β-七叶皂甙钠对脑出血大鼠的神经保护作用

目的探讨β-七叶皂甙钠对脑出血后血肿周围肿瘤坏死因子(TNF-α)表达及神经元凋亡的影响。方法实验大鼠随机分为假手术组、模型组、β-七叶皂甙钠治疗组,采用自体血注射法制作脑出血模型,术后2 h七叶皂甙钠组腹腔注射β-七叶皂甙钠(3.0 mg/kg),另2组给予等量生理盐水,连续用药(1次/d),给药后12 h、24 h、3 d和7 d分别用免疫组化法与TUNEL法检测肿瘤坏死因子的表达和神经元的凋亡情况。结果与假手术组比较,模型组TNF阳性细胞数以及凋亡的神经元明显增多(P<0.01);与模型组比较,七叶皂甙钠组血肿周围肿瘤坏死因子表达与神经元的凋亡明显下降(P<0.01,P<0.05)。结论β-七叶皂甙钠对脑出血后神经细胞损伤具有保护作用,其机制可能与抑制TNF的表达,减少神经元的凋亡有关。     

嗅鞘细胞移植联合应用督脉电针对大鼠脊髓损伤后脊髓诱发电位的影响※

背景：对于嗅鞘细胞移植治疗脊髓损伤的疗效目前尚无共识,或许单一细胞移植可能并不是修复脊髓损伤的最佳选择。如何选择适当的干预手段予以联合应用,并使之实现从实验室走向临床应用是细胞移植策略中的重点问题。 目的：探讨大鼠嗅鞘细胞移植与督脉电针联合应用修复大鼠脊髓损伤的可行性。 设计、时间及地点：随机对照动物实验,于2007-08/2008-08在清华大学二附院脑神经病研究所实验室完成。 材料：成年雄性Wistar大鼠70只,取10只用于制备嗅鞘细胞,剩余60只随机分为4组：模型对照组、嗅鞘细胞移植组、督脉电针组、联合组,15只/组。 方法：各组大鼠均建立脊髓全横断模型。造模后暴露脊髓,嗅鞘细胞移植组、联合组向填入脊髓横断处的明胶海绵内缓慢注射嗅鞘细胞悬液10 μL;模型对照组、督脉电针组同法注射等量DMEM-F12培养液。从造模成功后第2天开始,督脉电针组、联合组动物接受1次/d的督脉电针治疗,选大椎穴(DU14)、命门穴(DU4)进行针刺,针刺深度5 mm,大椎穴接正极,命门穴接负极,电针15 min,电针频率20 Hz,持续脉冲电流12~15 mV,连续7 d为1个疗程,疗程间隔2 d。 主要观察指标：造模后BBB运动功能评分的变化,脊髓诱发电位检测结果。 结果：各组动物均成活10周。与模型对照组比较,造模后4~10周嗅鞘细胞移植组、督脉电针组、联合组BBB运动功能评分均明显升高(P < 0.05),且联合组升高幅度明显高于嗅鞘细胞移植组、督脉电针组(P < 0.05)。与模型对照组比较,造模后4~10周嗅鞘细胞移植组、督脉电针组、联合组波幅电压明显升高(P < 0.05或P < 0.01),反应潜伏期均明显降低(P < 0.05或P < 0.01),且联合组差异变化尤为显著。嗅鞘细胞移植组与督脉电针组各指标之间比较无明显差异(P > 0.05)。 结论：嗅鞘细胞移植和督脉电针联合应用可促进脊髓损伤大鼠神经突触的再生,改善其肢体运动功能。     

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。     

亚低温联合β-七叶皂甙钠对实验性脑出血后AQP4表达及脑水肿的影响

目的 研究亚低温、β-七叶皂甙钠及二者联合对大鼠实验性脑出血后AQP4表达及脑水肿的影响.方法 270只健康成年SD大鼠随机分为假手术组30只,对照组、亚低温组、β-七叶皂甙钠组及联合组各60只,每组又分为5个亚组,分别于造模后1,2,3,5,7d断头取脑,其中半数大鼠进行脑含水量测定,另一半大鼠作免疫组织化学分析.在大鼠苍白球注射胶原酶制作脑出血模型,用冰块降温及白炽灯调整与动物距离照射加温的方法调节体温,采用干湿重法观察脑水肿的变化;应用免疫组织化学方法检测脑组织AQP4表达.结果 在各个时间点脑出血模型大鼠病灶侧脑含水量及AQP4的表达均明显高于假手术组(均P＜0.01),而亚低温组、七叶组及联合组均明显低于对照组(均P＜0.05);联合组在出血后5,7d病灶侧脑含水量及AQP4的表达均低于亚低温组及七叶组(均P＜0.05); AQP4表达水平与脑含水量呈正相关(r=0.970,P＜0.01).结论 亚低温及β-七叶皂甙钠均能明显减轻大鼠脑出血后脑水肿,而二者联合可能起到协同作用;亚低温及β-七叶皂甙钠可能通过抑制AQP4的表达而减轻脑水肿.     

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。     

嗅鞘细胞移植脊髓全横断损伤大鼠大脑皮质运动区转化生长因子β表达的影响☆

背景：多项研究已证实嗅鞘细胞能促进脊髓损伤大鼠神经功能的恢复,但其分子机制还不清楚。 目的：观察嗅鞘细胞移植对脊髓全横断大鼠大脑皮质运动区转化生长因子β mRNA表达的影响。 方法：采用酶消化法培养GFP转基因小鼠嗅鞘细胞,制成细胞悬液。建立SD大鼠T9脊髓全横断模型,造模后分为假手术组、模型组和嗅鞘细胞移植组。应用RT-PCR方法检测各组大鼠大脑皮质运动区转化生长因子β mRNA的表达变化,用β-actin作内参。 结果与结论：模型组大鼠造模后3 d大脑皮质运动区转化生长因子β mRNA的表达量高于假手术组(P < 0.05),造模后7,14,21和28 d回到假手术组水平。嗅鞘细胞移植后21 d,嗅鞘细胞移植组转化生长因子β mRNA的表达量低于模型组(P < 0.05)。提示全横断脊髓损伤致大脑皮质运动区转化生长因子β mRNA早期表达上调,随后与假手术组相比无差别;嗅鞘细胞移植后期可逆转转化生长因子β mRNA的表达变化,有助于脊髓损伤的恢复。     

抑制基质金属蛋白酶-9可延长大鼠脑栓塞后尿激酶溶栓时间窗

目的研究基质金属蛋白酶抑制剂强力霉素和三七皂甙对大鼠脑栓塞后不同时间尿激酶静脉溶栓效果及并发症的干预作用,评价基质金属蛋白酶抑制剂对尿激酶溶栓治疗时间窗的干预效果。方法采用大鼠自体血栓塞大脑中动脉闭塞(MCAO)模型,分别用免疫组织化学法、TTC染色、伊文氏蓝法和分光光度计法对基质金属蛋白酶-9(MMP-9)、脑梗死体积、血脑屏障通透性和脑出血量进行检测。结果相应时间段尿激酶(UK)溶栓组与缺血对照组比较MMP-9表达显著增高,血脑屏障通透性和脑出血量均有增加趋势,以12h UK组明显;6h UK组较缺血对照组脑梗死体积明显降低。强力霉素和三七皂甙联合尿激酶治疗的各组与相应时间点单用尿激酶组比较MMP-9表达显著降低,脑梗死体积明显下降,血脑屏障通透性和脑出血量均有改善。结论基质金属蛋白酶抑制剂联合溶栓治疗,提高溶栓疗效,减轻溶栓后血脑屏障破坏和出血性转化,可能有延长溶栓治疗时间窗的作用。     

蛛网膜下腔移植自体激活许旺细胞治疗大鼠脊髓损伤***

背景：许旺细胞能够分泌多种神经营养因子,促进脊髓损伤功能的恢复。但异体许旺细胞移植可引发自身免疫反应,且在移植方式上,局部移植无法避免二次损伤,静脉移植虽可以透过血脊髓屏障到达损伤局部,但不能达到有效的治疗浓度。 目的：探讨经蛛网膜下腔移植自体激活许旺细胞对脊髓损伤大鼠功能恢复的影响。 方法：66只大鼠均建立脊髓损伤模型,造模后随机分为3组,自体激活许旺细胞组通过结扎单侧隐神经从而激活许旺细胞,自体未激活许旺细胞组、模型对照组仅在相同部位手术但不结扎神经。切除各组手术远端1 cm神经,采用组织块法进行许旺细胞的体外分离培养及纯化。1周后,自体激活许旺细胞组、自体未激活许旺细胞组分别通过蛛网膜下腔注入经Hoechst33342标记的对应许旺细胞悬液,模型对照组仅注入等量DMEM。对脊髓损伤后肢体功能的恢复进行BBB运动功能评分及脚印分析,通过苏木精-伊红染色和GFAP染色从组织学角度评价脊髓损伤恢复情况。 结果与结论：从术后第4周开始,自体激活许旺细胞组BBB后肢功能评分明显优于另两组(P < 0.05)。移植后2周,可见迁移至大鼠脊髓损伤局部的许旺细胞。与自体未激活许旺细胞组比较,移植后5周自体激活许旺细胞组的前后足中心距离、后肢第3足趾外旋角度均显著减小(P < 0.05),移植后13周损伤区胶质瘢痕面积明显减小(P < 0.05),损伤区空洞面积明显减小(P < 0.05)。证实经蛛网膜下腔移植自体激活许旺细胞可以促进脊髓损伤的恢复。     

脑缺血再灌注大鼠细胞间黏附分子-1、血管细胞间黏附分子-1的表达及β-七叶皂甙钠的干预作用

目的研究局灶性脑缺血再灌注过程中脑缺血区细胞间黏附分子-1(ICAM-1)、血管细胞间黏附分子-1(VCAM-1)的表达规律，并探讨β-七叶皂甙钠对其干预的脑保护作用。方法采用线栓法建立大鼠脑缺血再灌注模型，同时应用β-七叶皂甙钠予以干预。用HE染色和免疫组化染色观察大鼠脑缺血后再灌注不同时点组织学改变和ICAM-1、VCAM-1的阳性表达。结果(1)β-七叶皂甙钠明显减轻缺血再灌注后的脑组织损伤；(2)脑缺血再灌注后缺血区微血管内皮细胞ICAM-1、VCAM-1表达增加，ICAM-1于再灌注后24h表达达高峰，VCAM-1.于再灌注后24～48h表达达高峰，随后降低，但再灌注后72h两者表达仍高于正常水平；(3)β-七叶皂甙钠可以显著降低脑缺血再灌注后24h、48h缺血区ICAM-1、VCAM-1的表达。结论脑缺血再灌注后ICAM-1、VCAM—1大量表达，可能是脑缺血再灌注损伤的机制之一；β-七叶皂甙钠能降低ICAM-1和VCAM-1的表达及减轻脑组织损伤，有脑保护作用。     

嗅黏膜嗅鞘细胞与肌基膜管联合移植修复脊髓损伤

目的：观察嗅黏膜来源的嗅鞘细胞与肌基膜管联合移植后对脊髓损伤的修复效果。 方法：1只SD大鼠行背正中切口，顺椎旁肌纤维切除约1.5 cm×0.8 cm×0.6 cm的肌条，复温、漂洗并挤压肌条以排出肌浆，制成肌基膜管。4只SD大鼠麻醉后取出嗅黏膜，胶原酶消化法分离培养嗅鞘细胞，调整浓度至1011 L-1。取SD大鼠50只，随机分成5组：嗅鞘细胞+肌基膜管联合组、嗅鞘细胞组、肌基膜管组、模型组、正常组，10只/组。除正常组外，其余组均建立脊髓损伤模型，于T10横断脊髓并切除约2 mm，将培养7 d的嗅鞘细胞与肌基膜管按组别分别植入脊髓断端，模型组用浸有DMEM的凝胶海绵桥接横断的脊髓。 结果：移植后第8周，嗅鞘细胞+肌基膜管联合组、嗅鞘细胞组大鼠运动功能明显恢复，出现大关节大幅度运动，且前者运动功能BBB评分升高尤为显著（P < 0.01）；肌基膜管组大鼠仅见小关节轻微活动；模型组大鼠后肢挛缩重，无明显功能恢复。嗅鞘细胞+肌基膜管联合组后肢体感诱发电位及运动诱发电位的潜伏期显著低于其他各组（P < 0.01）。苏木精-伊红染色和核转录因子免疫组化染色结果显示，嗅鞘细胞+肌基膜管联合组、嗅鞘细胞组的移植物与损伤脊髓整合较好，未见明显空洞，有大量染色呈阳性的纤维，纤维较长，由近侧端长入远侧端；肌基膜管组有空洞形成，染色阳性的纤维数量少，纤维细小且排列紊乱；模型组端断间充满瘢痕组织，未见明显染色阳性纤维。 结论：嗅鞘细胞移植可促进脊髓损伤后的轴突再生，肌基膜管作为一种生物管道，两者联合应用可明显促进脊髓损伤后的轴突再生及功能恢复。     

Matrix metalloproteinase-7 and matrix metalloproteinase-9 in pediatric multiple sclerosis

Matrix metalloproteinases and their tissue inhibitors play a key role in the pathogenesis of adult-onset multiple sclerosis, and were suggested as biomarkers of response to interferon-β, an established treatment in multiple sclerosis. However, data regarding pediatric population are scarce. We determined serum levels of matrix metalloproteinase-7, matrix metalloproteinase-9, and tissue inhibitor of matrix metalloproteinase-1 in children, and evaluated effects of interferon-β therapy on these measures. Serum samples from 14 children with relapsing, remitting multiple sclerosis at baseline and at month 12, and from 15 controls, were collected. Interferon-β treatment was initiated in eight patients. Mean serum matrix metalloproteinase-9 levels and matrix metalloproteinase-9/tissue inhibitor of matrix metalloproteinase-1 ratio were higher in patients compared with controls, and were reduced significantly in treated patients at month 12, but did not change in untreated patients. Mean matrix metalloproteinase-7 levels were lower in patients compared with controls, and increased significantly in the treated group, but did not change significantly in the untreated group. In pediatric multiple sclerosis, a shift in matrix metalloproteinase-9/tissue inhibitor of matrix metalloproteinase-1 balance toward proteolytic activity is evident, and interferon-β therapy demonstrates a beneficial effect on this disturbed balance.     

Increases in matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 mRNA after cerebral contusion and depolarisation

Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) play major roles in physiological extracellular matrix turnover during normal development and in pathological processes. In brain, increases in MMP activity occur, for example, in multiple sclerosis, Alzheimer's disease, and after head trauma. We examined MMP-9 and TIMP-1, -2, and -3 in events after head trauma. A time-course study was carried out using two different rat injury models, cerebral contusion and depolarisation. Brains were analysed by RT-PCR and in situ hybridisation. We observed a distinct and time-dependent upregulation of MMP-9 and TIMP-1 mRNA in ipsilateral cortical areas. MMP-9 mRNA levels were upregulated 1 day after cerebral contusion with a peak at Day 4. Depolarisation per se, which also occurs after traumatic brain injury, lead to delayed increase of MMP-9 mRNA, 4 days post application. At Day 14, MMP-9 mRNA levels were indistinguishable from controls in both models. TIMP-1 mRNA increases were observed in both models 4 hr after injury, and increased further at Days 1 and 4. At Day 14, mRNA levels declined and were no higher than control levels. No alterations in mRNA levels were noted for TIMP-2 or -3. Our results support earlier reports on MMP-9 involvement in brain injury. It also shows a role for TIMP-1 in the mechanisms of trauma, where depolarisation could be the mechanism responsible for this upregulation.     

Matrix metalloproteinase-9 and matrix metalloproteinase-2 gene polymorphisms in multiple sclerosis

We investigated the association of matrix metalloproteinase-9 (-1562C/T, +279R/Q) and matrix metalloproteinase-2 (-1575G/A, -1306C/T) gene polymorphisms with multiple sclerosis (MS) susceptibility, gender differences and disability in 244 patients and 132 healthy subjects. A significant decrease of the -1562T allele carriers in MS patients compared to controls (Pa=0.01, Pacorr=0.05) in -1562C/T MMP-9 gene polymorphism was found, (odds ratio (OR) -0.58, 95% confidence interval (CI):0.38-0.89). Significant differences were also demonstrated between female patients and healthy females (Pa=0.01, Pacorr=0.05), (OR-0.53, 95% CI:0.32-0.86). Other polymorphisms were not associated either with MS susceptibility or with phenotype of the disease. No association with disability was found.     

基质金属蛋白酶-9在脑卒中的两面性

基质金属蛋白酶(matrix metalloproteinases,MMPs)是一组锌离子依赖的蛋白酶家族,是维持组织变构的重要酶类.     

Response of matrix metalloproteinase-9 to olfactory nerve injury

Matrix metalloproteinases function in the remodeling of the extracellular matrix during growth and development as well as in injury and disease processes. We examined the role of matrix metalloproteinase-9 in a model of olfactory nerve injury in mice. We measured changes in matrix metalloproteinase-9 protein levels for up to 60 days following olfactory nerve transection. Matrix metalloproteinase-9 levels increased within hours after injury, peaked at day 1 and were elevated for approximately 2 weeks before returning to control levels over the 60-day time period. The increase in matrix metalloproteinase-9 was temporally associated with the degeneration of olfactory neurons that follows nerve transection and with increased gliosis. Our results demonstrate a temporal relationship between matrix metalloproteinase-9 elevation, degeneration of olfactory neurons and gliosis.     

Serum matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels in non-herpetic acute limbic encephalitis

The pathogenesis of non-herpetic acute limbic encephalitis (NHALE) has been not clear. Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) play important roles in the function of the blood–brain barrier. We measured the serum concentrations of MMP-9 and TIMP-1 by using enzyme-linked immunosorbent assay (ELISA) in 23 patients with NHALE in the acute and convalescent stages. Serum MMP-9 concentrations and ratios of serum MMP-9/TIMP-1 were significantly higher (1) in patients with NHALE in acute and convalescent stages than in control patients (all P < 0.001); (2) in patients with NHALE at the acute stage compared with those at the convalescent stage (P = 0.004, and P = 0.014, respectively). In contrast, serum TIMP-1 concentrations were significantly lower in patients with NHALE in the acute and convalescent stages than in control patients (both P < 0.001) but did not differ in patients with NHALE in the acute and convalescent stages. Our preliminary study suggests that the prolonged imbalance of MMP-9 and TIMP-1 is associated with the pathogenesis of NHALE.