大鼠损伤脊髓内异体骨髓基质干细胞移植后的存活、迁移及分化

目的 观察骨髓基质干细胞(BMSCs)经局部微注射后在成年大鼠脊髓内存活、迁移及向神经细胞分化的情况.方法 成年大鼠脊髓半横断后,损伤部位脊髓内注射经Hoechst标记的异体大鼠BMSCs,存活2个月后损伤部位脊髓切片观察细胞局部存活、迁移情况,同时行甲基受体蛋白-2(MAP-2)及神经胶质酸性蛋白(GFAP)免疫组织化学染色.结果 注射点周围可见密集的Hoechst标记细胞存活,细胞迁移主要沿脊髓纵轴方向并跨过损伤区,迁移距离超过0.5 cm,同时可见少量细胞沿水平方向迁移到注射点周围远隔部位,有少量移植细胞(少于10%)表现为MAP-2或GFAP免疫反应阳性.结论 大鼠脊髓损伤后局部移植BMSCs,移植细胞可在局部良好存活、增殖,并向损伤区迁移,少量移植细胞可向神经细胞方向分化.     

神经生长因子基因转染间充质干细胞移植对损伤脊髓保护的实验研究

目的 探讨神经生长因子(NGF)基因转染间充质干细胞(MSCs)移植对损伤脊髓的保护作用.方法 近交系Wistar大鼠(n=56),随机分为治疗组、空白组、对照组,采用改良的Allen打击法造成脊髓损伤(SCI)的模型;分离培养同种异体MSCs,纯化、扩增后,MSCs经绿色荧光蛋白(GFP)标记并被NGF基因转染后重新悬垂(1×108/ml)于SCI 7 d后移植入受损硬脊膜下.对照组注射等量的磷酸盐缓冲液(PBS),分别在MSCs移植后24 h和1、2周后取损伤脊髓段冰冻切片,.在荧光显微镜下观测移植细胞的分布情况;观测MSCs移植后胶质纤维酸性蛋白(GFAP)和NGF表达的变化;进行神经功能(BBB)评价. 结果 MSCs移植后可向损伤脊髓中心聚集,SCI后.治疗组GFAP和NGF的表达明显高于对照组(P<0.05);BBB评分显示治疗组和对照组神经功能差异有统计学意义. 结论 NGF基因转染的MSCs移植促进了脊髓神经功能的恢复,移植后具有一定的分布规律.     

神经干细胞单细胞与神经球治疗大鼠脊髓损伤的对比研究

目的比较神经干细胞(neural stem cells,NSCs)单细胞与神经球移植治疗大鼠脊髓损伤(spinal cordinjury,SCI)的效果,研究两种NSCs移植方法治疗SCI的有效性。方法取成年SD大鼠2只,体外分离脊髓组织并行NSCs培养,取第3代细胞行Hoechst33342、巢蛋白染色及贴壁分化鉴定。另取成年SD大鼠(体重230～250 g)60只,随机分为3组,每组20只,采用改良Allen法制备大鼠脊髓T10损伤模型。各组分别于SCI处缓慢注射5μL生理盐水(A组)、第3代NSCs单细胞(B组)、第3代NSCs神经球(C组)。分别于术前及术后3、7、14、21、28 d采用BBB行为功能评定量表评定各组大鼠后肢功能;术后各时间点取材行HE染色和微管相关蛋白2(microtubule-associated protein 2,MAP-2)免疫组织荧光染色观察。结果经形态学观察及鉴定,所培养的细胞为NSCs。术后3 d各组BBB评分较术前显著下降,术后3、7 d各组间BBB评分比较差异均无统计学意义(P>0.05);随时间延长BBB评分不同程度增加,术后14、21、28 d,B、C组BBB评分优于A组,C组优于B组,比较差异均有统计学意义(P<0.05)。HE染色示C组较A、B组脊髓结构清晰,瘢痕形成少。MAP-2免疫组织荧光染色示,术后3、7 d各组间阳性细胞数比较差异均无统计学意义(P>0.05);术后14、21、28 d,B、C组阳性细胞数显著多于A组,C组多于B组,差异有统计学意义(P<0.05)。结论采用NSCs神经球移植较单细胞移植更明显促进NSCs向神经元分化,更有利于SCI后下肢功能恢复。     

骨髓间充质干细胞表达神经营养因子及治疗脊髓损伤的研究

目的　研究大鼠骨髓间充质干细胞 (BMSC)表达脑源性神经营养因子 (BDNF)和神经生长因子 (NGF)以及BMSC移植对脊髓损伤的治疗作用。方法　取大鼠骨髓培养BMSC并传代 ,进行CD44、CD45和CD71免疫细胞化学染色鉴定。逆转录 聚合酶链反应 (RT PCR)检测BM SC中BDNF和NGFmRNA的表达。用NYU方法建立大鼠脊髓损伤模型 ,将 15 0 0 0个BMSC注射到损伤脊髓中。 1～ 5周后进行BBB运动功能评分 ,观察BMSC在脊髓中的迁移 ,进行NF、GFAP和Gal C免疫荧光检测。结果　BMSC贴壁生长 ,免疫细胞染色CD44 (+ )、CD45 (-)和CD71(+ ) ,表达BDNF和NGFmRNA。移植BMSC后脊髓损伤的大鼠运动功能改善 ,5周后BBB评分从对照组的 (11.6± 1.7)分提高到 (15 .4± 2 .2 )分。BMSC在脊髓内向头、尾两侧迁移约 5mm ,未检测出向神经细胞诱导转化。结论　BMSC表达神经营养因子BDNF和NGF ,移植后能促进大鼠脊髓损伤的运动功能恢复。     

人胚神经干细胞移植治疗大鼠脊髓损伤

目的 探讨人胚神经干细胞（hNSC）移植治疗脊髓损伤（SCI）的可行性。方法 分离、培养和鉴定hNSC；用5溴-2脱氧尿苷嘧啶（BrdU）标记hNSC，并将其移植到14只T10半横断的Wistar大鼠损伤脊髓内（另外14只T10半横断损伤的大鼠作为对照组，仅损伤脊髓内注射DMEM／F12培养液），用BrdU的FITC免疫荧光染色检测移植细胞的存活和迁徙，用NF-200、GFAP免疫组织化学鉴定移植细胞的分化，BBB评分评定大鼠功能恢复情况。结果 （1）获得了大量的hNSC；（2）用免疫组织化学可以检测到移植的hNSC能在体内长时间存活（达2个月）并向远处迁徙，并分化为神经元和胶质细胞；（3）检测到实验组大鼠BBB得分明显高于对照组大鼠（P〈0．01），在SCI后第10周时实验组和对照组BBB得分最大差距达到2．1分。结论 hNSC移植能促进SCI大鼠后肢功能恢复，它是SCI移植治疗较有价值的细胞资源。     

骨髓间充质干细胞联合定向诱导的神经元样细胞移植治疗脊髓损伤

[目的]探讨一定条件下骨髓间充质干细胞向神经元样细胞分化的能力,并进一步研究两种细胞联合移植治疗脊髓损伤(spinalcord injury,SCI)的效果。[方法]选取3个月龄雌性SD大鼠62只,2只处死后提取骨髓间充质干细胞用于细胞培养和分化研究,剩余大鼠采用改良Allen’s法制备T9～11SCI模型,然后随机分为4组(n=15),A组为空白对照组,B组为干细胞组,C组为神经元样细胞组,D组为联合移植组。诱导后的细胞采用免疫荧光方法检测细胞表面特异性标志,各组细胞用Hoechst33342标记,脊髓损伤模型建立1周后将细胞以局部注射的方法移植到损伤区,细胞移植后的1、2、4、6周对各组动物进行Basso-Beattie-Bresnahan(BBB)评分,并行HE染色、荧光显微镜、免疫荧光法检测细胞在体内的存活和分化。[结果]术后2、4、6周各细胞移植组BBB评分较空白对照组相比显著增加(P0.05),D组高于B、C两组(P0.05),B、C两组组间比较差异无统计学意义(P0.05)。HE染色示B、C、D组术后6周的脊髓空洞较A组均减小,以D组最明显;荧光显微镜显示移植的细胞存活于脊髓损伤的区域;免疫荧光染色显示诱导后的细胞与体内存活的细胞表面特异性标志神经元特异性烯醇化酶(neuron specific enolase,NSE)、神经丝蛋白200(neuroflament200,NF-200)表达呈阳性,胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)表达呈弱阳性,其中D组NSE和NF-200阳性细胞数量较多,B、C两组较少。[结论]体内体外一定条件下骨髓间充质干细胞都有向神经元样细胞分化的能力;骨髓间充质干细胞和定向诱导的神经元样细胞都可用于移植治疗脊髓损伤,但以两者联合移植治疗的效果最佳。     

人胚胎嗅鞘细胞移植修复大鼠脊髓全横断损伤

[目的]探索人胚胎嗅鞘细胞(hOECs)移植修复大鼠脊髓全横断损伤的可行性。[方法]分离、培养并鉴定人胚嗅鞘细胞,24只W istar大鼠,随机分为实验组和对照组,均行T10节段脊髓全横断。术后第9~10 d,实验组、对照组分别移植Hoechst33342标记的hOECs 5μl(2.5×105个细胞)、DMEM-F12培养基5μl。移植术后第1、2、4、6、8、10周进行BBB运动功能评分,取材行荧光化学(Hoechst33342)和免疫组织化学染色(P75、NF-200、Syn-aptophysin)。双盲条件下进行数据统计。[结果]移植的hOECs可以在损伤脊髓内存活10周以上,可向损伤脊髓头尾两端迁移;术后4~10周实验组的BBB运动功能评分明显高于对照组(P<0.01);P75染色实验组呈阳性反应;NF-200和Synaptophysin免疫组化染色,实验组神经纤维、突触数目和密度都较对照组高。[结论]hOECs移植对脊髓全横断损伤大鼠运动功能恢复具有促进作用。     

BMSCs联合去细胞肌肉生物支架修复大鼠脊髓半切损伤的实验研究

目的以去细胞肌肉生物支架(acellular muscle bioscaffolds,AMBS)接种BMSCs,同种异体移植修复大鼠脊髓半切损伤,观察两者联合移植对脊髓损伤的修复作用。方法取8周龄雌性SD大鼠,采用改良化学方法制备AMBS,并进行复合冷灭菌;密度梯度离心法提取、贴壁法培养BMSCs,取第3代细胞用Hoechst 33342荧光标记,采用注射法制备BMSCs-AMBS复合支架,14 d后扫描电镜及荧光显微镜观察其生物相容性。取成年雌性SD大鼠48只,制备T9～11脊髓半切损伤模型后随机分为4组(n=12),A组于缺损处移植BMSCs-AMBS复合支架,B组单独移植BMSCs,C组单独移植AMBS,D组注射PBS作为空白对照组,分别于术后1、2、3、4周行运动功能评分,术后4周行HE染色观察及免疫荧光检测。结果 Masson染色及HE染色示AMBS内部呈平行结构,主要为胶原纤维,几乎无肌纤维。BMSCs-AMBS复合培养14 d后荧光显微镜观察示Hoechst 33342标记BMSCs大量存活,扫描电镜可见BMSCs贴附于支架内表面生长。术后2～4周,大鼠BBB评分A组均高于其余3组(P<0.05),D组明显低于其余3组(P<0.05);术后4周B组明显高于C组(t=10.352,P=0.000)。术后4周,HE染色示脊髓空洞面积A组明显小于其余3组,免疫荧光染色示A组神经丝蛋白200、巢蛋白阳性细胞表达量高于其余3组,神经胶质原酸性蛋白(glial fibrillary acidic protein,GFAP)则明显低表达。A、B组荧光示踪的BMSCs移植到体内后主要迁移至对侧灰质前角,部分分化为神经元样细胞。A、B、C、D组GFAP荧光半定量分析积分吸光度(IA)值分别为733.01±202.04、926.42±59.46、1 069.37±33.42、1 469.46±160.53,A组明显低于其余3组,D组高于其余3组,差异均有统计学意义(P<0.05)。结论 AMBS具有相对规则的内部结构,与BMSCs有良好生物相容性,能抑制胶质瘢痕,促进BMSCs存活、迁徙、分化,是细胞移植理想的天然载体。两者联合移植修复大鼠脊髓损伤能发挥协同作用,促进运动功能恢复。     

BMSC定向分化为神经干样细胞后移植改善脊髓损伤大鼠的神经功能

目的 研究骨髓间充质干细胞(BMSC)定向分化为神经干样细胞后进行移植,改善脊髓损伤大鼠神经功能的作用及其机制,探讨适宜的移植时间.方法 取培养至第3代的BMSC,将其定向分化为神经干样细胞,并采用免疫荧光染色法进行鉴定.移植前用5溴2脱氧尿嘧啶核苷(BrdU)标记细胞,移植时将其缓慢输注到损伤部位.实验分3组,移植Ⅰ组和移植Ⅱ组分别于脊髓损伤后1和2周进行移植,对照组操作同移植Ⅰ组,仅将移植用细胞悬液改为等量的生理盐水.移植后1~6周,对各组大鼠进行运动功能评分,采用荧光免疫化学染色检测移植细胞的存活、分化及神经纤维再生的情况.采用HE染色观察脊髓损伤区的病理学改变.结果 BMSC诱导培养3 d后,神经巢蛋白呈阳性表达,将诱导后的细胞球继续培养,可见细胞均有不同程度的神经丝蛋白(NF200)及胶质纤维酸性蛋白(GFAP)阳性表达.移植后两移植组大鼠的运动功能评分均显著高于对照组(P＜0.05),移植Ⅰ组尤为明显.2个移植组均有大量的5溴2脱氧尿嘧啶核苷(BrdU)和神经巢蛋白双阳性细胞及部分BrdU和NF200双阳性细胞填充于脊髓损伤区,同时可见明显的神经纤维再生,脊髓损伤处的空洞面积明显小于对照组(P＜0.05),而移植I组神经功能的改善较移植Ⅱ组更加明显.结论 BMSC可定向诱导、分化为神经干样细胞,将其移植后可有效改善脊髓损伤大鼠的神经功能,脊髓损伤1周后的移植效果优于损伤2周后移植.

Abstract：

Objective To study the effect and mechanism of the neurological function recovery in rats with spinal cord injury (SCI) rats after the transplantation of neural stem cells which are directly differentiated from bone marrow mesenchymal stem cells (BMSC), and to investigate the suitable engraftment time.Methods The BMSC at 3rd passage were differentiated into neural stem cells (NSC), and immunofluorescence staining was used to identify the NSC. The oriented-induced cells were labeled with Brdu 3 days before they were transplanted, and they were slowly injected into the injured site of the SCI rats. The SCI rats were randomly divided into group Ⅰ (transplantation at first week postinjury), group Ⅱ (transplantation at 2nd week postinjury) and control group (the operation was the same as group Ⅰ, but the cell suspension was replaced by the equal volume of normal saline). The BBB scores after transplantation were recorded. The distribution and differentiation of transplanted cells were observed by using immunofluorescence staining with antibodies against Brdu combined with Nestion and Brdu combined with NF200. NF200 immunofluorescence staining was used to show the regeneration of nerve fibers. The pathological changes of the injured site were observed by HE staining.Results The nestin expression was positive after the BMSC were differentiated for 3 days, and if the induced spherical cells were cultured continuously, the different levels of NF200 and GFAP were found. BBB scores in group Ⅰ and group Ⅱ were significantly higher than in control group (P<0.05), especially in group Ⅰ. The immunofluorescence showed that a large number of Brdu and Nestin double-positive cells and some Brdu and NF200 double-positive cells filled the injured site and linked the two sides of the injured area in group Ⅰ and group Ⅱ, and the lesion area of the spinal cord was reduced as compared with control group (P<0.05). More importantly, further reduction in lesion area and improvement in neurological function were observed in group Ⅰ.Conclusion The BMSC can be differentiated into NSC. The transplantation of the NSC could effectively promote the nerve function recovery after SCI, and the effect of transplantation at first week postinjury was better than at 2nd week postinjury.     

人脐带间充质干细胞与自体激活雪旺细胞联合移植修复脊髓损伤的实验研究

目的 通过观察人脐带间充质干细胞(hUCMSCs)和大鼠自体激活雪旺细胞(AASCs)联合移植修复脊髓损伤的疗效,探讨AASCs对hUCMSCs体内存活、分化的影响.方法 分离、培养hUCMSCs和大鼠AASCs.通过IMPACTOR MODEL-Ⅱ型打击仪将80只Wistar成年雌性大鼠均制作成T10损伤模型,随机分为四组(n=20):DMEM移植对照组、hUCMSCs移植组、AASCs移植组、hUCMSCs与AASCs联合移植组.比较符组动物恢复情况,进行行为学评分(BBB评分),NF-200和GFAP染色观察细胞存活、分化情况,生物素葡聚糖胺示踪观察皮质脊髓束再生情况.结果 4周后各组间BBB评分差异有统计学意义(P<0.05),6周后联合移植组明显高于其他三组,差异有统计学意义(P<0.05).免疫组化染色示联合移植组的hUCMSCs存活数量,NF-200、GFAP阳性荧光面积均明显高于hUCMSCs移植组,差异有统计学意义(P<0.05),BDA顺行爪踪可见联合移植组于损伤区染色较多,部分纤维延续至损伤远端.结论 AASCs可支持移植的hUCMSCs在损伤部位存活并向神经方向分化,hUCMSCs与AASCs联合移植较二者单独移植能更有效地促进脊髓损伤后运动功能的恢复和轴突再生.     

Bone marrow stromal cell transplantation preserves gammaaminobutyric acid receptor function in the injured spinal cord

A surprising shortage of information surrounds the mechanisms by which bone marrow stromal cells (BMSC) restore lost neurologic functions when transplanted into the damaged central nervous system. In the present study, we sought to elucidate whether BMSCs express the neuron-specific gamma-aminobutyric acid (GABA) receptor when transplanted into injured spinal cord. To examine this, we harvested and cultured rat femoral BMSCs. We then subjected Sprague-Dawley rats to thoracic spinal cord injury (SCI) with a pneumatic impact device. Fluorescence-labeled BMSCs (n = 7) were transplanted stereotactically or the vehicle in which these cells were cultured (n = 4) was introduced stereotactically into the rostral site of SCI at 7 days after injury. We evaluated GABA receptor function by measuring the binding potential for 125I-iomazenil (125I-IMZ) through in vitro autoradiography at 4 weeks after BMSC transplantation and simultaneously examined the fate of the transplanted BMSCs by immunocytochemistry. We found that the transplanted BMSC migrated toward the core of the injury and were densely distributed in the marginal region at 4 weeks after transplantation. BMSC transplantation significantly increased the binding potential for 125I-IMZ (p = 0.0376) and increased the number of GABA receptor-positive cells (p = 0.0077) in the marginal region of the injury site. Some of the transplanted BMSCs were positive for microtubule-associated protein-2 and the alpha1 subunit of GABA(A) receptor in the region of injury. These findings suggest that BMSCs have the potential to support the survival of neurons in the marginal region of SCI and can partly differentiate into neurons, regenerating spinal cord tissue at the site of injury.     

骨髓间充质干细胞移植对大鼠脊髓损伤后氧化应激的影响

目的研究骨髓间充质干细胞（bone marrow mesenchymal stem cells,BMSCs）移植对大鼠脊髓损伤（spinal cord injury,SCI）后氧化应激的影响。方法取大鼠股骨和胫骨骨髓培养BMSCs并传代。参照Taoka方法制作30只大鼠脊髓压迫损伤模型,随机分为3组,损伤组（SCI）、假移植组（SCI＋生理盐水）、移植组（SCI＋BMSCs）。脊髓损伤30 min时,假移植组和移植组于损伤周围相应注射生理盐水和BMSCs。在损伤后第3天、7天、14天和28天,进行BBB（Basso-Beattie-Bresnahan,BBB）行为学评价。应用MTT方法检测血清中超氧化物岐化酶（SOD）活性和丙二醛（MDA）水平。结果脊髓损伤后,BMSCs移植第14天即可观察到大鼠后肢运动功能明显改善,第28天BBB评分有明显提高。与损伤组和假移植组大鼠相比,第7天、14天和28天移植组血中MDA水平降低（P〈0.05）;血中SOD水平较高（P〈0.05）。结论 BMSCs移植对SCI神经功能恢复有促进作用,其机制可能与其抑制氧化应激有关。     

骨髓基质细胞体外分化移植治疗大鼠脊髓损伤的初步研究

[目的]探讨大鼠骨髓基质细胞体外分化为神经干细胞后移植治疗大鼠脊髓损伤的可行性。[方法]骨髓基质细胞经培养及定向分化为神经干细胞，后者由5-溴脱氧尿嘧啶核苷法标记，制备大鼠脊髓损伤模型，伤后第9d移植神经干细胞，实验分组：细胞移植组、PBS填充组、正常对照组。应用组化法观察移植细胞是否存活，取材前24h显露坐骨神经，行辣根过氧化物酶逆行示踪法观察脊髓损伤处的修复重建。[结果]骨髓基质细胞在定向分化为神经干细胞后标记并移植于脊髓损伤区，标记的阳性细胞可在受体脊髓内检测到，辣根示踪技术显示细胞移植组较PBS填充组阳性细胞明显增多，差别有统计学意义。[结论]大鼠骨髓基质细胞在体外分化为神经干细胞后移植于脊髓损伤区，移植细胞可以存活，并参与脊髓损伤处神经传导通路的结构重建。     

bFGF与骨髓间充质干细胞联合应用对大鼠脊髓损伤的修复作用

目的:观察骨髓间充质干细胞(BMSCs)与成纤维细胞生长因子(bFGF)联合移植对大鼠脊髓损伤的修复作用,并探讨其机制。方法:利用血清培养技术获得SD大鼠BMSCs。80只健康雄性6周龄SD大鼠(重约240 g)随机分为4组,每组20只。假手术组行单纯椎板切除,不损伤脊髓,与其余3组同条件饲养。其余3组均采用左侧T9脊髓半切,建立脊髓损伤模型。制模9 d后进行损伤局部移植治疗,对照组损伤处植入吸附有生理盐水的明胶海绵;BMSCs移植组损伤处植入吸附有BMSCs的明胶海绵;bFGF+BMSCs移植组损伤处植入吸附有bFGF+BMSCs的明胶海绵。术后4、8周后Western blotting分析受损脊髓组织中NF-200、GFAP表达水平,Basso Beattie Bresnahan (BBB)运动功能评分量表评价大鼠的后肢功能恢复情况。结果:术后4、8周后BMSCs移植组和bFGF+BMSCs移植组的(BBB)评分较对照组改善(P0.05),且bFGF+BMSCs移植组与BMSCs移植组比较差异有统计学意义(P0.05);术后4、8周后NF200在对照组表达极少,在BMSCs移植组只有少量表达,而bFGF+BMSCs移植组呈高表达(P0.05)。GFAP在对照组表达高,BMSCs移植组少量表达,bFGF+BMSCs移植组呈现低表达(P0.05)。bFGF+BMSCs移植组与BMSCs移植组、对照组比较差异有统计学意义(P0.05)。结论:BMSCs与bFGF联合移植对大鼠脊髓损伤有修复作用,机制可能与其降低GFAP表达及升高NF-200表达有关。     

Transplantation of neurotrophin-3-expressing bone mesenchymal stem cells improves recovery in a rat model of spinal cord injury

Background

This study aimed to investigate the therapeutic effects of transplanting neutrophin-3 (NT-3)-expressing bone marrow-derived mesenchymal stem cells (BMSCs) in a rat model of spinal cord injury (SCI).

Methods

Forty-eight adult female Sprague–Dawley rats were randomly assigned to three groups: the control, BMSC, and NT-3-BMSC groups. BMSCs were infected with NT-3-DsRed or DsRed lentivirus and injected into the cerebrospinal fluid (CSF) via lumbar puncture (LP) 7 days after SCI in the NT-3-BMSC and BMSC groups, respectively. The hind-limb motor function of all rats was recorded using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale on days 1, 3, 7, 14, 21, 28, and 35 after transplantation. Haematoxylin-eosin (HE) staining, immunofluorescence labelling, and western blotting were performed at the final time point.

Results

Expressions of NT-3, brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF) proteins increased significantly in the NT-3-BMSC group, and hind-limb locomotor functions improved significantly in the NT-3-BMSC group compared with the other two groups. The cystic cavity area was smallest in the NT-3-BMSC group. In the NT-3-BMSC group, neurofilament 200 (NF200) and glial fibrillary acidic protein (GFAP) expression levels around the lesions were significantly increased and decreased, respectively.

Conclusions

Our findings demonstrate that transplantation of NT-3 gene-modified BMSCs via LP can strengthen the therapeutic benefits of BMSC transplantation. We observed that these modified cells increased locomotor function recovery, promoted nerve regeneration, and improved the injured spinal cord microenvironment, suggesting that it could be a promising treatment for SCI.     

同种异体软骨细胞与自体骨髓基质干细胞混合共培养构建软骨皮下移植的可行性研究

背景：软骨组织工程的种子细胞问题是目前研究的热点和难点,如何找到一种既能够避免对自体软骨进行取材又能够达到稳定软骨构建目的的方法呢？本研究尝试利用少量同种异体羊软骨细胞作为软骨诱导微环境提供者,与扩增后的羊自体BMSC混合共培养并植入皮下环境,探讨利用同种异体软骨细胞共培养构建软骨皮下移植的可行性。方法：本实验对山羊软骨细胞和BMSC分别进行取材和分离培养扩增,并将以上细胞分为以下四组进行混合并接种在PGA支架材料上：A组：100%自体软骨细胞;B组：30%自体软骨细胞＋70%自体BMSCs;C组：30%同种异体软骨细胞＋70%自体BMSCs;D组：100%同种异体软骨细胞。经过体外构建6周后植入羊皮下进行体内构建12周,对所形成的组织块进行大体观察和组织学染色等评价。结果：自体软骨细胞组和自体软骨细胞混合自体BMSC组皮下移植后可见成熟软骨组织形成,但同种异体软骨细胞参与的两组（包括同种异体软骨细胞混合自体BMSC的实验组和单纯异体软骨细胞组）在皮下环境中都因为较强的免疫反应未能形成软骨组织。结论：同种异体软骨细胞以及PGA支架材料的存在对于组织工程软骨在羊皮下环境的构建有负面影响。     

骨髓间充质干细胞移植促进移植气管上皮再生

目的 探讨经静脉移植的骨髓间充质干细胞(BMSCs)对深低温处理的同种异体气管移植后的存活和上皮再生作用.方法 用深低温冻储2周和6周的大鼠气管进行同种异体气管移植后,将PKH-26标记后的3～5代BMSCs经鼠尾静脉移植入受体内,通过观察局部PKH-26荧光检测和供体气管的组织学、上皮爬行和再生情况,评价BMSC对移植气管的新生上皮再生作用.结果 骨髓间充质干细胞移植并深低温冻储后的移植气管结构完整,组织学检查管腔内为假复层纤毛柱状上皮所覆盖,软骨无变性坏死;术后均能长期存活.PKH-26;标记的BMSCs在受损气管组织定植后呈现红色荧光.结论 BMSCs可迁移并修复受损组织,并通过促进移植气管上皮再生,从而促进气管的损伤恢复.

Abstract：

Objective To investigate the role of BMSCg on enhancing the implant survival and bacheal epithelium regeneration. Methods After transplanted with cryopreserved 2 weeks and 6 weeks allocraft, PHK-26 labeled 3-5 passage BMSCs were injected into the recipient rats via tail vein. Rats in the control groups were injected with the same amount of PBS.We observed the histology of the transplanted trachea including epithelium growth and regeneration, and the PKH-26 fluorescence levels at the para-anastomotic trachea to evaluate the role of BMSC transplantation on the epithelium regeneration. Results Rats from BMSCs injection group survived a long period. Histological observation showed that the tracheal lumen was covered by psudo-striated ciliated columnar epithelium. The cartilage structure was intact. There are no signs of denaturation and necrosis. In the PBS injection group, epithelium regeneration is better in PBS-6-week group than PBS-2-week group. The longest survival time in PBS-6-week group was 32 days, whereas it was 10 days in PBS-2-week group. In BMSCs injection group, rats in BMSC-6-week groups survived longer than 8-week group(12 rats were terminated at 1 week, 4 weeks and 8weeks as planned). There was one rat who survived and were terminated at the designated 8 weeks time point (there were 8regenerated epithelium was similar in the two BMSC transplanted groups. PKH-26 labeled BMSCs migrated to the implant site and showed red fluorescence, with most red fluorescence shown at the anastomotic part. Conclusion BMSCs can migrate to the impaired tissue to repair it. BMSCs may exert their reparation function via enhancing epithelium regeneration.     

In vivo fluorescence tracking of bone marrow stromal cells transplanted into a pneumatic injury model of rat spinal cord

Recent experimental studies have shown that bone marrow stromal cells (BMSC) differentiate into neural cells and reduce neurological deficits when transplanted into traumatized spinal cord. These findings have been derived primarily from histological analyses. We conducted a study directed chiefly at developing a non-invasive system for tracking BMSC transplanted into the spinal cord of living animals. In this study, we induced spinal cord injury (SCI) in rats with a pneumatic device. BMSC were harvested from transgenic mice expressing green fluorescence protein (BMSC-GFP), and were transplanted stereotactically into a control group of rats without SCI (n = 6) and a group with SCI (n = 3). At 2 and 4 weeks after transplantation, the dura mater was exposed and green fluorescence derived from the transplanted BMSC-GFP was observed. The distribution and differentiation of the transplanted cells were subsequently evaluated with immunohistochemistry. Green fluorescence could be detected around the transplantation site in three of six of the control rats. In all three rats subjected to SCI, green fluorescence was shown to spread from the site of BMSC-GFP injection toward the injury site, suggesting that the transplanted cells had migrated toward the lesion within the 4-week post-transplantation period. Histological evaluation suggested that the detected green fluorescence was emitted by cells that had distributed in the dorsal white matter, and demonstrated that some of the transplanted cells expressed neuronal or astrocytic markers. These results suggest the possibility of tracking BMSC transplanted into the spinal cord in living animals. Such noninvasive bioimaging techniques would be valuable for monitoring the fate of these transplanted cells and assessing the safety and efficacy of their transplantation.