than that of the control group.Basso,Beattie,Bresnahan scale（BBB）scores,hematoxylin-eosin staining,and western blot assay showed that at 1,2,4 and 8 weeks post-operation,BBB scores were increased;Nissl body staining was stronger;the number of Nissl-stained bodies was increased;the number of vacuoles gradually decreased;the number of synapses was increased;and the expression of neuronal marker,neurofilament protein 200,was increased in the hind limbs of the BMP7 group compared with the control group.Western blot assay showed that the expression of GFAP protein in BMP7 group and control group did not change significantly and there was no significant difference between the BMP7 and control groups.These data confirmed that local injection of BMP7 can promote neuronal regeneration after spinal cord injury and promote recovery of motor function in rats.

Changes in neurological and pathological outcomes in a modified rat spinal cord injury model with closed canal

Most animal spinal cord injury models involve a laminectomy,such as the weight drop model or the transection model.However,in clinical practice,many patients undergo spinal cord injury while maintaining a relatively complete spinal canal.Thus,open spinal cord injury models often do not simulate real injuries,and few previous studies have investigated whether having a closed spinal canal after a primary spinal cord injury may influence secondary processes.Therefore,we aimed to assess the differences in neurological dysfunction and pathological changes between rat spinal cord injury models with closed and open spinal canals.Sprague-Dawley rats were randomly divided into three groups.In the sham group,the tunnel was expanded only,without inserting a screw into the spinal canal.In the spinal cord injury with open canal group,a screw was inserted into the spinal canal to cause spinal cord injury for 5 minutes,and then the screw was pulled out,leaving a hole in the vertebral plate.In the spinal cord injury with closed canal group,after inserting a screw into the spinal canal for 5 minutes,the screw was pulled out by approximately 1.5 mm and the flat end of the screw remained in the hole in the vertebral plate so that the spinal canal remained closed;this group was the modified model,which used a screw both to compress the spinal cord and to seal the spinal canal.At 7 days post-operation,the Basso-Beattie-Bresnahan scale was used to measure changes in neurological outcomes.Hematoxylin-eosin staining was used to assess histopathology.To evaluate the degree of local secondary hypoxia,immunohistochemical staining and western blot assays were applied to detect the expression of hypoxia-inducible factor 1α(HIF-1α)and vascular endothelial growth factor(VEGF).Compared with the spinal cord injury with open canal group,in the closed canal group the Basso-Beattie-Bresnahan scores were lower,cell morphology was more irregular,the percentage of morphologically normal neurons was lower,the percentages of HIF-1α-and VEGF-immunoreactive cells were higher,and HIF-1αand VEGF protein expression was also higher.In conclusion,we successfully established a rat spinal cord injury model with closed canal.This model could result in more serious neurological dysfunction and histopathological changes than in open canal models.All experimental procedures were approved by the Institutional Animal Care Committee of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,China(approval No.HKDL201810)on January 30,2018.

Assessment of hindlimb motor recovery affer severe thoracic spinal cord injury in rats: classification of CatWalk XT■ gait analysis parameters

Assessment of locomotion recovery in preclinical studies of experimental spinal cord injury remains challenging. We studied the CatWalk XT■gait analysis for evaluating hindlimb functional recovery in a widely used and clinically relevant thoracic contusion/compression spinal cord injury model in rats. Rats were randomly assigned to either a T9 spinal cord injury or sham laminectomy. Locomotion recovery was assessed using the Basso, Beattie, and Bresnahan open field rating scale and the CatWalk XT■gait analysis. To determine the potential bias from weight changes, corrected hindlimb(H) values(divided by the unaffected forelimb(F) values) were calculated. Six weeks after injury, cyst formation, astrogliosis, and the deposition of chondroitin sulfate glycosaminoglycans were assessed by immunohistochemistry staining. Compared with the baseline, a significant spontaneous recovery could be observed in the CatWalk XT■parameters max intensity, mean intensity, max intensity at%, and max contact mean intensity from 4 weeks after injury onwards. Of note, corrected values(H/F) of CatWalk XT■parameters showed a significantly less vulnerability to the weight changes than absolute values, specifically in static parameters. The corrected CatWalk XT■parameters were positively correlated with the Basso, Beattie, and Bresnahan rating scale scores, cyst formation, the immunointensity of astrogliosis and chondroitin sulfate glycosaminoglycan deposition. The CatWalk XT■gait analysis and especially its static parameters, therefore, seem to be highly useful in assessing spontaneous recovery of hindlimb function after severe thoracic spinal cord injury. Because many CatWalk XT■parameters of the hindlimbs seem to be affected by body weight changes, using their corrected values might be a valuable option to improve this dependency.

改良椎板切除法构建脊髓损伤模型大鼠

背景:目前脊髓损伤已成为世界性难题,实验动物造模是探索疾病的第一步,但现缺乏较为有效的实验动物模型。目的:建立一种可复制、可调控、创伤小、死亡率低、出血量少、适用范围广、术中时间短的脊髓损伤大鼠模型。方法:将选用的体质量相似的40只SD大鼠随机分为常规组和改进组,每组20只,常规组采用Allen法构建脊髓损伤模型,改良组在原有模型的基础上,运用牙科磨钻代替器械咬除,比较两组大鼠手术时间、术中出血量、死亡率及击打后1,3,6,9,12,15 d的BBB运动功能学评分。结果与结论:改良继发性脊髓损伤模型建立方法比常规建模方法出血量少、死亡率低、造模时间短、BBB评分结果更集中,由此可证明改良后的击打方法更适用于继发性脊髓损伤模型的建立。

神经前体细胞巢蛋白在大鼠脊髓损伤后的表达

目的:探讨成年大鼠脊髓损伤后损伤(SCI)区局部巢蛋白(nestin)的表达及意义。方法:应用Allen法建立大鼠SCI模型,行为学评分采用BBB评分,用病理学和免疫组织化学方法检测脊髓在不同时段的病理改变和nestin的表达变化。结果:伤后第1天,脊髓实质灶状出血,小血管栓塞,部分神经细胞细胞核碎裂,见损伤区附近、软脊髓膜下的白质和脊髓中央管区有nestin表达,BBB评分低,随后增加,1—2周恢复幅度加大。第3天后损伤灶出现大量胶质细胞,损伤组织液化。第5天后液化灶逐渐扩大,出血减少,阳性神经元和阳性反应的平均积分光密度值达到高峰(P<0.05)。第7天后神经细胞退行性变更为严重,部分神经细胞崩解仅留其轮廓,胶质细胞增生明显。2周后出血已基本吸收,以损伤处为中心,囊腔开始形成,nestin表达明显下调(P<0.05)。结论:脊髓损伤可诱导损伤区周围短暂的nestin阳性表达,nestin可能在脊髓损伤后的再生与修复中起重要作用。

神经行为学检测和改良BBB运动功能评定在脑瘫大鼠运动功能评定中的应用

目的:探讨脑瘫大鼠运动功能评价的最佳方法。方法:采用孕鼠腹腔注射LPS制备脑瘫动物模型,随机选取对照组(A组)足月仔鼠60只,LPS组足月仔鼠120只分为早期干预组(B1组)和非干预组(B2组)各60只。各组于生后25d进行神经行为学检测,B1组中检测出的CP鼠(B1CP组)继续早期干预,B2组中检测出的CP鼠(B2CP组)常规饲养,A组中随机选取10只鼠作为对照组(A′组);A′组、B1CP组和B2CP组仔鼠分别于25d及42d进行神经行为学检测和运动功能评定。结果:①25dB1组鉴定出7只CP鼠,B2组13只CP鼠,A组中无CP鼠。②B1CP组第25天与第42天各项检测结果比较:悬吊试验、斜坡试验、旷场实验、拒俘反应及改良的BBB运动功能评分均有显著性差异(P﹤0.01);B2CP组和A′组大鼠25d与42d各项检测结果比较无显著性差异(P﹥0.05)。结论:①神经行为学检测可有效鉴定CP大鼠的运动功能。②改良BBB运动功能评定适用于CP大鼠的运动功能评定。③联合应用神经行为学检测与改良BBB运动功能评定可全面反映CP大鼠运动功能状况。

Hydrogen-rich saline injection into the subarachnoid cavity within 2 weeks promotes recovery after acute spinal cord injury

Hydrogen can relieve tissue-damaging oxidative stress, inflammation and apoptosis. Injection of hydrogen-rich saline is an effective method for transporting molecular hydrogen. We hypothesized that hydrogen-rich saline would promote the repair of spinal cord injury induced by Allen＇s method in rats. At 0.5, 1, 2, 4, 8, 12 and 24 hours after injury, then once daily for 2 weeks, 0.25 mL/kg hydrogen-rich saline was infused into the subarachnoid space through a catheter. Results at 24 hours, 48 hours, 1 week and 2 weeks after injury showed that hydrogen-rich saline markedly reduced cell death, inflammatory cell infiltration, serum malondialdehyde content, and caspa se-3 immunoreactivity, elevated serum superoxide dismutase activity and calcitonin gene-related peptide immunoreactivity, and improved motor function in the hindlimb. The present study confirms that hydrogen-rich saline injected within 2 weeks of injury effectively contributes to the repair of spinal cord injury in the acute stage.

电针夹脊穴对脊髓损伤大鼠皮层体感诱发电位的影响

目的探讨电针夹脊穴对脊髓损伤(SCI)大鼠皮层体感诱发电位(CSEP)的影响及其对神经功能恢复的促进作用。方法实验于2008年11月～2009年2月在黑龙江中医药大学实验动物中心完成。①制备SD大鼠T10脊髓平面的Allen's打击损伤模型,打击力度为50g.cm。50只实验动物用随机数字表法分为假手术组(A组)、单纯损伤组(B组)、甲基强的松龙(methylpred-nisolone,MP)治疗组(C组)、MP+造模6h电针治疗组(D组)、MP+造模2周电针治疗组(E组),10只/组。C、D、E组于损伤后30min内首次按30mg/kg,随后按5.4mg/kg.h给予MP,每1h给药1次,连续给23次;B组给予同C组等量的生理盐水,D、E组分别于损伤后6h和2周开始给予电针治疗,持续到第8周。②针刺方法:在T8和T12棘突下缘两侧4mm处取穴,0.25mm×25mm毫针垂直刺入5mm,使针尖触及椎板,采用KWD-808Ⅱ型脉冲电针仪,二组导线分别上下连接针柄,正极在上,负极在下,规律交流脉充电波,给予"疏密波",疏波频率2Hz,密波频率100Hz,交替持续时间1.5ms,波宽0.4ms,强度2mA,持续30min,1次/d。A、B、C组按照D组同样方法固定但不进行针刺治疗。③观察指标:1、2、4、6和8周BBB行为学评分;2、4、6、8周CSEP;每周1次。结果50只大鼠全部进入结果分析。所有大鼠在术前和A组术后BBB行为学评分和CSEP潜伏期检查结果均正常,组间无显著性差异(P>0.05);SCI大鼠各周BBB评分均小于A组,CSEP潜伏期长于A组,差异有显著性(P<0.05);1周时:4组动物运动功能均<7分,差异无显著性(P>0.05);2周时:C、D和E组评分>B组(P<0.05),但治疗组间差异无显著性(P>0.05);SCI大鼠CSEP潜伏期明显延长,但组间无显著性差异(P>0.05);4～8周时:各组SCI大鼠中D组评分最多并且潜伏期最短(P<0.05);4周时:评分E组、C组>B组,潜伏期E组、C组<B组,差异有显著性(P<0.05),C组和E组间无显著性差异(P>0.05);6周时:评分E组>C组>B组,潜伏期E组<C组<B组,差异有显著性(P<0.05);8周时:评分E组>C组、B组,潜伏期E组<C组、B组,差异有显著性(P<0.05),但B组和C组无显著性差异(P>0.05)。结论电针夹脊穴对脊髓损伤大鼠神经功能的恢复有促进作用,先期电针干预的效果好于后期。

Electroacupuncture promotes the recovery of motor neuron function in the anterior horn of the injured spinal cord

Acupuncture has been shown to lessen the inflammatory reaction after acute spinal cord injury and reduce secondary injury.However,the mechanism of action remains unclear.In this study,a rat model of spinal cord injury was established by compressing the T8-9 segments using a modified Nystrom method.Twenty-four hours after injury,Zusanli（ST36）,Xuanzhong（GB39）,Futu（ST32）and Sanyinjiao（SP6）were stimulated with electroacupuncture.Rats with spinal cord injury alone were used as controls.At 2,4 and 6 weeks after injury,acetylcholinesterase（ACh E）activity at the site of injury,the number of medium and large neurons in the spinal cord anterior horn,glial cell line-derived neurotrophic factor（GDNF）m RNA expression,and Basso,Beattie and Bresnahan locomotor rating scale scores were greater in the electroacupuncture group compared with the control group.These results demonstrate that electroacupuncture increases ACh E activity,up-regulates GDNF m RNA expression,and promotes the recovery of motor neuron function in the anterior horn after spinal cord injury.

川芎嗪对大鼠脊髓损伤后神经功能恢复作用的研究

目的探讨川芎嗪(TMP)对大鼠脊髓损伤后后肢运动功能恢复的影响。方法雄性成年SD大鼠24只,随机均分为假手术组、对照组及TMP治疗组。采用改良Allen法建立大鼠胸段脊髓打击模型,HE染色观察伤后4周伤段脊髓残存组织的面积,采用斜板试验和运动功能评分观察大鼠后肢运动功能的恢复情况。结果大鼠脊髓损伤后1～4周,TMP治疗组后肢运动功能评分明显高于对照组,两组间差异有显著性(P<0.05)。伤后4周,TMP组伤段残存脊髓组织的面积大于对照组(P<0.01)。结论TMP能明显减少脊髓损伤后伤区的坏死和萎缩,并促进大鼠后肢运动功能的恢复。

注射硫酸软骨素酶对大鼠脊髓损伤后腓肠肌乙酰胆碱酯酶的变化及运动功能的影响

目的探讨注射硫酸软骨素酶ABC对成年大鼠脊髓损伤后不同时期后肢运动功能的恢复及腓肠肌运动终板内乙酰胆碱酯酶的影响。方法 10周龄Wistar雄性大鼠40只,采用脊髓半横断法制作模型,健侧作为对照组（A组）,患侧随机分为单纯脊髓损伤组（B组）及术后注射硫酸软骨素酶ABC组（C组）。术后采用BBB评分法进行行为学观察,分别于损伤后3 d、7 d、14 d和28d各选取5只大鼠,酶化学染色法检测腓肠肌中乙酰胆碱酯酶（AChE）的表达。结果 C组在术后14~28 d BBB评分高于B组（P〈0.05）;B组和C组与A组相比,腓肠肌AChE活性均降低,但C组于术后14~28 d AchE活性高于B组（P〈0.05）。结论大鼠脊髓损伤后注射硫酸软骨素酶可以提高AChE的活性,并可提高大鼠患肢的运动功能。

Globose basal cells for spinal cord regeneration

Spinal cord injury （SCI） is a devastating condition with loss of motor and sensory functions below the injury level. Cell based therapies are experimented in pre-clinical studies around the world. Neural stem cells are located intra-craniafly in subventricular zone and hippocampus which are highly invasive sourc- es. The olfactory epithelium is a neurogenic tissue where neurogenesis takes place throughout the adult life by a population of stem/progenitor cells. Easily accessible olfactory neuroepithelial stem/progenitor cells are an attractive cell source for transplantation in SCI. Globose basal cells （GBCs） were isolated from rat olfactory epithelium, characterized by flow cytometry and immunohistochemically. These ceils were further studied for neurosphere formation and neuronal induction. T10 laminectomy was done to create drop-weight SCI in rats. On the 9th day following SCI, 5 × 105 cells were transplanted into injured rat spinal cord. The outcome of transplantation was assessed by the Basso, Beattie and Bresnahan （BBB） locomotor rating scale, motor evoked potential and histological observation. GBCs expressed neural stem cell markers nestin, SOX2, NCAM and also mesenchymal stem cell markers （CD29, CD54, CD90, CD73, CD105）. These cells formed neurosphere, a culture characteristics of NSCs and on induction, differentiated cells expressed neuronal markers ~III tubulin, microtubule-associated protein 2, neuronal nuclei, and neurofilament. GBCs transplanted rats exhibited hindlimb motor recovery as confirmed by BBB score and gastrocnemius muscle electromyography amplitude was increased compared to controls. Green fluorescent protein labelled GBCs survived around the injury epicenter and differentiated into βⅢ tubulin-immunoreactive neuron-like cells. GBCs could be an alternative to NSCs from an accessible source for autologous neurotransplantation after SCI without ethical issues.

Effects of neural stem cell transplantation on the motor function of rats with contusion spinal cord injuries:a meta-analysis

Objective:To judge the efficacies of neural stem cell(NSC)transplantation on functional recovery following contusion spinal cord injuries(SCIs).Data sources:Studies in which NSCs were transplanted into a clinically relevant,standardized rat model of contusion SCI were identified by searching the PubMed,Embase and Cochrane databases,and the extracted data were analyzed by Stata 14.0.Data selection:Inclusion criteria were that NSCs were used in in vivo animal studies to treat contusion SCIs and that behavioral assessment of locomotor functional recovery was performed using the Basso,Beattie,and Bresnahan lo-comotor rating scale.Exclusion criteria included a follow-up of less than 4 weeks and the lack of control groups.Outcome measures:The restoration of motor function was assessed by the Basso,Beattie,and Bresnahan locomotor rating scale.Results:We identified 1756 non-duplicated papers by searching the aforementioned electronic databases,and 30 full-text articles met the inclusion criteria.A total of 37 studies reported in the 30 articles were included in the meta-analysis.The meta-analysis results showed that transplanted NSCs could improve the motor function recovery of rats following contusion SCIs,to a moderate extent(pooled standardized mean difference(SMD)=0.73;95%confidence interval(CI):0.47–1.00;P<0.001).NSCs obtained from different donor species(rat:SMD=0.74;95%CI:0.36–1.13;human:SMD=0.78;95%CI:0.31–1.25),at different donor ages(fetal:SMD=0.67;95%CI:0.43–0.92;adult:SMD=0.86;95%CI:0.50–1.22)and from different origins(brain-derived:SMD=0.59;95%CI:0.27–0.91;spinal cord-derived:SMD=0.51;95%CI:0.22–0.79)had similar efficacies on improved functional recovery;however,adult induced pluripotent stem cell-derived NSCs showed no significant efficacies.Furthermore,the use of higher doses of transplanted NSCs or the administration of immunosuppressive agents did not promote better locomotor function recovery(SMD=0.45;95%CI:0.21–0.70).However,shorter periods between the contusion induction and the NSC transplantation showed slightly higher efficacies(acute:SMD=1.22;95%CI:0.81–1.63;subacute:SMD=0.75;95%CI:0.42–1.09).For chronic injuries,NSC implantation did not significantly improve functional recovery(SMD=0.25;95%CI:–0.16 to 0.65).Conclusion:NSC transplantation alone appears to be a positive yet limited method for the treatment of contusion SCIs.

Effects of decompression joint Governor Vessel electro-acupuncture on rats with acute upper cervical spinal cord injury

Decompression is the major therapeutic strategy for acute spinal cord injury,but there is some debate about the time window for decompression following spinal cord injury.An important goal and challenge in the treatment of spinal cord injury is inhibiting or reversing secondary injury.Governor Vessel electroacupuncture can improve symptoms of spinal cord injury by inhibiting cell apoptosis and improving the microenvironment of the injured spinal cord.In this study,Governor Vessel electroacupuncture combined with decompression at different time points was used to treat acute spinal cord injury.The rat models were established by inserting a balloon catheter into the atlanto-occipital space.The upper cervical spinal cord was compressed for 12 or 48 hours prior to decompression.Electroacupuncture was conducted at the acupoints Dazhui（GV14） and Baihui（GV 20）（2 Hz,15 minutes） once a day for 14 consecutive days.Compared with decompression alone,hind limb motor function recovery was superior after decompression for 12 and 48 hours combined with electroacupuncture.However,the recovery of motor function was not significantly different at 14 days after treatment in rats receiving decompression for 12 hours.Platelet-activating factor levels and caspase-9 protein expression were significantly reduced in rats receiving electroacupuncture compared with decompression alone.These findings indicate that compared with decompression alone,Governor Vessel electroacupuncture combined with delayed decompression（48 hours） is more effective in the treatment of upper cervical spinal cord injury.Governor Vessel electroacupuncture combined with early decompression（12 hours） can accelerate the recovery of nerve movement in rats with upper cervical spinal cord injury.Nevertheless,further studies are necessary to confirm whether it is possible to obtain additional benefit compared with early decompression alone.

Neurofilament 200 expression in a rat model of complete spinal cord injury following growth-associated protein-43 treatment

BACKGROUND： Growth-associated protein-43 （GAP-43） expression in the nervous system has been demonstrated to promote neural regeneration, neuronal growth and development, as well as synaptic reconstruction. Neurofilament 200 （NF200） expression could reflect degree of injury and repair in injured spinal axons. OBJECTIVE： To observe NF200 expression changes in a rat model of complete spinal cord injury following GAP-43 treatment and to explore the effects of GAP-43 following spinal cord injury. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Histology and Embryology of Kunming Medical University between March 2007 and October 2008. MATERIALS： GAP-43 and GAP-43 antibody were provided by Beijing Boao Biology, China; mouse anti-rat NF200 antibody was purchased from Chemicon, USA. METHODS： Female, 8-week-old, Sprague Dawley rats were randomly assigned into three groups following complete spinal cord injury, with 20 animals in each group： GAP-43 antibody, GAP-43, and model groups. In addition, each group was subdivided into four subgroups according to sampling time after modeling, Le., 3-, 5-, 9-, and 15-day groups, with 5 rats in each group. GAP-43 antibody or GAP-43 was injected into injury sites of the spinal cord, 5 μg/0.2 mL, respectively, twice daily for three consecutive days, followed by three additional days of injection, once daily. The model group did not receive any treatment following injury. MAIN OUTCOME MEASURES： NF200 expression in the damaged spinal area at different stages was detected by immunohistochemistry; lower limb motion function following injury was evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor rating scale. RESULTS： NF200 expression was significantly reduced in the GAP-43 antibody group, compared with GAP-43 and model groups, at 3 and 5 days after spinal cord injury （P 〈 0.05）. In addition, the model group expressed significantly less NF200 than the GAP-43 group （P 〈 0.05）. BBB scores from the GAP-43 antibody and model groups were remarkably less than the GAP-43 group （P 〈 0.05）. At 9 and 15 days of injury after drug withdrawal, NF200 expression was increased in the GAP-43 antibody group, and NF200 expression and BBB scores in the GAP-43 antibody and GAP-43 groups were significantly greater than in the model group （P 〈 0.05）. In particular, the GAP-43 group exhibited greater BBB scores than the GAP-43 antibody group at day 9 （P 〈 0.05）. CONCLUSION： GAP-43 promoted NF200 expression and recovery of lower limb function. Early administration of GAP-43 antibody produced reversible nerve inhibition, which was rapidly restored following withdrawal.

嗅鞘细胞与氯化锂联合修复成年大鼠急性脊髓损伤的实验研究

为观察联合应用氯化锂(LiCl)后,嗅鞘细胞(OECs)移植对大鼠急性脊髓损伤修复效果,并探讨二者之间可能的相互作用,本研究利用多中心急性脊髓损伤打击器(MASCIS impactor)制作大鼠脊髓打击伤模型,然后随机分为OECs组、LiCl组、OECs+LiCl组及空白对照组。分期用实验性脊髓损伤运动功能BBB评分法对后肢运动功能评分,并进行组织学检查,评价及比较各组修复效果。结果显示:OECs组与OECs+LiCl组BBB评分较LiCl组与对照组在2周后各时段有显著性差异(P<0.01);OECs+LiCl组BBB评分在4周后显著高于OECs组(P<0.01);组织学检查观察到OECs组与OECs+LiCl组的组织学改变与LiCl组和对照组有显著性差异,而且OECs+LiCl组相对于OECs组表现出更明显的促神经纤维再生。以上结果提示OECs对脊髓损伤的修复作用在联合LiCl后更加显著,表明二者具有良好的协同作用关系。

大鼠脊髓横断损伤后CNTF mRNA的表达变化

目的观察睫状神经营养因子(CNTF)mRNA在脊髓全横断大鼠损伤后的表达变化,探讨CNTF在脊髓损伤修复中的作用。方法40只SD大鼠,随机分为假手术组和脊髓损伤组(SCI组),后者根据取材时间又分为术后1d、3d、7d和14d组。SCI组动物选择在T10节段全横断脊髓,假手术组除不横断脊髓外其余步骤与SCI组相同。动物处死前进行BBB评分评估后肢运动功能的变化。取手术部位头端和尾端0.5cm脊髓,采用RT-PCR技术检测CNTFmRNA在各组脊髓中的表达变化。结果行为学评分随着损伤时间的推移呈小幅度增加,但后肢无运动功能恢复;术后1d组和3d组横断点尾端脊髓中CNTFmRNA的表达与假手术组相比上调(P<0.05)。而7d组和14d组的表达量又逐渐恢复正常,与假手术组比较差异无统计学意义。结论脊髓损伤早期CNTF的表达变化可能与脊髓损伤修复有关。