Cograft of neural stem cells and schwann cells overexpressing TrkC and neurotrophin-3 respectively after rat spinal cord transection

Effectively bridging the lesion gap is still an unmet demand for spinal cord repair. In the present study, we tested our hypothesis if cograft of Schwann cells (SCs) and neural stem cells (NSCs) with genetically enhanced expression of neurotrophin-3 (NT-3) and its high affinity receptor TrkC, respectively, could strengthen neural repair through increased NSC survival and neuronal differentiation at the epicenter after complete T10 spinal cord transection in adult rats. Transplantation of NT-3-SCs?+?TrkC-NSCs in Gelfoam (1?×?10(6)/implant/rat; n?=?10) into the lesion gap immediately following injury results in significantly improved relay of the cortical motor evoked potential (CMEP) and cortical somatosensory evoked potential (CSEP) as well as ameliorated hindlimb deficits, relative to controls (treated with LacZ-SCs?+?LacZ-NSCs, NT-3-SCs?+?NSCs, NSCs alone, or lesion only; n?=?10/group). Further analyses demonstrate that NT-3-SCs?+?TrkC-NSCs cografting augments levels of neuronal differentiation of NSCs, synaptogenesis (including inhibitory/type II-like synapses) and myelin formation of SCs, in addition to neuroprotection and outgrowth of serotonergic fibers in the lesioned spinal cord. Compared with controls, the treated spinal cords also show elevated expression of laminin, a pro-neurogenic factor, and decreased presence of chondroitin sulfate proteoglycans, major inhibitors of axonal growth and neuroplasticity. Together, our data suggests that coimplantation of neurologically compatible cells with compensatorily overexpressed therapeutic genes may constitute a valuable approach to study, and/or develop therapies for spinal cord injury (SCI).     

电刺激联合神经营养素3可促进脊髓损伤大鼠内源性神经干细胞的增殖和分化

文题释义： 神经营养素3：是神经生长因子基因家族的成员,可促进多种中枢和外周神经元的存活和分化,调节神经元突触活动,并对神经系统发育和成熟起重要作用。神经营养素3在损伤条件下对神经元具有保护作用,因而在治疗神经系统疾病和神经损伤中有临床应用前景。 内源性神经干细胞：正常机体中,神经干细胞一般处于静息状态,在特定的生理或病理刺激下被激活,其中侧脑室外侧壁的室下带和海马齿状回的颗粒下带是产生神经干细胞最为活跃的区域,神经系统损伤后,在多种细胞因子、调控基因的调节下发生增殖、迁移和分化等。 背景：由于外源性神经干细胞的获取有限,且容易产生免疫排斥以及伦理问题等严重制约其向临床转化,因此如何激活内源性神经干细胞并促进其生长增殖、分化,成为近期科研工作者究的热点。 目的：探讨电刺激联合神经营养素3对大鼠脊髓损伤后内源性神经干细胞增殖及向神经元分化的作用。 方法：将96只SD大鼠随机分为假手术组、脊髓损伤组、电刺激组、电刺激+神经营养素3组,每组24只。假手术组仅暴露脊髓,其他3组大鼠应用改良Allen法建立脊髓损伤模型,造模后给予相应措施进行干预。造模后7,14,21,28 d时,以BBB评分评价大鼠后肢运动功能,电生理学检查运动诱发电位潜伏期;造模后28 d取材,进行苏木精-伊红染色观察脊髓病理变化,免疫组化染色观察内源性神经干细胞的增殖和分化情况。实验方案经兰州大学第二医院医学伦理委员会批准。 结果与结论：①与假手术组相比,脊髓损伤组大鼠的BBB评分明显降低(P < 0.01),脊髓组织可见大量炎症细胞浸润,并存在多个空洞;与脊髓损伤组相比,电刺激组、电刺激+神经营养素3组大鼠后肢功能开始逐渐恢复,电刺激+神经营养素3组BBB评分明显高于电刺激组(P < 0.05),上述病理损伤变化明显改善;②脊髓损伤组7,14 d及电刺激组大鼠7 d时双后肢运动诱发电位潜伏期均未测出,电刺激组、电刺激+神经营养素3组21,28 d时运动诱发电位潜伏期较模型组缩短(P < 0.05),电刺激+神经营养素3组潜伏期缩短更显著    (P < 0.05);③BrdU和Nestin阳性细胞数、微管相关蛋白2的表达：电刺激+神经营养素3组>电刺激组>脊髓损伤组;胶质纤维酸性蛋白的表达：脊髓损伤组>电刺激组>电刺激+神经营养素3组。结果表明脊髓损伤大鼠经电刺激及神经营养素3干预后,促进内源性神经干细胞增殖和向神经元分化,病理损伤明显减轻,后肢运动功能显著改善。 ORCID: 0000-0002-6353-8874(张培根) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

人骨髓间质干细胞和嗅鞘细胞移植对大鼠急性脊髓损伤功能修复的比较研究

目的对比人骨髓基质细胞(BMSCs)与人胚嗅鞘细胞(OECs)移植对大鼠脊髓损伤功能修复的影响。方法将45只SD大鼠分成脊髓损伤后BMSCs移植组(BMSCs组)、OECs移植组(OECs组)和PBS对照组(PBS组),通过BBB评分、运动诱发电位(MEP)评估脊髓传导功能的改善状况,免疫组织化学方法检测移植细胞存活和分化情况,病理形态学方法观察组织结构修复情况。结果BMSCs组BBB评分高于OECs组(P<0.05);两细胞治疗组MEP潜伏期明显缩短(P<0.05);BMSCs组嗜银染色可见脊髓损伤近端有较多再生纤维向远端延伸,形成神经纤维束,而OECs组再生纤维较少;两种移植细胞均可在损伤处部分存活,BMSCs组可见BMSCs来源的细胞Nestin、NF、GFAP的阳性表达。结论BMSCs移植比OECs移植能更有效促进大鼠急性脊髓损伤修复。     

Integration of donor mesenchymal stem cell-derived neuron-like cells into host neural network after rat spinal cord transection

Functional deficits following spinal cord injury (SCI) primarily attribute to loss of neural connectivity. We therefore tested if novel tissue engineering approaches could enable neural network repair that facilitates functional recovery after spinal cord transection (SCT). Rat bone marrow-derived mesenchymal stem cells (MSCs), genetically engineered to overexpress TrkC, receptor of neurotrophin-3 (NT-3), were pre-differentiated into cells carrying neuronal features via co-culture with NT-3 overproducing Schwann cells in 3-dimensional gelatin sponge (GS) scaffold for 14 days in vitro. Intra-GS formation of MSC assemblies emulating neural network (MSC-GS) were verified morphologically via electron microscopy (EM) and functionally by whole-cell patch clamp recording of spontaneous post-synaptic currents. The differentiated MSCs still partially maintained prototypic property with the expression of some mesodermal cytokines. MSC-GS or GS was then grafted acutely into a 2 mm-wide transection gap in the T9-T10 spinal cord segments of adult rats. Eight weeks later, hindlimb function of the MSC-GS-treated SCT rats was significantly improved relative to controls receiving the GS or lesion only as indicated by BBB score. The MSC-GS transplantation also significantly recovered cortical motor evoked potential (CMEP). Histologically, MSC-derived neuron-like cells maintained their synapse-like structures in vivo; they additionally formed similar connections with host neurites (i.e., mostly serotonergic fibers plus a few corticospinal axons; validated by double-labeled immuno-EM). Moreover, motor cortex electrical stimulation triggered c-fos expression in the grafted and lumbar spinal cord cells of the treated rats only. Our data suggest that MSC-derived neuron-like cells resulting from NT-3-TrkC-induced differentiation can partially integrate into transected spinal cord and this strategy should be further investigated for reconstructing disrupted neural circuits.     

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).     

脊髓全横断大鼠模型的构建

背景：脊髓全横断模型在造模时常难以保证神经纤维的完全离断。 目的：构建大鼠脊髓全横断损伤模型。 方法：将大鼠随机分为模型组和假手术组。模型组构建脊髓T10节段全横断模型;假手术组动物仅打开椎管与硬脊膜而后缝合,但不损伤脊髓。建模后1,3,5,7 d分别进行BBB评分以评估后肢运动功能,检测其体感诱发电位和运动诱发电位来评估神经传导通路的完整性,并行形态学观察来评估脊髓肉眼观病理形态。 结果与结论：与假手术组相比,模型组大鼠在建模后1,3,5,7 d时,其BBB评分降低(P < 0.01),未检测出体感和运动诱发电位。形态学观察结果显示模型组大鼠脊髓完全横断,而假手术组脊髓形态完整。结果提示实验成功构建了大鼠脊髓全横断模型。     

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。     

Sustained intraspinal delivery of neurotrophic factor encapsulated in biodegradable nanoparticles following contusive spinal cord injury

Glial cell line derived neurotrophic factor (GDNF) induces neuronal survival and tissue repair after spinal cord injury (SCI). A continuous GDNF supply is believed to gain greater efficacy in the neural restoration of the injured spinal cord. Accordingly, nanovehicle formulation for their efficient delivery and sustained release in injured spinal cord was examined. We first used fluorescence-labeled bovine serum albumin (FBSA) loaded in biodegradable poly(lactic acid-co-glycolic acid) (PLGA) for intraspinal administration after SCI and for in vitro study. Our results showed that the preservation of PLGA-FBSA was observed in the injured spinal cord at 24h, and PLGA-FBSA nanoparticles were well absorbed by neurons and glia, indicating that PLGA as a considerable nanovehicle for the delivery of neuroprotective polypeptide into injured spinal cord. Furthermore, intraspinal injection of GDNF encapsulated in PLGA (PLGA-GDNF) nanoparticles into the injured spinal cord proximal to the lesion center had no effect on gliosis when compared to that observed in SCI rats receiving PLGA injection. However, local administration of PLGA-GDNF effectively preserved neuronal fibers and led to the hindlimb locomotor recovery in rats with SCI, providing a potential strategy for the use of PLGA-GDNF in the treatment of SCI.     

运动诱发电位和BBB评分在大鼠脊髓损伤功能评价中的相关性研究

目的 探讨大鼠脊髓损伤功能评价指标运动诱发电位(MEP)和Basso-Beattie-Bresnahan (BBB)评分的相关性。方法 成年雌性SD大鼠16只,采用数字表法随机分为对照组和实验组,每组8只。对照组只施行手术,不给予外力打击。实验组应用PSI-IH装置复制脊髓损伤模型。记录并分析损伤前以及损伤后3 h、1 d、3 d、1周、2周、3周、4周、5周、6周大鼠脊髓运动诱发电位(scMEP)和肌肉运动诱发电位(mMEP),同时采用BBB评分对大鼠后肢运动功能进行评定。6周后观察大鼠脊髓组织学结构变化。结果 实验组大鼠脊髓损伤后3 h scMEP波幅减小,为正常波幅的32.69%±0.83%,2周后为正常波幅的52.93%±2.23%并处于稳定状态,但均低于对照组(P值均＜0.01);损伤后3 h mMEP波形消失,1 d后恢复至正常波幅的1.16%±0.17%,3 d后波幅明显恢复,4周后达正常波幅的48.20%± 3.70%并处于稳定状态,但均低于对照组(P值均＜0.01)。实验组大鼠脊髓损伤后3 h和1 d,所有大鼠BBB评分均为0分,3 d后评分(1.38±0.52)分,4周后评分(11.50±0.93)分,达到稳定状态,但均低于对照组(P值均＜0.01)。实验组大鼠脊髓损伤后3 h~6周,scMEP与BBB评分均为显著相关(r值为0.732~0.908,P值均＜0.05)。实验组大鼠脊髓损伤后1~6周mMEP与BBB评分呈中度至高度相关(r值为0.718～0.951,P值均＜0.05)。对照组大鼠以上各指标均无显著变化。结论 大鼠脊髓损伤发生后,scMEP、mMEP和BBB评分三个脊髓功能指标会先后顺序恢复,而且scMEP、mMEP与BBB评分均存在着一定的相关性。大鼠脊髓损伤后,scMEP、mMEP是较BBB评分更为灵敏的脊髓功能评价指标。     

电针刺激对神经干细胞移植治疗脊髓损伤大鼠后肢功能的影响

背景：单纯的神经干细胞移植对受损脊髓组织的修复作用并不理想,为了进一步提高移植细胞在体内的存活、增殖及定向分化为神经元的比例,必须进一步改善脊髓损伤区的微环境。 目的：观察神经干细胞移植联合电针刺激对脊髓损伤大鼠后肢功能及电生理的影响。 方法：将脊髓损伤模型SD大鼠72只按随机数字表法分为4组：对照组尾静脉注入培养液,神经干细胞组经尾静脉注入等体积神经干细胞悬液,电针刺激组自模型完成6 h起采用督脉加体穴电针1周,联合组尾静脉注射神经干细胞后,同时采用督脉加体穴电针1周。分别于造模前、造模后1,3 d、1-4 周通过BBB评分、斜板试验进行运动功能评定。造模后4周取材行病理切片苏木精-伊红染色,荧光显微镜观测CM-Dil 标记的神经干细胞存活及分布情况,辣根过氧化物酶示踪观察神经纤维再生情况,运动诱发电位和体感诱发电位观察大鼠神经电生理恢复情况。 结果与结论：造模后2-4周大鼠下肢运动功能评价联合组优于神经干细胞组及电针刺激组,神经干细胞组和电针刺激组优于对照组。造模后4周,神经干细胞组和电针刺激组损伤区可见少量神经轴索样结构,脊髓空洞较小,联合组可见较多神经轴索样结构,未见脊髓空洞。造模后4周,CM-Dil 阳性细胞和辣根过氧化物酶阳性神经纤维数：联合组>神经干细胞组与电针刺激组>对照组,各组之间差异有显著性意义(P < 0.05)。运动诱发电位和体感诱发电位的潜伏期：联合组<神经干细胞组与电针刺激组<对照组,各组之间差异有显著性意义(P < 0.05);运动诱发电位和体感诱发电位的波幅：联合组>神经干细胞组与电针刺激组>对照组,各组之间差异有显著性意义(P < 0.05)。结果提示神经干细胞移植的同时联合电针刺激能够促进脊髓损伤大鼠神经突触的再生,改善其大鼠肢体运动功能及电生理功能。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程      

移植胚鼠神经干细胞对大鼠脊髓损伤后红核神经元损伤的影响

目的研究神经干细胞(NSCs)移植对大鼠脊髓损伤(SCI)后红核神经元的作用。方法5-溴脱氧尿嘧啶核苷(BrdU)法标记处于对数生长期的NSCs,采用电控脊髓损伤打击装置制作大鼠脊髓损伤模型。实验分为3组:NSCs组、SCI组和假手术组(Sham组)。SCI后3 d进行NSCs移植,用免疫组化法观察移植细胞的存活及迁移情况,用辣根过氧化物酶(HRP)逆行示踪技术标记红核神经元,并用四甲基联苯胺(TMB)呈色反应显示红核脊髓束神经元的存活情况,用行为学(BBB)评分法观察大鼠瘫痪肢体的恢复情况。结果在损伤脊髓区域可检测到BrdU标记的阳性NSCs,中脑HRP标记红核神经元数目明显多于SCI组(P<0.01),BBB评分亦明显高于SCI组(P<0.01)。结论体外培养的胚胎大鼠NSCs在移植到脊髓损伤区域后可存活和迁移,对SCI后中脑红核神经元具有保护作用,从而促进了大鼠肢体功能的恢复。     

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。     

嗅鞘细胞移植对大鼠脊髓半横断损伤后轴突再生及后肢功能恢复的作用

为了对嗅鞘细胞移植治疗大鼠脊髓损伤(spinal cord injury, SCI)后轴突再生及后肢功能恢复进行综合性的评价,本实验采用22只雌性成年SD大鼠,并随机分成A、B、C、D 4组。其中A、B、D组行左侧T11 ～T12节段脊髓半横断手术,然后A组移植嗅鞘细胞(olfactory ensheathing cells,OECs)悬液;B组移植DMEM/F12培养液;D组移植核荧光试剂(Hoechst33342)标记的嗅鞘细胞,用于鉴定嗅鞘细胞在体内的存活情况;C组作为正常对照组。术后6周内,对大鼠进行BBB评分、IP斜板试验并观察皮质体感诱发电位(cortical somatosensory evoked potential, CSEP)、运动诱发电位(motor evoked potential, MEP)的潜伏期。将辣根过氧化物酶(HRP)注射到横断面尾段脊髓,逆行追踪观察横断面头段脊髓及对侧中脑红核内HRP逆标细胞数,并观察左侧后肢小腿三头肌肌细胞横截面积及直径的变化。结果显示:(1)移植后的OECs数量未见明显减少,细胞核形态较好,细胞未向头、尾侧迁移;(2)移植3周后BBB评分及IP斜板,试验A、B组较C组明显低(P<0.05),但A组明显高于B组(P<0.05);(3)A、B组的CSEP及MEP潜伏期较C组明显延长(P<0.05),但A组要比B组明显缩短(P<0.05);(4)HRP逆行追踪观察到对侧中脑红核大细胞区及脊髓T9 ～T11节段逆标细胞的数量,A组明显多于B组,但A、B组均少于C组;(5)左侧后肢小腿三头肌肌细胞的横截面积及直径,A、B组均较C组减少,但A组减小的幅度明显小于B组。以上结果表明OECs移植能促进半横断脊髓轴突的再生及后肢功能的恢复。     

Pituitary adenylate cyclase-activating polypeptide prevents cell death in the spinal cord with traumatic injury

Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a potent factor in the regulation of neurotransmission, neuroprotection, neurogenesis and anti-inflammation. We here examined the neuroprotective effect of PACAP on injury to the spinal cord tissue of adult rats, induced by dropping a 10 g NYU impactor from the height of 25 mm (moderate injury) or 50 mm (severe injury). PACAP was found to effectively attenuate cell apoptosis in the spinal cord with moderate injury. However, treatment with PACAP had a lesser effect on decreasing DNA fragmentation in the lesion center of the spinal cord with severe contusion injury. Yet, greater extended neural fibers and motor neurons were observed in the rostral and caudal regions of the PACAP-treated spinal cord when compared to that seen in the PBS-treated control. Our findings indicate the beneficial effect of PACAP for the treatment of spinal cord injury (SCI).     

Effects of methylprednisolone on the neural conduction of the motor evoked potentials in spinal cord injured rats

Methylprednisolone(MP), a glucocorticoid steroid, has an anti-inflammatory action and seems to inhibit the formation of oxygen free radicals produced during lipid peroxidation in a spinal cord injury(SCI). However, the effects of MP on the functional recovery after a SCI is controversial. The present study was conducted to determine the effects of MP on the recovery of neural conduction following a SCI. A SCI was produced using the NYU spinal cord impactor. A behavioral test was conducted to measure neurological disorders, and motor evoked potentials (MEPs) were recorded. According to the behavioral test, using BBB locomotor scaling, MP-treated animals showed improved functional recoveries when compared to saline-treated animals. MEP latencies in the MP-treated group were shortened when compared to those in the control group. Peak amplitudes of MEPs were larger in the MP-treated group than those in the control group. The thresholds of MEPs tended to be lower in the MP-treated group than those in the control group. These results suggest that MP may improve functional recovery after a SCI.     

电场刺激联合聚乙二醇治疗大鼠脊髓损伤的实验研究EI北大核心CSCD

外加直流电场刺激(EFS)可抑制脊髓损伤(SCI)后损伤组织局部Ca2+内流,有效抑制脊髓继发性损伤的发生。但电场刺激结束后,损伤局部Ca2+会重新开始内流并激发后续病理生理学连锁反应,影响了EFS治疗SCI的效果。聚乙二醇(PEG)是一种亲水性的高分子材料,具有促进细胞膜融合及受损细胞膜修复的作用。本文旨在研究EFS联合PEG治疗Sprague-Dawley(SD)大鼠SCI的效果。脊髓损伤后的SD大鼠被随机分为对照组(无治疗,n=10)、电场组(EFS治疗30 min,n=10)、PEG组(浸润50%PEG的明胶海绵覆盖损伤处5 min,n=10)和联合组(电场刺激和PEG联合治疗,n=10)。术后不同时间进行运动诱发电位(MEP)测量、运动行为学评分以及脊髓切片染色分析。研究结果表明,术后8周联合组大鼠MEP潜伏期差和波幅差以及脊髓空洞面积比均显著低于对照组、电场组和PEG组,而运动功能评分和脊髓神经组织残余面积比均显著高于对照组、电场组和PEG组。以上结果提示,联合治疗方法能减轻大鼠脊髓损伤后的病理损伤程度,促进大鼠电生理及运动功能的恢复,其疗效优于EFS和PEG单独使用时的效果。     

Transplantation of dendritic cells promotes functional recovery from spinal cord injury in common marmoset

We previously reported that implantation of dendritic cells (DCs) into the injured site activates neural stem/progenitor cells (NSPCs) and promotes functional recovery after spinal cord injury (SCI) in mice. Working toward clinical application of DC therapy for SCI, we analyzed whether DCs promote functional recovery after SCI in a non-human primate, the common marmoset (CM). CMs are usually born as dizygotic twins. They are thus natural bone marrow and peripheral blood chimeras due to sharing of the placental circulation between dizygotic twins, leading to functional immune tolerance. In this study, to identify adequate CM donor-and-host pairs, mixed leukocyte reaction (MLR) assays were performed. Then, CM-DCs were generated from the bone marrow of the twin selected to be donor and transplanted into the injured site of the spinal cord of the other twin selected to be host, 7 days after injury. Histological analyses revealed fewer areas of demyelination around the injured site in DC-treated CMs than in controls. Immunohistochemical analysis showed that more motor neurons and corticospinal tracts were preserved after SCI in DC-treated CMs. Motor functions were evaluated using three different behavior tests and earlier functional recovery was observed in DC-treated CMs. These results suggest DC therapy to possibly be beneficial in primates with SCI and that this treatment has potential for clinical application.     

高压氧前处理脊髓损伤大鼠前角运动神经元的凋亡*☆

背景：脊髓损伤后难以修复,损伤后保护残存的神经元是促进神经再生的关键。 目的：验证高压氧预处理可以通过抑制早期的细胞凋亡来保护脊髓前角运动神经元。 方法：随机将26只雄性Wistar大鼠等分成模型组和实验组。实验组在给予高压氧5 d后与模型组同时制作脊髓T9~10全横断模型。 结果与结论：尼氏染色显示脊髓T9~T10全横断后8 h及1 d,脊髓前角的浓染的细胞多见,与模型组相比,实验组脊髓前角浓染的细胞较少。TUNEL染色也显示脊髓T9~T10全横断后脊髓损伤后8 h~1 d,2组大鼠脊髓前角内均可见大量的凋亡神经元,3 d时凋亡神经元数量减少。相比于模型组,高压氧预处理8 h,1 d后大鼠脊髓前角凋亡神经元较少(P < 0.05,        P < 0.01)。说明高压氧预处理能对脊髓损伤后前角运动神经元起保护作用。       

Projections from the lateral vestibular nucleus to the spinal cord in the mouse

The present study investigated the projections from the lateral vestibular nucleus (LVe) to the spinal cord using retrograde and anterograde tracers. Retrogradely labeled neurons were found after fluoro-gold injections into both the cervical and lumbar cord, with a smaller number of labeled neurons seen after lumbar cord injections. Labeled neurons in the LVe were found in clusters at caudal levels of the nucleus, and a small gap separated these clusters from labeled neurons in the spinal vestibular nucleus (SpVe). In the anterograde study, BDA-labeled fiber tracts were found in both the ventral and ventrolateral funiculi on the ipsilateral side. These fibers terminated in laminae 6–9. Some fibers were continuous with boutons in contact with motor neurons in both the medial and lateral motor neuron columns. In the lumbar and sacral segments, some collaterals from the ipsilateral vestibulospinal tracts were found on the contralateral side, and these fibers mainly terminated in laminae 6–8. The present study reveals for the first time the fiber terminations of the lateral vestibular nucleus in the mouse spinal cord and therefore enhances future functional studies of the vestibulospinal system.     

胶原/丝素蛋白支架联合神经干细胞治疗创伤性脊髓损伤北大核心

背景:随着交通事故、坠落伤、运动损伤等不断增多,创伤性脊髓损伤已成为危及脊髓健康的一个重要问题。目的:探讨胶原/丝素蛋白支架联合神经干细胞治疗创伤性脊髓损伤的疗效。方法:①分别提取胶原和丝素蛋白原料,将二者以质量比2∶4混合,采用真空冷冻干燥法制备胶原/丝素蛋白支架;将第3代GFP小鼠神经干细胞接种至胶原/丝素蛋白支架上,光学显微镜和扫描电镜下观察神经干细胞生长情况。②采用随机数字表达将40只成年SD大鼠分5组,正常组不进行任何处理,模型组建立T10段脊髓缺损模型,干细胞组脊髓缺损处注射神经干细胞,支架组脊髓缺损处植入胶原/丝素蛋白支架,联合组脊髓缺损处植入接种神经干细胞的胶原/丝素蛋白支架,每组8只。术后每周进行旷场实验BBB评分和斜坡实验,术后第8周行神经诱发电位检测、苏木精-伊红和免疫荧光染色,评价创伤性脊髓损伤大鼠恢复情况。结果与结论:①光学显微镜和扫描电镜下观察显示,胶原/丝素蛋白支架上有利于神经干细胞的黏附、伸展与分化。②旷场实验BBB评分和斜坡实验结果显示,脊髓损伤各组大鼠的运动功能随时间的延长均有不同程度的恢复,各治疗组大鼠的运动功能的恢复速度与程度均优于模型组,其中以联合组大鼠运动功能恢复最好。术后第8周,脊髓损伤后各治疗组大鼠的运动诱发电位和体感诱发电位的潜伏期、振幅检测结果均优于模型组(P<0.05),联合组检测结果优于干细胞组、支架组(P<0.05)。术后第8周苏木精-伊红染色显示,模型组大鼠脊髓损伤部位修复效果最差,联合组修复效果最好;免疫荧光染色显示,模型组大鼠脊髓损伤部位神经丝蛋白阳性细胞最少,各治疗组神经丝蛋白阳性细胞均多于模型组,其中以联合组最多。③胶原/丝素蛋白支架联合神经干细胞对创伤性脊髓损伤大鼠双下肢功能改善和脊髓组织修复具有一定效果。