神经干细胞移植促进鼠脊髓损伤后髓鞘结构的修复

目的 观察神经干细胞移植治疗对鼠脊髓损伤后髓鞘结构修复的作用并探讨其作用机制。方法 制备鼠T10脊髓损伤模型,体外培养、诱导鼠神经干细胞,定量评价神经干细胞移植对脊髓损伤后髓鞘结构修复的影响。结果 与对照组相比,神经干细胞移植组明显地增强了蛋白前脂蛋白信使核糖核酸(PLP mRNA)的表达,促进了髓鞘碱性蛋白(MBP)性的髓鞘再生和髓鞘结构的修复。结论 神经干细胞移植通过增强髓鞘的再生而促进了脊髓损伤后髓鞘结构的修复,是急性脊髓损伤一种有效的治疗方案。     

甲基强的松龙和神经干细胞移植联合治疗大鼠脊髓损伤

目的：观察甲基强的松龙和神经干细胞移植对大鼠脊髓损伤后神经结构修复和功能恢复的治疗作用并探讨其作用机制。方法：制备大鼠胸10脊髓损伤模型，体外培养、诱导分化大鼠神经干细胞，定量评价甲基强的松龙和神经干细胞移植对脊髓损伤后神经结构修复和功能恢复的影响。结果：与对照组相比，移植组明显地增强了生长相关蛋白（GAP－43）mRNA的表达，促进了乙酰胆碱转移酶（ChAT)阳性脊髓运动神经元的再生、神经结构的修复和下肢运动功能的恢复（P＜0．05）。结论：甲基强的松龙和神经干细胞移植通过增强GAP－43 mRNA的表达、运动神经元的再生而促进了脊髓损伤后神经结构的修复和功能的恢复，是急性脊髓损伤的一种有效的治疗方案。     

BDNF-GFP转染神经干细胞修复大鼠脊髓损伤：发挥干细胞与神经因子的双重效应？

摘要 背景：神经干细胞移植入大鼠脊髓损伤模型可以促进功能恢复,基因治疗已被广泛用于治疗脊髓损伤。 目的：确定BDNF-GFP转染后神经干细胞移植对大鼠脊髓损伤的修复效果。 设计,时间和背景：本实验是在中国医科大学基础医学院发育生物学实验室与2009年5月至2010年1月完成。 材料：10只新生Wistar大鼠和88只2-3个月大,雌雄不限的Wistar大鼠。 方法：以携带BDNF-GFP基因的腺病毒转染神经干细胞。88只Wistar大鼠中假手术组8只, 80只大鼠制成T9左侧横断模型,并随机分成四组：BDNF和GFP修饰的神经干细胞移植组,GFP修饰的神经干细胞移植组;单纯神经干细胞移植组和模型组。在各神经干细胞移植组,脊髓损伤后向横断处显微注射等体积细胞,模型组在相同的部位注射等体积的PBS。 主要观察指标： BBB评分检测脊髓损伤模型运动功能恢复情况;制备脊髓损伤模型2周后取材,免疫组化评估BDNF-GFP转染的神经干细胞移植后的细胞学特点;制备脊髓损伤模型2、4、6、8周Real-time PCR检测脊髓横断处BDNF表达情况。 结果： BDNF-GFP转染后神经干细胞在脊髓半切模型中存活并表达BDNF和GFP,移植该细胞后的大鼠体内高表达具有生物活性的BDNF,且脊髓损伤动物运动功能较对照组明显恢复。 结论：移植BDNF-GFP转染后神经干细胞可能是一种修复脊髓损伤的有效的方法。 关键词：神经干细胞,脑源性神经营养因子;绿色荧光蛋白;脊髓损伤;移植。     

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。     

骨髓间充质干细胞尾静脉移植脊髓损伤大鼠脑源性神经营养因子及神经生长因子的表达

背景：骨髓间充质干细胞移植对脊髓损伤有治疗作用,但其机制尚不完全清楚。 目的：应用免疫组织化学方法观察骨髓间充质干细胞静脉移植损伤脊髓局部脑源性神经营养因子及神经生长因子的表达,分析骨髓间充质干细胞移植治疗大鼠脊髓损伤的作用途径。 方法：运用改良Allen法制备T10脊髓外伤性截瘫大鼠模型,假手术组6只,脊髓损伤组24只随机分为对照组和骨髓间充质干细胞移植组。骨髓间充质干细胞移植组、假手术组接受骨髓间充质干细胞单细胞悬液1 mL(1×106 cells)自大鼠尾静脉缓慢注射移植,对照组静脉注射PBS 1 mL。 结果与结论：脊髓损伤后损伤局部的脑源性神经营养因子、神经生长因子表达增加,骨髓间充质干细胞静脉注射移植后能促进脊髓损伤局部脑源性神经营养因子、神经生长因子更进一步的表达,这可能是促进神经结构及神经功能恢复的因素之一。     

神经生长因子联合神经干细胞移植治疗大鼠脊髓损伤

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,研究证实神经生长因子兼有神经元营养和促突起生长双重作用,可以有效的促进脊髓损伤后神经功能的恢复。 目的：观察神经干细胞移植联合应用神经生长因子对脊髓损伤后大鼠运动功能恢复的影响。 方法：SD大鼠42只,建立急性脊髓损伤模型后随机分成3组,伤后1周于损伤处分别注入培养液、单纯神经干细胞或神经干细胞联合神经生长因子。于伤后1,2,4,6,8周进行BBB评分和斜板实验等运动功能检测。伤后4周取材行病理切片苏木精-伊红染色及BrdU免疫组化染色,伤后8周取材行辣根过氧化物酶示踪观察及体感诱发电位观察神经电生理恢复情况。 结果与结论：伤后4周单纯神经干细胞组、神经干细胞联合神经生长因子组大鼠后肢运动功能均有较明显恢复,神经干细胞联合神经生长因子组较单纯神经干细胞组快,差异有显著性意义(P < 0.05)。培养液组亦有所恢复,但程度较轻。病理切片显示培养液组未见神经轴索通过。单纯神经干细胞组可见少量神经轴索样结构,神经干细胞联合神经生长因子组可见较多神经轴索样结构。BrdU的阳性细胞数及HRP阳性神经纤维数：神经干细胞联合神经生长因子组>单纯神经干细胞组>培养液组且各组之间差异有显著性意义(P < 0.01)。神经干细胞联合神经生长因子组大鼠体感诱发电位的潜伏期、波幅优于单纯神经干细胞组(P < 0.05),明显优于培养液组(P < 0.01)。结果提示神经干细胞移植对于后肢功能的恢复有促进作用,联合应用神经生长因子有协同效果。     

干细胞移植治疗脊髓损伤进展

<正>脊髓损伤是一种以脊髓结构破坏,功能细胞凋亡为主要表现的损伤。脊髓损伤的病理机制主要为神经元的损失、轴突联系的中断,以及渐进性的脱髓鞘病变。目前临床上尚未发现完全治愈脊髓损伤,使其达到结构及功能恢复的治疗方法。已有的神经营养因子治疗方法,促进神经细胞再生的效果有限,而干细胞移植治疗可能是现阶段修复脊髓损伤的唯一有效方法。一、干细胞的种子细胞的选择移植种子细胞的种类繁多,基于种子细胞所处的不同阶段,主要分为以下4种:胚卵干细胞、胚胎干细胞,新生干细胞     

异体骨髓间充质干细胞移植治疗大鼠脊髓损伤

背景：脊髓损伤的修复目前尚无良好的治疗手段,细胞移植能促进神经轴突再生及脊髓功能恢复,为治疗脊髓损伤提供了可能,但因脊髓损伤模型及移植方式不同,其治疗效果并不相同。 目的：验证异体骨髓间充质干细胞移植对大鼠脊髓损伤的治疗作用。 方法：全骨髓贴壁法分离大鼠骨髓间充质干细胞。健康SD大鼠随机分为3组,细胞移植组、对照组和假手术组。细胞移植组和对照组采用改良Allen重物打击法制造大鼠脊髓损伤模型,假手术组仅暴露脊髓。术后4周,每周进行运动功能评分,ELISA检测脊髓损伤组织中脑源性神经营养因子、神经生长因子表达;免疫荧光染色检测脊髓组织中NF200和胶质纤维酸性蛋白表达。 结果与结论：与对照组比较,细胞移植组大鼠运动功能明显改善,脊髓组织中脑源性神经营养因子、神经生长因子蛋白含量明显增高(P < 0.05);移植组大鼠脊髓囊腔较小,NF200表达明显增加,胶质纤维酸性蛋白表达减少。提示异体骨髓间充质干细胞移植能增加损伤脊髓神经生长因子含量,抑制胶质瘢痕形成,促进神经轴突再生,改善大鼠脊髓损伤后运动功能恢复。     

骨髓间充质干细胞移植联合吡拉西坦修复大鼠脊髓损伤

背景：单纯的干细胞移植对脊髓损伤的修复作用并不理想,主要是因为脊髓损伤后损伤区域神经组织的水肿、缺血、缺氧等引起继发性损伤造成的。 目的：在骨髓间充质干细胞移植治疗大鼠脊髓损伤的同时应用吡拉西坦,观察两者对大鼠脊髓损伤恢复的影响。 方法：雌性Wistar大鼠参照改良Allen打击法制备大鼠脊髓损伤模型。随机分成3组,即单纯损伤组、骨髓间充质干细胞移植组及骨髓间充质干细胞移植联合吡拉西坦组。于伤后1,2,4,6,8周进行BBB评分和斜板实验等运动功能检测。第4周取材行病理切片苏木精-伊红染色,通过SRY-PCR检测雄性大鼠Y染色体上特有的基因SRY,从而得知移植骨髓间充质干细胞是否存活。8周后取材,行辣根过氧化物酶示踪观察,并通过透射电镜观察轴突的再生情况。 结果与结论：伤后4周,骨髓间充质干细胞移植组、联合治疗组大鼠后肢运动功能均有较明显恢复,联合治疗组较骨髓间充质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。病理切片单纯损伤组未见神经轴索通过;骨髓间充质干细胞移植组可见少量神经轴索样结构;联合治疗组可见较多神经轴索样结构。骨髓间充质干细胞移植组、联合治疗组有SRY基因表达,单纯损伤组未检测到SRY基因。辣根过氧化物酶阳性神经纤维数联合治疗组﹥骨髓间充质干细胞移植组>单纯损伤组,差异具有显著性意义(P < 0.05)。透射电镜下,骨髓间充质干细胞移植组、联合治疗组正中横断面可见新生的无髓及有髓神经纤维。提示骨髓间充质干细胞移植联合吡拉西坦促进大鼠损伤脊髓结构和功能恢复的效果明显优于单纯细胞移植组,两者联用具有协同效应。     

干细胞移植治疗脊髓损伤进展简

脊髓损伤是一种以脊髓结构破坏,功能细胞凋亡为主要表现的损伤。脊髓损伤的病理机制主要为神经元的损失、轴突联系的中断,以及渐进性的脱髓鞘病变。目前临床上尚未发现完全治愈脊髓损伤,使其达到结构及功能恢复的治疗方法。已有的神经营养因子治疗方法,促进神经细胞再生的效果有限,而干细胞移植治疗可能是现阶段修复脊髓损伤的唯一有效方法。     

Transplantation of in vitro-expanded fetal neural progenitor cells results in neurogenesis and functional recovery after spinal cord contusion injury in adult rats

Neural progenitor cells, including neural stem cells, are a potential expandable source of graft material for transplantation aimed at repairing the damaged CNS. Here we present the first evidence that in vitro-expanded fetus-derived neurosphere cells were able to generate neurons in vivo and improve motor function upon transplantation into an adult rat spinal-cord-contusion injury model. As the source of graft material, we used a neural stem cell-enriched population that was derived from rat embryonic spinal cord (E14.5) and expanded in vitro by neurosphere formation. Nine days after contusion injury, these neurosphere cells were transplanted into adult rat spinal cord at the injury site. Histological analysis 5 weeks after the transplantation showed that mitotic neurogenesis occurred from the transplanted donor progenitor cells within the adult rat spinal cord, a nonneurogenic region; that these donor-derived neurons extended their processes into the host tissues; and that the neurites formed synaptic structures. Furthermore, analysis of motor behavior using a skilled reaching task indicated that the treated rats showed functional recovery. These results indicate that in vitro-expanded neurosphere cells derived from the fetal spinal cord are a potential source for transplantable material for treatment of spinal cord injury.     

Multipotent embryonic spinal cord stem cells expanded by endothelial factors and Shh/RA promote functional recovery after spinal cord injury

Cell transplantation is a promising way to treat spinal cord injury and neurodegenerative disorders. Neural stem cells taken from the embryonic spinal cord are an appealing source of cells for transplantation because these cells are committed to making spinal cord progeny. However these stem cells are rare and require expansion in tissue culture to generate sufficient cells for transplantation. We have developed a novel method for expanding embryonic mouse spinal cord stem cells using a co-culture system with endothelial cells. This method improves neural stem cell survival and preserves their multipotency, including their ability to make motor neurons. Transplantation of endothelial-expanded neural stem cells that were treated with sonic hedgehog(Shh) and retinoic acid (RA) during the expansion phase, into an adult mouse SCI model resulted in significant recovery of sensory and motor function.     

组织工程脊髓移植治疗大鼠脊髓半切块状损伤

目的 研究组织工程脊髓移植治疗大鼠脊髓半切块状损伤的疗效.方法 以聚乳酸-羟基乙酸(PLGA)为细胞支架,多聚赖氨酸为细胞外基质,神经十细胞(NSCs)为种子细胞,体外构建组织工程脊髓.制作大鼠T10脊髓右半切块状损伤模型,随机分成3组:实验组在损伤区移植组织工程脊髓,对照组A移植NSCs,对照组B移植PLGA.移植治疗12周,每周均行BBB评分定量评价肢体运动功能.伤后第12周辣根过氧化物酶(HRP)神经逆行示踪评价脊髓传导束的恢复程度,并取损伤处脊髓组织行免疫组织化学染色,观察移植区的形态结构修复.结果 伤后12周实验组的BBB运动功能评分较对照组明显提高,差异有统计学意义(P＜0.05).HRP神经逆行示踪显示:实验组鼠右侧大脑组织中可见大量的HRP标记阳性神经元,而两对照组仅见有少量HRP阳性神经元;免疫组织化学染色显示:实验组移植区NF阳性神经元和GAP-43阳性神经轴索数量较多,修复了缺损,而对照组极少,仍留下不同程度的缺损.结论 组织工程脊髓移植治疗促进了半切块状损伤脊髓的形态结构修复和功能恢复,疗效明显优于单纯的NSCs移植和PLGA移植.     

生物素标记葡聚糖胺神经束路示踪见证神经干细胞移植后皮质脊髓书的再生

实验旨在运用生物素标记葡聚糖胺神经束路示踪标记神经干细胞移植治疗脊髓损伤后皮质脊髓束的再生和神经的重新支配状况,结果表明神经干细胞移植治疗胸10脊髓横断损伤大鼠运动功能评分在横断损伤3周后逐渐升高。治疗后12周有部分生物素标记葡聚糖胺阳性标记的皮质脊髓束再生通过脊髓横断损伤部位,电镜检查发现再生的生物素标记葡聚糖胺阳性标记的神经终末与损伤远端神经元形成新的突触联系。说明生物素标记葡聚糖胺神经束路示踪能有效提供脊髓损伤后神经恢复的解剖形态学依据。     

Treatment of spinal cord injury by transplantation of fetal neural precursor cells engineered to express BMP inhibitor

Spontaneous recovery after spinal cord injury is limited. Transplantation of neural precursor cells (NPCs) into lesioned adult rat spinal cord results in only partial functional recovery, and most transplanted cells tend to differentiate predominantly into astrocytes. In order to improve functional recovery after transplantation, it is important that transplanted neural precursor cells appropriately differentiate into cell lineages required for spinal cord regeneration. In order to modulate the fate of transplanted cells, we advocate transplanting gene-modified neural precursor cells. We demonstrate that gene modification to inhibit bone morphogenetic protein (BMP) signaling by noggin expression promoted differentiation of neural precursor cells into neurons and oligodendrocytes, in addition to astrocytes after transplantation. Furthermore, functional recovery of the recipient mice with spinal cord injury was observed when noggin-expressing neural precursor cells were transplanted. These observations suggest that gene-modified neural precursor cells that express molecules involved in cell fate modulation could improve central nervous system (CNS) regeneration.     

Transplantation of an adipose stem cell cluster in a spinal cord injury

We investigated whether transplantation of a three-dimensional cell mass of adipose-derived stem cells (3DCM-ASCs) improved hind limb functional recovery by the stimulation of angiogenesis and neurogenesis in a spinal cord injury. In in-vitro experiments, we confirmed that 3DCM-ASCs differentiated into CD31-positive endothelial cells. To evaluate the therapeutic effect of 3DCM-ASCs in vivo, PBS, human adipose tissue-derived stem cells, and 3DCM-ASCs were transplanted into a spinal cord injury model. The 3DCM-ASCs transplanted into the injured spinal cord differentiated into CD31-positive endothelial cells and remained differentiated. Transplantation of 3DCM-ASCs into the injured spinal cord significantly elevated the density of vascular formations through angiogenic factors released by the 3DCM-ASCs at the lesion site, and enhanced axonal outgrowth at the lesion site. Consistent with these results, the transplantation of 3DCM-ASCs significantly improved functional recovery compared with both ASC transplantation and PBS treatment. These findings suggest that transplantation of 3DCM-ASCs may be an effective stem cell therapy for the treatment of spinal cord injuries and neural ischemia.     

Neural stem/progenitor cell‐laden microfibers promote transplant survival in a mouse transected spinal cord injury model

Previous studies have demonstrated that transplantation of neural stem/progenitor cells (NS/PCs) into the lesioned spinal cord can promote functional recovery following incomplete spinal cord injury (SCI) in animal models. However, this strategy is insufficient following complete SCI because of the gap at the lesion epicenter. To obtain functional recovery in a mouse model of complete SCI, this study uses a novel collagen‐based microfiber as a scaffold for engrafted NS/PCs. We hypothesized that the NS/PC–microfiber combination would facilitate lesion closure as well as transplant survival in the transected spinal cord. NS/PCs were seeded inside the novel microfibers, where they maintained their capacity to differentiate and proliferate. After transplantation, the stumps of the transected spinal cord were successfully bridged by the NS/PC‐laden microfibers. Moreover, the transplanted cells migrated into the host spinal cord and differentiated into three neural lineages (astrocytes, neurons, and oligodendrocytes). However, the NS/PC‐laden scaffold could not achieve a neural connection between the rostral end of the injury and the intact caudal area of the spinal cord, nor could it achieve recovery of motor function. To obtain optimal functional recovery, a microfiber design with a modified composition may be useful. Furthermore, combinatorial therapy with rehabilitation and/or medications should also be considered for practical success of biomaterial/cell transplantation‐based approaches to regenerative medicine. © 2015 Wiley Periodicals, Inc.     

Transplantation of placenta-derived mesenchymal stem cell-induced neural stem cells to treat spinal cord injury

Because of their strong proliferative capacity and multi-potency, placenta-derived mesenchymal stem cells have gained interest as a cell source in the field of nerve damage repair. In the present study, human placenta-derived mesenchymal stem ceils were induced to differentiate into neural stem cells, which were then transplanted into the spinal cord after local spinal cord injury in rats. The motor functional recovery and pathological changes in the injured spinal cord were observed for 3 successive weeks. The results showed that human placenta-derived mesenchymal stem cells can differentiate into neuron-like cells and that induced neural stem cells contribute to the restoration of injured spinal cord without causing transplant rejection. Thus, these cells promote the recovery of motor and sensory functions in a rat model of spinal cord injury. Therefore, human placenta-derived mesenchymal stem cells may be useful as seed cells during the repair of spinal cord injury.