DNA聚合酶β抑制剂齐墩果酸对帕金森病小鼠模型的保护作用

目的 观察DNA聚合酶β抑制剂齐墩果酸对帕金森病小鼠模型的保护作用.方法 利用MPTP腹腔注射法制作小鼠帕金森病模型,在MPTP注射前后分别给予DNA聚合酶β抑制剂齐墩果酸干预,用免疫组织化学染色法检测小鼠中脑酪氨酸羟化酶（TH）阳性神经元,免疫印迹法检测中脑腹侧TH蛋白和活化的Caspase-3表达水平,HPLC法检测纹状体中多巴胺及其代谢产物的水平.结果 小鼠腹腔注射MPTP后出现行为学异常,中脑黑质多巴胺能神经元损伤,中脑腹侧TH表达降低,活化的caspase-3水平增高,同时纹状体多巴胺及其代谢产物3,4二羟基苯乙酸（DOPAC）水平降低.齐墩果酸干预能够显著改善小鼠的行为学评分,增加黑质多巴胺能神经元数量,抑制caspase-3活化,并增加纹状体多巴胺和DOPAC水平.结论 齐墩果酸可能对帕金森病小鼠多巴胺能神经元具有保护作用.     

丁基苯酞对帕金森模型小鼠中脑黑质多巴胺能神经元数及TH、TNF-α蛋白表达的影响

目的研究丁基苯酞(dl-3n-butylphthalide,NBP)对由MPTP诱导的C57BL/6小鼠帕金森模型中脑黑质多巴胺能神经元数及TH、TNF-α蛋白表达的影响,进一步探讨其保护机制。方法 24只C57BL/6小鼠,随机分成3组:正常对照组,MPTP组,NBP治疗组。MPTP腹腔注射法制备帕金森模型,免疫组织化学法观察中脑黑质TH阳性神经元细胞数,蛋白质印迹法观察中脑黑质TH、TNF-α蛋白含量的变化。结果 (1)与正常对照组比较,MPTP组可见帕金森病小鼠中脑黑质TH阳性神经元明显减少(P0.01);与MPTP组比较,NBP治疗组帕金森病小鼠中脑黑质TH阳性神经元数目明显增加(P0.01);(2)与正常对照组比较,MPTP组帕金森病模型小鼠中脑黑质TH蛋白表达减少(P0.01),而TNF-α蛋白表达增加(P0.05);(3)与MPTP组比较,NBP治疗组帕金森病模型小鼠中脑黑质TH蛋白表达明显增加(P0.01),而TNF-α蛋白表达减少(P0.05)。结论丁基苯酞可能通过提高中脑黑质中TH的含量及减少TNF-α炎性介质表达发挥对MPTP所致C57BL/6小鼠帕金森模型的神经元保护作用。     

枸杞多糖对帕金森病小鼠的抗氧化作用和神经保护效应北大核心CSCD

目的研究枸杞多糖(Lycium barum polysaccharide,LBP)对帕金森病(Parkinson disease,PD)小鼠黑质多巴胺(dopamine,DA)能神经元的影响。方法采用MPTP制备PD小鼠模型,经左旋多巴(Levodopa,LDOPA)和LBP处理后,用爬杆实验评价各组小鼠的行为表现,通过酪氨酸羟化酶(tyrosine hydroxylase,TH)免疫组织化学染色观察黑质致密部DA能神经元存活情况,并用生化技术对中脑组织超氧化物歧化酶(super oxidase dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)和过氧化氢酶(catalase, CAT)活力及丙二醛(malonaldehyde, MDA)含量进行检测。结果 MPTP制备的PD模型小鼠爬杆实验得分远低于对照组(3.53±1.32 vs. 7.61±1.53,P<0.01),黑质致密部TH阳性神经元数量较对照组有大幅减少(340±31 vs. 1204±112,P<0.01),中脑组织SOD、GSH-Px和CAT酶活力也显著低于对照组,而MDA含量则显著高于对照组(P<0.01)。经过L-DOPA处理的小鼠爬杆实验得分较MPTP组有大幅改善(6.87±1.51 vs. 3.53±1.32,P<0.01),但TH阳性神经元数量仍较对照组有显著下降(295±63 vs. 1204±112,P<0.01),中脑SOD、GSH-Px和CAT酶活力甚至低于MPTP组小鼠,而MDA含量则高于MPTP组(P<0.05)。经过50 mg/kg和100 mg/kg LBP处理的小鼠爬杆实验得分均高于MPTP组(5.07±1.28 vs. 3.53±1.32;5.20±1.37 vs. 3.53±1.32,P<0.01),而低于对照组和L-DOPA组(P<0.05);TH阳性神经元数量也较MPTP组(655±78 vs. 340±31;704±38 vs. 340±31,P<0.01)或L-DOPA组(655±78 vs. 295±63;704±38 vs. 295±63,P<0.01)明显增多,但仍少于对照组(P<0.01);SOD、GSH-Px和CAT酶活力均较MPTP组或L-DOPA组有显著升高,MDA含量则较上述两组有显著下降(P<0.01)。结论 LBP能有效降低PD小鼠中脑氧化应激损伤,对黑质致密部DA能神经元起到保护作用。     

头孢曲松钠联合地塞米松治疗小儿化脓性脑膜炎的临床分析

目的 分析药物治疗小儿化脓性脑膜炎的临床价值。方法 选择我院2017年3月至2019年7月内接诊的80例小儿化脓性脑膜炎患者，遵循药物差异分组原则分为对照组（38例，头孢曲松钠常规治疗）和观察组（42例，联合开展地塞米松治疗），观察两组在临床疗效、症状和体征恢复时间、治疗前后血清炎症因子水平改善情况以及用药安全性。结果 观察组的总有效率较对照组高（P<0.05）。治疗后观察组较对照组症状和体征恢复时间缩短（P<0.05）；住院时间也较对照组短（P<0.05）。治疗后观察组较对照组血清炎症因子各指标水平较低（P<0.05）。观察组的不良反应发生率较对照组低（P<0.05）。结论 头孢曲松钠常规治疗的基础上联合地塞米松治疗，提升了临床疗效，缩短了症状和体征恢复时间，降低了血清炎症因子水平，提高了临床用药安全性。     

立体定向微创手术对脑胶质瘤患者近远期疗效和神经功能评分的影响

目的 分析立体定向微创手术对脑胶质瘤患者近远期疗效和神经功能评分的影响。方法 选取2016年1月—2017年12月该院204例脑胶质瘤患者，依据患者治疗方式的不同，分为对照组（采取传统开颅手术）89例和研究组（采取立体定向微创手术）115例。评价两组近远期临床疗效，比较两组手术时间、术后住院天数和治疗前后中国卒中量表（CSS）评分、改良Barthel指数评分情况。结果 相比对照组，研究组治疗总有效率升高（P<0.05），而手术时间和术后住院天数均减少（P<0.01）。相比治疗前，两组治疗后CSS评分均下降，改良Barthel指数评分均升高（P<0.05）；相比对照组，研究组治疗后CSS评分下降，改良Barthel指数评分升高（P<0.05）。研究组2年内复发率低于对照组，存活率高于对照组（P<0.05）。结论 采取立体定向微创手术治疗可有效改善脑胶质瘤患者近远期疗效，可促进机体神经功能的恢复，同时可有效降低复发率，提高存活率。     

脑血流动力学与缺血性脑卒中患者脑白质病变严重程度的相关性研究

目的 研究缺血性脑卒中患者脑血流动力学与脑白质病变严重程度之间相关性。方法 分析2015年7月至2019年8月收治的108例缺血性脑卒中患者资料，采用Fazekas量表对患者脑白质病变严重程度进行分级。比较不同脑白质病变严重程度、患者颅内大动脉硬化程度和脑血流动力学指标，进行患者脑血流动力学与脑白质病变严重程度之间相关性分析，并分析脑白质中重度病变的危险因素。结果 Fazekas量表<3分者61例纳入轻度病变组，≥ 3分者47例纳入中重度病变组。中重度病变患者颅内大动脉硬化严重程度高于轻度病变组（P<0.05）。中重度病变组脑部动脉搏动指数（PI）显著高于轻度病变组；收缩期峰值血流（Vs）、平均血流（Vm）以及舒张末期血流（Vd）等脑血流动力学指数显著低于轻度病变组（P<0.05）。颅内大动脉硬化程度、PI与脑白质病变严重程度正相关（r=0.416，0.527；P<0.05），Vs、Vm以及Vd等脑血流参数与脑白质病变严重程度负相关（r=-0.316，-0.524，-0.668；P<0.05）。颅内大动脉硬化程度与PI为脑白质中重度病变的危险因素（P<0.05）。结论 缺血性脑卒中患者脑白质病变严重程度与患者脑血流动力学指标异常有关，而颅内动脉硬化会加重患者脑白质病变严重程度。     

微创钻孔引流术联合加速康复外科理念在脑出血治疗中的应用

目的 研究探讨微创钻孔引流手术联合加速康复外科（ERAS）理念在高血压脑出血患者治疗中的临床效果。方法 选取2019年4月—2020年6月该院收治的高血压脑出血（出血量30~50 mL）患者80例，采用随机数表法分为传统围手术期组（微创钻孔引流手术加传统围手术期方案）和ERAS围手术期组（微创钻孔引流手术加ERAS理念方案），各40例，记录两组患者术后不良反应、并发症及血清学指标等情况。结果 ERAS围手术期组的颅内感染、肺部感染和尿路感染发生率低于传统围手术期组（P<0.05）。与传统围手术期组相比，ERAS围手术期组患者监护室住院时间更短，住院费用降低（P<0.05）。ERAS围手术期组的Barthel指数（BI）评分和欧洲卒中量表（ESS）评分均优于传统围手术期组（P<0.05）。ERAS围手术期组术后第3天的C-反应蛋白（CRP）和白细胞介素-6（IL-6）水平低于传统围手术期组（P<0.05）。两组的手术切口愈合情况、手术时间及术后再出血方面差异无统计学意义（P>0.05）。结论 微创钻孔引流联合ERAS理念能减少患者术后应激，可加快恢复速度，减少脑出血患者的并发症，安全有效。     

早期强化降压与标准降压治疗对高血压脑出血老年患者功能改善及预后的影响比较

目的 探讨早期强化降压与标准降压治疗对高血压脑出血老年患者术后功能改善及预后的影响。方法 选取四川省巴中市中心医院南坝分院高血压脑出血老年患者200例（2016年3月-2019年1月），按照随机数字表法分为强化降压组（n=100）与标准降压组（n=100）。强化降压组在常规干预基础上采取强化降压治疗，标准降压组采取指南标准降压治疗。统计两组治疗前及治疗后第1、7及14天时神经功能（NIHSS）、血肿体积与血肿扩大率、核因子κβ（NF-κβ）、血管性血友病因子（vWF）、肿瘤坏死因子-α（TNF-α）、基质金属蛋白酶-9（MMP-9）值，治疗后3个月随访统计预后效果。结果 ①神经功能：不同时间点间的神经功能评分有差别（P<0.05），组间的神经功能评分有差别（P<0.05），强化降压组与标准降压组的神经功能评分变化趋势有差别（P<0.05）；②血肿体积与血肿扩大率：治疗后第1天两组血肿体积较治疗前增加，但强化降压组小于标准降压组，强化降压组的第7天血肿清除率（91.00%）高于标准降压组（74.00%），差异有统计学意义（P<0.05）；③NF-κβ、vWF、TNF-α及MMP-9水平：不同时间点间的NF-κβ、vWF、TNF-α及MMP-9水平有差别（P<0.05），组间的NF-κβ、vWF、TNF-α及MMP-9水平有差别（P<0.05），强化降压组与标准降压组的NF-κβ、vWF、TNF-α及MMP-9水平变化趋势有差别（P<0.05）；④预后效果：强化降压组预后效果优于标准降压组，预后良好率（60.00%）高于标准降压组（38.00%），差异有统计学意义（P<0.05）。结论 采取早期强化降压治疗高血压脑出血效果优于指南标准降压，可有效改善患者神经功能，抑制血肿扩大，调节血清NF-κβ、vWF等指标水平，利于改善预后效果。     

白头翁皂苷D对胶质瘤细胞转移和凋亡的影响及机制研究

目的 探究白头翁皂苷D （PSD）对胶质瘤细胞U251MG转移和凋亡的影响及可能机制。方法 采用CCK-8试剂盒检测正常星形胶质细胞和U251MG细胞活力；选用0.0、1.0、2.0及5.0 μmol/L PSD处理U251MG，将细胞分为4组：PSD 0.0 μmol/L组、PSD 1.0 μmol/L组、PSD 2.0 μmol/L组和PSD 5.0 μmol/L组。划痕实验检测细胞迁移能力；Transwell检测细胞侵袭能力；Hoechst 33258染色检测细胞凋亡状况；RT-PCR检测mRNA表达水平；蛋白免疫印迹检测基质金属蛋白酶-2（MMP-2）、尿激酶型纤溶酶原激活物（uPA）、纤溶酶原激活物抑制剂-1（PAI-1）、血管内皮生长因子（VEGF）、cleaved caspase-3、cleaved caspase-9、肝细胞生长因子受体（c-MET）蛋白表达水平。结果 PSD抑制正常星形胶质细胞和胶质瘤细胞U251MG细胞活力。与PSD 0.0 μmol/L组相比较，PSD 1.0、2.0及5.0 μmol/L组细胞迁移率降低（P<0.01），MMP-2、uPA、PAI-1、VEGF、c-MET蛋白水平降低（P<0.05），PSD 1.0 μmol/L组细胞侵袭数降低（P<0.05），PSD 2.0及5.0 μmol/L组细胞侵袭数降低（P<0.01），细胞凋亡率升高（P<0.05），cleaved caspase-3、cleaved caspase-9蛋白水平升高（P<0.05）。结论 PSD通过靶向c-MET抑制胶质瘤细胞U251MG迁移和侵袭，并诱导细胞凋亡。     

阿尔茨海默病和帕金森病扩大的血管周围间隙分布特点

目的 探讨阿尔兹海默病、帕金森病及高血压病患者扩大的脑内血管周围间隙（EPVS）分布特点及其临床意义。方法 纳入从2012年1月起就诊于中国医科大学附属盛京医院神经内科的阿尔兹海默病（AD组）、帕金森病（PD组）患者各100例，同时纳入年龄、性别基本匹配且无以上疾病的高血压（HBP组）患者100例、健康中老年人（N组）100例。所有受试者均经3.0 T头部磁共振成像检查，通过观察半卵圆中心区、基底节区以及海马区这三个层面的T2WI和FLAIR的成像表现，比较4组受试者EPVS数量和分布特点，分析EPVS数目与年龄之间的关系以及AD组MMSE评分与EPVS数量之间的关系。结果 4组受试者无论是在半卵圆中心区还是基底节区，EPVS均存在解剖学分布差异（P<0.001）。4个组间的EPVS数目差异具有统计学意义（P<0.001），AD组、HBP组、PD组均高于N组。在半卵圆中心区，AD组的EPVS数目（11.23）高于其他3组（HBP=8.97、PD=7.88、N=3.00）。在基底节区，HBP组的EPVS数目（7.21）高于其他3组（PD=5.85、AD=4.87、N=2.95）。在海马区，AD组、HBP组、PD组之间的EPVS数目无显著性差异。进一步计算半卵圆中心区的EPVS占全部脑区EPVS数目的比值发现，AD组的EPVS百分比（69.41%）高于其他3组（HBP=54.75%、PD=57.49%、N=46.35%），AD组与HBP组的百分比差异具有统计学意义（P<0.001）。Spearman相关分析发现，AD组、HBP组、PD组的EPVS数目与年龄呈正相关（r_s=0.34、0.41、0.49，P<0.01），而与N组无相关性。AD组半卵圆中心区的EPVS数目与MMSE评分之间呈负相关（r_s=-0.251，P<0.05），在基底节区两者之间无相关性。结论 AD组的EPVS分布以半卵圆中心为主，HBP组的EPVS分布以基底节区为主，PD组的EPVS未发现脑区间分布差异的特点。AD、HBP、PD组患者的EPVS数目随年龄增长而增多。AD组患者半卵圆中心区层面的EPVS数目越多，认知功能障碍越严重。EPVS数目可能对评估认知障碍程度有重要价值。     

Neuroprotective effect of the angiotensin-converting enzyme inhibitor perindopril in MPTP-treated mice

Abstract

The angiotensin -converting enzyme (ACE) inhibitor perindopril has been shown to exert benefical effects on the dopaminergic system. Here, we investigated the effects of perindopril on the dopaminergic system in mice after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment, in comparison with a Ca²⁺ antagonist, amlodipine. Administration of perindopril showed dose-dependent neuroprotective effects against MPTP-induced striatal dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) depletion. However, administration of amlodipine showed no significant effects on striatal dopamine depletion after MPTP treatment. In our immunohistochemical studies with antibodies against tyrosine hydroxylase (TH), microtubule-associated protein 2a, b (MAP2), dopamine transporter (DAT), parvalbumin (PV), glial fibrillary acidic protein (GFAP) and Cu/Zn-superoxide dismutase (Cu/Zn-SOD), the administration of perindopril significantly attenuated MPTP-induced substantia nigra and striatal damage. This drug also blocked the increases in GFAP-positive astrocytes in the striatum and substantia nigra after MPTP treatment. Furthermore, the administration of perindopril showed a protective effect against the intense Cu/Zn-SOD immunoreactivity in the neurons and glial cells in both the striatum and substantia nigra after MPTP treatment. These results indicated that the ACE inhibitor perindopril can protect against MPTP-induced striatal dopamine and DOPAC depletion in mice. The protective effect may be, at least in part, caused by the reduction of free radicals caused by MPTP. The present study also demonstrated that perindopril is effective against MPTP-induced neurodegeneration of the nigro-striatal dopaminergic pathway. Furthermore, our results provided further evidence that free radical scavengers may be effective in the treatment of neurodegenerative diseases such as Parkinson's disease.     

Artemisinin exerts a protective effect in the MPTP mouse model of Parkinson's disease by inhibiting microglial activation via the TLR4/Myd88/NF-KB pathway

Aims

We performed cell and animal experiments to explore the therapeutic effect of artemisinin on Parkinson's disease (PD) and the TLR4/Myd88 signaling pathway.

Methods

C57 mice were randomly divided into the blank, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced and artemisinin-treated groups. Clinical symptoms, the number of dopaminergic (DAergic) neurons in the substantia nigra, and microglial cell activation were compared among the three groups. Subsequently, BV-2 cell activation and TLR4/Myd88 pathway component expression were compared among the blank, MPP⁺-treated, artemisinin-treated, and TLR4 activator-treated groups.

Results

Behavioral symptoms were improved, the number of DAergic neurons in the substantia nigra of the midbrain was increased, and microglial cell activation was decreased in artemisinin-treated MPTP-induced PD model mice compared with control-treated MPTP-induced PD model mice (p < 0.05). The cell experiments revealed that artemisinin treatment reduced MPP⁺-induced BV-2 cell activation and inhibited the TLR4/Myd88 signaling pathway. Moreover, the effect of artemisinin on the BV-2 cell model was inhibited by the TLR4 activator LPS (p < 0.05).

Conclusion

Artemisinin may reduce damage to DAergic neurons in a PD mouse model by decreasing microglial activation through the TLR4-mediated MyD88-dependent signaling pathway. However, this finding cannot explain the relationship between microglia and DAergic neurons.     

Prevention of nitric oxide-mediated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease in mice by tea phenolic epigallocatechin 3-gallate

In animal models of Parkinson's disease (PD), the toxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is mediated by oxidative stress, especially by nitric oxide (NO). Inhibition of NO synthase (NOS) activity in the brain produces a neuroprotective effect against PD induced by MPTP Green tea containing high levels of (-)-epigallocatechin 3-gallate (EGCG) was administered to test whether EGCG attenuates MPTP-induced PD in mice through the inhibition of NOS expression. Both tea and the oral administration of EGCG prevented the loss of tyrosine hydroxylase (TH)-positive cells in the substantia nigra (SN) and of TH activity in the striatum. These treatments also preserved striatal levels of dopamine and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid (HVA). Both tea and EGCG decreased expressions of nNOS in the substantia nigra. Also tea plus MPTP and EGCG plus MPTP treatments decreased expressions of neuronal NO synthase (nNOS) at the similar levels of EGCG treatment group. Therefore, the preventive effects of tea and EGCG may be explained by the inhibition of nNOS in the substantia nigra.     

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。     

Chemokines in the MPTP model of Parkinson's disease: absence of CCL2 and its receptor CCR2 does not protect against striatal neurodegeneration

Recent studies have invoked inflammation as a major contributor to the pathogenesis of Parkinson's disease (PD). We determined the role of members of the chemokine system, key inflammatory mediators, in PD pathogenesis. In the MPTP model of murine PD, several chemokines, including CC chemokine ligand 2 (CCL2, Monocyte Chemoattractant Protein-1) and CCL3 (Macrophage Inflammatory Protein-1alpha), were upregulated in the striatum and the ventral midbrain. Astrocytes were the predominant source of CCL2 and CCL3 in the striatum and the substantia nigra, and dopaminergic neurons in the substantia nigra constitutively expressed these two chemokines. MPTP treatment resulted in decreased CCL2 expression and increased CCL3 expression in the surviving dopaminergic neurons. Because we found that CCL2 induced production of TNF-alpha in microglial cells, a cytokine known to play a detrimental role in PD, we anticipated that deletion of the genes encoding CCL2 and CCR2, its major receptor, would confer a protective phenotype. However, MPTP-induced striatal dopamine depletion was comparable in double knockout and wild-type mice. Our results demonstrate that chemokines such as CCL2 are induced following MPTP treatment, but that at least within the context of this PD model, the absence of CCL2 and CCR2 does not protect against striatal dopamine loss.     

Neuroprotective effect of the angiotensin-converting enzyme inhibitor perindopril in MPTP-treated mice

The angiotensin -converting enzyme (ACE) inhibitor perindopril has been shown to exert beneficial effects on the dopaminergic system. Here, we investigated the effects of perindopril on the dopaminergic system in mice after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment, in comparison with a Ca(2+) antagonist, amlodipine. Administration of perindopril showed dose-dependent neuroprotective effects against MPTP-induced striatal dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) depletion. However, administration of amlodipine showed no significant effects on striatal dopamine depletion after MPTP treatment. In our immunohistochemical studies with antibodies against tyrosine hydroxylase (TH), microtubule-associated protein 2a, b (MAP2), dopamine transporter (DAT), parvalbumin (PV), glial fibrillary acidic protein (GFAP) and Cu/Zn-superoxide dismutase (Cu/Zn-SOD), the administration of perindopril significantly attenuated MPTP-induced substantia nigra and striatal damage. This drug also blocked the increases in GFAP-positive astrocytes in the striatum and substantia nigra after MPTP treatment. Furthermore, the administration of perindopril showed a protective effect against the intense Cu/Zn-SOD immunoreactivity in the neurons and glial cells in both the striatum and substantia nigra after MPTP treatment. These results indicated that the ACE inhibitor perindopril can protect against MPTP-induced striatal dopamine and DOPAC depletion in mice. The protective effect may be, at least in part, caused by the reduction of free radicals caused by MPTP. The present study also demonstrated that perindopril is effective against MPTP-induced neurodegeneration of the nigro-striatal dopaminergic pathway. Furthermore, our results provided further evidence that free radical scavengers may be effective in the treatment of neurodegenerative diseases such as Parkinson's disease.     

Intrastriatal glial cell line-derived neurotrophic factors for protecting dopaminergic neurons in the substantia nigra of mice with Parkinson disease

BACKGROUND: Substantia nigra is deep in position and limited in range, the glial cell line-derived neurotrophic factor (GDNF) injection directly into substantia nigra has relatively greater damages with higher difficulty. GDNF injection into striatum, the target area of dopaminergic neuron, may protect the dopaminergic neurons in the compact part of substantia nigra through retrograde transport. OBJECTIVE: To investigate the protective effect of intrastriatal GDNF on dopaminergic neurons in the substantia nigra of mice with Parkinson disease (PD), and analyze the action pathway. DESIGN: A controlled observation. SETTING: Neurobiological Laboratory of Xuzhou Medical College. MATERIALS: Twenty-four male Kunming mice of 7–8 weeks old were used. GDNF, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were purchased from Sigma Company (USA); LEICAQWin image processing and analytical system. METHODS: The experiments were carried out in the Neurobiological Laboratory of Xuzhou Medical College from September 2005 to October 2006. The PD models were established in adult KunMing mice by intraperitoneal injection of MPTP. The model mice were were randomly divided into four groups with 6 mice in each group: GDNF 4-day group, phosphate buffer solution (PSB) 4-day group, GDNF 6-day group and PSB 6-day group. Mice in the GDNF 4 and 6-day groups were administrated with 1 μL GDNF solution (20 μg/L, dispensed with 0.01 mol/L PBS) injected into right striatum at 4 and 6 days after model establishment. Mice in the PSB 4 and 6-day groups were administrated with 0.01 mol/L PBS of the same volume to the same injection at corresponding time points. ② On the 12th day after model establishment, the midbrain tissue section of each mice was divided into 3 areas from rostral to caudal sides. The positive neurons of tyroxine hydroxylase (TH) and calcium binding protein (CB) with obvious nucleolus and clear outline were randomly selected for the measurement, and the number of positive neurons in unit area was counted. MAIN OUTCOME MEASURES: Number of positive neurons of TH and CB in midbrain substantia nigra of mice in each group. RESULTS: All the 24 mice were involved in the analysis of results. The numbers of TH+ and CB+ neurons in the GDNF 4-day group (54.33±6.92, 46.33±5.54) were obviously more than those in the PBS 4-day group (27.67±5.01, 21.50±5.96, P < 0.01). The numbers of TH+ and CB+ neurons in the GDNF 6-day group (75.67±5.39, 69.67±8.69) were obviously more than those in the PBS 6-day group (27.17±4.50, 21.33±5.72, P < 0.01) and those in the GDNF 4-day group (P < 0.01). CONCLUSION: Intrastriatal GDNF can protect dopaminergic neurons in substantia nigra of PD mice, and it may be related to the increase of CB expression.     

Mice lacking alpha-synuclein are resistant to mitochondrial toxins

Abnormalities in the function of alpha-synuclein are implicated in the pathogenesis of Parkinson's disease (PD). We found that alpha-synuclein-deficient mice are resistant to MPTP-induced degeneration of dopaminergic neurons. There was dose-dependent protection against loss of both dopamine in the striatum and dopamine transporter (DAT) immunoreactive neurons in the substantia nigra. These effects were not due to alterations in MPTP processing. We found that alpha-synuclein-deficient mice are also resistant to both malonate and 3-nitropropionic acid (3-NP) neurotoxicity. There was reduced generation of reactive oxygen species in alpha-synuclein-deficient mice following administration of 3-NP. These findings implicate alpha-synuclein as a modulator of oxidative damage, which has been implicated in neuronal death produced by MPTP and other mitochondrial toxins.     

Expression of S-100 protein is related to neuronal damage in MPTP-treated mice

S-100beta is a calcium-binding protein expressed at high levels in brain and is known as a marker of brain damage. However, little is known about the role of S-100beta protein during neuronal damage caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). To determine whether S-100beta protein is induced in glial cells after MPTP treatment, we investigated the expression of S-100 protein immunohistochemically, using MPTP-treated mice. We also examined the change of neurons and glial cells in mice after MPTP treatment. The present study shows that tyrosine hydroxylase (TH) immunoreactivity decreased gradually in the striatum and substantia nigra from 1 day after MPTP treatment. Thereafter, TH-immunopositive cells and fibers decreased in the striatum and substantia nigra at 3 days after MPTP treatment. In contrast, S-100-immunopositive cells and glial fibrillary acidic protein (GFAP)-immunopositive cells increased markedly in the striatum and substantia nigra at 3 days after MPTP treatment. Seven days after MPTP treatment, S-100-immunopositive cells decreased in the striatum and substantia nigra. However, the number of GFAP-immunopositive cells increased in these regions. In double-labeled immunostaining with anti-S-100 and anti-GFAP antibodies, S-100 immunoreactivity was observed only in the GFAP-positive astrocytes. These results provide evidence that astrocytic activation may play a role in the pathogenesis of MPTP-induced degeneration of dopaminergic neurons. Furthermore, the present study demonstrates that S-100 protein is expressed selectively by astrocytes, but not by microglia, after MPTP treatment. These results provide valuable information for the pathogenesis of the acute stage of Parkinson's disease.     

D-deprenyl protects nigrostriatal neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic neurotoxicity

Selegiline (L-deprenyl) is believed to render protection against l-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-neurotoxicity to a significant extent via a free radical scavenging mechanism, which is independent of its ability to inhibit monoamine oxidase-B (MAO-B) in the brain. We investigated the hydroxyl radical (.OH) scavenging action and neuroprotective effect of D-deprenyl, its less active isomer, in MPTP-induced dopaminergic neurotoxicity in mice to test whether the chemical structure of the molecule or its biological effects contribute to this property. To achieve this goal we studied the effects of D-deprenyl on: (1).OH production in a Fenton reaction; (2) MPTP-induced.OH generation and dopamine (DA) depletion in vivo, employing a sensitive HPLC-electrochemical procedure; and (3) formation of MPP(+) in vivo in the striatum following systemic administration of MPTP, employing an HPLC-photodiode array detection system. D-deprenyl inhibited ferrous citrate-induced.OH in vitro (0.45 microM) and MPTP-induced.OH in vivo in substantia nigra (SN) and in the striatum (1.0 mg/kg, i.p.). D-deprenyl did not, but L-deprenyl (0.5 mg/kg dose) did significantly inhibit formation of MPP(+) in the striatum 90 min following systemic MPTP injection. It failed to affect MAO-B activity at 0.5 mg/kg in the striatum, but effectively blocked MPTP-induced striatal DA depletion. The potency of D-deprenyl to scavenge MPTP-induced.OH in vivo and to render protection against the dopaminergic neurotoxicity without affecting dopamine turnover, MAO-B activity, or formation of MPP(+) in the brain indicates a direct involvement of.OH in the neurotoxic action of MPTP and antioxidant effect in the neuroprotective action of deprenyl.