急性脊髓损伤模型大鼠白细胞介素1β和核因子κB的表达

背景：在脊髓损伤后的继发性损伤过程中,白细胞介素1β参与刺激其他细胞因子和损伤介质的合成。 目的：观察白细胞介素1受体拮抗剂对急性脊髓损伤模型大鼠损伤脊髓白细胞介素1β与核因子κB表达的影响。 方法：采用改良Allen法建立SD大鼠急性脊髓损伤模型,造模后分别在损伤处敷含白细胞介素1受体拮抗剂或仅有生理盐水的明胶海绵,于脊髓损伤1,48,72 h取损伤段脊髓标本,免疫组织化学染色检测白细胞介素1β与核因子κB的表达。 结果与结论：经白细胞介素1受体拮抗剂治疗后,损伤脊髓组织白细胞介素1β和核因子κB的表达均显著降低。说明白细胞介素1受体拮抗剂可通过抑制白细胞介素1β和核因子κB的表达,减轻局部炎症反应,对急性脊髓损伤大鼠损伤段脊髓发挥保护作用。     

睫状神经营养因子对坐骨神经切断吻合后大鼠脊髓前角胶质纤维酸性蛋白

背景：睫状神经营养因子具有多种生物活性,在神经系统发育、分化和损伤修复中具有重要意义。 目的：观察睫状神经营养因子对坐骨神经切断吻合后大鼠相应脊髓节段前角星形胶质细胞的特异标记物胶质纤维酸性蛋白表达的影响。 方法：将SD大鼠随机分为对照组、模型组、生理盐水组及药物组。除对照组外,对所有大鼠实施双侧坐骨神经切断吻合术,药物组手术区局部注射睫状神经营养因子100 ng/kg,1次/d,生理盐水组局部注射等量生理盐水。术后1,3,7,14,21,28 d取相应脊髓节段,免疫组织化学染色观察胶质纤维酸性蛋白的表达,苏木精-伊红染色、TUNEL染色对脊髓前角神经元进行计数。 结果与结论：大鼠坐骨神经切断吻合后相应脊髓节段星形胶质细胞胞体大,突起分枝多且粗大,神经元数目逐渐减少,凋亡神经元增多,胶质纤维酸性蛋白表达增高。与模型组和生理盐水组比较,药物组神经元存活数目增多,凋亡减少,胶质纤维酸性蛋白表达明显增加(P < 0.05或P < 0.01)。同时,药物组大鼠的运动功能障碍较轻,恢复较快。说明睫状神经营养因子可以通过促进大鼠脊髓前角胶质纤维酸性蛋白的表达起到神经保护作用。 关键词：胶质纤维酸性蛋白;睫状神经营养因子;星形胶质细胞;神经元凋亡;周围神经损伤     

脊髓损伤模型大鼠神经胶质细胞增殖与胶质纤维酸性蛋白的表达

背景：星形胶质细胞可以通过细胞裂解释放各种神经营养因子,并可促进损伤脊髓的修复。 目的：观察脊髓损伤模型大鼠神经胶质纤维酸性蛋白的表达及对其后肢功能恢复的影响。 方法：将SD大鼠采用Allen's法撞击T9~10节段致脊髓损伤,造模成功后蛛网膜下腔移植骨形态发生蛋白7,并设置仅蛛网膜下腔移植His蛋白的正常SD大鼠做对照。用BBB评分法评估两组大鼠后肢的运动功能,用免疫组织化学染色法和Western-blot法观察各组神经胶质纤维酸性蛋白的表达。 结果与结论：BBB评分结果显示,模型组大鼠脊髓损伤后下肢功能自行恢复率达68%。模型组脊髓损伤3和7 d,损伤区域神经胶质纤维酸性蛋白表达逐渐增加(P < 0.05),随后逐渐下降,于脊髓损伤28 d后逐渐恢复到对照组水平(P > 0.05)。脊髓损伤后1~14 d两组胶质纤维酸性蛋白表达逐渐升高(P > 0.05)。结果证实,脊髓损伤后蛛网膜下腔移植骨形态发生蛋白7可诱导星形胶质细胞增殖,神经胶质纤维酸性蛋白的表达增强,进而促进脊髓损伤大鼠后肢功能的恢复。     

异体骨髓间充质干细胞移植治疗大鼠脊髓损伤

背景：脊髓损伤的修复目前尚无良好的治疗手段,细胞移植能促进神经轴突再生及脊髓功能恢复,为治疗脊髓损伤提供了可能,但因脊髓损伤模型及移植方式不同,其治疗效果并不相同。 目的：验证异体骨髓间充质干细胞移植对大鼠脊髓损伤的治疗作用。 方法：全骨髓贴壁法分离大鼠骨髓间充质干细胞。健康SD大鼠随机分为3组,细胞移植组、对照组和假手术组。细胞移植组和对照组采用改良Allen重物打击法制造大鼠脊髓损伤模型,假手术组仅暴露脊髓。术后4周,每周进行运动功能评分,ELISA检测脊髓损伤组织中脑源性神经营养因子、神经生长因子表达;免疫荧光染色检测脊髓组织中NF200和胶质纤维酸性蛋白表达。 结果与结论：与对照组比较,细胞移植组大鼠运动功能明显改善,脊髓组织中脑源性神经营养因子、神经生长因子蛋白含量明显增高(P < 0.05);移植组大鼠脊髓囊腔较小,NF200表达明显增加,胶质纤维酸性蛋白表达减少。提示异体骨髓间充质干细胞移植能增加损伤脊髓神经生长因子含量,抑制胶质瘢痕形成,促进神经轴突再生,改善大鼠脊髓损伤后运动功能恢复。     

胶质细胞源性神经营养因子缓释微球及NogoA, ChABC缓释微球联合应用损伤脊髓再生的形态学变化*☆

摘要 背景：促进轴突再生的原则是改善抑制再生的环境和提高轴突生长能力,措施主要有轴突生长抑制因子阻滞剂和神经营养因子应用。用可降解微球加载药物是一种在局部提供持续药物释放的方法。 目的：探讨胶质细胞源性神经营养因子、NogoA、ChABC 缓释微球联合应用促进大鼠损伤脊髓再生病理形态学修复的作用。 方法：建立SD大鼠T10 脊髓完全横断伤模型,分别在损伤局部给予生理盐水、胶质细胞源性神经营养因子、胶质细胞源性神经营养因子缓释微球、NogoA缓释微球、ChABC 缓释微球及3种微球联合治疗,并设立未造模的正常组及假手术组。损伤后10周,每组行四甲基若丹明葡聚糖胺顺行示踪,及神经丝蛋白200、生长相关蛋白43、胶质细胞源性神经营养因子免疫组化检查,并采用免疫组化图像分析系统进行定量分析。 结果与结论：胶质细胞源性神经营养因子、NogoA、ChABC 缓释微球联合能提高脊髓损伤局部神经丝蛋白200、生长相关蛋白43、胶质纤维酸性蛋白的表达水平,显示局部脊髓再生修复加强,其效果优于单用胶质细胞源性神经营养因子缓释微球。提示,胶质细胞源性神经营养因子缓释微球及NogoA,ChABC 缓释微球联合促大鼠损伤脊髓再生修复其效果优于单用胶质细胞源性神经营养因子缓释微球。 关键词：胶质细胞源性神经营养因子;微球;聚乳酸-聚羟基乙酸共聚物;脊髓损伤;神经再生 doi:10.3969/j.issn.1673-8225.2011.03.014     

HIF-1α基因修饰神经干细胞移植对大鼠损伤脊髓NF200和GFAP表达的影响

【摘要】目的研究低氧诱导因子-1α（HI-1α）基因修饰的神经干细胞移植对大鼠脊髓损伤后神经丝蛋白200（NF200）和胶质纤维酸性蛋白（GFAP）表达的影响及意义。方法采用电控脊髓损伤打击装置制作大鼠脊髓损伤模型。按随机数字表将120只SD大鼠平均分为4组：假手术组（Sham组）,单纯损伤组（SCI组）,神经干细胞组（NSC组）和HIF-1α基因修饰NSC组（HIF—NSC组）。应用免疫组化法检测受伤脊髓中HIF-1α、NF200和GFAP的表达。结果HIF-NSC组中HIF-1αt免疫阳性细胞平均光密度值比其他各组各时间点均高（P〈O．01）,且表达高峰延迟至移植后14d;除第1天外,HIF—NSC组NF200表达比SCI组和NSC组明显增高（P〈0．05）,移植后28dNF200免疫阳性轴突数目也比SCI组和NSC组明显增多（P〈0．01）;移植后7d、14d、28dGFAP免疫阳性细胞面积均比SCI组和NSC组明显减少（P〈0．01）。结论HIF-1α基因修饰NSC移植可引起HIF-1α在损伤脊髓内有效表达,且能明显的促进NF200的表达,并能在脊髓损伤的后期抑制GFAP的表达。这提示HIF-1α基因修饰的NSC移植可减少受伤脊髓中胶质细胞的增生和胶质疤痕的形成,促进轴突再生。     

PPAR-γ对大鼠脊髓损伤后神经功能影响的研究

目的观察PPAR-γ对大鼠脊髓损伤后GFAP(胶质纤维酸性蛋白)及新生星形胶质细胞表达的影响。方法 SD大鼠108只,分成损伤组、PPAR-γ激动剂及拮抗剂治疗组。损伤后观察BBB评分、GFAP及新生星形胶质细胞的表达。结果激动剂治疗组BBB(BBB运动功能评分)及GFAP表达较损伤组GFAP的表达在1~2 w时间点内表达增加(P0.05),拮抗剂治疗组GFAP的表达较脊髓损伤组GFAP的表达在1~4 w时间点内表达减少(P0.05)。激动剂组新生星形胶质细胞在1~2 w明显增加(P0.05),而拮抗剂治疗组表达明显减少(P0.05),有统计学差异。结论 PPAR-γ激活后促进GFAP及星形胶质细胞的表达,起到神经保护作用。     

miRNA-9修饰骨髓间充质干细胞治疗大鼠脊髓损伤的实验研究

目的 通过观察miRNA-9在骨髓间充质干细胞(MSCs)分化为神经元过程中的作用,探讨基因修饰在脊髓损伤治疗中的作用.方法 分离培养大鼠MSCs并构建miRNA-9-1慢病毒载体.成功建立84只大鼠急性脊髓损伤模型,并按照随机数字表法分为对照组、MSCs组及miRNA组,每组28只.脊髓损伤后1周,对MSCs组大鼠进行MSCs移植,对miRNA组大鼠移植miRNA-9-1慢病毒载体感染的MSCs,对照组大鼠仅在损伤部位注射等量的生理盐水.选择不同时间点对大鼠后肢进行Basso Beattie Bresnahan(BBB)评分,并行神经丝蛋白200(NF-200)和胶质纤维酸性蛋白(GFAP)免疫组织化学染色,对各组阳性表达面积百分比进行比较.结果 细胞移植4周后,各组大鼠BBB评分差异有统计学意义,其中miRNA组评分较MSCs组及对照组明显提高,差异有统计学意义(P＜0.05).免疫组织化学染色示miRNA组的NF-200阳性面积较MSCs组及对照组明显增大,GFAP阳性面积较MSCs组及对照组明显减小,各组间的差异具有统计学意义(P＜0.05).结论 miRNA-9在MSCs横向分化为神经元中起重要调控作用,并通过促进轴突再生,减少脊髓损伤部位反应性胶质细胞的数量等机制促进脊髓损伤后的功能修复.     

重组人粒细胞集落刺激因子对实验性脑出血大鼠星形胶质细胞表达的影响

背景：星形胶质细胞是中枢神经系统的主要成分之一,具有对各种损伤产生强烈反应的特性,脑出血后星形胶质细胞大量表达、活性增强,这种由常态转变为反应性状态的星形胶质细胞的病理生理学意义是目前研究热点。 目的:探讨重组人粒细胞集落刺激因子对脑出血后星形胶质细胞表达的影响。 设计、时间及地点：随机对照动物实验,于2006-03/11在泸州医学院中心实验室完成。 材料：清洁级健康雄性SD大鼠50只,随机分为3组：假手术组10只、模型组20只、实验组20只。重组人粒细胞集落刺激因子为深圳新鹏生物工程有限公司产品。 方法：模型组、实验组利用鼠脑立体定向仪、采用断尾取自体血法制备脑出血动物模型,假手术组用等量生理盐水代替自体血,余干预措施与模型组一致。造模1 h后,实验组大鼠腹腔注射重组人粒细胞集落刺激因子 60 μg/kg,余2组未注射任何物质。 主要观察指标：分别于干预后6 h,24 h,48 h,72 h,7 d采用免疫组织化学ABC法检测胶质纤维酸性蛋白阳性细胞的表达。 结果：假手术组未见胶质纤维酸性蛋白阳性细胞的表达。模型组干预6 h即有少量胶质纤维酸性蛋白阳性细胞表达,48 h后开始增多,至72 h胶质纤维酸性蛋白阳性细胞数量达高峰(P < 0.05),7 d后仍有大量胶质纤维酸性蛋白阳性细胞表达,但较72 h时有所减少。实验组干预6 h时胶质纤维酸性蛋白阳性细胞的表达与模型组相似,干预24 h,48 h,72 h,7 d时胶质纤维酸性蛋白阳性细胞较模型组明显减少( P < 0.05),细胞变形程度减轻。 结论：重组人粒细胞集落刺激因子能够抑制脑出血后星形胶质细胞的过度活化,可能对损伤脑组织重建和功能恢复起重要作用。     

半乳糖凝集素-1对急性脊髓损伤模型大鼠的保护作用及其机制

目的研究半乳糖凝集素-1(Galectin-1)对大鼠急性脊髓损伤的保护作用及其机制。方法 45只SPF级SD大鼠随机平均分为Galectin-1组、甲泼尼龙(MP)组和生理盐水对照组(生理盐水组)。以Allen's法打击脊髓造模,分别在术后1 d、7 d、14 d每组各取5只大鼠,先做BBB评分及斜板试验,然后处死大鼠取损伤处脊髓组织进行苏木精-伊红(HE)染色及胶质纤维酸性蛋白(GFAP)免疫组化染色检测,同时用酶联免疫吸附测定(ELISA)法检测血清白细胞介素-10(IL-10)的含量。结果术后1 d,3组大鼠BBB评分、斜板试验结果及血清IL-10含量的差异无统计学意义(均P0.05);术后7 d、14 d,MP组和Galectin-1组的BBB评分、斜板试验结果及血清IL-10含量均较生理盐水组高(均P0.05),而MP组与Galectin-1组之间的差异均无统计学意义(均P0.05)。HE染色显示术后各时间点,Galectin-1组和MP组脊髓损伤肿胀及出现核固缩或解离神经元的数量少于生理盐水组。术后1 d,3组大鼠脊髓星形胶质细胞(GFAP表达阳性)数量无明显区别;术后7 d、14 d,Galectin-1组及MP组明显多于生理盐水组,而Galectin-1组与MP组则无明显差别。结论Galectin-1对大鼠急性脊髓损伤具有一定的保护作用,其机制可能是通过增强机体IL-10的表达,从而抑制损伤后的炎症反应而发挥脊髓保护作用的。     

硫氧还原蛋白结合蛋白基因多态性与精神分裂症的关联分析

目的探索硫氧还原蛋白结合蛋白（TXNIP）基因与精神分裂症的关联关系。方法以182个精神分裂症核心家系为研究对象，应用聚合酶链反应和限制性片段长度多态性技术（PCR-RFLP）对TXNIP基因标签单核苷酸多态性（htSNP）rs9245进行基因分型；使用传递不平衡（TDT）、基于单体型的单体型相对危险度分析（HHRR）检测TXNIP基因与精神分裂症之间的关联关系。结果①患者组、父母组htSNP rs9245位点各基因型的分布均符合Hardy-Weinberg平衡法则（矿值分别为0．68，0．02，df=1，P〉0．05）；②单体型相对风险分析（HHRR）显示htSNP rs9245位点等位基因在患者组和父母组的频数分布为χ^2=3．42，P=0．064；③传递不平衡检验（TDT）分析显示，杂合子父母传递给受累子女与非传递等位基因频率分布为χ^2=3．40，P=0．065，虽然差异未达到显著性，但接近边缘显著性。结论本研究虽未发现TXNIP基因htSNP rs9245与精神分裂症的发生存在关联，但不能排除两者的阳性关联，尚需选择更多SNP及扩大样本量进一步分析。     

Immunocytochemical demonstration of interphotoreceptor retinoid-binding protein in cerebellar medulloblastoma

Summary Previously, immunoreactive rod-opsin and S-antigen (arrestin), two highly characteristic markers of retinal photoreceptors and pinealocytes, were shown to be present in certain medulloblastoma cells. It, thus, has been suggested that such cells differentiate along the photoreceptor lineage. This is corroborated in the present immunocytochemical investigation using antibodies against another photoreceptor-cell marker, the interphotoreceptor retinoid-binding protein (IRBP). As shown in preparations of human retina and pineal organ, IRBP can be successfully demonstrated in formalinfixed and paraffin-embedded tissue: the IRBP immunoreaction is located to the outer and inner segments of retinal photoreceptor cells and to perikarya of certain pinealocytes. Examination of formalin-fixed, paraffinembedded biopsy specimens of 66 cerebellar medulloblastomas revealed varying numbers of IRBP-immunoreactive tumor cells in 19 cases that were formerly shown to contain rod-opsin and S-antigen immunoreaction. IRBP-immunoreactive tumor cells were also found in a retinoblastoma and a pineocytoma, but not in neuroblastoma, ganglioneuroblastoma, glioblastoma, oligodendroglioma and astrocytoma. The results indicate: (1) cerebellar medulloblastomas are heterogeneous in their differentiation potential; (2) one type of medulloblastoma displays photoreceptor characteristics; (3) this type appears to be closely related to retinoblastoma and pineal cell tumors; and (4) all three types of tumors may display additional common features to be explored in future studies.     

Activation of mitogen-activated protein kinases in experimental cerebral ischemia

OBJECTIVES: Mitogen-activated protein kinases (MAPK) regulate cell survival and differentiation. The aim of the present study is to investigate the activation pattern of different MAPKs [extracellular signal-regulated kinase (ERK), c-jun-N-terminal kinase (JNK) and p38] after cerebral ischemia. MATERIAL AND METHODS: Rats were subjected to cerebral ischemia using a model for transient (2 h) and permanent middle cerebral artery occlusion (MCAO). The rats were allowed 6 h to 1 week of survival before immunohistochemical evaluation with phospho-specific antibodies, recognizing activated MAPKs. RESULTS: ERK was activated in ipsilateral blood vessels, neurons and glia, but also in contralateral vessels. JNK activation was absent in neurons but appeared in arterial blood vessels and glia at the lesion side. Active p38 was observed in macrophages in maturing infarcts. CONCLUSIONS: ERK and JNK may participate in the angiogenic response to cerebral ischemia. ERK, but not JNK, was activated in neurons, possibly indicating a pathophysiologic role. Active p38 might be involved in the inflammatory reaction.     

An immunohistochemical study of glial fibrillary acidic (GFA) protein and S-100 protein in the colon affected by Hirschsprung's disease

Summary The supportive cells of the enteric nervous system were examined in gut tissues from 15 patients with Hirschsprung's disease by means of immunohistochemistry, utilizing antisera to glial fibrillary acidic (GFA) protein and S-100 protein. In the normoganglionic segment, GFA protein immunoreactivity was predominantly found in association with the myenteric plexus and to a lesser extent in the submucous plexus. On the other hand, the extrinsic, hypertrophic nerve fasciculi were selectively immunostained with GFA protein antiserum throughout the entire length of the aganglionic intestinal walls from all children studied. The large fasciculi were numerous in the distal aganglionic segment and commonly appeared in the intermuscular zone and submucosal connective tissue. Both small-and mediumsized nerve fasciculi with GFA protein immunoreactivity were also encountered within the circular muscle layer of the proximal aganglionic segment. A subpopulation of supportive cells within the hypertrophic nerve fasciculi showed immunoreactivity for GFA protein, while all supportive elements of these fasciculi were stained for S-100 protein. The intrinsic nerve fibers within the circular muscle layer of normoganglionic segments were stained for S-100 protein, but not for GFA protein. The present study supports our previous findings that two types of supportive cells can be differentiated by immunohistochemistry in the enteric nervous system, utilizing antisera to GFA protein and S-100 protein. It is also concluded that the demonstration of GFA protein by immunohistochemical methods favors the diagnosis of aganglionic colons with Hirschsprung's disease, since GFA protein immunoreactivity is confined to the extrinsic, hypertrophic nerve fasciculi characteristic of aganglionic bowels.     

Region-specific immunoassays for human myelin basic protein

Three monoclonal antibodies reactive with human myelin basic protein have been used to develop immunoradiometric assays for this protein. Clone 1, a mouse IgG2a, is reactive with an epitope in the region 129-138. Clone 2, a mouse IgG1, is reactive with the region 119-131. Clone 12, a rat IgG, is reactive with the region 86-96. Competition experiments show that the reactions of Clone 1 and Clone 2 are mutually exclusive, probably because of steric effects. In contrast, when either Clone 1 or Clone 2 react they cause minimal interference with the subsequent binding of Clone 12. Less than 1 ng/ml of myelin basic protein can be detected in each of the two immunoradiometric assays developed. Clone 12 can also be used on its own in a competitive immunoassay to detect around 2 ng/ml. Using an extraction technique before the assay, serum or plasma can also be investigated. Assays for defined regions of myelin basic protein should prove valuable in identifying the products of myelin catabolism in patients with demyelinating disease.     

Brain injury-dependent expression of activity-dependent neuroprotective protein

Activity-dependent neuroprotective protein (ADNP), a crucial brain development factor, contains a unique sequence, termed NAPVSIPQ, which protects mice against closed head injury (CHI). The aim of this study was to determine whether CHI affects ADNP mRNA expression in the injured brain hemisphere. Male C57JBL/6J mice were subjected to CHI. Brains were removed 5 h, 24 h, 7 d, and 29 d post-CHI. A comparison was made between ADNP mRNA in the injured versus the noninjured hemisphere using real-time polymerase chain reaction. A nonsignificant change (p>0.05) was found 5 h, 24 h, and 7 d post-CHI. However, a significant increase (p < 0.05) in ADNP mRNA expression was detected in the injured cerebral hemisphere 29 d post-CHI. The data presented may be associated with ADNP’s crucial involvement in brain development and response to injury.     

Light microscopy of GTP-binding protein (Go) immunoreactivity within the retina of different vertebrates

To examine species differences in the distribution pattern of guanosine triphosphate (GTP)-binding protein (Go) within the vertebrate retina, paraffin-embedded retinae from a number of vertebrate species, including the goldfish, frog, turtle, chicken, monkey, and human, were immunohistochemically stained with affinity-purified antibody against the alpha-subunit of Go. Go-immunoreactive products were found to be located in the neuropil, but not in the cell bodies of neurons, in the retina of all these species. However, some species differences were observed. In the frog, monkey and human, the inner plexiform layer (IPL) was homogeneously stained with this antibody, but in the goldfish, turtle and chicken, the IPL was heterogeneously stained. In the frog, chicken, turtle and human, the outer plexiform layer (OPL) was densely stained with this antibody, but in the goldfish and monkey, the OPL was rather faintly immunoreactive to the antibody. In the goldfish, monkey and human, the outer nuclear layer (ONL) was not immunoreactive to the Go-antibody, whereas in the frog, turtle and chicken, the ONL was immunoreactive to it. The implications of these species differences in Go localization in the vertebrate retina are discussed.     

The role of low-density receptor-related protein 1 (LRP1) as a competitive substrate of the amyloid precursor protein (APP) for BACE1

Cleavage of APP by BACE1 is the first proteolytic step in the production of amyloid-beta (Aβ), which accumulates in senile plaques in Alzheimer's disease. Through its interaction with APP, the low-density receptor-related protein 1 (LRP1) enhances APP internalization. Recently, BACE1 has been shown to interact with and cleave the light chain (lc) of LRP1. Since LRP1 is known to compete with APP for cleavage by gamma-secretase, we tested the hypothesis that LRP1 also acts as a competitive substrate for β-secretase. We found that the increase in secreted APP (sAPP) mediated by over-expression of BACE1 in APP-transfected cells could be decreased by simultaneous LRP1 over-expression. Analysis by multi-spot ELISA revealed that this is due to a decrease in sAPPβ, but not sAPPα. Interaction between APP and BACE1, as measured by immunoprecipitation and fluorescence lifetime assays, was impaired by LRP1 over-expression. We also demonstrate that APP over-expression leads to decreased LRP1 association with and cleavage by BACE1. In conclusion, our data suggest that - in addition to its role in APP trafficking - LRP1 affects APP processing by competing for cleavage by BACE1.