骨髓间充质干细胞旁分泌作用与脑缺血后的细胞凋亡*

背景：骨髓间充质干细胞移植治疗脑缺血的机制之一是骨髓间充质干细胞的旁分泌作用,而目前对于这一机制的研究报道较少。 目的：观察骨髓间充质干细胞旁分泌作用对脑缺血后细胞凋亡的抑制作用并探索相关机制。 方法：体外培养大鼠骨髓间充质干细胞,建立大鼠大脑中动脉缺血模型。24只SD大鼠随机数字表法分为4组,每组6只。细胞移植给药组：大鼠纹状体内移植骨髓间充质干细胞后给予ERK1/2抑制剂U0126;非移植给药组：注射等量的PBS后给予U0126;细胞移植对照组：移植骨髓间充质干细胞后给予溶剂对照;非移植对照组：注射等量的PBS后给予溶剂对照。7 d后通过Western blot检测血管内皮细胞生长因子、磷酸化ERK1/2蛋白的表达;TUNEL染色检测梗死区周围及皮质区细胞凋亡情况。 结果与结论：细胞移植组较非移植组大鼠纹状体内血管内皮细胞生长因子蛋白的表达明显增高,磷酸化ERK1/2表达增强,细胞凋亡数明显减少;经U0126处理后,血管内皮细胞生长因子的表达没有变化,而随着磷酸化ERK1/2的表达受到抑制,细胞凋亡数明显增高。提示骨髓间充质干细胞在大脑纹状体内可以旁分泌血管内皮细胞生长因子,并通过激活ERK1/2抑制了脑梗死区细胞的凋亡。     

高频超声评价干细胞自体移植对兔缺血肢体血管再生的影响

背景：研究发现干细胞可分化为血管内皮细胞，并可进一步分化形成新生毛细血管，自体骨髓间充质干细胞移植促进血管再生正是利用这一原理达到治疗下肢缺血的目的。 目的：采用高频二维超声及彩色多普勒血流成像检测评价自体骨髓间充质干细胞移植后兔缺血肢体血管再生的情况。 设计、时间及地点：随机对照动物实验，于2007-03/2008-04在无锡市第三人民医院完成。 材料：新西兰大白兔24只，随机分为模型对照组、细胞移植组，12只/组。 方法：2组兔均建立后肢缺血动物模型，造模1周后，细胞移植组取体外分离培养的Brdu标记的自体骨髓间充质干细胞，在腓肠肌部位皮下分多点注射，细胞悬液总体积0.5 mL，细胞总量2×106个；模型对照组于相同部位注射等量生理盐水。 主要观察指标：对兔股动脉及股浅动脉起始段行高频二维超声及彩色多普勒血流成像检测，测量股动脉血管内径、血流峰值速度、血流加速时间；取缺血部位肌肉组织，免疫组织化学染色检测移植细胞分布情况及病理学检查血管再生情况。 结果：移植后2周，高频超声检查细胞移植组兔股动脉内径、血流峰值速度均大于模型对照组，血流加速时间小于模型对照组(P < 0.01)。免疫组织化学染色后移植部位可见抗Brdu染色阳性细胞的存在，病理切片示细胞移植组血管密度明显高于模型对照组。 结论：自体骨髓间充质干细胞移植具有促进血管生成的作用，有望成为一种简单有效的治疗下肢缺血的方法，同时高频超声检测股动脉为自体骨髓间充质干细胞移植效果评价提供了有效实用的方法。     

骨髓间充质干细胞预移植1周后构建心肌缺血再灌注损伤大鼠模型

背景：急性心肌梗死用溶栓或介入手段开通阻塞血管后,因心肌缺血再灌注损伤而很难达到满意的疗效。 目的：观察骨髓间充质干细胞移植对大鼠心肌缺血再灌注损伤的修复作用。 方法：取健康3周龄SD大鼠的骨髓细胞悬液,进行骨髓间充质干细胞体外扩增培养。受体SD大鼠接受骨髓间充质干细胞或无血清DMEM心肌注射1周后建立心肌缺血再灌注损伤模型,心肌缺血0.5 h再灌注2 h后测定血清乳酸脱氢酶水平、心肌组织总超氧化物歧化酶活力及丙二醛水平;采用缺口末端标记法检测心肌细胞凋亡情况;免疫组化法检测Bcl-2、Bax蛋白的表达变化。 结果与结论：分离培养的骨髓间充质干细胞增殖旺盛,纯度较高,且均质性和稳定性好;与缺血再灌注组相比,细胞移植组乳酸脱氢酶的漏出减少,总超氧化物歧化酶活性增加,丙二醛含量减少(P < 0.01);细胞移植组心肌细胞凋亡指数显著低于缺血再灌注组(P < 0.01);细胞移植组Bcl-2 蛋白表达高于缺血再灌注组(P < 0.05),Bax/Bcl-2 比值低于缺血再灌注组(P < 0.05)。结果表明骨髓间充质干细胞移植对大鼠心肌缺血再灌注损伤的修复可起促进作用。     

骨髓间充质干细胞治疗肾缺血再灌注损伤的旁分泌机制*☆

背景：骨髓间充质干细胞治疗肾缺血再灌注损伤的机制除了干细胞分化成肾细胞参与损伤修复外,还存在其他多种机制参与保护受损的肾脏。 目的：探讨骨髓间充质干细胞治疗肾缺血再灌注损伤的旁分泌机制。 方法：体外培养、纯化并体外DAPI标记大鼠骨髓间充质干细胞,并将其移植入肾缺血再灌注损伤模型大鼠体内,观察骨髓间充质干细胞对肾缺血再灌注损伤肾功能的保护作用和在受体鼠体内的迁移情况,并应用免疫组织化学法检测骨髓间充质干细胞治疗后第2天缺血肾脏组织中血管内皮生长因子（VEGF）、肿瘤坏死因子-α(TNF-α)（用中文表示）等细胞因子的表达。 结果与结论：与注射生理盐水的对照组比较,细胞移植组大鼠血清肌酐和尿素氮水平在移植后第1、2天明显降低(P < 0.05),但细胞移植组移植后第1、2天肾组织中均未见DAPI阳性细胞;第3、4天则逐渐可见DAPI阳性细胞。免疫组织化学染色结果显示,与对照组相比,移植后第2天肾组织中可见较多血管内皮生长因子（VEGF）阳性细胞,而肾组织中肿瘤坏死因子-α(TNF-α)阳性细胞明显减少。结果显示旁分泌机制参与了骨髓间充质干细胞治疗肾缺血再灌注损伤。     

骨髓间充质干细胞移植大鼠脑缺血区微血管密度和肝细胞生长因子的表达

背景：应用骨髓间充质干细胞移植治疗脑缺血可促进损伤神经功能的恢复,目前其作用机制尚未明确。 目的：分析骨髓间充质干细胞移植对大鼠脑缺血保护作用的机制。 方法：采用线栓法复制大鼠大脑中动脉栓塞模型,随机分为假手术组、大脑中动脉栓塞组、溶剂对照组和骨髓间充质干细胞组。骨髓间充质干细胞组于脑梗死1 d后经侧脑室注射入骨髓间充质干细胞,溶剂对照组则注射同等剂量的PBS。 结果与结论：大鼠脑缺血后缺血区皮质可见大量的微血管生成,2周达高峰。骨髓间充质干细胞组缺血区微血管密度显著高于大脑中动脉栓塞组和溶剂对照组(P < 0.01)。治疗后4,7,14 d骨髓间充质干细胞组脑组织中肝细胞生长因子的表达水平显著高于大脑中动脉栓塞组和溶剂对照组(P < 0.01)。提示骨髓间充质干细胞移植可促进大鼠缺血区微血管生成,改善缺血区血运,从而改善脑缺血大鼠的神经功能。     

骨髓间充质干细胞移植及生长相关蛋白43表达在脑修复中的作用

背景：研究证实骨髓间充质干细胞移植能够促进脑功能恢复,并对大鼠脑皮质及海马结构损伤具有修复作用,可能与细胞的自身代偿以及神经生长递质的参与有关,也可能是由于神经应激性损伤刺激靶组织细胞分泌各种神经因子的表达有关。 目的：从细胞生物学的角度,观察大鼠脑缺血损伤后骨髓间充质干细胞移植对神经再生及脑的修复作用。 方法：参考改良Nagasawa法建立大脑中动脉闭塞再灌注模型后,实施骨髓间充质干细胞移植,并分别进行跑台运动训练和水迷宫康复训练,进行神经功能评分及学习记忆评分。采用TUNEL法检测脑皮质区及海马区凋亡神经元的表达以及免疫组化技术检测生长相关蛋白43蛋白在两区的表达变化。 结果与结论：移植组16 h移植骨髓间充质干细胞在皮质区及海马CA1区表达明显增加;7 d细胞表达达高峰,分化细胞明显增加。移植后运动训练7,19,21 d移植组mNSS评分低于模型组(P均< 0.01);移植组大鼠水迷宫试验平台潜伏期的时间较模型组明显缩短(P < 0.05);移植组大鼠穿越平台次数较模型组增多(P < 0.05);缺血再灌注24 h凋亡细胞达高峰,3 d梗死体积测量为最大值;再灌注19 d生长相关蛋白43达高峰。提示大鼠脑缺血损伤介导了神经功能缺损,骨髓间充质干细胞移植促进了神经再生,生长相关蛋白43表达上调抑制神经元凋亡,进一步促进了脑梗死灶的修复。     

高压氧联合骨髓间充质干细胞移植修复缺氧缺血性脑损伤

背景：单纯骨髓间充质干细胞移植对脑梗死组织的修复作用并不理想,需要结合药物及生物工程材料等手段进行综合治疗。 目的：验证高压氧结合骨髓间充质干细胞移植修复大鼠缺氧缺血性脑损伤的效果。 方法：体外培养大鼠骨髓间充质干细胞。应用线栓法建立大脑中动脉阻塞大鼠模型,按随机区组法分为3组,即对照组、骨髓间充质干细胞移植组及高压氧+骨髓间充质干细胞移植组。静脉移植后24 h,3 d及伤后1,2 周行Longa行为学评分,检测神经功能的损伤情况。移植2周后,应用RT-PCR法测定生长相关蛋白43 mRNA的表达,并以BrdU免疫组化和苏木精-伊红染色行梗死处组织学检查以证实恢复程度。 结果与结论：移植后1周,高压氧+骨髓间充质干细胞移植组大鼠神经功能障碍评分低于骨髓间充质干细胞移植组,骨髓间充质干细胞移植组低于对照组(P < 0.05)。2周后脑梗死周围组织生长相关蛋白43 mRNA的表达高压氧+骨髓间充质干细胞移植组高于骨髓间充质干细胞移植组,骨髓间充质干细胞移植组高于对照组(P < 0.05)。BrdU免疫组化和苏木精-伊红切片中的神经元数量高压氧+骨髓间充质干细胞移植组多于骨髓间充质干细胞移植组,骨髓间充质干细胞移植组多于对照组(P < 0.05)。提示高压氧联合骨髓间充质干细胞静脉移植治疗大鼠缺氧缺血性脑损伤可明显改善大鼠的神经功能,效果优于单纯骨髓间充质干细胞移植。     

裸鼠肢体缺血后炎性细胞浸润及相关因子表达的动态变化***☆

背景：有研究表明组织缺血后可发生代偿性血管新生，但缺血后局部炎症反应的变化规律及与血管新生的关系至今尚不明确。 目的：观察裸鼠肢体缺血后组织中炎性细胞浸润及相关因子表达的动态变化。 方法：用股动脉结扎法建立裸鼠肢体缺血模型，于缺血后3 d，1，2，3，4周观察裸鼠肢体缺血状态的改变，应用苏木精-伊红染色、免疫组织化学染色分别观察缺血组织一般形态学、微血管数量和巨噬细胞浸润的变化，应用Western blot和RT-PCR检测核因子κB、单核细胞趋化蛋白1和血管内皮生长因子表达的动态变化。 结果与结论：裸鼠肢体缺血程度于造模后一两周最为严重，缺血后的肌肉纤维萎缩、变形，单核细胞趋化蛋白1和血管内皮生长因子表达最高(P < 0.01)。微血管数量于缺血后2周时最多(P < 0.01)。造模后3 d~2周，缺血组织中有大量炎性细胞浸润，部分裸鼠的肢体出现缺血性坏疽，尤以缺血2周时最严重，核因子κB表达增强(P < 0.01)。结果提示，核因子κB和单核细胞趋化蛋白1基因介导的炎症反应是肢体缺血发生后的代偿性变化，刺激了血管内皮生长因子的基因表达和短暂的血管新生过程，但由于微血管的生成数量有限，尚不足以代偿肢体缺血坏疽的发生。 关键词：肢体缺血；动脉；炎性介质；基因表达；核因子κB；单核细胞趋化蛋白1；组织构建     

骨髓间充质干细胞自体移植促进兔缺血肢体的血管生成

背景：常规药物治疗、介入或血管旁路移植手术对下肢动脉闭塞症的远期疗效均不理想。近年来采用干细胞的血管再生疗法在梗死部位修复或重新建立有效侧支循环逐渐成为可能。 目的：验证骨髓间充质干细胞自体移植对兔缺血后肢血管再生的促进作用。 设计、时间及地点：随机对照动物实验，于2005-08/2006-11在江苏省血吸寄生虫病防治研究所完成。 材料：选用新西兰大白兔8只，制备兔后肢缺血模型。按随机数字表法分为2组，实验组及对照组各4只。 方法：分离培养实验组兔骨髓间充质干细胞，5-溴-2-脱氧尿苷标记，将骨髓间充质干细胞制成悬液注射于实验组兔后肢缺血部位；对照组注射等量生理盐水。 主要观察指标：2 周后行兔股动脉二维及彩色多普勒超声检测，观察移植前后的血管内径、血流峰值速度及血流加速时间等；取缺血部位肌肉组织，通过免疫荧光及苏木精-伊红染色观察移植细胞分布及血管生成情况。 结果：细胞移植2周后实验组兔的股动脉内径、血流峰值速度均大于对照组(P < 0.01)，血流加速时间短于对照组(P < 0.01)。免疫荧光染色结果显示实验组兔移植部位有抗5-溴-2-脱氧尿苷染色阳性细胞存在；苏木精-伊红染色结果显示实验组缺血部位血管密度高于对照组。 结论：骨髓间充质干细胞具有促进血管生成的作用，自体移植可望成为一种简单的、有效的治疗下肢缺血的方法。     

慢病毒载体介导血管生长素1基因修饰骨髓间充质干细胞对颈动脉粥样硬化的影响

背景：骨髓间充质干细胞易于被外源基因转染,且具有向损伤组织趋化聚集的特性,便于将目的基因导入其中并发挥治疗性作用,可以通过分化为血管内皮细胞修复损伤的血管内膜。 目的：探讨慢病毒载体介导的血管生长素1基因修饰骨髓间充质干细胞移植后,对大鼠颈动脉粥样硬化的影响。 设计、时间及地点：随机对照动物实验,于2007-02/2008-05在福建省高血压研究所及福建医大附属第一医院中心实验室完成。 材料：4周龄雄性SD大鼠32只,8只用于制备骨髓间充质干细胞,剩余24只随机分为3组：模型对照组、空载体组、血管生长素1转染组,8只/组。 方法：以重组慢病毒为载体构建血管生长素1基因工程干细胞,以绿色荧光蛋白为报告基因,调整细胞密度为(1.0~2.0)× 1010 L-1。3组大鼠均采用球囊损伤法+高脂饮食构建颈动脉粥样硬化模型,造模后即刻,空载体组将未感染的0.1 mL骨髓间充质干细胞悬液注入颈总动脉外膜,分3点注射;血管生长素1转染组同法注入等量重组慢病毒感染的骨髓间充质干细胞悬液,饲养2个月后处死大鼠,取颈动脉组织。 主要观察指标：Western blot法检测转基因干细胞中血管生长素1的表达,荧光免疫组织化学及苏木精-伊红染色检测动脉内膜/中膜面积比。 结果：24只大鼠均进入结果分析。血管生长素1转染组表达血管生长素1蛋白,另2组无血管生长素1蛋白表达。移植后2个月,荧光显微镜下空载体组、血管生长素1转染组动脉壁内均可见绿色荧光蛋白阳性细胞;各组均可见动脉内膜增生,斑块形成;与模型对照组比较,空载体组内膜面积/中膜面积值无明显变化(P > 0.05),血管生长素1转染组内膜面积/中膜面积值明显减小(P < 0.05)。 结论：经血管生长素1基因修饰的骨髓间充质干细胞移植可明显减轻动脉粥样硬化程度。     

Transplantation of human mesenchymal stem cells promotes functional improvement and increased expression of neurotrophic factors in a rat focal cerebral ischemia model

Previous studies have suggested that intravenous transplantation of mesenchymal stem cells (MSCs) in rat ischemia models reduces ischemia‐induced brain damage. Here, we analyzed the expression of neurotrophic factors in transplanted human MSCs and host brain tissue in rat middle cerebral artery occlusion (MCAO) ischemia model. At 1 day after transient MCAO, 3 × 10⁶ immortalized human MSC line (B10) cells or PBS was intravenously transplanted. Behavioral tests, infarction volume, and B10 cell migration were investigated at 1, 3, 7, and 14 days after MCAO. The expression of endogenous (rat origin) and exogenous (human origin) neurotorphic factors and cytokines was evaluated by quantitative real‐time RT‐PCR and Western blot analysis. Compared with PBS controls, rats receiving MSC transplantation showed improved functional recovery and reduced brain infarction volume at 7 and 14 days after MCAO. In MSC‐transplanted brain, among many neurotrofic factors, only human insulin‐like growth factor 1 (IGF‐1) was detected in the core and ischemic border zone at 3 days after MCAO, whereas host cells expressed markedly higher neurotrophic factors (rat origin) than control rats, especially vascular endothelial growth factor (VEGF) at 3 days and epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) at 7 days after MCAO. Intravenously transplanted human MSCs induced functional improvement, reduced infarct volume, and neuroprotection in ischemic rats, possibly by providing IGF‐1 and inducing VEGF, EGF, and bFGF neurotrophic factors in host brain. © 2009 Wiley‐Liss, Inc.     

Human umbilical cord blood‐derived mesenchymal stem cells improve functional recovery through thrombospondin1, pantraxin3, and vascular endothelial growth factor in the ischemic rat brain

Cell therapy is a potential therapeutic method for cerebral ischemia, which remains a serious problem. In the search for more effective therapeutic methods, many kinds of stem cells from various tissues have been developed and tested as candidate therapeutic agents. Among them, human umbilical cord blood (hUCB)‐derived mesenchymal stem cells (MSCs) are widely used for cell therapy because of their genetic flexibility. To confirm that they are effective and understand how they affect ischemic neural cells, hUCB‐MSCs were directly administered ipsilaterally into an ischemic zone induced by middle cerebral artery occlusion (MCAO). We found that the neurobehavioral performance of the hUCB‐MSC group was significantly improved compared with that of the vehicle‐injected control group. The infarct was also remarkably smaller in the hUCB‐MSC group. Additionally, hUCB‐MSC transplantation resulted in a greater number of newly generated cells and angiogenic and tissue repair factors and a lower number of inflammatory events in the penumbra zone. To determine why these events occurred, hUCB‐MSCs were assayed under hypoxic and normoxic conditions in vitro. The results showed that hUCB‐MSCs exhibit higher expression levels of thrombospondin1, pantraxin3, and vascular endothelial growth factor under hypoxic conditions than under normoxic conditions. These results were found to be correlated with our in vivo immunofluorescent staining results. On the basis of these findings, we suggest that hUCB‐MSCs may have a beneficial effect on cerebral ischemia, especially through angiogenesis, neurogenesis, and anti‐inflammatory effects, and thus could be used as a therapeutic agent to treat neurological disorders such as cerebral ischemia. © 2015 Wiley Periodicals, Inc.     

人脐血间充质干细胞静脉移植治疗大鼠局灶性脑缺血的实验研究

目的 探讨来源于人脐血的间充质干细胞经静脉移植治疗大鼠局灶性脑缺血的可行性及其机制.方法 将人脐血间充质干细胞在体外纯化、扩增并经BrdU标记后,经尾静脉移植到局灶性脑缺血大鼠体内,通过神经缺损评分观察移植后大鼠神经行为学改善情况,通过组织学方法观察移植到脑内的人脐血间充质干细胞表达脑源性神经营养因子和缺血灶周围微血管密度变化的情况.结果 人脐血间充质干细胞移植组大鼠的神经缺损评分显著低于对照组(P＜0.05);移植到脑内的人脐血间充质干细胞主要选择性分布于缺血灶周围区域并表达脑源性神经营养因子,移植组大鼠梗死灶周围的微血管密度显著高于对照组(P＜0.01).结论 经静脉注射移植人脐血间充质干细胞能明显促进局灶性脑缺血大鼠的神经行为功能恢复,促进缺血灶周边区微血管增生可能是人脐血间充质干细胞移植治疗局灶性脑缺血的机制之一.     

Transplantation with hypoxia‐preconditioned mesenchymal stem cells suppresses brain injury caused by cardiac arrest–induced global cerebral ischemia in rats

Cardiac arrest–induced global cerebral ischemia is a main cause of neurological dysfunction in emergency medicine. Transplantation with bone marrow mesenchymal stem cells (MSCs) has been used in stroke models to repair the ischemic brain injury, but it is little studied in models with global cerebral ischemia. In the present study, a hypoxia precondition was used to improve the efficacy of MSC transplantation, given the low survival and migration rates and limited differentiation capacities of MSCs. We found that hypoxia can increase the expansion and migration of MSCs by activating the PI3K/AKT and hypoxia‐inducible factor‐1α/CXC chemokine receptor‐4 pathways. By using a cardiac arrest–induced global cerebral ischemic model in rats, we found that transplantation of hypoxia‐preconditioned MSCs promoted the migration and integration of MSCs and decreased neuronal death and inflammation in the ischemic cortex. © 2017 Wiley Periodicals, Inc.     

Enhancement of neuroplasticity through upregulation of beta1-integrin in human umbilical cord-derived stromal cell implanted stroke model

Neuroplasticity subsequent to functional angiogenesis is an important goal for cell-based therapy of ischemic neural tissues. At present, the cellular and molecular mechanisms involved are still not well understood. In this study, we isolated mesenchymal stem cells (MSCs) from Wharton's jelly (WJ) to obtain clonally expanded human umbilical cord-derived mesenchymal stem cells (HUCMSCs) with multilineage differentiation potential. Experimental rats receiving intracerebral HUCMSC transplantation showed significantly improved neurological function compared to vehicle-treated control rats. Cortical neuronal activity, as evaluated by proton MR spectroscopy (1H-MRS), also increased considerably in the transplantation group. Transplanted HUCMSCs migrated towards the ischemic boundary zone and differentiated into glial, neuronal, doublecortin+, CXCR4+, and vascular endothelial cells to enhance neuroplasticity in the ischemic brain. In addition, HUCMSC transplantation promoted the formation of new vessels to increase local cortical blood flow in the ischemic hemisphere. Modulation by stem cell-derived macrophage/microglial interactions, and increased beta1-integrin expression, might enhance this angiogenic architecture within the ischemic brain. Inhibition of beta1-integrin expression blocked local angiogenesis and reduced recovery from neurological deficit. In addition, significantly increased modulation of neurotrophic factor expression was also found in the HUCMSC transplantation group. In summary, regulation of beta1-integrin expression plays a critical role in the plasticity of the ischemic brain after the implantation of HUCMSCs.     

Anti-monocyte chemoattractant protein-1 gene therapy protects against focal brain ischemia in hypertensive rats.

Monocyte chemoattractant protein-1 (MCP-1) is expressed in the ischemic cortex after focal brain ischemia and appears to exacerbate ischemic damage. The authors examined the effect of gene transfer of dominant negative MCP-1, called 7ND, 90 minutes after induction of focal brain ischemia in hypertensive rats. Adenoviral vectors encoding mutant MCP-1 (Ad7ND; n = 11), or Escherichia coli beta-galactosidase (AdlacZ; n = 17) as control were injected into the lateral ventricle of male spontaneously hypertensive rats. Both AdlacZ (n = 12) and Ad7ND (n = 6) administration provided transgene expression as early as 6 hours after injection and the expression further increased on day 1, followed by a sustained detection on day 5. Five days after ischemia, infarct volume (75 +/- 13 mm, n = 5, mean +/- SD) significantly reduced to 72% of control (104 +/- 22 mm3, n = 5, P < 0.05) by 7ND gene transfer. Numbers of leukocytes in the vessels (48.3 +/- 32.9/cm2) and macrophage/monocyte infiltration (475.2 +/- 125.5/mm2) of the infarct area in the Ad7ND group were significantly less than those measured in the AdlacZ group (143.8 +/- 72.1/cm2 and 671.8 +/- 125.5/mm2, P < 0.05, respectively). In summary, the postischemic gene transfer of dominant negative MCP-1 attenuated the infarct volume and infiltration of inflammatory cells, suggesting potential usefulness of the anti-MCP-1 gene therapy.     

MIP-1alpha and MCP-1 Induce Migration of Human Umbilical Cord Blood Cells in Models of Stroke

Monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein (MIP-1alpha) are implicated in monocyte infiltration into the central nervous system (CNS) under pathological conditions. We previously showed that in vivo human umbilical cord blood cells (HUCB) migrate toward brain injury after middle cerebral artery occlusion (MCAO). We hypothesized that MCP-1 and MIP-1alpha may participate in the recruitment of HUCB towards the injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO), and 24 hours later the production of MCP-1 and MIP-1alpha in the brain was examined with immunohistochemistry, ELISA, and western blotting. The chemotactic effect of MCP-1 and MIP-1alpha, and the expression of MCP-1 receptor CCR2 and MIP-1alpha receptor CCR1, CCR5 on the surface of HUCB were also examined. MCP-1 and MIP-1alpha expression were significantly increased in the ischemic hemisphere of brain, and significantly promoted HUCB cell migration compared to the contralateral side. This cell migration was neutralized with polyclonal antibodies against MCP-1 or MIP-1alpha. Also chemokine receptors were constitutively expressed on the surface of HUCB cells. The data suggested that the increased chemokines in the ischemic area can bind cell surface receptors on HUCB, and induce cell infiltration of systemically delivered HUCB cells into the CNS in vivo.     

小檗碱对大鼠脑缺血后MCP-1表达的影响

目的探讨小檗碱处理对大鼠脑缺血后单核细胞趋化蛋白-1（MCP-1）表达的影响及小檗碱对脑缺血的神经保护作用。方法建立大鼠短暂性全脑缺血模型，采用尼氏体亚甲蓝染色观察脑缺血后大鼠脑海马CA1区神经元存活情况；采用免疫荧光染色方法检测脑缺血后大鼠缺血脑组织中MCP-1的表达情况。结果（1）与假手术组比较，脑缺血组大鼠脑海马CA1区神经元明显缺失，而小檗碱处理组大鼠脑海马CA1区神经元存活数明显多于缺血对照组；（2）与假手术组比较，脑缺血组大鼠脑缺血区MCP-1表达显著增多，而小檗碱处理显著降低了大鼠脑缺血区MCP-1的阳性表达。结论脑缺血引起MCP-1表达上调，提示MCP-1可能参与脑缺血损伤。小檗碱可抑制缺血脑组织MCP-1的表达，推测其可能经此途径减轻脑缺血的炎症反应而发挥一定的神经保护作用。     

Mesenchymal stem cell transplantation modulates neuroinflammation in focal cerebral ischemia: contribution of fractalkine and IL-5

Mesenchymal stem cells (MSCs) are reported to possess immunomodulatory properties. Previous reports have demonstrated the beneficial effects of MSC-transplantation in focal cerebral ischemia animal models. In this study, we have investigated the neuroimmunomodulatory functions of human MSCs, transplanted in a rat focal ischemia model of transient middle cerebral artery occlusion (MCAO). Our results revealed that in a human mesenchymal stem cell line, B10 cell transplantation decreased the accumulation of Iba-1(+) microglia and GFAP(+) astrocytes, and inhibited proinflammatory gene expression in the core and ischemic border zone (IBZ). Among the proinflammatory genes iNOS, which was expressed in microglia/macrophage, was persistently inhibited up to 7days after MCAO. In vivo laser capture microdissection and double immunofluorescence staining, and in vitro B10 cell culture experiments showed that, in inflammatory conditions, B10 cells expressed cytokines and growth factors including IL-5, fractalkine, IGF-1, GDNF and VEGF. Fractalkine and IL-5 inhibited cytokine-induced proinflammatory gene expression including iNOS in a human microglia cell line. Thus, our results demonstrate that MSC transplantation suppresses MCAO focal ischemia-induced inflammation, possibly through expression of fractalkine and IL-5.