嗅鞘细胞移植脊髓损伤大鼠Sema3A及其受体NP-1基因的表达

背景：嗅鞘细胞移植促进脊髓损伤修复机制中对神经生长抑制导向因子的研究较少。 目的：观察嗅鞘细胞移植对脊髓半横断损伤后神经生长抑制导向因子Sema3A及其受体NP-1在RNA水平表达的变化。 方法：17只SD大鼠随机分为嗅鞘细胞移植组、DMEM/F12 培养液移植组和正常对照组。制作T11~T12水平大鼠脊髓左侧半横断损伤模型,立刻分别注射嗅鞘细胞悬液或等量的DMEM/F12 培养液。 结果与结论：6周后取横断水平前后两个脊髓节段,用RT-PCR的方法对Sema3A、NP-1的mRNA进行半定量分析。①嗅鞘细胞在大鼠脊髓内仍有大量存活。②Sema3A及NP-1 mRNA的量,DMEM/F12 培养液移植组明显多于正常对照组(P < 0.05),嗅鞘细胞移植组与培养液移植组比较明显下调,且与正常对照组比较差异无显著性意义(P > 0.05)。③提示嗅鞘细胞移植有效减少了神经生长抑制导向因子Sema3A及其受体NP-1 mRNA的表达。     

嗅鞘细胞移植修复大鼠脊髓损伤的组织病理学变化☆

背景：对于脊髓损伤,目前临床尚无有效的治疗对策,近年来嗅鞘细胞移植对脊髓损伤修复取得了一定的进展。 目的：观察嗅鞘细胞移植在缓解损伤脊髓的病理反应和超微结构变化,及其在发生发展中的作用。 方法：60只大鼠随机分为空白组,模型组,嗅鞘胞移植组和DF12组,每组15只。空白组：仅切开T10全椎板及T9,T11部分椎板,对脊髓未作其他处理,明胶海绵轻柔压迫止血;模型组：仅切断脊髓,未作特殊处理;嗅鞘细胞移植组和DF12组：切断脊髓后用微量注射器分别注射嗅鞘细胞和DF12培养液,随后缝合切口。脊髓损伤后1,3,7,14,28,42,56 d每组麻醉2只受检大鼠,取材做光镜观察和电镜观察。 结果与结论：单纯脊髓横切损伤后,发生了出血、水肿、变性、坏死以及囊腔形成,胶质细胞增生和神经纤维再生。嗅鞘细胞移植后,明显减轻了神经元和神经纤维的坏死变性程度,减轻病理反应,并能对损伤神经元实施保护;防止了胶质细胞过度增生形成瘢痕屏障,明显增加了再生神经纤维的数量。提示嗅鞘细胞移植对损伤脊髓具有减轻病理反应和促进修复的作用。     

嗅鞘细胞移植后大鼠损伤脊髓神经生长因子的表达

目的 研究嗅鞘细胞移植对大鼠损伤脊髓内的神经生长因子(NGF)表达的影响,以从NGF角度探讨嗅鞘细胞移植修复大鼠脊髓损伤的机制.方法 48只SD大鼠用NYU -Ⅱ撞击机(10g-25 mm)损伤T10脊髓制作脊髓损伤(SCI)模型,随机分为嗅鞘细胞组、DMEM组各24只;另设立正常对照组6只.将GFP-嗅鞘细胞细胞悬液移植入嗅鞘细胞组大鼠损伤处,DMEM组用单纯的DMEM/F12液代替,正常对照组不做任何处理.移植术后1d、7d、14 d、21 d,用BBB评分法测定脊髓运动功能,RT - PCR方法比较各时间点NGF表达差异.移植术后第21天应用免疫组化比较嗅鞘细胞组、DMEM组、正常对照组大鼠脊髓损伤区NGF的表达差异.结果 移植后1d、7d、14 d、21 d,嗅鞘细胞移植组运动功能评分均高于同期DMEM组.NGF表达量在术后第1天最高,第7天达峰值,之后缓慢降低.移植后第21天,嗅鞘细胞移植组脊髓NGF表达量高于同期DMEM组和正常对照组.结论 嗅鞘细胞移植可上调损伤脊髓NGF的表达,从而促进了损伤脊髓的修复.     

嗅鞘细胞静脉移植治疗脊髓损伤

背景：嗅鞘细胞移植治疗脊髓损伤在众多疗法中效果较佳,成为最有前景的治疗方法之一。目前移植方法为局部移植,存在操作复杂、创伤大、重复移植治疗困难等缺点。寻找一种简单易行且疗效好的移植方法成为各国学者研究的热点。 目的：分析嗅鞘细胞静脉移植治疗脊髓损伤的可行性和疗效。 方法：制备Wistar大鼠脊髓半切模型,随机分4组：嗅鞘细胞髓内局部移植组、嗅鞘细胞静脉移植组、D/F12静脉移植组和空白对照组。定期行CBS功能评分及组织学检查,评价脊髓修复情况。 结果与结论：嗅鞘细胞髓内局部移植组、嗅鞘细胞静脉移植组的功能恢复和组织学改变优于D/F12静脉移植组和空白对照组,嗅鞘细胞髓内局部移植组、嗅鞘细胞静脉移植组间无显著差别。说明嗅鞘细胞静脉移植可向脊髓损伤部位迁移并修复脊髓损伤,其疗效与嗅鞘细胞髓内局部移植相当。     

嗅鞘细胞移植对脊髓慢性压迫形态和脑源性神经营养因子表达的影响

背景：嗅鞘细胞是介于星形胶质细胞和许旺细胞之间的一类特殊的胶质细胞,具有切实有效的促进神经再生修复的作用,但其相关机制还没确定。 目的：观察嗅球成鞘细胞移植对脊髓慢性压迫损伤后脊髓功能形态和脑源性神经营养因子的影响,以及嗅鞘细胞移植后脊髓慢性压迫损伤动物脊髓功能的修复。 设计、时间及地点：对照动物实验，细胞学观察，于2005-11/2007-03在上海中医药大学脊柱病研究所完成。 材料：新生SD雄性大鼠采用酶消化法培养原代大鼠嗅鞘细胞，并将其制成细胞悬液。雄性3月龄SD大鼠以螺钉持续性压迫大鼠C4脊髓建立脊髓慢性压迫动物模型。 方法：造模后大鼠分为模型组、嗅鞘细胞组、DMEM/Ham’s F-12 培养液组、正常组，每组12只。嗅鞘细胞组在距离脊髓压迫区域上下0.5 mm处选4点注射,按1μL/点脊髓内注射109 L-1嗅鞘细胞，注入速度为1μL/ min。 主要观察指标：应用光学显微镜、电子显微镜观察脊髓形态的变化，采用免疫组织化学、PT-PCR 的方法检测脊髓组织脑源性神经营养因子的分泌，以改良的Gale联合行为评分法对脊髓功能进行评定， 结果：免疫组织化学检测显示，嗅鞘细胞移植能部分改善大鼠脊髓灰质神经细胞的凋亡程度，延缓白质神经纤维的减少，促进髓鞘的修复与再生。与模型组、DMEM/Ham’s F-12 培养液组比较， 嗅鞘细胞移植治疗后脊髓组织中脑源性神经营养因子表达明显增加（P < 0.01）。与模型组、DMEM/Ham’s F-12 培养液组比较，嗅鞘细胞移植能较大程度的改善大鼠脊髓功能（P < 0.05）。 结论：嗅鞘移植能够部分改善脊髓损伤后脊髓组织的病理形态，促进脊髓组织中脑源性神经营养因子的表达，减轻脊髓慢性压迫后的功能损害。     

嗅鞘细胞移植促进脊髓损伤修复：可通过抑制损伤区NogoA、NgR及RhoA表达实现？

目的：观察嗅鞘细胞移植前后脊髓损伤区勿动蛋白（NogoA）、NgR及RhoA的动态变化,探讨嗅鞘细胞移植治疗脊髓损伤的可能机制。 方法：实验于2006年9月/2007年5月在西安交大医学院环境与基因重点实验室完成。①实验动物：成年SD大鼠40只,随机数字表法分为正常组、模型组、嗅鞘细胞组、DF12对照组,10只/组。另取30只健康成年雄性SD大鼠作为嗅鞘细胞的来源。②实验方法：除正常组外,其余各组均建立全横切脊髓损伤模型。嗅鞘细胞组将原代培养12d的嗅鞘细胞悬液调整为1×1011 L-1,在距损伤缘上下各1mm处分4点应用微量注射器注射,深度1.0mm,每处各注射1μL。DF12对照组同法每点注射等量DF12培养液,模型组、正常组不进行任何处理。③实验评估：各组分别于移植后1, 4, 8周采用免疫组化技术及Western blot技术动态检测脊髓损伤区NogoA、NgR及RhoA表达的变化。同时在移植后8周行嗜银染色检测组织形态学变化及应用BBB法评价移植后各组动物下肢功能。 结果：①组织形态学变化。嗅鞘细胞移植8周后除正常组外,其余各组均可见明显的神经纤维再生,但模型组与DF12对照组大部分纤维排列紊乱,再生纤维方向性较差;嗅鞘细胞组可见明显的新生轴突,且神经纤维跨越损伤部位修复脊髓损伤,无论在数量还是质量上均优于模型组及DF12对照组。②移植后8周各组下肢运动功能检测BBB评分结果的比较：嗅鞘细胞组BBB评分均明显高于模型组、DF12对照组,且差异有显著性意义（P<0.01）。③免疫组化技术及Western blot技术均显示正常组NogoA、NgR及RhoA的表达明显低于其余3组（P<0.05）,而模型组和DF12对照组差异无显著性意义（P>0.01）;同时OECs组与模型组和DF12对照组比较亦有显著性差异（P<0.05）。结论：嗅鞘细胞移植可能通过降低脊髓损伤区NogoA、NgR及RhoA的表达,从而促进损伤脊髓的修复。     

嗅鞘细胞移植对脊髓损伤区勿动蛋白表达的影响

背景：近年来人们认为只要能抑制脊髓损伤后神经再生的不利因素就能促进损伤脊髓的再生，抑制因子包括髓鞘相关抑制分子和胶质瘢痕。其中髓鞘相关抑制分子主要有勿动蛋白、髓磷脂相关糖蛋白及少突起胶质细胞髓鞘相关糖蛋白。 目的：观察嗅鞘细胞移植前后脊髓损伤区勿动蛋白的动态变化。 设计、时间及地点：开放性实验，于2006-09/2007-05在西安交大医学院教育部环境与基因重点实验室完成。 材料：8周龄成年SD大鼠40只，体质量（2.50±0.25）kg，雌雄不拘，随机数字表法分为正常组、模型组、嗅鞘细胞组、DF12对照组，10只/组。另取30只健康成年雄性SD大鼠用于嗅鞘细胞的取材，体质量200~250 g。 方法：除正常组外，其余各组均建立全横切脊髓损伤模型。嗅鞘细胞组将原代培养12 d的嗅鞘细胞悬液调整为1×1011 L-1，在距损伤缘上下各1 mm处分4点应用微量注射器注射，深度1.0 mm，每处各注射1 μL。DF12对照组同法每点注射等量DF12培养液，模型组、正常组不进行任何处理。 主要观察指标：各组分别于移植后1，4，8周采用免疫组织化学技术动态检测脊髓损伤区勿动蛋白的变化。同时在移植后8周行嗜银染色检测组织形态学变化。 结果：①勿动蛋白的变化：正常组勿动蛋白吸光度值明显低于其余3组（P < 0.05）。移植后1，4，8周，嗅鞘细胞组脊髓损伤区勿动蛋白均明显低于模型组和DF12对照组（P < 0.01），而模型组和DF12对照组差异无显著性意义（P > 0.01）。②组织形态学变化：嗅鞘细胞移植8周后，除正常组外，其余各组均可见明显的神经纤维再生，但模型组与DF12对照组大部分纤维排列紊乱，再生纤维方向性较差；嗅鞘细胞组可见明显的新生轴突，且神经纤维跨越损伤部位修复脊髓损伤，无论在数量还是质量上均优于模型组及DF12对照组。 结论：嗅鞘细胞移植可能通过降低脊髓损伤区勿动蛋白水平促进损伤脊髓的修复。     

接受嗅鞘细胞移植脊髓损伤大鼠电生理及后肢功能变化

背景：研究证实嗅鞘细胞有利于神经元存活,并可促进轴突再生。 目的：探讨嗅鞘细胞移植治疗大鼠脊髓损伤的效果。 方法：健康成年雌性SD大鼠40只,随机分为盐水对照组、细胞移植组,20只/组。另取10只SD大鼠用于嗅鞘细胞的分离培养。盐水对照组、细胞移植组大鼠均建立脊髓损伤模型,取双侧第8~10对肋间神经各2 cm,交叉植入脊髓缺损处(近端白质与远端灰质、远端白质与近端灰质),细胞移植组局部注射嗅鞘细胞2×106个,盐水对照组局部注射等量无菌生理盐水。通过体感诱发电位和运动诱发电位的检测,观察神经电生理恢复情况;BBB后肢运动功能评分结果;通过BDA顺行神经示踪,观察运动传导束恢复情况。 结果与结论：细胞移植组大鼠体感诱发电位及运动诱发电位的潜伏期、波幅明显优于盐水对照组(P < 0.01);细胞移植组大鼠BBB后肢运动功能评分较生理盐水组明显提高(P < 0.01);细胞移植组脊髓损伤区有较多BDA标记阳性神经纤维通过,其数量明显多于盐水对照组(P < 0.01)。证实局部注射嗅鞘细胞可以较好地恢复大鼠脊髓损伤后的神经电生理及后肢运动功能。     

嗅鞘细胞移植脊髓损伤大鼠后Semaphorin3A的表达

脊髓损伤后损伤区Semaphorin3A(Sema3A)表达明显升高,嗅鞘细胞移植对此会有何影响？实验发现单纯脊髓横切损伤后,会出现脊髓出血、水肿、变性、坏死,囊腔形成,胶质细胞增生和神经纤维再生等病理反应。嗅鞘细胞移植后,脊髓的上述病理反应明显减轻,损伤区神经元和神经纤维的坏死程度下降,损伤区Sema3A表达降低。证实嗅鞘细胞移植可通过降低Sema3A表达对损伤脊髓神经元起保护作用。     

不同来源嗅鞘细胞修复脊髓损伤的效果比较

背景：研究表明嗅鞘细胞所分泌的细胞黏附分子和神经营养因子具有保护脊髓神经元和促进脊髓轴突再生的效应。 目的：比较嗅球及嗅黏膜固有层来源的嗅鞘细胞异体移植修复脊髓损伤的能力。 设计、时间及地点：随机对照动物实验,于2007-06/2008-06在西电集团医院中心实验室完成。 材料：随机选取雄性3月龄及23月龄SD大鼠各6只,分为实验组(23月龄)和对照组(3月龄),用于嗅鞘细胞的体外培养和纯化;SD大鼠30只随机分为乳鼠嗅球嗅鞘细胞移植组、正常嗅黏膜嗅鞘细胞移植组、对照组,每组10只。 方法：30只SD大鼠制造脊髓损伤模型,分别将体外培养的乳鼠和SD大鼠嗅鞘细胞进行脊髓损伤模型的异体移植,对照组不做移植。 主要观察指标：术后4,8周,进行BBB神经功能评分,诱发电位,组织病理学观察。 结果：实验过程中大鼠死亡7只,各组死亡率大致相同。移植后第4,8周时,乳鼠嗅鞘细胞移植组、正常嗅黏膜嗅鞘细胞组评分差异无显著性意义(P > 0.05),均显著高于空白对照组(P < 0.001);嗅鞘细胞移植2组评分8周高于4周(P < 0.01)。术后4周,各组动物均未引出运动诱发电位,移植后8周时,2组嗅鞘细胞移植组动物均可引出运动诱发电位,2组差异无显著性意义(P > 0.05),空白对照组动物仍未引出运动诱发电位(P < 0.001)。移植后8周,2组嗅鞘细胞移植组脊髓损伤区有较多细胞浸润,对照组细胞数目较少。 结论：来源于嗅球与嗅黏膜的嗅鞘细胞对脊髓损伤修复均有促进作用,且两者作用无明显差异。     

低能激光照射嗅鞘细胞促进脊髓损伤大鼠神经功能的修复

BACKGROUND： Previous studies have demonstrated that low-power laser （LPL） irradiation can promote the regeneration of peripheral nerves and central nerves, as well as influence cellular proliferation. Therefore, it is thought to be a potential treatment for spinal cord injury. OBJECTIVE： Utilizing histological observations and behavioral evaluations, the aim of this study was to investigate the influence of transplanted olfactory ensheathing cells （OECs）, irradiated by LPL, on functional repair of rats following transversal spinal cord injury. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the animal experimental center in the First Affiliated Hospital of Xinjiang Medical University between January 2007 and February 2008. MATERIALS： A total of 52 Sprague Dawley rats were included in this experiment. Twelve rats were used to harvest OECs, some of which were irradiated by LPL on days 3, 5, and 7 in culture. The remaining 40 rats were used to establish T12 complete spinal cord transection injury. DMEM/F12 medium was purchased from Sigma, USA, Fluorogold was provided by Chemicon, USA, and the LY/JG650-D500-16 low-power laser was produced by Xi＇an Lingyue Electromechanical Science And Technology Co., Ltd., China. METHODS： The successful rat models were randomly divided into three groups： OEC transplantation, LPL-irradiated OEC transplantation, and control. These animals were microinjected with OEC suspension, LPL-irradiated OEC suspension, and DMEM/F12 medium （10μL） respectively 4 weeks after spinal cord was completely transected at the T12 level. MAIN OUTCOME MEASURES： Spinal cord injury was observed using hematoxylin-eosin staining Expression of nerve growth factor receptor p75 and glial fibrillary acidic protein were determined using immunohistochemical staining. Regeneration of spinal nerve fibers in rats was assayed by Fluorogold retrograde labeling method. Basso, Beattie and Bresnahan （BBB） scores were used to evaluate motor functions of rat lower limbs. RESULTS： Structural disturbances were observed following spinal cord injury in each group, and a large amount of scar tissue covered the broken ends, accompanied by porosis and inflammatory cell infiltration. Following OEC transplantation, the distal end connected to the proximal end. nerve growth factor receptor p75 and glial fibrillary acidic protein immunohistochemistry revealed positive OECs in the cephalad and caudal area of rats that received LPL-irradiated OEC transplantation. In the OECs group, only glial fibrillary acidic protein staining was observed. No staining was found in the control group. Neural fibers labeled with Fluorogold extended across the lesion area and into the cephalad and caudal area in the OECs and LPL-irradiated OECs groups, but were not present in the control group. BBB scores revealed statistically significant differences among the three groups （P 〈 0.05）： OECs irradiated by LPL group 〉 OECs group 〉 control group. CONCLUSION： Transplantation of OECs and LPL-irradiated OECs promoted functional repair in the injured spinal cord of rats, although LPL-irradiated OECs resulted in greater beneficial effects.     

Olfactory ensheathing cells can reduce the tissue loss but not the cavity formation in contused spinal cord of rats

In recent years, olfactory ensheathing cells (OECs) have been used as a therapeutic strategy to repair the anatomical structure and promote the function recovery of injured spinal cord in both animal and human. In this study, OECs were transplanted into contused spinal cords of adult rats. After dorsal laminectomy at T10 vertebra, spinal cord was injured by a force of 10 g with NYU II impactor from 25 mm above the exposed cord. The contused spinal cord received injections of OECs in DMEM or DMEM alone at one week after injury. The migration and distribution of OECs in the contused spinal cord were observed by the light microscope. The intact tissue area, injured tissue area, cavity size, number of myelinated nerve fibers and neurons labeled by CB-HRP in T8 segment were measured and counted by the semi-quantitative techniques at 6 weeks after transplantation. Locomotor ability and conductive function of the spinal cord were evaluated by the BBB score and cortical somatosensory evoked potentials (CSEP) recording. OECs were found in both lesion site and tissue near the lesion. The intact tissue area was significantly larger in the OECs-transplanted rats than that in the DMEM-injected animals, whereas the injured tissue area was significantly smaller in the OECs-rats than that in the DMEM-rats. The number of myelinated nerve fibers in the lesion site and preserved neurons in T8 was significantly greater in the OECs-group than in the DMEM-group, but the cavity size detected was not significantly different between the two groups. The BBB score and CSEP recording showed a better performance of locomotor ability and conductive function in the OECs-transplanted rats than in the DMEM-injected animals. These results indicate that OECs can counteract secondary tissue degeneration after spinal cord injury. Although they cannot reduce the cavity formation, they can promote morphological preservation and functional improvement of the contused spinal cord.     

Olfactory ensheathing cell transplantation and inhibition of NogoA, NgR and RhoA expression in the damaged zone to ameliorate spinal cord injury

BACKGROUND:Olfactory ensheathing cell(OEC)transplantation promotes repair of spinal cord injury. Neural regeneration inhibits binding of the myelin protein Nogo to its receptor(NgR),activates downstream inhibitory signal RhoA, and leads to axonal degeneration.OBJECTIVE: To determine the relationship between OECs transplantation for spinal cord injury and NogoA, NgR, and RhoA protein expression in the damaged zone.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed from September 2006 to May 2007 at the Key Laboratory of Environment and Genes in Xi'an Jiaotong University School of Medicine, China.MATERIALS: OECs were harvested from healthy, adult, male, Sprague Dawley rats aged 6 months. Mouse anti-rat NogoA, NgR, and RhoA monoclonal antibodies were utilized for detection.METHODS: A total of 40 adult Sprague Dawley rats were randomly assigned to four groups: normal, model, OECs, and DF12, with 10 animals in each group. Transverse section spinal cord injury was established in the OECs and DF12 groups, followed by injection of 1 μL OECs suspension(1×108/mL)or equivalent DF12 medium at 1 mm above and below the injury site.MAIN OUTCOME MEASURES: Immunohistochemistry and Western blot were utilized to detect NogoA, NgR, and RhoA expression in the spinal cord injury lesions. Morphological changes were observed by argyrophilia staining, and lower extremity function of the animals was assessed using Basso, Beattie, and Bresnahan scores.RESULTS: Eight weeks following OECs transplantation, a significant increase in new axons was observed in the OECs group, and nerve fibers crossed the injury site to repair spinal cord injury.Qualitative and quantitative results from the OECs group were superior to the model and DF12 groups. At 8 weeks after transplantation, Basso, Beattie, and Bresnahan scores were significantly greater in the OECs group compared with the model and DF12 groups(P< 0.01), but expression of NogoA, NgR, and RhoA protein was significantly decreased compared with the model and DF12 groups(P< 0.05).CONCLUSION: OEC transplantation could inhibit NogoA, NgR, and RhoA expression in spinal cord injury lesions, thereby promoting repair of spinal cord injury.     

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.     

甲基强的松龙联合嗅鞘细胞移植对急性脊髓损伤大鼠运动功能和诱发电位的影响

背景：嗅鞘细胞移植和甲基强的松龙是两种非常有前途的治疗脊髓损伤方法,关于二者联合治疗脊髓损伤的报道较少,结果也不尽相同。 目的：通过对大鼠行为学评分和诱发电位学检测了解嗅球嗅鞘细胞移植和甲基强的松龙对大鼠急性脊髓损伤的修复作用以及二者之间有无协同作用。 方法：以NYU脊髓打击法建立大鼠急性T10脊髓损伤模型,术后分别注射嗅鞘细胞、甲基强的松龙、嗅鞘细胞+甲基强的松龙、无血清的DF12培养液、生理盐水。于术后8周进行后肢体感诱发电位、运动诱发电位检测,并通过BBB评分了解各组大鼠手术前、后运动功能的变化。 结果与结论：术后8周,嗅鞘细胞组、甲基强的松龙组、嗅鞘细胞+甲基强的松龙组与损伤组、DF12组比较,大鼠后肢BBB评分明显升高,体感诱发电位、运动诱发电位 N1波潜伏期缩短,波幅升高,差异有显著性意义(P < 0.05)。嗅鞘细胞+甲基强的松龙组与嗅鞘细胞组、甲基强的松龙组比较,大鼠后肢BBB评分明显升高,体感诱发电位、运动诱发电位N1波潜伏期缩短,波幅升高,差异有显著性意义(P < 0.05)。说明嗅鞘细胞移植和甲基强的松龙单独应用均可以显著促进急性脊髓损伤大鼠运动功能恢复。二者联合促进急性脊髓损伤大鼠运动功能恢复的效果更加显著。     

Olfactory ensheathing cell transplantation alters the expression of chondroitin sulfate proteoglycans and promotes axonal regeneration after spinal cord injury

Cell transplantation is a potential treatment for spinal cord injury. Olfactory ensheathing cells (OECs) play an active role in the repair of spinal cord injury as a result of the dual characteristics of astrocytes and Schwann cells. However, the specific mechanisms of repair remain poorly understood. In the present study, a rat model of spinal cord injury was established by transection of T10. OECs were injected into the site, 1 mm from the spinal cord stump. To a certain extent, OEC transplantation restored locomotor function in the hindlimbs of rats with spinal cord injury, but had no effect on the formation or volume of glial scars. In addition, OEC transplantation reduced the immunopositivity of chondroitin sulfate proteoglycans (neural/glial antigen 2 and neurocan) and glial fibrillary acidic protein at the injury site, and increased the immunopositivity of growth-associated protein 43 and neurofilament. These findings suggest that OEC transplantation can regulate the expression of chondroitin sulfate proteoglycans in the spinal cord, inhibit scar formation caused by the excessive proliferation of glial cells, and increase the numbers of regenerated nerve fibers, thus promoting axonal regeneration after spinal cord injury. The study was approved by the Animal Ethics Committee of the Medical College of Xi’an Jiaotong University, China (approval No. 2018-2048) on September 9, 2018.

Chinese Library Classification No. R456; R741; Q636.1     

Protection of corticospinal tract neurons after dorsal spinal cord transection and engraftment of olfactory ensheathing cells

Transplantation of olfactory ensheathing cells (OECs) into the damaged rat spinal cord leads to directed elongative axonal regeneration and improved functional outcome. OECs are known to produce a number of neurotrophic molecules. To explore the possibility that OECs are neuroprotective for injured corticospinal tract (CST) neurons, we transplanted OECs into the dorsal transected spinal cord (T9) and examined primary motor cortex (M1) to assess apoptosis and neuronal loss at 1 and 4 weeks post-transplantation. The number of apoptotic cortical neurons was reduced at 1 week, and the extent of neuronal loss was reduced at 4 weeks. Biochemical analysis indicated an increase in BDNF levels in the spinal cord injury zone after OEC transplantation at 1 week. The transplanted OECs associated longitudinally with axons at 4 weeks. Thus, OEC transplantation into the injured spinal cord has distant neuroprotective effects on descending cortical projection neurons.