基质细胞衍生因子1及其受体CXCR4在内源性神经干细胞迁移中的作用

背景：神经干细胞具有体外、体外迁移的特性,但关于其迁移的具体机制还不十分清楚。 目的：探讨基质细胞衍生因子1及其受体CXCR4在神经干细胞体内迁移中的作用。 方法：制备脑皮质微量注射脂多糖脑损伤大鼠模型,于建模后3,5,7 d灌注取脑,采用冰冻切片免疫组织化学方法,动态监测基质细胞衍生因子1和nestin表达的时相变化。 结果与结论：免疫组织化学染色观察显示：基质细胞衍生因子1随时间推移表达的量逐渐增多。Nestin阳性细胞有明显向外延伸和迁移的迹象,尖端指向脂多糖注射区。结果可见基质细胞衍生因子1趋化体内表达其特异性受体的内源性神经干细胞向脂多糖注射区迁移。     

基质细胞衍生因子1对内源性神经干细胞的趋化迁移作用

背景：目前研究表明,基质细胞衍生因子1在参与趋化迁移内源性神经干细胞中起着非常重要的作用,但其具体迁移机制尚不明确。目的：观察外源性基质细胞衍生因子1 对大鼠内源性神经干细胞的趋化迁移作用及海马区神经干细胞的激活增殖情况。方法：通过向SD大鼠海马区上大脑皮质内注射外源性基质细胞衍生因子1(注射量为5 μL,质量浓度为500 μg/L)建立动物模型,于3,7,14,21 d后灌注取脑,通过石蜡切片免疫组织化学检测大鼠皮质内注射区及海马区nestin阳性细胞表达情况,并设实验对照组与空白对照组。结果与结论：石蜡切片免疫组织化学显示：实验组注射区周围及海马区nestin表达阳性细胞的数量随时间推移逐渐增多,3,7 d时注射区及海马区nestin表达阳性细胞少量表达,14 d时注射区及海马区nestin表达阳性细胞进一步增多,并向注射区形成明显的迁移趋势,21 d时注射区及海马区nestin表达阳性细胞更多。实验对照组及空白实验组未见上述表现。结果表明外源性基质细胞衍生因子1 可能诱导海马区神经干细胞的增殖分化,参与内源性神经干细胞的趋化迁移过程。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

软骨损伤后基质细胞衍生因子1的表达

背景：研究表明基质细胞衍生因子1对骨髓间充质干细胞的迁移、聚集有影响。 目的：观察软骨损伤后不同时间损伤修复区组织基质细胞衍生因子1的表达以及与骨髓间充质干细胞迁移的关系。 方法：建立兔软骨损伤模型,分别于建模后2,5,7,10,14,28 d取损伤灶及边缘区组织,检测基质细胞衍生因子1表达和体外细胞迁移实验,观察基质细胞衍生因子1对骨髓间充质干细胞、软骨细胞的迁移影响。 结果与结论：基质细胞衍生因子1的表达呈现出时间变化的趋势,软骨损伤后第7天达到高峰(P < 0.05)。体内移植的骨髓间充质干细胞主要聚集在软骨损伤灶周围,但在封闭CXC趋化因子受体4后,此聚集现象逐渐减弱(P < 0.05)。结果证实,局部组织中基质细胞衍生因子1的表达在软骨损伤早期明显升高,对骨髓间充质干细胞向软骨损伤修复区迁移有重要作用。     

基质细胞衍生因子1趋化神经干细胞迁移的体外效应

背景：神经干细胞的迁移在神经系统的发育和损伤修复中起着至关重要的作用,近来研究表明趋化因子参与神经干细胞的迁移,但关于其迁移机制目前尚不清楚。 目的：观察体外条件下基质细胞衍生因子1对胎鼠海马神经干细胞的趋化迁移作用。 方法：通过无血清法体外分离、培养及鉴定胎鼠海马神经干细胞;细胞免疫荧光及RT-PCR检测其CXCR4是否表达;观察不同浓度基质细胞衍生因子1对神经干细胞的趋化迁移作用,中和CXCR4受体以验证基质细胞衍生因子1趋化迁移作用的特异性。 结果与结论：胎鼠海马来源神经干细胞表达趋化因子受体CXCR4,呈阳性。RT-PCR琼脂糖凝胶电泳后出现643 bp特异性扩增条带。体外条件下基质细胞衍生因子1趋化迁移随浓度而增强,500 μg/L为最佳趋化浓度。加入抗CXCR4多克隆抗体中和后,神经干细胞迁移较基质细胞衍生因子1组明显减少,与对照组比较,差异无显著性意义(P > 0.05),提示抗CXCR4多克隆抗体可阻断趋化迁移作用。     

静脉移植骨髓基质干细胞对脑缺血大鼠神经功能及神经细胞凋亡的影响

目的： 探讨骨髓基质干细胞静脉移植后进入大鼠局灶性缺血脑内的短期存活情况及其对脑缺血大鼠神经功能的影响。方法: 将BrdU标记大鼠骨髓基质干细胞后，经尾静脉注射到局灶性脑缺血大鼠体内，分别在脑缺血术后1 d、7 d、14 d和28 d通过神经功能评分观察移植后大鼠神经行为学变化情况，通过组织学方法观察移植到脑内的骨髓基质干细胞存活状态和脑内缺血区与非缺血区神经细胞死亡情况，用RT-PCR方法观察到骨髓基质干细胞表达细胞因子及神经营养因子。结果: 骨髓基质干细胞移植组在14 d和28 d大鼠神经功能评分显著低于对照组（P<0.05），神经功能得到明显改善。静脉移植的骨髓基质干细胞在移植的1 d主要分布在损伤侧大脑中动脉周围组织间质中，在第3d沿着损伤侧的下丘脑迁移至海马的CA1(cornu ammonis 1, CA1)区；骨髓基质干细胞移植组大鼠梗死灶周围的死亡细胞在14 d和28 d明显少于对照组（P<0.05）。结论: 经静脉注射移植骨髓基质干细胞能迁移到损伤区并能够明显促进局灶性脑缺血大鼠的神经行为功能恢复；抗凋亡、分泌神经营养因子改善微环境、动员神经干细胞并迁移至缺血区可能是静脉注射骨髓基质干细胞治疗局灶性脑缺血的机制。     

兔肩袖腱骨愈合过程中基质细胞衍生因子1的表达及作用机制

背景：近年在腱骨损伤领域部分学者将基质细胞衍生因子1搭载在组织工程支架上用以促进腱骨愈合，取得了较好的成效，但在基质细胞衍生因子1促进腱骨愈合机制及自然愈合过程中其是否参与修复，目前尚未明确。目的：研究兔肩袖全层冈上肌断裂后腱骨愈合过程中基质细胞衍生因子1表达，及其在腱骨损伤时对干细胞的迁移作用和最佳体外促迁移浓度。方法：随机取成年新西兰大白兔18只建立肩袖损伤模型，另取3只为空白对照。于造模后3,5,7,14,21,28 d各处死3只并处死空白组兔，取腱骨连接处组织保存在-80℃冰箱。应用ELISA反应检测损伤后各时间点愈合处基质细胞衍生因子1表达。取幼兔股骨骨髓间充质干细胞分离培养鉴定，通过transwell实验验证基质细胞衍生因子1对干细胞的促迁移作用效果及体外促迁移最佳浓度，将培养到P3代的干细胞与Brdu共培养后注入兔耳缘静脉，通过免疫组化染色验证干细胞是否迁移至损伤处。结果与结论：(1)基质细胞衍生因子1在肩袖腱骨愈合过程呈双峰表达，于伤后3 d明显增高(P <0.01)随后下降，于伤后5 d达最低，后再次升高于伤后14 d达峰值(P <0.01)，然后下降；(...     

碱性成纤维细胞生长因子对全脑缺血再灌注大鼠脑皮质内源性神经干细胞的影响

探讨碱性成纤维细胞生长因子(bFGF)对全脑缺血再灌注大鼠脑皮质内源性神经干细胞增殖、迁移和分化的影响。本研究以"四血管法"制作全脑缺血再灌注模型,采用免疫组化方法检测BrdU和Nestin在不同组别各时间点的表达,用RT-PCR技术半定量检测大鼠脑皮质NSE mRNA的表达。结果显示假手术组大鼠脑皮质基本未见到BrdU和Nestin阳性细胞表达,NSE mRNA表达没有变化;模型组大鼠脑皮质的BrdU和Nestin阳性细胞在全脑缺血再灌注3d后开始增加,7d达到高峰,NSE mRNA表达无明显增加;bFGF治疗组BrdU、Nestin阳性细胞较模型组在缺血各时间点均明显增加(P0.05),11d达到高峰,NSE mRNA表达与假手术组和模型组相比第15d表达有明显增加(P0.05)。结果表明全脑缺血再灌注能够引起内源性神经干细胞的原位增殖,bFGF可促进全脑缺血再灌注大鼠内源性神经干细胞原位增殖,并延长增殖期,而且有明显促进内源性神经干细胞向神经元分化的作用。     

穹窿海马伞切割后大鼠海马伞内神经干细胞的观察研究

目的观察穹窿海马伞切割侧和非切割侧大鼠海马伞内神经干细胞的表达情况。方法切割SD大鼠右侧穹窿海马伞,于术后2d经腹腔注射BrdU,连续5d,术后7d取脑冰冻切片,进行BrdU/Nestin免疫荧光双标检测。结果穹窿海马伞切割侧海马伞内的BrdU阳性细胞数和Nestin阳性细胞数均明显多于非切割侧,且出现较多的BrdU/Nestin双标的阳性细胞,而非切割侧未见BrdU/Nestin双标的阳性细胞。结论穹窿海马伞切割后,切割侧海马伞内出现较多增殖的神经干细胞,我们推测海马伞的损伤,导致海马伞内局部微环境发生变化,产生某些信号物质,刺激脑内其他部位的神经干细胞增殖并迁移到海马伞内。     

SDF-1/CXCR4对缺血性卒中后神经发生的调节作用研究进展

脑缺血损伤后表达增高的基质细胞来源因子-1(SDF-1)和C-X-C趋化因子受体4(CXCR4)可以调控内源性神经干细胞增殖、分化和迁移。     

基质细胞衍生因子1对骨髓间充质干细胞迁移及皮肤创伤修复的影响

背景：基质细胞衍生因子1对骨髓间充质干细胞具有强烈的趋化作用,且基质细胞衍生因子1与骨髓间充质干细胞均能促进组织创伤愈合,然而有关两者与皮肤创伤愈合的研究文献报道较少。 目的：观察基质细胞衍生因子1在皮肤创伤修复过程中对骨髓间充质干细胞定向迁移及皮肤创面愈合的影响。 方法：选取30只SD大鼠随机分为5组,各组大鼠尾静脉注射PKH26标记的骨髓间充质干细胞,注射1周后于背部制作皮肤创伤模型,造模后于皮肤创伤处多点注射不同质量浓度的基质细胞衍生因子1(1,2,10,50 μg/L)。注射14 d后观察并记录大鼠皮肤愈合情况,免疫荧光染色观察创面组织骨髓间充质干细胞数量、分布情况,苏木精-伊红染色观察创面组织病理变化,Western blot检测创面组织Ⅰ型胶原及Ⅲ型胶原蛋白表达情况。 结果与结论：当基质细胞衍生因子1质量浓度为10 μg/L时,骨髓间充质干细胞在皮肤创面的数量最多,创伤修复效果最好。同样基质细胞衍生因子1能够调节Ⅰ型胶原及Ⅲ型胶原在创面的表达,基质细胞衍生因子1质量浓度为10 μg/L时,Ⅰ型胶原及Ⅲ型胶原表达最高。结果表明适宜质量浓度的基质细胞衍生因子1 (10 μg/L)能够更好地促进骨髓间充质干细胞迁移,从而促进皮肤创伤愈合。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

甲基强的松龙影响脊髓损伤后内源性神经干细胞的迁移

BACKGROUND:After spinal cord injury, endogenous neural stem cells are activated to proliferate and migrate to repair damaged tissue. As a clinical medicine, methylprednisolone shows a lot of functions, but its effects on endogenous neural stem cells are still unknown. OBJECTIVE:To explore the effects of methylprednisolone on the proliferation and migration of endogenous neural stem cells after spinal cord injury. METHODS:Seventy-five Sprague-Dawley rats were used to make animal models of T10 complete paraplegia using Allen’s method, and randomized into methylprednisolone, normal saline and model groups. Rats in these three groups were given intraperitoneal injection of 1 g/L methylprednisolone solution at a dose of 30 mg/kg for 10 minutes and at a dose of 5.4 mg/kg/h for 23 hours, given intraperitoneal injection of normal saline at the same dose and given no treatment, respectively. Neurological and motor functions were assessed by somatosensory evoked potential and Basso Beattie Bresnahan scores at 7, 14, 21, 28 days after spinal cord injury. BrdU and Nestin staining of the injured spinal cord segment was conducted. RESULTS AND CONCLUSION:A large amount of BrdU- and Nestin-positive cells were visible in all the groups, and the number of these cells reached the peach at 14 days after spinal cord injury. Methylprednisolone was found to inhibit BrdU-, Nestin- or double-positive cells, indicating methylprednisolone can inhibit the proliferation and migration of endogenous neural stem cells. The results of Basso Beattie Bresnahan scores showed no notable improvement in the motor function of the limbs. Methylprednisolone also showed no significant effects on the motor evoked potential latency, but promoted nerve conduction recovery. All these findings indicate that methylprednisolone has some hindering effects on spinal cord repair by inhibiting the proliferation and migration of endogenous neural stem cells after spinal cord injury.     

促红细胞生成素促进脊髓损伤大鼠移植神经干细胞存活和迁移

背景：如何有效促进移植入脊髓损伤组织内的神经干细胞存活和迁移,是目前神经修复研究的重点。 目的：观察促红细胞生成素对脊髓损伤大鼠移植神经干细胞存活、增殖和迁移的影响。 方法：将60只SD大鼠随机分为3组,均制备脊髓横断损伤模型。造模7 d,神经干细胞移植组和促红细胞生成素组于脊髓损伤处移植BrdU标记的神经干细胞7 μL(1×10⁹ L^-1),脊髓损伤对照组移植DMEM/F12培养基;促红细胞生成素组腹腔内注射促红细胞生成素5 000 U/kg,1次/d,连续注射7 d,其余两组注射等量生理盐水。于细胞移植后8周取损伤脊髓组织。 结果与结论：造模2周后,神经干细胞移植组和促红细胞生成素组BBB评分明显高于脊髓损伤对照组(P < 0.05),造模4周后,促红细胞生成素组BBB评分明显高于神经干细胞移植组(P < 0.05)。免疫荧光染色显示促红细胞生成素组大鼠损伤脊髓组织BrdU阳性细胞数量及迁移距离均大于神经干细胞移植组(P < 0.05)。说明促红细胞生成素能促进损伤脊髓组织原位移植的神经干细胞的存活与迁移,加速神经功能修复。     

脑缺血再灌注损伤后神经细胞增殖相关因子基因的表达

目的：观察大鼠脑缺血再灌注后神经细胞巢蛋白、干细胞因子（SCF）和神经细胞粘附分子（NCAM）基因的表达。方法：成年SD大鼠,以线栓法建立大脑中动脉缺血再灌注模型,随机分为缺血1．5h再灌注2h～14d组和假手术组。原位杂交技术检测脑缺血再灌注后脑组织巢蛋白SCF和NCAM mRNA的表达。结果：脑缺血再灌注后,巢蛋白mRNA表达在大部分时相点,均明显高于假手术组。SCF mRNA的表达除早期时相点外,均明显高于假手术组。NCAM mRNA于再灌注2h后开始表达,12h～1d达高峰,7d后逐渐减少,14d降至假手术组水平。结论：脑缺血再灌注后SCF mRNA表达可能具有促进神经干细胞增殖作用,NCAM表达可能参与了损伤后脑组织的修复过程。     

The role of SDF-1α–ECM crosstalk in determining neural stem cell fate

The consequences of central nervous system injury are far-reaching and debilitating and, while an endogenous repair response to neural injury has been observed in recent years, the mechanisms behind this response remain unclear. Neural progenitor/stem cell (NPSC) migration to the site of injury from the neural stem cell niches (e.g. subventricular zone and hippocampus) has been observed to be vasophilic in nature. While the chemotactic stimuli directing NPSC homing to injury is not well established, it is thought to be due in part to an increasing gradient of chemotactic cytokines, such as stromal cell-derived factor 1α (SDF-1α). Based on these recent findings, we hypothesize that critical crosstalk between SDF-1α and the extracellular matrix (ECM) drives injury-induced NPSC behavior. In this study, we investigated the effect of SDF-1α and ECM substrates (Matrigel, laminin, and vitronectin) on the migration, differentiation, and proliferation of NPSCs in vitro using standard assays. The results demonstrated that SDF-1α and laminin-based ECM (Matrigel and laminin) significantly and synergistically enhanced NPSC migration and acute neuronal differentiation. These effects were significantly attenuated with the addition of AMD3100 (an antagonist against the SDF-1α receptor, CXCR4). SDF-1α alone significantly increased NPSC proliferation regardless of ECM substrate, however no synergy was observed between SDF-1α and the ECM. These results serve to elucidate the relationship between adhesive and soluble signaling factors of interest and their effect on NPSC behavior following neural injury. Furthermore, these results better inform the next generation of biomaterials aimed at stimulating endogenous neural regeneration for neural injury and neurodegenerative diseases.     

RhoA基因沉默联合脐带间充质干细胞移植脑损伤大鼠功能的恢复

背景：研究认为Rho激酶可致使神经生长锥塌陷,对神经修复具有抑制作用。 目的：脐带间充质干细胞移植同时联合RNAi介导的RhoA基因沉默,观察两者对脑损伤大鼠恢复的影响。 方法：健康Wistar大鼠84只,采用液压颅脑损伤仪,给予253.312 5-303.975 kPa液压冲击力,制成重型液压颅脑损伤模型,随机分成为对照组,脐带间充质干细胞移植组,联合组(脐带间充质干细胞移植联合RhoA基因沉默)。CM-Dil标记的脐带间充质干细胞移植后采用改良神经功能损伤评分系统(mNSS)评价大鼠神经功能恢复情况,在创伤性脑损伤后21-28 d进行Morris水迷宫试验。4周后处死并行全脑冷冻切片苏木精-伊红染色及荧光显微镜观察CM-Dil标记的脐带间充质干细胞的存活和分布情况,采用RT-PCR检测各组损伤区脑组织RhoA基因的表达量。 结果与结论：移植后1,2,3,4周,大鼠神经学缺损评分脐带间充质干细胞移植组低于对照组(P < 0.05),联合组明显低于对照组(P < 0.01)。Morris水迷宫试验各组平均逃避潜伏期均逐渐缩短, 联合组3-5 d时平均潜伏时间较脐带间充质干细胞移植组缩短(P < 0.05),较对照组明显缩短(P < 0.01);联合组穿越平台次数及在目标象限游泳距离与总距离百分比均高于对照组和脐带间充质干细胞移植组(P < 0.05)。移植4周后,脑组织冰冻切片和苏木精-伊红染色切片中的神经元数量和CM-Dil阳性细胞数联合组多于脐带间充质干细胞移植组,脐带间充质干细胞移植组多于对照组(P < 0.05);联合组RhoA mRNA表达水平较对照组和脐带间充质干细胞移植组显著降低(P < 0.05)。提示脐带间充质干细胞移植可明显改善重型颅脑损伤后大鼠的神经学功能,联合应用RhoA基因沉默有协同效果。     

碱性成纤维细胞生长因子促进脊髓损伤小鼠内源性神经干细胞的增殖

BACKGROUND:So far steroid pulse therapy and surgical decompression are the main accepted therapies for spinal cord injury, but these methods make no effects on injured neurons. Nerve growth factors and endogenous neural stem cells play a role in the neuronal regeneration and remyelination, which provides a new idea for spinal cord injury treatment. OBJECTIVE:To explore the effect of the basic fibroblast growth factor on proliferation of endogenous neural stem cells after spinal cord injury and to analyze its relationship with the increased fluoro-gold labeled neurons. METHODS:Totally 48 Kunming mice were randomly divided into four groups including normal, spinal cord injury, treatment and sham operation groups. Acute spinal cord injury models were established in the spinal cord injury and treatment groups, and the normal group was subjected to operation that did not damage the spinal cord. At 2 hours after regaining consciousness, the treatment group was given daily injection of MTPBS containing 25 μg/kg basic fibroblast growth factors and 1% album. And at 7 days, laminectomy was carried out again at the L1 segment in the former three groups and a small piece of sterile gelfoam soaked with fluoro-gold was inserted into the incision. The sham operation group was given no processing. Afterwards, mouse motor behavior was assessed using Rotarod and Platform Hang tests; neurons in the corticospinal and rubrospinal tracts were labeled with fluoro-gold; the number of endogenous neural stem cells positive for nestin was detected by immunohistochemistry method. Besides, the correlation between the number of fluoro-gold labeled neurons and the number of endogenous neural stem cells was assessed. RESULTS AND CONCLUSION:The basic fibroblast growth factor could significantly improve the mouse motor behavior after spinal cord injury. And the number of endogenous neural stem cells was significantly increased after the basic fibroblast growth factor injection, which was related to the increased fluoro-gold labeled neurons. In conclusion, basic fibroblast growth factors play an important role in the proliferation of endogenous neural stem cells after spinal cord injury. Furthermore, endogenous neural stem cells improve locomotive behaviors by encouraging the neuronal proliferation.     

Endogenous neural stem cells in central canal of adult rats acquired limited ability to differentiate into neurons following mild spinal cord injury

Endogenous neural stem cells in central canal of adult mammalian spinal cord exhibit stem cell properties following injury. In the present study, the endogenous neural stem cells were labeled with Dil to track the differentiation of cells after mild spinal cord injury (SCI). Compared with 1 and 14 days post mild injury, the number of endogenous neural stem cells significantly increased at the injured site of spinal cord on 3 and 7 days post-injury. Dil-labeled βIII-tublin and GFAP expressing cells could be detected on 7 days post-injury, which indicated that the endogenous neural stem cells in central canal of spinal cord differentiated into different type of neural cells, but there were more differentiated astrocytes than the neurons after injury. Furthermore, after injury the expression of inhibitory Notch1 and Hes1 mRNA began to increase at 6 hours and was evident at 12 and 24 hours, which maintained high levels up to 7 days post-injury. These results indicated that a mild SCI in rat is sufficient to induce endogenous neural stem cells proliferation and differentiation. However, the ability to differentiate into neurons is limited, which may be, at least in part, due to high expression of inhibitory Notch1 and Hes1 genes after injury.