Experience-dependent expression of Nogo-A and Nogo receptor in the developing rat visual cortex

Nogo-A and Nogo receptor (NgR) expression in the visual cortex following a critical developmental period (postnatal days 20-60) has been previously shown. However, little is known regarding Nogo-A and NgR expression between postnatal day 0 and initiation of the critical period. The present study analyzed Nogo-A and NgR expression at four different time points: postnatal day 0 (P0), before critical period (P14), during critical period (P28), and after critical period (P60). Results showed significantly increased Nogo-A mRNA and protein expression levels in the visual cortex following birth, and expression levels remained steady between P28 and P60. NgR mRNA or protein expression was dramatically upregulated with age and peaked at P14 or P28, respectively, and maintained high expression to P60. In addition, Nogo-A and NgR expression was analyzed in each visual cortex layer in normal developing rats and rats with monocular deprivation. Monocular deprivation decreased Nogo-A and NgR mRNA and protein expression in the rat visual cortex, in particular in layers II-III and IV in the visual cortex contralateral to the deprived eye. These findings suggested that Nogo-A and NgR regulated termination of the critical period in experiencedependent visual cortical plasticity.     

甲基泼尼松龙对实验性变态反应性脑脊髓炎大鼠脑组织 Nogo-A 及其受体 NgR 蛋白表达的影响

目的 探讨甲基泼尼松龙(MP)对实验性变态反应性脑脊髓炎(EAE)大鼠脑组织Nogo-A及其受体(NgR)蛋白表达的影响.方法 将60只Wistar大鼠随机分为正常对照组(10只)和实验组(50只).实验组大鼠通过皮下注射粗制髓磷脂碱性蛋白建立EAE模型,24只造模成功大鼠随机分为EAE组、大剂量MP(MP-H)组和小...     

大鼠颅脑损伤后损伤脑组织Nogo-A及其受体的表达变化

目的探讨Nogo—A及其受体（NgR）在大鼠颅脑损伤后损伤脑组织的表达变化。方法将136只SD大鼠按随机数字表法分成对照组、假损伤组、轻型颅脑损伤组、中型颅脑损伤组、重型颅脑损伤组,采用自制改良的Feeney’s自由落体装置制作大鼠颅脑损伤模型;伤后12h、24h、3d、7d和14d采用免疫组化染色法检测损伤脑组织中Nogo—A和NgR蛋白的表达。结果伤后各时间点,各型颅脑损伤组Nogo—A表达水平均明显高于假损伤组（P〈0.05）;重型、中型、轻型颅脑损伤组之间Nogo—A表达均有显著差异（P〈0．05）。而NgR的表达水平则在伤后3、7、14d各型颅脑损伤组才明显高于假损伤组（P〈0．05）,各损伤组之间也有统计学差异（P〈0．05）。结论Nogo—A和NgR在不同程度的损伤脑组织中表达差异显著,且有各自的表达规律。     

Expression of Nogo-A mRNA after injury of the rat central nervous system

BACKGROUND： Nogo protein has been identified as an inhibitor of axonal growth, which was highly expressed in central nervous system; however, there are only a few studies on changes of Nogo-A expression following central nervous system injury. OBJECTIVE： To investigate the dynamic expression of Nogo-A mRNA after rat central nervous system injury. DESIGN： Randomized controlled animal study. MATERIALS： Thirty-five rats were randomly divided into two groups, normal animal group （n = 5） and model group （n = 30）. The model group was then divided into six subgroups at six time points： 12, 24 hours and 3, 9, 15, and 21 days post-injury, with five rats in each subgroup. METHODS： The left parietal lobe of rats was contused by free-fall strike, and total RNA was extracted from the entire brain tissue. Semi-quantitative RT-PCR was used to detect Nogo-A mRNA expression, and the ratio between expression of the target gene and glyceraldehyde phosphate dehydrogenase was used to determine the relative expression level. MAIN OUTCOME MEASURES： To determine whether Nogo-A mRNA expression was higher than usual following brain injury. RESULTS： The level of Nogo-A mRNA started to increase 12 hours after injury （P 〈 0.05） and decreased slightly by 24 hours post-injury. Expression increased again on day 3 and reached a peak on day 9. Nogo-A mRNA expression started to decrease on day 15, and then decreased to normal levels at days 21 （P 〉 0.05）. CONCLUSION： After injury of the central nervous system, Nogo-A may play a pivotal role in obstructing regeneration of the nerve.     

Nogo-A和NgR在老年大鼠脑组织中的表达分布

目的研究Nogo—A和NgR在老年大鼠脑内的表达阳性分布。方法免疫组织化学方法（ABC法）。结果Nogo-A和NgR在老年大鼠脑内的神经元和神经纤维有广泛的表达且阳性反应的强度不同。结论Nogo-A和NgR在老年大鼠脑内广泛表达可能在衰老中发挥作用。     

Selective temporal and regional alterations of Nogo-A and small proline-rich repeat protein 1A (SPRR1A) but not Nogo-66 receptor (NgR) occur following traumatic brain injury in the rat

Axons show a poor regenerative capacity following traumatic central nervous system (CNS) injury, partly due to the expression of inhibitors of axonal outgrowth, of which Nogo-A is considered the most important. We evaluated the acute expression of Nogo-A, the Nogo-66 receptor (NgR) and the novel small proline-rich repeat protein 1A (SPRR1A, previously undetected in brain), following experimental lateral fluid percussion (FP) brain injury in rats. Immunofluorescence with antibodies against Nogo-A, NgR and SPRR1A was combined with antibodies against the neuronal markers NeuN and microtubule-associated protein (MAP)-2 and the oligodendrocyte marker RIP, while Western blot analysis was performed for Nogo-A and NgR. Brain injury produced a significant increase in Nogo-A expression in injured cortex, ipsilateral external capsule and reticular thalamus from days 1-7 post-injury (P < 0.05) compared to controls. Increased expression of Nogo-A was observed in both RIP- and NeuN positive (+) cells in the ipsilateral cortex, in NeuN (+) cells in the CA3 region of the hippocampus and reticular thalamus and in RIP (+) cells in white matter tracts. Alterations in NgR expression were not observed following traumatic brain injury (TBI). Brain injury increased the extent of SPRR1A expression in the ipsilateral cortex and the CA3 at all post-injury time-points in NeuN (+) cells. The marked increases in Nogo-A and SPRR1A in several important brain regions suggest that although inhibitors of axonal growth may be upregulated, the injured brain is also capable of expressing proteins promoting axonal outgrowth following TBI.     

法舒地尔对大鼠脑缺血再灌注后Rho激酶、Nogo-A表达的影响

目的观察法舒地尔对大鼠缺血再灌注后Rho激酶、Nogo-A表达的影响,探讨其可能的机制。方法将72只成年健康雄性SD大鼠随机分为3组:A假手术组、B缺血再灌注组、C法舒地尔治疗组,每组24只,再分为1 d、3 d、7 d、14 d 4个时间点,每个时间点6只。采用Zea-Longa线栓法建立大脑中动脉缺血再灌注(MCAO)模型,应用免疫组化法观察缺血侧海马CA1区Rho激酶、Nogo-A的表达。结果 (1)B组、C组各时间点Rho激酶表达均高于A组(P<0.05),术后7d最为明显,C组Rho各时间点表达较B组减少(P<0.05)。(2)B组、C组Nogo-A蛋白表达较A组明显增多(P<0.05),C组各时间点的表达较B组减少(P<0.05)。结论法舒地尔可有效抑制缺血再灌注后Rho激酶及Nogo-A的激活从而达到促使轴突再生的作用。     

Nogo-A及其受体与癫痫大鼠海马苔藓纤维发芽的关系

目的研究神经轴突再生抑制因子Nogo-A及其受体NgR蛋白在癫痫大鼠海马细胞内的表达水平,探讨Nogo-A及NgR与癫痫大鼠海马苔藓纤维发芽(mossy fiber sprouting,MFS)发生、发展的关系,为进一步明确癫痫发病机制提供研究依据。方法采用红藻氨酸(KA)颈部皮下注射法建立大鼠癫痫模型。(1)采用链霉素抗生物素蛋白-过氧化物酶(SP)法对大鼠海马中Nogo-A及NgR蛋白进行检测,并用图像分析仪对染色结果进行分析;(2)应用Timm's硫化银法对大鼠海马脑片进行染色,并对结果进行半定量分析。结果(1)实验组Nogo-A蛋白表达与对照组差别无显著性意义(P>0.05);(2)注射KA后4h NgR蛋白表达降低,至造模后7d,NgR蛋白表达升高至正常水平,实验组与对照组之间比较,组内、组间表达均有显著性差异(P<0.01);(3)Timm's硫化银染色结果显示:最早在造模2w后可见海马苔藓状纤维发芽,染色结果为淡染,至造模后2个月发芽脑片染色为深染。结论红藻氨酸造模后癫痫大鼠海马Nogo-A蛋白表达无改变;NgR蛋白表达在造模初期呈现降量调节;癫痫大鼠海马苔藓状纤维发芽的发生可能与NgR蛋白水平...     

高压氧治疗对慢性脑缺血大鼠认知功能的影响及其作用机制

目的 探讨高压氧（hyperbaric oxygen，HBO）治疗对慢性脑缺血（chronic cerebral ischemia，CCI）大鼠
学习记忆能力的影响及其作用机制。
方法 选取240只雄性SD大鼠随机分为假手术组、CCI组和HBO组，每组80只。采用双侧颈总动脉阻
断法建立CCI模型，HBO组建模12 h后开始进行HBO治疗28 d，压力0.2 MPa，每日1次，每次60 mi n。采用
Morri s水迷宫实验评估7、14、21、28 d大鼠的学习记忆能力，每个时间点20只，检测前均进行3 d训练，
记录各组大鼠的逃避潜伏时间、穿越平台次数。28 d后处死大鼠取海马组织进行HE染色评估神经元
损伤病理变化，RT-PCR法检测Nogo-A mRNA，Western blot法检测Nogo-A蛋白的表达水平。
结果 ①与假手术组比较，CCI 组7、14、21、28 d逃避潜伏时间均延长（均P＜0.05），28 d跨越平台次
数减少（P＜0.05）；与CCI 组比较，HBO组7、14、21、28 d逃避潜伏时间均缩短（均P＜0.05），28 d跨越
平台次数增加（P＜0.05）。②HE染色显示HBO组神经元损伤程度较CCI组减轻；③CCI组Nogo-A mRNA
和Nogo-A蛋白表达水平均较假手术组升高（均P＜0.05），HBO组表达水平均较CCI组下降（P＜0.05）。
结论 HBO治疗可改善慢性脑缺血大鼠认知功能，其机制可能与下调海马组织中Nogo-A的表达水平
有关。     

高压氧治疗对慢性脑缺血大鼠认知功能的影响及其作用机制

目的 探讨高压氧（hyperbaric oxygen,HBO）治疗对慢性脑缺血（chronic cerebral ischemia,CCI）大鼠 学习记忆能力的影响及其作用机制。 方法 选取240只雄性SD大鼠随机分为假手术组、CCI组和HBO组,每组80只。采用双侧颈总动脉阻 断法建立CCI模型,HBO组建模12 h后开始进行HBO治疗28 d,压力0.2 MPa,每日1次,每次60 mi n。采用 Morri s水迷宫实验评估7、14、21、28 d大鼠的学习记忆能力,每个时间点20只,检测前均进行3 d训练, 记录各组大鼠的逃避潜伏时间、穿越平台次数。28 d后处死大鼠取海马组织进行HE染色评估神经元 损伤病理变化,RT-PCR法检测Nogo-A mRNA,Western blot法检测Nogo-A蛋白的表达水平。 结果 ①与假手术组比较,CCI 组7、14、21、28 d逃避潜伏时间均延长（均P＜0.05）,28 d跨越平台次 数减少（P＜0.05）;与CCI 组比较,HBO组7、14、21、28 d逃避潜伏时间均缩短（均P＜0.05）,28 d跨越 平台次数增加（P＜0.05）。②HE染色显示HBO组神经元损伤程度较CCI组减轻;③CCI组Nogo-A mRNA 和Nogo-A蛋白表达水平均较假手术组升高（均P＜0.05）,HBO组表达水平均较CCI组下降（P＜0.05）。 结论 HBO治疗可改善慢性脑缺血大鼠认知功能,其机制可能与下调海马组织中Nogo-A的表达水平 有关。     

大鼠脑挫伤后Nogo-A mRNA表达水平变化的实验研究

目的观察大鼠脑挫伤后Nogo-AmRNA在神经组织表达量的变化。方法取35只SD大鼠,随机分为7组,每组各5只。1组设为正常对照组,其余6组分别在脑挫伤(自由落体打击脑损伤)后12、24h及3、9、15、21d处死,取脑组织提取RNA,采用半定量RT-PCR法,检测正常及各损伤组Nogo-AmRNA的相对水平。结果脑组织中Nogo-AmRNA表达量在损伤后12h开始出现明显升高(0.1373±0.0009),24h表达稍有下降(0.1067±0.0008),3d后再次上升(0.1220±0.0010),至第9天达到高峰(0.1762±0.0007)并维持于较高水平,至伤后15d(0.1397±0.0005)缓慢下降,伤后21d(0.0129±0.0002)恢复至伤前水平。结论中枢神经损伤后,Nogo-A在抑制神经再生过程中可能发挥着重要作用。     

Nogo-A蛋白的表达与少突胶质细胞肿瘤恶性程度呈负相关

目的探讨Nogo—A蛋白在少突胶质细胞肿瘤中的表达水平与该肿瘤恶性程度之间的关系。方法选取来自临床上经病理检查确诊为少突胶质细胞肿瘤的组织标本,其中少突胶质细胞瘤16例,间变型少突胶质细胞瘤10例。免疫组织化学染色检测Nogo—A的表达,并与同视野下瘤细胞的核分裂与核异型性比例作相关分析;另外,把病理标本按照分级进行蛋白印迹试验。结果免疫组织化学结果显示,Nogo—A免疫阳性染色的光密度值与肿瘤细胞核分裂、核异型比例呈明显的负相关,对蛋白印迹试验结果进行光密度分析也发现少突胶质细胞瘤中的Nogo-A蛋白条带灰度值明显高于间变型少突胶质细胞瘤中的灰度值。结论Nogo-A蛋白在少突胶质细胞肿瘤中的表达水平与该肿瘤恶性程度呈负相关。     

Nogo-A蛋白的表达与少突胶质细胞肿瘤恶性程度呈负相关(英文)

目的探讨Nogo-A蛋白在少突胶质细胞肿瘤中的表达水平与该肿瘤恶性程度之间的关系。方法选取来自临床上经病理检查确诊为少突胶质细胞肿瘤的组织标本,其中少突胶质细胞瘤16例,间变型少突胶质细胞瘤10例。免疫组织化学染色检测Nogo-A的表达,并与同视野下瘤细胞的核分裂与核异型性比例作相关分析;另外,把病理标本按照分级进行蛋白印迹试验。结果免疫组织化学结果显示,Nogo-A免疫阳性染色的光密度值与肿瘤细胞核分裂﹑核异型比例呈明显的负相关,对蛋白印迹试验结果进行光密度分析也发现少突胶质细胞瘤中的Nogo-A蛋白条带灰度值明显高于间变型少突胶质细胞瘤中的灰度值。结论Nogo-A蛋白在少突胶质细胞肿瘤中的表达水平与该肿瘤恶性程度呈负相关。     

大鼠脊髓损伤后Nogo-A表达变化的免疫组织化学研究

目的观察大鼠脊髓损伤后不同时间点Nogo—A蛋白在脊髓的表达变化。方法大鼠分脊髓损伤组、假手术组和正常对照组。损伤动物存活1d、3d、7d后，分别进行Nogo—A抗体的免疫组织化学染色。结果损伤部位的灰质神经元和白质少突胶质细胞均呈明显的Nogo—A免疫阳性反应，随着损伤后存活时间的延长，两者的阳性反应细胞相对染色强度及数量均逐渐下降。结论脊髓损伤后，Nogo—A在灰质神经元有表达，其表达相对强度和表达细胞数量先明显增加，随后逐渐减少，与少突胶质细胞的表达变化相似。     

Nogo-A and nogo receptor expression in demyelinating lesions of multiple sclerosis

A myelin-associated neurite outgrowth inhibitor, Nogo-A, plays a key role in inhibition of axonal regeneration following injury and ischemia in the central nervous system (CNS). Because axonal injury is a pathologic hallmark of multiple sclerosis (MS), we have investigated the expression of Nogo-A and its receptor NgR in four MS and 12 non-MS control brains by immunohistochemistry. Nogo-A expression was markedly upregulated in surviving oligodendrocytes at the edge of chronic active demyelinating lesions of MS and ischemic lesions of acute and old cerebral infarction, whereas NgR expression was greatly enhanced in reactive astrocytes and microglia/macrophages in these lesions when compared with their expression in the brains of neurologically normal controls. Nogo-A and NgR were also identified in a subpopulation of neurons. In contrast, Nogo-A was undetectable in reactive astrocytes and microglia/macrophages and NgR was not expressed on oligodendrocytes in any cases examined. Western blot analysis and double labeling immunocytochemistry identified the constitutive expression of NgR in cultured human astrocytes. These results suggest that Nogo-A expressed on oligodendrocytes might interact with NgR presented by reactive astrocytes and microglia/macrophages in active demyelinating lesions of MS, although biologic effects caused by Nogo-A/NgR interaction among glial cells remain unknown.     

NgR在实验性自身免疫性脑脊髓炎中的表达及NgR(310)ecto-Fc的干预作用

目的 探讨NgR(310)ecto-Fc在实验性自身免疫性脑脊髓炎(EAE)中的干预作用及其作用机制.方法 90只Lewis大鼠按随机数字表法分为3组,即A组(未治疗)、B组[开始免疫后第1天即给予NgR(310)ecto-Fc进行治疗]及C组[刚发病即给予NgR(310)ecto-Fc进行治疗],每组各30只.采用免疫组化法观察各组实验大鼠脊髓组织中NgR的表达变化及阳性细胞计数,同时观察干预前后临床评分变化.结果 免疫后第15天、第25天B、C两组平均临床评分(3.020±1.017,1.365±0.127;2.853±0.958,1.275±0.092)较A组(4.476±1.525,1.894±0.135)明显降低,比较差异有统计学意义(P＜0.05);B组和C组之间平均临床评分比较差异无统计学意义(P＞0.05).所有实验大鼠的脊髓组织中均可见NgR的表达;免疫后第15天、第25天B、C两组NgR阳性细胞计数(79.07±10.31,45.89±4.77;70.47±7.40,40.63±4.15)较A组(101.12±11.97,62.95±7.11)明显减少,比较差异有统计学意义(P＜0.05);B组与C组NgR阳性细胞计数比较差异无统计学意义(P＞0.05).结论 NgR(310)ecto-Fc能够减轻EAE模型的临床症状,可能是其通过抑制NgR的表达,从而同时封闭3个髓磷脂相关抑制因子(Nogo-A、MAG及OMgp)的作用,到达促进轴突再生的作用.     

Expression of the Nogo-A system in cortical lesions of pediatric patients with tuberous sclerosis complex and focal cortical dysplasia type IIb

The reticulon protein Nogo-A is an important regulator of neurite growth, axonal plasticity, and cell migration in the central nervous system. Previous studies have shown markedly elevated levels of Nogo-A in human temporal lobe epilepsy. In the present study, we examined the expression pattern of the Nogo-A system in cortical lesions of pediatric patients with tuberous sclerosis complex and focal cortical dysplasia type IIb. These disorders are characterized by malformations of cortical development and are frequently associated with intractable epilepsy. We found that the messenger RNA and protein levels of the Nogo-A receptor (NgR) and the downstream targets of Nogo-A, LINGO-1, TROY, and RhoA but not P75 were upregulated in the cortices of patients compared with autopsy control samples. Immunohistochemical analyses indicated that Nogo-A and NgR were strongly expressed in misshapen cells, particularly dysmorphic neurons, balloon cells, and giant cells. TROY was diffusely expressed in the malformations of cortical development. Most of theNogo-A/NgR-positive misshapen cells were colabeled with neuronal rather than astrocytic markers. Taken together, our results suggestthat the activation of Nogo-A via the NgR/LINGO-1/TROY signal transduction pathways, but not NgR/LINGO-1/P75, may be involved in the development and/or seizure activity of cortical lesions in tuberous sclerosis complex and focal cortical dysplasia type IIb.     

低血糖后葡萄糖再灌注大鼠海马Nogo-A蛋白的表达

目的探讨胰岛素诱导大鼠低血糖后葡萄糖再灌注对大鼠海马Nogo-A蛋白表达的影响。方法41只4个月龄雄性Wistar大鼠随机分为3组:假手术组(Sham)、低血糖组(HG)、低血糖后葡萄糖再灌注组(HG/GR)。采用DAPI染色观察大鼠海马神经元的凋亡、坏死变化;免疫组织化学染色和Western免疫印迹检测大鼠海马Nogo-A蛋白的表达变化。结果①Nogo-A免疫组化染色:Nogo-A表达量Sham大于HG和HG/GR,三组之间比较,P<0.05;②Western免疫印迹:Nogo-A的表达量,Sham最大,HG次之,HG/GR最小,三组之间差异有统计学意义P<0.01,HG和HG/GR两组之间比较差异无统计学意义(P>0.05)。结论低血糖后再灌注葡萄糖,大鼠海马神经元坏死及凋亡程度增加,Nogo-A蛋白表达降低。