鱼藤酮致大鼠脑内α-突触核蛋白的表达分布变化(英文)

目的研究鱼藤酮所致的帕金森病大鼠的脑内α-突触核蛋白(α-synuclein, ASN)分布。方法 Wistar大鼠随机分成两组,分别给予鱼藤酮和/ 或溶剂(对照组)皮下注射,4 周后取脑组织,对黑质部位HE 染色,光镜下观察Lewy小体形态;对黑质、海马、纹状体等脑区进行酪氨酸羟化酶(tyrosine hydroxylase, TH)、ASN 免疫组织化学染色。结果在对照组大鼠脑内,ASN 广泛分布于各脑区,尤其在皮质、纹状体、海马等纤维投射丰富的区域。鱼藤酮处理的大鼠脑中,黑质TH阳性多巴胺能神经元数目减少、纹状体区TH阳性纤维脱失,黑质部位可见Lewy小体样结构;ASN阳性染色在各个脑区均有增强但各个脑区增强程度不一,黑质部位神经元胞浆和胞核内均有ASN明显聚集,纹状体可见ASN聚集围绕在细胞周围。海马部位偶见ASN在胞浆中点状聚集,胞核中无明显改变。结论在鱼藤酮皮下注射导致的帕金森病大鼠的脑内,ASN在多个脑区中表达增加,而在黑质纹状体部位聚集最为明显,蛋白分布由多巴胺能神经元的突触末端向胞浆和胞核扩展。     

鱼藤酮对大鼠脑内多巴胺能神经元损伤的机制研究

目的研究鱼藤酮对大鼠脑内多巴胺能神经元的毒性作用机制。方法健康成年雄性Wistar大鼠背部皮下注射鱼藤酮制备帕金森病动物模型。采用免疫细胞化学、透射电镜技术及分光光度法技术检测大鼠脑内多巴胺能神经元的损伤及纹状体中氧化应激参数的改变。结果鱼藤酮组大鼠中脑酪氨酸羟化酶(TH)免疫反应阳性神经元数明显少于对照组(P<0.01),纹状体中TH免疫反应强度明显降低(P<0.05),透射电镜可见鱼藤酮组黑质多巴胺能神经元内线粒体损伤,树突变性,其内微粒、微管聚集,同时纹状体发生了明显的氧化损伤。结论氧化应激和超微结构改变是鱼藤酮对大鼠脑内多巴胺能神经元损伤的主要发病机制。     

α-硫辛酸对帕金森病大鼠脑内多巴胺能神经元的保护作用及其机制探讨

目的观察α-硫辛酸(LA)对鱼藤酮致帕金森(PD)大鼠模型黑质多巴胺能神经元的保护作用。方法健康成年雄性Wistar大鼠背部皮下注射鱼藤酮制备PD大鼠模型,药物治疗组同时给予大鼠腹腔注射LA。采用分光光度法检测大鼠脑内丙二醛(MDA)和还原型谷胱甘肽(GSH),Western blot检测大鼠中脑黑质及纹状体酪氨酸羟化酶(TH)的表达变化。结果与对照组相比,鱼藤酮组大鼠纹状体中MDA明显增高(P<0.01)而GSH含量明显降低(P<0.01),TH蛋白在黑质和纹状体与对照组比较明显降低(P<0.05);LA干预后与鱼藤酮组相比MDA明显降低及GSH明显增高(P<0.05),TH蛋白表达明显增加(P<0.05)。结论氧化应激在PD发病中起着非常重要的作用,LA能有效减轻PD大鼠脑内氧化应激损伤、保护脑内多巴胺能神经体系,同时改善PD样症状。     

磁共振检测脑铁含量在帕金森病中的应用

帕金森病(PD)是中老年常见的中枢神经系统变性疾病.其基本病理特征是黑质致密区多巴胺能神经元变性伴胞浆内嗜酸性包涵体即Lewy小体形成,导致黑质纹状体通路破坏及尾状核、壳核中多巴胺含量减少.     

鱼藤酮帕金森病大鼠模型建立的研究

目的探讨鱼藤酮帕金森病大鼠模型的建立方法.方法采用背部皮下注射鱼藤酮,然后观察大鼠的行为学及黑质-纹状体的酪氨酸羟化酶免疫活性变化、海马病理学变化.结果经过1～8周观察,鱼藤酮处理大鼠出现明显的行为学、黑质-纹状体酪氨酸羟化酶免疫活性变化,海马无明显病理学变化,模型显示出帕金森病的典型特征.结论背部皮下注射鱼藤酮的方法可成功制作帕金森病大鼠模型.     

鱼藤酮致帕金森病大鼠行为学与黑质病理损伤的关系

目的 研究鱼藤酮所致大鼠帕金森病模型行为学变化及与黑质多巴胺能神经损伤的关系.方法 Wistar大鼠每日颈背部皮下注射鱼藤酮油乳液(2 mg/kg),按所建立的评分标准记分,有记分即终止给药.中脑黑质病理切片行酪氨酸羟化酶(TH)免疫组化染色.结果 鱼藤酮用药36 d,96%的大鼠出现行为学改变,记分为1～2分者51%,4～6分者15%,8～10分者30%.约3%不敏感.记2分及以上的动物,黑质细胞缺失显著.从黑质TH染色细胞胞体的形态及突起损伤程度见,随着行为学记分的增加损伤加剧.结论 动物行为变化主要是黑质多巴胺能神经受损和缺失所引起.行为学记分能相应反映黑质多巴胺能神经元的损伤程度.     

鱼藤酮致鼠黑质脑片多巴胺能神经元损伤的实验研究

目的 探讨低剂量鱼藤酮对乳鼠中脑黑质脑片多巴胺能神经元的毒性作用及依达拉奉的保护作用.方法 取Wistar乳鼠中脑黑质脑片进行培养,酪氨酸羟化酶(TH)免疫组化染色观察多巴胺神经元毁损情况,western-blot测定各组脑片α-突触核蛋白(α-Synuclein)含量,扫描电镜观察脑片超微病理结构变化.结果 黑质脑片多巴胺神经元的数目随鱼藤酮浓度及培养时间的增加而明显减少,多巴胺神经元的超微病理显示氧化应激性损害,α-Synuclein的含量随鱼藤酮浓度的增加而升高,依达拉奉 鱼藤酮组较鱼藤酮组能够减少多巴胺能神经元的凋亡并使α-Synuclein的表达量减少.结论 成功利用黑质脑片器官型培养体系建立了帕金森病(Pakinson's disease)模型;低剂量鱼藤酮导致选择性多巴胺神经元的凋亡,并导致α-Synuclein的含量增加,自由基清除剂依达拉奉对此有保护作用.     

蛋白酶体功能与帕金森病相关性实验研究

目的 观察蛋白酶体抑制剂诱导大鼠黑质多巴胺能神经元α-突触核蛋白（α-synuclein，α-Syn）的表达及聚集．探讨蛋白酶体功能在帕金森病（PD）发病中的作用机制。方法采用立体定向将蛋白酶体抑制剂Lactacystin注射至大鼠黑质部位。以免疫荧光法观察黑质区多巴胺能神经元变性缺失，并应用免疫荧光双标法观察多巴胺能神经元内蛋白聚集的包涵体及其主要成分α-Syn的表达．然后通过原位杂交分析α-Syn mRNA表达及Western印迹法检测黑质α-Syn表达量改变。结果注射Lactacystin第7天大鼠开始出现自发性活动减少．阿扑吗啡尚可诱导出旋转行为；3周后患侧黑质部位酪氨酸羟化酶（TH）阳性细胞明显减少。TH与硫磺素、硫磺素与α-Syn复合染色呈阳性。α-Syn mRNA表达量升高，蛋白表达水平增加。结论Lactacystin诱导大鼠黑质细胞α-Syn表达升高并出现蛋白聚集可能是导致PD发病的机制之一。     

急性鱼藤酮中毒大鼠α-突触核蛋白与酪氨酸羟化酶的表达

目的探讨鱼藤酮中毒大鼠α-突触核蛋白与酪氨酸羟化酶免疫活性的变化。方法采用大鼠背部皮下持续注射小剂量鱼藤酮的方法,观察大鼠运动功能和生物学特征的变化。结果接受鱼藤酮注射的大鼠均出现明显的运动功能障碍,最严重表现是运动不能。大部分大鼠的黑质-纹状体酪氨酸羟化酶阳性神经元数目减少,全部大鼠的黑质细胞内均有α-突触核蛋白的过度表达。结论鱼藤酮中毒大鼠可以产生帕金森病的运动障碍及有关病理生理学特征。     

α-共核蛋白异常积聚及其在帕金森病发病机制中的作用

帕金森病(PD)的主要病理改变为黑质多巴胺神经元变性和Lewy体形成.纤维化积聚的α-共核蛋白(ASN)是Lewy体的主要组成成分.研究证实ASN寡聚体具神经毒性,ASN异常积聚被认为在PD发病机制中发挥了关键作用.ASN的基因突变、过度表达、异常修饰或清除减少都可能引起其异常积聚.异常积聚的ASN通过刺激免疫反应、诱导多巴胺神经元凋亡、降低自噬作用、破坏高尔基体组成等途径导致多巴胺神经元变性.本文针对α-共核蛋白异常积聚的具体机制及其在帕金森病发病过程中的作用作一综述.     

帕金森病大鼠模型黑质白介素-6表达的实验研究

目的探讨白介素-6(IL-6)和小胶质细胞在帕金森病发病机制中作用,阐述小胶质细胞激活后作用的合理模式。方法采用立体定向术将神经毒素6-羟基多巴(6-OHDA)注入大鼠右侧纹状体制作偏侧帕金森病大鼠模型。造模2月后,计数黑质致密部神经元和小胶质细胞数目,观察黑质致密部病理形态学变化,并采用免疫组织化学方法观察黑质致密部IL-6表达水平的变化。结果光镜下观察模型组右侧黑质致密部多巴胺能神经元几乎消失,小胶质细胞数目明显增多,与假手术组及正常对照组相比,差异有显著性(P<0.05)。免疫组化染色显示模型组右侧黑质致密部可见明显的小胶质细胞核周的棕褐色阳性表达,而模型组左侧与假手术组及正常对照组右侧黑质均未见明显阳性着染区。结论神经毒素6-OHDA可导致神经元释放小胶质细胞激活态物质,激活小胶质细胞释放IL-6介导细胞毒作用,促进神经元的慢性变性坏死。     

Gene therapy of Parkinson's disease using adeno-associated virus (AAV) vectors

Parkinson's disease (PD) is characterized by the progressive loss of the dopaminergic neurons in the substantia nigra and a severe decrease in dopamine in the striatum. A promising approach to the gene therapy of PD is intrastriatal expression of dopamine-synthesizing enzymes [tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC)]. The most appropriate gene-delivery vehicles for neurons are adeno-associated virus (AAV) vectors, which are derived from non-pathogenic virus. Therefore, TH and AADC genes were introduced into the striatum in the lesioned side using separate AAV vectors in parkinsonian rats, and the coexpression of TH and AADC resulted in better behavioral recovery compared with TH alone. Another strategy for gene therapy of PD is the protection of dopaminergic neurons in the substantia nigra using an AAV vector containing a glial cell line-derived neurotrophic factor (GDNF) gene. Combination of dopamine-supplement gene therapy and GDNF gene therapy would be a logical approach to the treatment of PD.     

Valproic Acid is Neuroprotective in the Rotenone Rat Model of Parkinson’s Disease: Involvement of α-Synuclein

Valproic acid (VPA), an established antiepileptic and antimanic drug, has recently emerged as a promising neuroprotective agent. Among its many cellular targets, VPA has been recently demonstrated to be an effective inhibitor of histone deacetylases. Accordingly, we have adopted a schedule of dietary administration (2% VPA added to the chow) that results in a significant inhibition of histone deacetylase activity and in an increase of histone H3 acetylation in brain tissues of 4 weeks-treated rats. We have tested this schedule of VPA treatment in an animal model of Parkinson’s disease (PD), in which degeneration of nigro-striatal dopaminergic neurons is obtained through sub-chronic administration of the mitochondrial toxin, rotenone, via osmotic mini pumps implanted to rats. The decrease of the dopaminergic marker tyrosine hydroxylase in substantia nigra and striatum caused by 7 days toxin administration was prevented in VPA-fed rats. VPA treatment also significantly counteracted the death of nigral neurons and the 50% drop of striatal dopamine levels caused by rotenone administration. The PD-marker protein α-synuclein decreased, in its native form, in substantia nigra and striatum of rotenone-treated rats, while monoubiquitinated α-synuclein increased in the same regions. VPA treatment counteracted both these α-synuclein alterations. Furthermore, monoubiquitinated α-synuclein increased its localization in nuclei isolated from substantia nigra of rotenone-treated rats, an effect also prevented by VPA treatment. Nuclear localization of α-synuclein has been recently described in some models of PD and its neurodegenerative effect has been ascribed to histone acetylation inhibition. Thus, the ability of VPA to increase histone acetylation is a novel candidate mechanism for its neuroprotective action.     

Differential regulation of glutamic acid decarboxylase mRNA and tyrosine hydroxylase mRNA expression in the aged manganese-treated rats

Recent studies have implicated chronic elevated exposures to environmental agents, such as metals (e.g. manganese, Mn) and pesticides, as contributors to neurological disease. Eighteen-month-old rats received intraperitoneal injections of manganese chloride (6 mg Mn/kg/day) or equal volume of saline for 30 days in order to study the effect of manganese on the dopamine- and GABA-neurons. The structures studied were substantia nigra, striatum, ventral tegmental area, nucleus accumbens and globus pallidus. First, we studied the enzymatic activity of mitochondrial complex II succinate dehydrogenase (SDH). We found an overall decrease of SDH in the different brain areas analyzed. We then studied the mRNA levels for tyrosine hydroxylase (TH) and the dopamine transporter (DAT) by in situ hybridization. TH mRNA but not DAT mRNA was significantly induced in substantia nigra and ventral tegmental area following Mn treatment. Correspondingly, TH immunoreactivity was increased in substantia nigra and ventral tegmental area. Manganese treatment significantly decreased GAD mRNA levels in individual GABAergic neurons in globus pallidus but not in striatum. We also quantified the density of glial fibrillary acidic protein (GFAP)-labeled astrocytes and OX-42 positive cells. Reactive gliosis in response to Mn treatment occurred only in striatum and substantia nigra and the morphology of the astrocytes was different than in control animals. These results suggest that the nigrostriatal system could be specifically damaged by manganese toxicity. Thus, changes produced by manganese treatment on 18-month-old rats could play a role in the etiology of Parkinson's disease.     

蛋白酶体抑制剂诱导大鼠黑质变性伴包涵体形成

目的 观察蛋白酶体抑制剂Lactacystin诱导大鼠黑质变性伴包涵体形成及运动行为学的改变,探讨蛋白酶体功能下降在帕金森病(PDl发病机制中的作用. 方法 24只SD大鼠采用随机数字表法分为kactacystin实验组和生理盐水组.每组12只,Lactacystin实验组将蛋白酶体抑制剂Lactacystin立体定向注射人大鼠左侧黑质致密部(SNc).生理盐水组注射等体积生理盐水;观察大鼠自主行为和阿朴吗啡(APO)诱导的旋转行为的改变;Nissl染色法观察SNc病理改变;免疫组化法观察SNc及纹状体酪氨酸羟化酶(TH)和SNc中α-共核蛋白的表达;透射电镜观察SNc超微结构的改变. 结果 Lactacystin实验组大鼠给药7 d后出现自发性活动减少、动作缓慢、震颤、且症状逐步加重.APO可诱导出向健侧的旋转运动;Nissl染色发现Lactacystin实验组左侧SNc神经元数量减少,尼氏体结构松散;免疫组化结果表明21 d后Lactacystin实验组左侧SNc出现变性,TH免疫阳性神经元数量减少,α-共核蛋白表达增强,纹状体内TH免疫阳性纤维数量减少;电镜观察到蛋白质聚集形成的包涵体. 结论 Lactacystin单侧SNc注射可以诱导大鼠黑质变性伴包涵体形成及大鼠行为改变.蛋白酶体功能下降可能在PD发病机制中起重要作用.     

抗帕颗粒对帕金森病模型小鼠酪氨酸羟化酶神经元的影响

目的 探讨抗帕颗粒对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)帕金森病(PD)模型小鼠黑质纹状体酪氨酸羟化酶(TH)阳性神经元的影响。方法 90只健康雄性C57BL/6小鼠,鼠龄8～12周,并随机分为3组,即正常对照组30只、PD模型对照组30只、PD模型干预组30只; MPTP腹腔注射(40 mg·kg^-1·d^-1×7 d)制备小鼠PD模型; 正常对照组及PD模型对照组予生理盐水1 mL·d^-1灌胃,PD模型干预组给予抗帕颗粒40 mg·kg^-1·d^-1灌胃,连续喂养4个月; 黑质纹状体切片、HE染色、免疫组织化学染色TH神经元及Western blotting检测TH蛋白的表达量。结果 ①正常对照组30只(30/30只)最终均存活,PD模型对照组4个月存活27只(27/30只),PD模型干预组4个月存活28只(28/30只); ②PD模型对照组、PD模型干预组小鼠每次注射MPTP后先有短暂兴奋[持续(7.61±2.17)min],表现为四处窜跳,随即出现全身中重度震颤,皮毛及尾巴时有竖立,活动减少,持续(24.23±3.89)min后震颤消失,随后出现活动减少; ③HE染色显示正常对照组大量褐色TH阳性细胞,PD模型对照组TH阳性细胞数明显减少,PD模型干预组TH阳性细胞数有所增加; ④免疫组织化学染色后经Imagepro-Plus 5.1系统分析,正常对照组TH阳性细胞面积为64 145 μm²,高倍镜下可见大量胞质为褐色颗粒的TH阳性细胞; PD模型对照组TH阳性细胞染色面积为40 012 μm²,高倍镜下见TH细胞数明显减少; PD模型干预组TH阳性细胞染色面积为60 952 μm²,高倍镜下见TH阳性细胞数较PD模型对照组增加; ⑤Western blotting检测显示正常对照组TH蛋白表达量与PD模型对照组和PD模型干预组比较均有明显差异(P<0.001),PD模型对照组TH蛋白表达量与PD模型干预组比较也有明显差异(P<0.05)。结论 抗帕颗粒可使PD小鼠黑质纹状体中多巴胺能神经元一定程度地减少丢失,对多巴胺能神经元的数量、形态及功能具有一定的保护作用。     

Parallel relationship between microglial activation and substantia nigra damage in a rotenone-induced Parkinson's disease rat model

BACKGROUND:Inflammatory injury induced by microglial activation plays an important role in the occurrence and development of Parkinson’s disease (PD). However, few studies have examined the relationship between microglia and substantia nigra damage or dopaminergic neuron loss in animals with rotenone-induced PD. OBJECTIVE: To explore the relationship between activated microglia and loss of the substantia nigra, and the changes in concentration and dose of rotenone in the brain of rats with rotenone-induced ...     

硫辛酸对帕金森病小鼠模型自噬蛋白表达水平的影响

目的 探讨硫辛酸(lipoic acid,LA)对MPTP诱导的C57BL/6帕金森病(Parkinson's disease,PD)小鼠模型黑质及纹状体TH、parkin、PINK1、DJ-1自噬相关蛋白表达水平的影响。方法 将60只C57BL/6小鼠随机分为PD模型组、正常组、治疗组、预保护组,采用背部皮下注射MPTP制作PD模型(每组各15只),行为学评价造模,Western Blotting法检测黑质、纹状体TH、parkin、PINK1、DJ-1蛋白的表达水平,免疫组化法观察黑质及纹状体阳性神经元数,免疫荧光检测PINK1的表达水平。结果(1)与正常组比较,PD模型组小鼠黑质、纹状体内TH、Parkin、PINK1、DJ-1的表达水平均明显降低(P<0.01);(2)与PD模型组比较,预保护组黑质、纹状体内TH、PINK1、Parkin、DJ-1表达水平均明显增高(P<0.05);(3)与治疗组比较,预保护组小鼠黑质、纹状体内TH、PINK1、Parkin表达水平略增高,预保护组DJ-1表达水平略降低,但两组比较无统计学差异(P>0.05)。结论 线粒体自噬参与PD小鼠的发病过程; 硫辛酸可能通过上调PD小鼠自噬相关蛋白的表达水平而发挥对多巴胺神经元的保护作用,从而为PD的防治提供新的思路。     

Alterations in TH- and ChAT-immunoreactive neurons in the DMV and gastric dysmotility in an LPS-induced PD rat model

To study movement disorder in Parkinson's disease (PD), an animal model of PD can be created by injecting lipopolysaccharide (LPS) into the substantia nigra of rats. In addition to body movement disorders, patients with PD often experience gastrointestinal (GI) dysfunction, such as gastroparesis. However, the underlying mechanism of these disorders remains unclear. The dorsal motor nucleus of vagus (DMV) is a well-known visceral nucleus that regulates GI function. The present study investigated alterations in DMV neurons and gastric motility in rats with LPS-induced PD (LPS-PD rats). Gastric motility was recorded using a strain gauge force transducer in vivo. The distributions of tyrosine hydroxylase (TH)- and choline acetyltransferase (ChAT)-positive neurons in the DMV were determined using immunofluorescence and confocal laser microscopy. Our results indicated that in LPS-PD rats, the number of neurons in the substantia nigra, including neurons with TH immunoreactivity, was markedly reduced, although glial cell proliferation was clearly observed. However, enhanced TH immunoreactivity and decreased ChAT immunoreactivity were found in the DMV. Furthermore, weakened gastric motility was recorded in anesthetized LPS-PD rats. In conclusion, rats with LPS-induced PD exhibited gastric dysmotility with an alteration in DMV neurons. This PD model may be used to study autonomic nervous system disorders that are often observed in patients with early-stage PD.     

Distribution of nitric oxide synthase positive neurons in the substantia nigra of rats with liver cirrhosis

BACKGROUND: Nitrogen monoxide plays an important role in the physiological activity and pathological process of striatum in substantia nigra, and the nitric oxide synthase in substantia nigra may have characteristic changes after liver cirrhosis. OBJECTIVE: To observe the distribution and forms of nitric oxide synthase (NOS) positive neurons and fibers in substantia nigra of rats with liver cirrhosis. DESIGN: A comparative observational experiment. SETTINGS: Beijing Friendship Hospital; Capital Medical University. MATERIALS: Twenty 4-month-old male Wistar rats (120–150 g) of clean grade, were maintained in a 12-hour light/dark cycle at a constant temperature with free access to standard diet and water. Cryostat microtome (LEICA, Germany); All the reagents were purchased from Sigma Company. METHODS: The experiment was carried out in the Department of Anatomy (key laboratory of Beijing city), Capital Medical University from July 2000 to March 2002. The rats were randomly divided into normal group (n =10) and liver fibrosis group (n =10). Rats in the liver fibrosis group were subcutaneously injected with 60% CCl4 oil at a dose of 5 mL/kg for the first time, and 3 mL/kg for the next 14 times, twice a week, totally 15 times. Liver fibrosis of grades 5–6 was taken as successful models. Whereas rats in the normal group were not given any treatment. Four months after CCl4 treatment, all the rats were anesthetized to remove brain, and frontal frozen serial sections were prepared. The expressions of nitric oxide synthase positive neurons in substantia nigra of rats were observed under inverted microscope. The number and gray scale of cell body of nitric oxide synthase positive neurons in substantia nigra were detected with NADPH-diaphorase staining. MAIN OUTCOME MEASURES: ① Number and gray scale of cell body of nitric oxide synthase positive neurons in substantia nigra; ② Expressions of nitric oxide synthase positive neurons in substantia nigra. RESULTS: All the 20 rats were involved in the analysis of results. ① The nitric oxide synthase positive neurons in substantia nigra were obviously fewer in the liver cirrhosis group than in the normal group (P < 0.01), and the gray scale of the positive cell body was higher in the liver cirrhosis group than in the normal group (P < 0.05). ② Abundant nitric oxide synthase positive neurons were observed in substantia nigra of normal rats, the cell body of nitric oxide synthase positive neurons was clear and transparent, with short own cloudy processes. In substantia nigra of rats with liver cirrhosis, the body of nitric oxide synthase positive neurons were observed shrink obviously, less fibrin than normal. CONCLUSION: Rats with liver cirrhosis may suffer from the physiological dysfunction of neurons due to lack of fibers. The nitric oxide synthase positive neurons in substantia nigra can shrink and reduce.