神经干细胞移植修复大鼠脊髓半切伤的研究

目的：观察神经干细胞移植修复脊髓半切伤的疗效并探讨移植最佳时机。方法：制备大鼠T13-L1脊髓半切伤模型，取胎龄13、5d胎鼠大脑组织，体外分离、培养、诱导神经干细胞，并采用免疫细胞化学技术分别检测NSC（neural stemcell）特征性标志Nestin（巢蛋白）表达和用血清诱导分化为大量神经元NSE（neuron specific enolas）和神经胶质细胞GFAP（glial fibrillary acidic protein）表达。用明胶海绵吸附BrdU（5-溴脱氧尿嘧啶）标记好的神经干细胞悬液移植到脊髓半横断处，移植时间选择损伤后立即移植、损伤后第9、14d。观察移植后的大鼠行为的变化，通过CBS（combine behavioral score）评分和爬网格实验评价大鼠的运动功能恢复情况，并进行免疫组化鉴定，光学显微镜观察移植神经干细胞的存活和迁移。结果：在上述条件下培养及传代的细胞不断分裂增殖，形成悬浮生长的呈Nestin阳性的神经球；用血清诱导分化为大量表达NSE阳性的神经元和GFAP阳性的神经胶质细胞。与对照组相比，神经干细胞移植组明显修复了损伤结构，改善了下肢的功能，尤其是第9d移植组。结论：神经干细胞移植促进了脊髓损伤后神经结构和功能的恢复，是治疗脊髓半切伤一种有效方案，考虑综合因素移植干细胞的最佳时机应选损伤后9d左右。     

神经组织工程修复脊髓损伤的研究进展

由于脊髓损伤的重大影响,针对损伤后促进神经轴突的再生进行了大量的研究。作为一个新兴的迅速发展的领域,因能作为神经轴突生长的导向,组织工程已经受到了广泛的关注。众多的组织工程基质包括:支架材料、细胞和生物分子,其已经显示出支持轴突再生和促进功能恢复的潜力。就促进神经修复的支架材料、细胞、生物分子和目前治疗脊髓损伤的方法做一综述。     

不同时间点静脉移植嗅鞘细胞修复脊髓损伤

背景:嗅鞘细胞具有促进轴突再生、为受伤的宿主细胞提供营养支持以及调节炎症反应的能力,是修复脊髓损伤具有潜力的细胞。目的:探讨通过静脉移植嗅鞘细胞治疗脊髓损伤的最佳移植时间窗。方法:SPF雄性SD大鼠30只,采用脊髓半横断建立大鼠脊髓损伤模型,并随机分为5组:脊髓损伤后注射嗅鞘细胞1 d移植组、3 d移植组、7 d移植组、10 d移植组及PBS对照组。应用荧光量子点标记嗅鞘细胞;分别于1,3,7,10 d时间点通过尾静脉移植应用量子点标记的嗅鞘细胞;PBS对照组脊髓损伤后注射PBS。注射后1 d取损伤处的脊髓;应用小动物成像仪测定不同时间点转移到损伤处荧光的数值,通过荧光的强度衡量转移到损伤处细胞的量;应用嗅鞘细胞Anti-p75 NGF Receptor抗体做损伤处脊髓的免疫组织化学。实验方案经宁夏医科大学动物实验伦理委员会批准(编号:2017-073)。结果与结论:①荧光量子点可以标记嗅鞘细胞;②荧光测定结果与免疫组织化学染色结果:1,3,7,10 d时间点通过尾静脉移植的嗅鞘细胞均有细胞转移到损伤处,7 d移植的嗅鞘细胞转移到损伤处的最多;③结果说明,脊髓损伤不同时间点注射的嗅鞘细胞均可以转移到脊髓损伤处,损伤后7 d移植的嗅鞘细胞转移到损伤处的细胞数量最多,可以作为移植的最佳时间窗。     

神经干细胞及其在脊髓修复中的应用潜能

本文综述了近年来神经干细胞研究的进展。主要论述神经干细胞的来源、分离、培养和鉴定、神经干细胞的分化及其与其它干细胞的联系、神经干细胞增殖分化的调控,并探讨其在脊髓损伤修复中的应用潜能。     

Effect of Schwann cell transplantation combined with electroacupuncture on axonal regeneration and remyelination in rats with spinal cord injury

Axonal impairment and demyelination after compressed spinal cord injury lead to serious neurological dysfunction. Increasing studies have suggested that Schwann cells (SCs) transplantation is a reliable, effective, and promising method for treating spinal cord injury. However, single SCs transplantation is insufficient to promote the full recovery of neurological function. Additional approaches are required to support SCs transplantation as a treatment for spinal cord injury. In the study, we investigated whether the combination of electroacupuncture (EA) and SCs transplantation was a reliable intervention for spinal cord injury. We found that rats in the combination group had significantly higher functional locomotor scores than those received single treatment. By immunostaining, we found EA can not only improve survival and proliferation of transplanted SCs but also inhibit SC apoptosis and block the formation of an astrocytic scar. Additionally, EA promoted regenerated axons extending “bullet-shaped” growth cones into the lesion. Remarkably, EA can modify astrogliosis to promote axonal regeneration following SCs transplantation through inducing extension of astrocytic processes in the SCs graft interface. More importantly, the combination of SCs engraftment and EA can enhance corticospinal-tract axonal regeneration and remyelination after spinal cord injury through up-regulating neuregulin 1 type III in SCs and its downstream signaling mediators. Thus, it is concluded that SCs effectively promote axonal recovery after spinal cord injury when combined with EA stimulation. The experimental results have reinforced the theoretical basis of EA for its clinical efficacy in patients with spinal cord injury and merited further investigation for potential clinical application.     

神经干细胞移植对小鼠脊髓损伤的影响

目的观察神经干细胞(NSCs)移植对脊髓损伤(SCI)小鼠功能恢复的影响。方法分离、培养、增殖和纯化E14-17d小鼠的NSCs,并通过免疫荧光法对其进行鉴定。将绿色荧光蛋白转基因小鼠的NSCs移植到小鼠脊髓损伤模型体内,术后进行行为学和病理学检测,观察小鼠功能恢复情况。运用改良Allen's法制备小鼠T10-T11脊髓损伤动物模型,动物分为假手术组(12只)、模型组(12只),治疗组(12只)和对照组6(12只)。治疗组每只小鼠自眶静脉注射NSCs悬液200μl(2×10个细胞),对照组只注射DMEM/F12培养基200μl。术后1d、3d、7d、14d、21d、28d和56d,进行BBB运动功能评分和病理学检测,观察植入区细胞生长变化情况。结果 BBB评分显示:治疗组明显高于对照组(<0.01),治疗组与假手术组相比没有明显差异(>0.05),说明NSCs移植后小鼠的行为学得到了明显改善,功能有所恢复。病理学检测发现,移植后NSCs不仅迁移到脊髓损伤区,而且与宿主细胞较好地整合。结论移植的E14-17d胚胎小鼠NSCs不仅可在脊髓损伤部位存活并和宿主细胞整合,而且可促进小鼠后肢运动功能恢复。     

脊髓压迫性损伤大鼠海马和脊髓内BDNF的表达变化

目的探讨脑源性神经营养因子(BDNF)在脊髓压迫性损伤后的表达变化及作用。方法用自行设计的方法制作脊髓压迫模型,免疫荧光检测BDNF在星形胶质细胞、神经元和上下行轴突的表达;WB检测BDNF在大鼠海马及脊髓的表达。结果随着时间延长,受损部位的BDNF+-GFAP荧光强度逐渐增强;BDNF+-Tuj1荧光强度逐渐减弱;受损部位相邻上下段的BDNF+-NF200比受损部位的明显增强。海马和脊髓受损中心相邻的上、下段的BDNF蛋白表达在损伤后1d达到峰值,然后逐渐下降(P0.05);而脊髓受损中心的BDNF蛋白表达逐渐下降(P0.05)。结论脊髓损伤后,BDNF的表达下调,随伤后时间呈一定规律变化,是引起受损部位神经元表达下降的原因之一。     

微囊化兔坐骨神经组织移植对大鼠脊髓损伤神经元的影响

目的：观察大鼠脊髓半横断损伤后植入微囊化兔坐骨神经组织对一氧化氮合酶(NOS)表达的影响。方法：尼氏染色和NADPH-d组织化学染色。利用图像分析系统检测染色标记细胞数和阳性细胞平均面积、平均光密度。结果：脊髓损伤后神经元数量减少,尼氏体脱失、溶解。术后3d,微囊组NOS阳性细胞数、阳性细胞平均面积及平均光密度均明显高于单损组;术后7d微囊组NOS阳性细胞数和阳性细胞平均面积较细胞组高;术后14d,细胞组NOS阳性细胞数急剧增高超过微囊组,但微囊组仍平稳上升。结论：微囊化兔坐骨神经组织移植能诱导早期NOS表达增加及抑制后期NO过量产生,减轻脊髓继发性损伤,有利于损伤脊髓的修复和再生。     

嗅鞘细胞移植修复脊髓损伤

背景：脊髓损伤后导致损伤平面以下的运动、感觉及自主神经功能障碍,其修复一直是神经科学研究领域的一大难题。 目的：对嗅鞘细胞移植治疗脊髓损伤的可能机制及在实验研究、临床应用等方面进行分析,探讨其对脊髓神经功能恢复的作用。 方法：回顾性分析以往嗅鞘细胞移植治疗脊髓损伤的实验基础研究和临床研究的状况,分析嗅鞘细胞移植后的存活数量和时间与损伤脊髓结构和功能的恢复关系,明确限定临床研究入选病例及排除病例的标准,明确移植细胞的来源、类型及植入方法,建立客观有效的评估标准。 结果与结论：嗅鞘细胞移植治疗脊髓损伤动物实验已经取得了满意的效果,脊髓功能评分及感觉与运动功能均较移植前明显提高(P < 0.001),动物实验中成功的经验为临床试验和应用提供了依据,部分临床试验最长患者随访5年,但因临床研究病例数较少,随访期短,到目前还不能判断其大宗病例的最终恢复程度,还需要进一步观察和研究。但这一研究结果的重要意义有助于找到合理的策略,使嗅鞘细胞发挥最大的修复效果。     

Electromyographic assessment of damage to the injured spinal cord

The possibility of assessing the degree of damage to the spinal cord by electromyography in the early stage of treatment was demonstrated. The following indices obtained during attempts at movement are evidence of the absence of anatomical loss of continuity of the spinal cord: 1) in the case of injury at level D₅–D₁₀, absence of delay in activation of the lower segments of the long muscles of the trunk compared with their upper segments; 2) in the case of trauma at the level D₁₀-L₁, the presence of activity in the thigh and leg muscles, even if recordable only as single potentials of low amplitude; 3) whatever the level of trauma, the appearance of activity in symmetrical muscles of one lower limb during the attempt to move the opposite limb. In most cases, even if only one index is positive, the patient's motor functions will be restored by restitution.Material for this work was obtained by periodic examination of patients under treatment by Dr. A. N. Trankvillitati, Honored Physician of the RSFSR. Neurological examinations in the course of the investigation were made by Candidate of Medical Sciences L. S. Goncharova.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. A. Vishnevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 10, pp. 25–29, October, 1975.     

低频电磁场促进骨髓间充质干细胞移植修复大鼠脊髓损伤的实验研究

背景：骨髓间充质干细胞移植治疗脊髓损伤被视为一种有前途的治疗方法,如何更有效地促进骨髓间充质干细胞在脊髓损伤区存活,加速脊髓损伤肢体运动功能的恢复是目前研究的重点。前期研究发现,低频电磁场能够促进骨髓间充质干细胞的增殖分化,低频电磁场是否可应用于骨髓间充质干细胞移植治疗脊髓损伤还需进一步研究。 目的：探讨低频电磁场对移植骨髓间充质干细胞脊髓损伤大鼠后肢运动功能恢复的影响。 方法：采用脊髓压迫法制备64只T10不完全性脊髓损伤大鼠模型,随机等分为对照组、骨髓间充质干细胞组、电磁场组和电磁场+骨髓间充质干细胞组。造模成功后,骨髓间充质干细胞组和电磁场+骨髓间充质干细胞组大鼠脊髓损伤原部位注射大鼠全贴壁法分离培养BrdU标记的骨髓间充质干细胞,对照组和电磁场组注射a-MEM培养液。造模术后24 h,电磁场组和电磁场+骨髓间充质干细胞组予60 min/d的低频电磁场刺激(频率50 Hz、强度5 mT)。 结果与结论：骨髓间充质干细胞移植后第21天,电磁场+骨髓间充质干细胞组BBB评分与其他组相比,差异有显著性意义(P < 0.05),与其他各组比较,电磁场+骨髓间充质干细胞组移植细胞后,大鼠BrdU阳性细胞在脊髓损伤区域生长并与脊髓组织融合,存活细胞数量较其他组多;空洞面积小;损伤区胶质纤维酸性蛋白表达更少,而基质金属蛋白2表达更多;脊髓损伤大鼠下肢运动功能恢复最快(P < 0.05)。提示低频电磁场促进了移植骨髓间充质干细胞脊髓损伤大鼠后肢运动功能的恢复,可能与低频电磁场有利于损伤区移植骨髓间充质干细胞的存活,上调基质金属蛋白2的表达并减少胶质瘢痕的形成有关。     

神经干细胞在治疗实验性脊髓损伤中的应用进展

20世纪90年代初首次体外分离神经干细胞(NSC)获得成功,给脊髓损伤(SCI)的治疗带来了新的希望。在大量应用NSC治疗实验性SCI的研究中,对于NSC的应用主要有三种方法:①单纯的NSC移植;②以NSC为载体的转基因治疗;③NSC联合生物材料的应用。研究取得了可喜的成就,但同时也存在一些尚未解决的问题。试从上述三个方面对应用NSC治疗实验性SCI研究的近期进展及所存在的一些问题加以综述。     

Impact of exercise on neuroplasticity-related proteins in spinal cord injured humans

The present study investigated the effects of exercise on the serum concentrations of brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), prolactin (PRL) and cortisol (COR) in 11 chronically spinal cord-injured athletes. In these subjects BDNF concentration at rest was sixfold higher compared with the concentrations reported earlier in able-bodied persons, while IGF-1, PRL and COR were within normal range. Ten minutes of moderate intensity handbiking (54% of the maximal heart rate) during a warm-up period (W) induced an increase (P<0.05) of BDNF of approximately 1.5-fold from basal level at rest, while a decrease to basal level was found after an immediately succeeding handbiking time trial (89% of the maximal heart rate) over the marathon distance of 42 km (M). An increase (P<0.01) of serum IGF-1 was found after W and this levels remained elevated (P<0.01) until the end of M. W had no significant effects on the serum PRL and COR, however, M induced an increase (P<0.01) of both hormones. This is the first study showing elevated BDNF concentrations at rest in spinal cord-injured athletes. Furthermore, short moderate intensity handbiking but not immediately following long lasting high intensity handbiking further increases serum BDNF concentrations. IGF-1 response to exercise differs to BDNF response as this neuroplasticity-related protein remains elevated during the long lasting physical demand with high intensity. The augmented PRL concentration suggests that a possible mechanism by which exercise promotes neuroplasticity might be the activation of neural serotonergic pathways as 5-HT is the main PRL releasing factor. Elevated COR concentrations after M are unlikely to be deleterious to neuroplasticity as COR concentrations remain within the physiological range. The present study suggests that exercise might be beneficial to enhance neuroprotection and neuroplasticity, thereby improving recovery after spinal cord injury.     

人发角蛋白植入对大鼠脊髓损伤功能与形态的影响

目的：研究脊髓损伤后植入人发角蛋白（human hair keratin，HHK）对动物行为学影响及其对损伤脊髓的形态学影响与HHK本身的形态学变化。方法：采用重物下落撞击法制备大鼠脊髓损伤模型，在损伤处移植入HHK，分别于植入后5、10、15、20、25、30d进行行为学检查，于20d与30d脊髓进行形态学观察。结果：HHK植入后在30d内对大鼠的行为学影响与模型对照组没有统计学意义，但HHK可降解吸收融入损伤的脊髓组织，而受损伤的脊髓组织中可见大量胶质细胞、成纤维细胞与巨噬细胞浸润、神经纤维与髓鞘朗革非氏细胞。结论：HHK可能在脊髓损伤后的修复与重建中起作用。     

复方丹参注射液对大鼠急性脊髓损伤后神经再生的影响

目的　探讨丹参对急性脊髓损伤的影响及作用机制。方法给实验性脊髓损伤大鼠腹腔注射复方丹参注射液 ,观测脊髓组织学及超微结构变化。结果用药后大鼠脊髓内髓鞘断裂减轻 ,吞噬细胞清除组织降解物 ,神经元变性恢复。结论　丹参对大鼠急性脊髓损伤后神经修复及再生有促进作用     

嗅鞘细胞移植治疗慢性脊髓损伤的临床研究进展

背景：虽然迄今为止大量的体外和动物实验都证实了嗅鞘细胞对脊髓损伤的修复作用,但是利用嗅鞘细胞移植治疗脊髓损伤的临床试验尚处于起步阶段。 目的：观察嗅鞘细胞移植治疗慢性脊髓损伤的临床安全性、有效性及实用性。 方法：由第一作者检索至2012年5月为止 PubMed数据及CNKI中国期刊全文数据库有关嗅鞘细胞移植治疗慢性脊髓损伤的临床试验研究及安全性、疗效方面相关的报道,以“olfactory ensheathing cells, spinal cord injury, clinical research”为英文检索词,“嗅鞘细胞移植,脊髓损伤”为中文检索词。 结果与结论：计算机初检得到133篇文献,阅读标题和摘要进行初筛,排除重复性研究,共34篇文献符合纳入标准。结果显示,利用嗅鞘细胞移植治疗脊髓损伤,在体外试验和动物模型中获得了良好的效果。在临床试验方面,到目前为止,嗅鞘细胞病灶直接移植治疗慢性脊髓损伤按嗅鞘细胞来源分主要集中在以下几个方面：①胚胎嗅鞘细胞移植。②嗅黏膜移植。③嗅黏膜源性嗅鞘细胞移植。3种嗅鞘细胞移植方法的总体安全性(96.4%)和有效性(23.4%)较高,但是其移植方法均存在明显的不足。提示嗅鞘细胞移植治疗慢性脊髓损伤的安全性和有效性还需要进一步验证,转化为临床应用还有很长的路要走。     

Regeneration of the rat spinal cord after thoracic segmentectomy: Restoration of the anatomical integrity of the spinal cord

Segmentectomy of the spinal cord (SC) was performed in 28 rats at the level of the tenth thoracic vertebra. Scar formation at the operation site was studied, along with the completeness of the anatomical integrity of the SC, in control animals (group 1) and after filling of the defect with the neural matrix Spherogel (group 2) and with Spherogel containing embryonic nerve cells (group 3). The defect in the SC in animals of the control group was filled with fibrin masses by 1–2 weeks, while connective tissues scars were already formed by this time in rats of experimental groups 2 and 3. By 10–11 weeks, these animals showed partial recovery of movement in the three lower limb joints. The scar tissue and adjacent zones of the SC showed large quantities of regenerating fine myelinated nerve fibers. These were clearly evident in the zones of the cranial and caudal margins, to the extent of the appearance of typical SC tissue. In preparations obtained from control animals, fine myelinated fibers were noted in the immediate vicinity of SC substance, while nerve fibers were few in number in scar tissue and the cellular bands of the transitional zone. __________ Translated from Morfologiya, Vol. 127, No. 2, pp. 39–43, March–April, 2005.     

Combined use of spinal cord-mimicking partition type scaffold architecture and neurotrophin-3 for surgical repair of completely transected spinal cord in rats

A body of evidence has suggested that tissue-engineered nerve grafts hold promise for the surgical repair of spinal cord injuries. In this study, a novel nerve graft was prepared to be implantated into a 5?mm gap which was caused by a complete transection of the rat spinal cord. The graft was featured by incorporation of neurotrophin-3 into a chitosan-based tube scaffold with a spinal cord-mimicking, partition-type architecture, which was prepared based on the morphometric insights of normal spinal cord anatomy. A set of behavioral, functional, and histological examinations were carried out to evaluate the repair. Results from Basso, Beattie, and Bresnahan tests, motor evoked potential measurements, anterograde tracing, and histological analyses suggested that the combined application of chitosan as the scaffold biomaterial, a spinal cord-mimicking partition-type as the scaffold architecture, and neurotrophin-3 (NT-3) as the bioactive component might probably create synergetic promotion on spinal cord regeneration. This composite nerve graft yielded significantly better results in axonal regeneration and function restoration as compared to its scaffold alone or other types of hollow tube scaffold alone.     

大鼠脊髓星形胶质细胞的分离与纯化

目的:纯化培养和鉴定新生大鼠的脊髓星形胶质细胞,建立稳定的星形胶质细胞培养体系,为研究创伤后慢性神经病理性痛的脊髓机制奠定基础。方法:根据成纤维细胞与星形胶质细胞生长倍增时间的差异,用阿糖胞苷(Ara-C)抑制成纤维细胞生长分裂的方法获取星形胶质细胞,用胶质原纤维酸性蛋白(GFAP)免疫荧光法对其鉴定。同时与差速贴壁培养法进行对比。结果:用Ara-C处理后,可获得较高纯度的星形胶质细胞,经鉴定其纯度可达90%以上,而对照组几乎全部为成纤维细胞。结论:Ara-C处理能彻底清除成纤维细胞,从而保持星形胶质细胞的正常生长繁殖,达到纯化星形胶质细胞的目的。     

Heterogeneous PHPMA hydrogels for tissue repair and axonal regeneration in the injured spinal cord

A biocompatible heterogeneous hydrogel of poly[N-(2-hydroxypropyl) methacrylamide] (PHPMA) showing an open porous structure, viscoelastic properties similar to the neural tissue and a large surface area available for cell interaction, was evaluated for its ability to promote tissue repair and axonal regeneration in the transected rat spinal cord. After implantation, the polymer hydrogel could correctly bridge the tissue defect, form a permissive interface with the host tissue to favour cell ingrowth, angiogenesis and axonal growth occurred within the microstructure of the network. Within 3 months the polymer implant was invaded by host derived tissue, glial cells, blood vessels and axons penetrated the hydrogel implant. Such polymer hydrogel matrices which show neuroinductive and neuroconductive properties have the potential to repair tissue defects in the central nervous system by promoting the formation of a tissue matrix and axonal growth by replacing the lost of tissue.