骨髓间充质干细胞不同移植途径治疗大鼠脊髓损伤的比较

背景：在适当的生长环境下，中枢神经系统内的一些受损的神经元轴突有少许再生，并能与靶细胞形成功能性的突触联系。 目的：比较局部注射和尾静脉注射途径移植骨髓间充质干细胞对大鼠脊髓损伤神经功能恢复的作用。 设计、时间及地点：细胞组织学对照观察，于2007-03/2008-04在承德医学院完成。 材料：健康成年雄性SD大鼠40只，由解放军军事医学科学院动物中心（北京）提供。 方法：取4只大鼠，采用密度梯度离心法和贴壁法体外分离培养骨髓间充质干细胞，传至第2代于临用前24 h行BrdU标记。余36只大鼠均建立T12脊髓损伤模型，1周后随机分为3组，局部注射组于损伤部位上下位点注射1×106个骨髓间充质干细胞至损伤大鼠体内；尾静脉注射组通过尾静脉移植等量骨髓间充质干细胞至损伤大鼠体内；模型对照组不行细胞移植。 主要观察指标：神经功能缺损BBB评分，苏木精-伊红染色病理学检测，细胞分化免疫组化染色结果。 结果：细胞移植后2，4，6周，模型对照组神经功能缺损BBB评分均显著低于局部注射组、尾静脉注射组（F=721.373，F=1 114.450，F=1 004.099，P均 < 0.01）；局部注射组神经功能缺损BBB评分均显著高于尾静脉注射组（t=55.261，t=71.385，t=78.135，P均 < 0.01）。苏木精-伊红染色结果显示，模型对照组损伤脊髓组织有较多空腔，横断处形成大量空泡；局部注射组无明显空腔，空泡小而少，间质水肿较轻。移植后4，6周，部分植入的骨髓间充质干细胞呈微管相关蛋白2及胶质纤维酸性蛋白双阳性表达。 结论：局部注射和尾静脉注射两种途径移植的骨髓间充质干细胞均可在脊髓损伤处存活、分化并改善神经功能，且局部注射的效果优于尾静脉注射。     

脐血间充质干细胞移植对脑梗死大鼠神经功能及细胞凋亡的影响

目的 观察脐血间充质干细胞(UCBMSCs)对脑梗死大鼠神经功能及神经细胞凋亡的影响.方法 实验分假手术组、对照组、移植组,采用颈内动脉线栓法制作脑梗死大鼠模型,移植组于成模后1 d、4 d经尾静脉移植2×106 UCBMSCs,假手术组和对照组尾静脉注射等量PBS,移植后7 d、14 d进行神经功能评分,TUNEL法...     

骨髓间充质干细胞移植治疗大鼠脑内出血

目的研究自体骨髓间充质干细胞(BMSCs)移植对脑出血大鼠的运动功能改善效果,以及采用不同移植方法后细胞在受损脑组织中的分布规律。方法采用立体定向技术向纹状体内注射自体新鲜心室腔血液构建SD大鼠脑出血模型,30只雄性SD大鼠随机分为A组:自然恢复组(对照组);B组:尾静脉移植组;C组:立体定向移植组,于移植后7 d、14 d进行神经功能缺损评分,并在荧光显微镜下观察BMSCs存活、迁移和分布情况。结果 C组大鼠神经功能恢复优于B组,BMSCs均能够迁移分布至大鼠脑损伤区。结论 BMSCs移植对脑出血后大鼠神经功能的恢复具有明显的促进作用。立体定向移植组大鼠神经功能恢复优于尾静脉移植组。     

大鼠骨髓间充质干细胞静脉移植治疗大鼠脑损伤

目的了解大鼠骨髓间充质干细胞（BMSCs）经鼠尾静脉移植后在脑内的表达情况及对大鼠脑创伤后神经运动功能的影响。方法将溴脱氧尿苷（BrdU）标记培养的BMSCs分别在大鼠脑创伤后第1天（实验组1，n=6）、第3天（实验组2，n=10）、第7天（实验组3，，F7）经大鼠尾静脉注射移植，另取6只脑创伤大鼠（实验组4）在伤后第3天经尾静脉移植BrdU标记的全骨髓，尾静脉注射仅．MEM脑创伤大鼠作为对照组（n=6）。应用免疫组化染色，了解移植细胞在脑内的表达情况。脑创伤后第1、3、7、14天评价移植对大鼠神经运动功能的影响。结果脑创伤后14d时神经运动功能评分分别为实验组1：31．83±1．60，实验组2：31．10±1．79，实验组3：28，43±1．72，实验组4：28．67±1．37，对照组：26．00±1．00．各组间差异有显著性（P=0．000）。在移植各组的创伤侧脑组织，可见BrdU染色阳性细胞，并以脉络丛、脑室周围、血管周围分布较多。对实验组2进行免疫组化双染色，未发现BrdU＋神经元特异性烯醇化酶（NSE1、BrdU＋胶质纤维酸蛋白（GFAP）双染色细胞。结论大鼠BMSCs经鼠尾静脉移植．在一定时期内能改善大鼠脑创伤后神经运动功能；脑内可以发现移植细胞存活．但移植细胞是否转化为神经元仍然需要进一步的实验证实。     

神经干细胞移植减少脑出血大鼠神经功能的凋亡

目的探讨神经干细胞移植对脑出血大鼠神经功能的影响。方法采用立体定位仪制作脑出血大鼠模型,随机将大鼠分为sham组、ICH组及NSCs组,通过mNSS评分定量评价细胞移植后,观察脑出血大鼠在第1、3、7、14、28天的神经功能的行为学的动态变化;进行Caspase-3的免疫组织化学及灰度分析,观察其表达情况。结果NSCs组mNSS评分在14、28d均较ICH组明显改善(P0.05)。NSCs组大鼠脑血肿周围组织的Caspase-3的表达水平较ICH组明显降低(P0.05)。结论 NSCs移植能有效改善脑出血大鼠的神经功能评分,其机制可能是通过调节Caspase-3的表达减少细胞凋亡。     

胚胎神经干细胞在出血性脑卒中大鼠脑内移植的实验研究

目的 研究胚胎神经干细胞出血性脑卒中大鼠脑内移植对神经功能缺损改善作用.方法 30只SD大鼠随机分配到单纯脑出血组(A,10只)、培养液移植组(B,10只)及NSCs移植组(C,10只).制作脑出血模型后3d,C组将神经于细胞经Hoechst标记后移植到病灶区,B组注射等量培养液.通过移植前后神经功能评分检测神经功能缺损修复情况,以及冰冻切片后组织免疫荧光检测移植神经干细胞的分化情况.结果 实验中分离、培养的神经干细胞经标记移植人大鼠脑内后,经免疫荧光检测证实能够在血肿腔周边分化成神经元和星形胶质细胞.移植术后2周内3组间大鼠神经功能改善无明显差异.但从移植术后第21天到第28天,神经干细胞移植组大鼠的神经功能改善显著好于培养液移植组和单纯脑出血组P＜0.001,有统计学意义.结论 神经干细胞移植入脑出血大鼠脑内后能够存活并分化为神经元及星形胶质细胞,促进改善大鼠的神经功能,是一种很有发展前途的治疗方法,值得进一步深入研究.     

铁超载与脑出血后脑损伤的相关性

目的 探讨血清铁蛋白作为体内铁负荷的指标,能否反映脑出血后继发性脑损伤与顸后的相关性.方法 经头颅CT证实符合入选标准的脑出血患者（ICH组）50例,发病后第3天与第28天采用化学发光法测定血清铰蛋白水平,酶联免疫吸附法测定一氧化氮（NO）,并作相应的头颅MRI检查,同时进行临床神经功能缺损程度评分.同期健康对照组（Con组）50例测定血清铁蛋白、NO水平,头颅MRI检查.结果 ICH组患者血清铁蛋白在第3天升高为（397.94±209.70）μg/L,与Con组比较（158.33±96.02）μg/L,差异有统计学意义（t=-7.345 8,P＜0.01）;在第28天明显下降为（162.06±123.50）μg/L,与发病后第3天比较差异有统计学意义（t=8.474 7,P＜0.05）.发病第3天血清NO水平为（43.69±34.08）μmmol/L,与Con组（41.56±42.80） μmmol/L比较差异无统计学意义（t=-0.275 3,P＞0.05）,但与发病第28天（17.42±20.88） μmmol/L比较差异有统计学意义（t=6.147 8,P＜0.01）.在发病第3天临床神经功能缺损程度评分与脑水肿绝对体积相关（B=0.766,P＜0.05）;在发病第28天临床神经功能缺损程度评分与侧脑室体部横径指数（B=16.6852,P＜0.01）、Huckman指数（B =-4.6077,P＜0.01）、脑沟宽度（B=32.3613,P＜0.01）相关.结论 脑出血后血清铁蛋白在发病后第3天升高,同期临床神经功能缺损程度评分与脑水肿绝对水肿体积之间呈正相关,此时的血清铁蛋白水平可能提示脑水肿高峰期水肿体积的大小.在发病第28天呈下降趋势,血清铁蛋白水平的变化可提示脑出血的预后,可能为今后脑出血后水肿的评估和治疗提供线索.     

BMSCs移植对大鼠脑梗死后神经功能恢复及Nogo-A表达的影响

目的探讨骨髓间充质干细胞（Bone Marrow-derived mesenchymal stem cells,BMSCs）静脉移植对大鼠脑梗死后神经功能恢复及对Nogo-A表达的影响。方法将大鼠随机分成假手术组、模型对照组、溶剂对照组和移植组。全骨髓贴壁法分离培养大鼠BMSCs,线栓法制作大鼠MCAO模型;移植组自尾静脉注射BMSCs悬液,溶剂对照组注射磷酸盐缓冲液;造模成功后第3、7、14和21 d通过神经功能缺损程度评分,观察其恢复状况;RT-PCR法检测Nogo-AmRNA的表达水平,免疫组化方法检测Nogo-A蛋白的表达水平。结果移植组第7、14和21 d神经功能恢复优于对照组;移植组第3、14和21 d脑组织损伤区周边组织中Nogo-AmRNA表达水平和Nogo-A蛋白的表达水平较对照组降低（P〈0.05）。结论 BMSCs移植可促进大鼠脑梗死后的神经功能恢复,其作用机制可能与下调Nogo-A的表达水平有关。     

尾静脉移植骨髓间充质干细胞治疗脑缺血损伤大鼠的研究

目的通过尾静脉途径移植大鼠骨髓间充质干细胞(MSCs)到大脑中动脉闭塞模型(MCAO)的大鼠体内,观察MSCs移植对大鼠缺血性脑损伤后神经功能恢复的作用并探讨其作用机制。方法分离和培养大鼠的MSCs,线栓法制作脑缺血再灌注模型。将48只SD大鼠随机分为对照组和尾静脉移植组2组,移植组在造模7d后尾静脉途径将MSCs植入MCAO大鼠体内,对照组仅造模。比较两组大鼠在不同时间的神经功能评分的差异,免疫组化染色和脑源性神经生长因子(BDNF)分泌的情况。结果移植后1d两组之间无统计学差异;在2w、1m、2m、3m时移植组NSS评分均低于对照组;免疫组化结果发现尾静脉组见到双侧半球均可见较多的Brdu阳性细胞。移植后1m即可见到MSCs分化为Brdu+NSE、Brdu+GFAP免疫组化双阳性细胞。不同时间点移植组的BDNF分泌较对照组明显增高。结论 MSCs可以在体外分离、培养和传代,尾静脉移植的MSCs可在宿主脑内存活和分化并改善神经功能。MSCs移植后可促进脑内BDNF的分泌。     

骨髓间充质干细胞移植治疗脑出血大鼠的实验研究

目的探讨骨髓间充质干细胞移植对脑出血大鼠的行为和血肿周围神经细胞凋亡的影响。方法全骨髓贴壁法分离培养大鼠骨髓间充质干细胞,使用立体定向纹状体注入胶原酶法制作大鼠脑出血模型。SD大鼠30只,随机分为对照组和移植组(各15只),对照组制作脑出血模型,不移植;移植组制作脑出血模型并于造模后48 h经立体定向脑内注射1×105个干细胞,并于移植后1 d、3 d、5 d、7 d、14 d进行神经功能缺损评分,对照组在相应时间点同样评分,各组再根据时间的不同随机分成五个亚组(每组3只),在相应时间点处死大鼠行免疫组织化学法检测细胞凋亡。结果在移植后1 d、3 d,两组大鼠评分及血肿周围脑组织内凋亡细胞的数量均较高,两组之间无显著性差异。在移植后第5 d、7 d,两组大鼠评分及血肿周围脑组织内凋亡细胞的数量开始下降,移植组下降幅度大于对照组,两组之间差异显著。移植后14 d,两组之间无显著性差异。结论骨髓间充质干细胞移植可明显促进大鼠脑出血后神经功能的恢复,其机制可能与下调血肿周围神经细胞凋亡有关。     

Stem cell transplantation for treatment of cerebral ischemia in rats Effects of human umbilical cord blood stem cells and human neural stem cells

BACKGROUND:Exogenous neural stem cell transplantation promotes neural regeneration. However, various types of stem cells transplantation outcomes remain controversial. OBJECTIVE:To explore distribution, proliferation and differentiation of human neural stem cells (hNSCs) and human umbilical cord blood stem cells (hUCBSCs) following transplantation in ischemic brain tissue of rats, and to compare therapeutic outcomes between hNSCs and hUCBSCs. DESIGN, TIME AND SETTING:Randomized controlled animal studies were performed at the Experimental Animal Center of Nanjing Medical University and Central Laboratory of Second Affiliated Hospital of Nanjing Medical University of China from September 2008 to April 2009. MATERIALS:hNSCs were harvested from brain tissue of 10-13 week old fetuses following spontaneous abortion, and hUCBSCs were collected from umbilical cord blood of full-term newborns at the Second Affiliated Hospital of Nanjing Medical University of China. hNSCs and hUCBSCs were labeled by 5-bromodeoxyuridine (BrdU) prior to transplantation. METHODS:Rat models of cerebral ischemia were established by the suture method. A total of 60 healthy male Sprague Dawley rats aged 7-9 weeks were randomly assigned to hNSC transplantation, hUCBSC transplantation and control groups. The rat models in the hNSC transplantation, hUCBSC transplantation and control groups were infused with hNSC suspension, hUCBSC suspension and saline via the caudal vein, respectively. MAIN OUTCOME MEASURES:The distribution, proliferation and differentiation of hNSCs and hUCBSCs in ischemic brain tissue were observed using immunohistochemical methods. Neurological function in rats was assessed using the neurological severity score. RESULTS:The number of BrdU-positive cells was significantly greater in the hNSC transplantation group compared with hUCBSC transplantation group at 14 days following transplantation (P < 0.05). The number of BrdU-positive cells reached a peak at 28 days following transplantation. Nestin-positive, glial fibrillary acidic protein-positive, cyclic nucleotide 3' phosphohydrolase-positive and neuron specific enolase-positive cells were visible following transplantation. No significant difference was determined in the constituent ratio of various cells between hNSC and hUCBSC transplantation groups (P > 0.05). The neurological severity score was significantly decreased in rats at 21 days following transplantation (P < 0.05). No significant difference was detected in neurological severity score between hNSC and hUCBSC transplantation groups at various time points (P > 0.05). CONCLUSION:The transplanted hNSCs and hUCBSCs can migrate into ischemic brain tissue, proliferate and differentiate into neuron-like, astrocyte-like and oligodendrocyte-like cells, and improve neurological function in rats with cerebral ischemia.     

Functional recovery and microenvironmental alterations in a rat model of spinal cord injury following human umbilical cord blood-derived mesenchymal stem cells transplantation

BACKGROUND: Transplantation of human umbilical cord blood-derived mesenchymal stem cells (MSCs) has been shown to benefit spinal cord injury (SCI) repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE: To observe changes in nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and interleukin-8 (IL-8) expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS: Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS: A total of 62 Wister rats were randomly assigned to control (n = 18), model (n = 22, SCI + PBS), and transplantation (n = 22, SCI + MSCs) groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine (BrdU)-labeled MSCs (24 hours before injection) were intravascularly transplanted. MAIN OUTCOME MEASURES: The rats were evaluated using the Basso, Beattie and Bresnahan (BBB) locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation.RESULTS: A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group (P< 0.05), which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks (P < 0.05), but IL-8 levels remained unchanged (P > 0.05).CONCLUSION: MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.     

脐带血间充质干细胞移植对大鼠脑创伤的影响

目的 探讨脐带血间充质于细胞(CB-MSC)移植对脑创伤大鼠的治疗作用及其在体内分化为神经元样细胞的可行性.方法 健康Wistar大鼠采用随机数字表法分为3组:(1)损伤组,开颅钻孔打击脑组织不移植细胞;(2)移植对照组,开颅创伤脑组织后在创伤区注射生理盐水1.25μ;(3)CB-MSC移植组,开颅创伤脑组织后在创伤区注射含CB-MSC混悬液.每组各18只.CB-MSC从脐带血中分离、培养得到,采用BrdU标记.分别于移植后3 d及10 d进行大鼠行为学评分,2周和4周行Y迷宫试验.移植后2周和5周对植人脑内的CB-MSC进行免疫组织化学检测,镜下观察胶质纤维酸性蛋白(GFAP)和神经元特异性烯醇化酶(NSE)阳性细胞.结果移植后10d 3组大鼠行为学评分差异有统计学意义(p<0.05),移植后2周和4周大鼠学习、记忆评分差异亦有有统计学意义(P<0.05).移植后2周和5周在CB-MSC移植组细胞移植区均发现BrdU-GFAP和BrdU-NSE阳性细胞,其他2组均未发现.结论 CB-MSC移植可促进大鼠脑创伤恢复,提高学习和记忆能力,CB-MSC在体内可以向神经元样细胞分化.     

注射用七叶皂苷钠联合脐带间充质干细胞移植改善脑梗死大鼠神经功能

背景：单纯的脐带间充质干细胞移植修复受损脑组织的作用并不十分理想。 目的：观察脐带间充质干细胞移植联合注射用七叶皂苷钠治疗大鼠脑梗死的效果。 方法：应用线栓法建立大鼠大脑中动脉阻塞模型,随机分为对照组、细胞移植组、七叶皂苷钠+ 细胞移植组,分别尾静脉注射细胞培养液、1×1010 L-1脐带间充质干细胞悬液、尾静脉1×1010 L-1脐带间充质干细胞悬液同时经腹腔注射七叶皂苷钠 5 mg/(kg•d),连续5 d。 结果与结论：移植后1周,七叶皂苷钠+细胞移植组大鼠神经功能障碍评分低于细胞移植组及对照组(P < 0.05);七叶皂苷钠+细胞移植组大鼠脑梗死周围组织AQP9 及AQP4 mRNA的表达低于细胞移植组,却高于对照组(P < 0.05);七叶皂苷钠+细胞移植组CM-Dil阳性细胞和神经元数量多于细胞移植组及对照组(P < 0.05)。提示脐带间充质干细胞移植联合注射用七叶皂苷钠治疗大鼠脑梗死可明显改善大鼠的神经功能。     

人脐带间充质干细胞移植对大鼠脊髓损伤神经功能恢复的评价

目的 观察人脐带间充质干细胞（human umbilical cordmesenchymal stem cell，hUCMSC）移植对大鼠脊髓损伤神经功能恢复的影响。方法 SD大鼠70只，随机分为3组：脊髓半切＋hUCMSC组（n=30）、脊髓半切＋PBS组（n=30）和假手术组（n=10）。脊髓半切＋hUCMSC组和PBS组又分为头侧注射、尾侧注射和头尾两侧注射三个亚组。移植后1、7、14、21、28d观察大鼠神经功能恢复情况，应用免疫组化检测移植到脊髓的hUCMSC胶质纤维酸性蛋白（GFAP）和神经元特异性烯醇化酶（NSE）表达情况。结果 大鼠脊髓半切损害后，hUCMSC组动物较PBS组有明显的神经功能恢复。植入后28d在宿主脊髓中存活的hUCMSC细胞MABl281（mouse antiuman nuclei monoclonal antibody）染色阳性，免疫组化双标染色显示MABl28l阳性细胞亦分别有NSE或GFAP表达并向损伤部位迁移，hUCMSC来源的GFAP阳性细胞可见明显的树突生长。结论 hUCMSC移植到宿主损伤脊髓后可以存活、向损伤部位迁移，并向神经元样和星形胶质细胞分化，且可促进大鼠脊髓损伤后神经功能恢复。hUCMSC作为一种来源广泛的干细胞用于治疗脊髓损伤可能具有重要的价值。     

Electro-acupuncture at Conception and Governor vessels and transplantation of umbilical cord bloodderived mesenchymal stem cells for treating cerebral ischemia/reperfusion injury简

Mesenchymal stem cell transplantation is a novel means of treating cerebral ischemia/reper- fusion, and can promote angiogenesis and neurological functional recovery. Acupuncture at Conception and Governor vessels also has positive effects as a treatment for cerebral ischemia/ reperfusion. Therefore, we hypothesized that electro-acupuncture at Conception and Governor vessels plus mesenchymal stem cell transplantation may have better therapeutic effects on the promotion of angiogenesis and recovery of neurological function than either treatment alone. In the present study, human umbilical cord blood-derived mesenchymal stem cells were isolated, cultured, identified and intracranially transplanted into the striatum and subcortex of rats at 24 hours following cerebral ischemia/reperfusion. Subsequently, rats were electro-acupunctured at Conception and Governor vessels at 24 hours after transplantation. Modified neurological severity scores and immunohistochemistry findings revealed that the combined interventions of electro-acupuncture and mesenchymal stem cell transplantation clearly improved neurological impairment and up-regulated vascular endothelial growth factor expression around the isch- emic focus. The combined intervention provided a better outcome than mesenchymal stem cell transplantation alone. These findings demonstrate that electro-acupuncture at Conception and Governor vessels and mesenchymal stem cell transplantation have synergetic effects on promot- ing neurological function recovery and angiogenesis in rats after cerebral ischemia/reperfusion.     

Effect of intravenous transplantation of bone marrow mesenchymal stem cells on neurotransmitters and synapsins in rats with spinal cord injury

Bone marrow mesenchymal stem cells were isolated, purified and cultured in vitro by Percoll density gradient centrifugation combined with the cell adherence method. Passages 3-5 bone marrow mesenchymal stem cells were transplanted into rats with traumatic spinal cord injury via the caudal vein. Basso-Beattie-Bresnahan scores indicate that neurological function of experimental rats was significantly improved over transplantation time (1-5 weeks). Expressions of choline acetyltransferase, glutamic acid decarboxylase and synapsins in the damaged spinal cord of rats was significantly increased after transplantation, determined by immunofluorescence staining and laser confocal scanning microscopy. Bone marrow mesenchymal stem cells that had migrated into the damaged area of rats in the experimental group began to express choline acetyltransferase, glutamic acid decarboxylase and synapsins, 3 weeks after transplantation. The Basso-Beattie- Bresnahan scores positively correlated with expression of choline acetyltransferase and synapsins. Experimental findings indicate that intravenously transplanted bone marrow mesenchymal stem cells traverse into the damaged spinal cord of rats, promote expression of choline acetyltransferase, glutamic acid decarboxylase and synapsins, and improve nerve function in rats with spinal cord injury.     

缺氧预处理后骨髓源神经干细胞联合脑源性神经生长因子移植治疗大鼠脑缺血再灌注损伤的研究

目的 研究缺氧预处理后骨髓源性神经干细胞（source n eural s tem c ells o f b one m arrow,BMSCs- NSCs）联合脑源性神经生长因子（brain-derived neurotrophic factor,BDNF）立体定向移植治疗大鼠脑缺 血再灌注损伤的疗效,为高原地区脑梗死的细胞移植治疗提供动物实验基础。 方法 72只SD大鼠随机分为缺氧预处理组和常氧组,每组各36只,缺氧预处理组造模前3 d进行低 氧预处理（hypoxic preconditioning,HPC）。两组均制作大脑中动脉阻塞再灌注（middle cerebral artery occlusion/reperfusion,MCAO/R）模型。每组分为3个亚组（BMSCs-NSCs+BDNF组、BMSCs-NSCs组和对 照组,每组各12只）,分别梗死灶同侧尾状核内立体定向移植BMSCs-NSCs+BDNF、BMSCs-NSCs和 DMEM/F12培养基。移植后3 d、7 d、14 d、21 d、28 d、35 d进行神经功能缺损评分,每个时间点每组 取2只大鼠,断头取脑后行免疫组织化学染色,观察5-溴脱氧尿嘧啶（5-Bromo-deoxyuridine,Brdu）阳 性细胞的迁移路径,行CD133、Nestin、微管相关蛋白2（microtubule-associated protein 2,MAP-2）、兔 抗微管蛋白（β-tubulin）、胶质纤维酸性蛋白（glial fibrillary acidic protein,GFAP）、半乳糖神经酰胺 （Galactosylceramidase,Galc）免疫荧光染色,了解骨髓源性神经球分化情况。 结果 常氧BMSCs-NSCs+BDNF组、常氧BMSCs-NSCs组、缺氧预处理BMSCs-NSCs+BDNF组、缺氧预处 理BMSCs-NSCs组7 d、14 d、21 d、28 d和35 d的神经功能评分均显著低于同组3 d时的神经功能评分。移 植3 d时缺氧预处理对照组神经功能学评分显著低于常氧对照组（P =0.040）;移植7 d时缺氧预处理 BMSCs-NSCs+BDNF组神经功能评分显著低于常氧BMSCs-NSCs+BDNF组（P =0.031）。无论缺氧预处 理组还是常氧组,BMSCs-NSCs+BDNF组CD133、Nestin、MAP-2、β-tubulli n、GFAP、Gal c免疫荧光染色光 密度值（integral optical density,IOD）均显著高于BMSCs-NSCs组（均P＜0.001）;BMSCs-NSCs+BDNF组、 BMSCs-NSCs移植组各检测指标IOD均高于对照组（均P＜0.001）。 结论 大鼠缺氧预处理后BMSCs-NSCs联合BDNF立体定向移植可显著提高BMSCs-NSCs的效果。缺氧 预处理并不能促进外源性BMSCs-NSCs分化,但却能明显改善大鼠神经功能。     

沉默RhoA基因对骨髓间充质干细胞静脉移植治疗脑梗死大鼠的作用

研究证实,RhoA基因在神经继发损伤中发挥着重要的作用,通过基因沉默降低其表达,可以有效阻断继发性神经损伤。RhoA蛋白介导的神经突生长抑制作用是影响骨髓间充质干细胞移植后修复效果的重要原因。 目的：验证是否可以通过沉默RhoA基因的方法,改良骨髓间充质干细胞静脉移植对大鼠脑梗死的治疗效果。 方法：体外培养骨髓间充质干细胞,经小分子干扰RNA转染以沉默RhoA基因表达,用Western blot法检测神经干细胞在转染前后RhoA基因的表达。建立大脑中动脉闭塞模型,分为3组,通过尾静脉分别注入RhoA基因沉默的骨髓间充质干细胞悬液、骨髓间充质干细胞悬液及不含干细胞的培养液(对照组)。注入移植液后24 h,3 d,1,2 周行Bederson评分检测神经功能的损伤情况。造模2周后处死大鼠取材,行免疫组织化学和苏木精-伊红染色观察大脑梗死处组织学变化。 结果与结论：经分子干扰RNA转染后24 h的骨髓间充质干细胞RhoA基因表达较转染前显著降低(P=0.002)。沉默RhoA基因后的骨髓间充质干细胞移植治疗,无论从组织学上还是功能学上疗效都有明显的提高。提示用RNA干扰的方法使骨髓间充质干细胞的RhoA基因沉默,再通过尾静脉注射的方法移植到大鼠颅脑损伤区,移植的骨髓间充质干细胞可以更好地在损伤部位存活,增殖分化与迁移,促进脑梗死后大鼠神经功能的恢复。