二苯乙烯苷对MPTP诱导的帕金森病小鼠模型黑质多巴胺转运体的影响

目的:研究2,3,5,4’-四羟基二苯乙烯-2-o-β-D-葡萄糖苷(2,3,5,4’-tetrahydroxystibene-2-o-β-D-gluco-side,TSG)对帕金森病(Parkinson’s disease,PD)小鼠黑质多巴胺转运体(dopamine transporter,DAT)表达的影响。方法:将1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)注入小鼠腹腔制作PD模型,然后采用爬杆实验和悬挂实验检测小鼠的行为学变化,免疫荧光组织化学法观察黑质DAT阳性神经元数目。结果:行为学检测结果表明:模型组小鼠较正常对照组爬杆时间延长,悬挂能力下降(P<0.01),而TSG干预后可有效缩短小鼠的爬杆时间,并提高其悬挂能力(P<0.05,P<0.01)。免疫荧光结果显示:模型组小鼠黑质DAT阳性神经元的数目明显少于正常对照组(P<0.01),而TSG干预后,小鼠DAT阳性神经元数目的减少降低(P<0.05,P<0.01)。结论:TSG可改善PD小鼠的行为学、提高黑质DAT阳性神经元的存活数目,表明TSG对黑质多巴胺能神经元有一定的保护作用。     

京尼平苷对MPTP所致帕金森病小鼠模型的神经保护作用研究

目的:观察京尼平苷对MPTP帕金森病小鼠黑质多巴胺能神经元的保护作用和对帕金森病的治疗作用。方法:制作MPTP帕金森病小鼠模型,将C57BL/6小鼠随机分为四组:对照组、京尼平苷组、MPTP组、和治疗组(MPTP+Geniposide)。通过行为学实验(转棒实验、游泳试验)、TH免疫组化实验和TUNEL染色,观察京尼平苷对MPTP小鼠行为学、黑质多巴胺能神经元数目和凋亡细胞数目的影响。结果:MPTP组出现了典型的PD行为学改变,小鼠掉落潜伏期和游泳行为评分均低于对照组(P0.01),黑质致密部TH阳性细胞数目较对照组明显减少(P0.001),凋亡细胞数目明显增多(P0.001)。治疗组与MPTP组相比,能明显改善MPTP诱导的C57BL/6小鼠的行为学异常,小鼠掉落潜伏期明显延长(P0.01),游泳行为评分亦显著提高(P0.01),同时,TH阳性细胞数目明显增多(P0.001),凋亡细胞数目明显减少(P0.001)。结论:京尼平苷能够明显改善MPTP引起的小鼠行为学改变,并能够抑制小鼠黑质TH阳性神经元的减少和凋亡细胞的增加。提示京尼平苷对MPTP帕金森病小鼠DA能神经元具有神经保护效应,这种保护作用可能与京尼平苷的抗凋亡作用有关。     

二苯乙烯苷通过抑制ROS减轻6-OHDA诱导的PC12细胞凋亡

目的:探讨2,3,5,4'-四羟基二苯乙烯-2-o-β-D-葡萄糖苷(2,3,5,4'-tetrahydroxystibene-2-o-β-D-glucoside,TSG)对6-羟基多巴胺(6-hydroxydopamine,6-OHDA)诱导的PC12细胞凋亡的影响及其可能的机制.方法:4-甲基偶氮唑蓝(MTT)检测...     

红景天苷对MPTP诱导的帕金森病小鼠黑质多巴胺转运蛋白的影响

目的:探讨红景天苷(salidroside,Sal)对帕金森病(Parkinson’s disease,PD)小鼠黑质多巴胺转运蛋白(dopamine transporter,DAT)表达的影响。方法:将神经毒素1-甲基-4苯基-1,2,3,6-四氢吡啶(1-methyl-4-phen-yl-1,2,3,6-tetrahydropyridine,MPTP)注入C57BL/6小鼠腹腔内,制备PD模型,Rotarod实验和游泳实验观察小鼠行为学变化,免疫荧光组织化学法检测黑质DAT阳性神经元数目的变化。结果:行为学实验结果显示,Rotarod实验中模型组小鼠在滚轴上运动的时间明显短于正常组(P<0.01),给予不同剂量的Sal后,小鼠在滚轴上运动的时间有所延长,并呈剂量依赖性(P<0.05,P<0.01)。游泳实验结果与Rotarod结果一致,模型组小鼠游泳时间明显短于正常组(P<0.01),给予不同剂量Sal后,小鼠游泳时间不同程度增加(P<0.05,P<0.01)。免疫荧光结果显示,模型组小鼠黑质中DAT阳性神经元的数目明显少于正常组(P<0.01),而给予不同剂量Sal干预后,小鼠DAT阳性神经元数目的减少有所恢复(P<0.05,P<0.01)。结论:Sal可以改善PD小鼠行为协调能力,提高DAT阳性神经元存活的数目,并呈剂量依赖性,表明Sal对多巴胺(dopamine,DA)能神经元具有一定的保护作用。     

二苯乙烯苷通过抑制氧化应激对MPP~+诱导的PC12细胞凋亡的保护作用

为了探讨2,3,5,4’-四羟基二苯乙烯-2-ο-β-D-葡萄糖苷(2,3,5,4’-tetrahydroxystibene-2-ο-β-D-glucoside,TSG)对1-甲基-4-苯基吡啶离子(1-methyl-4-phenylpyridinium,MPP+)诱导PC12细胞凋亡的影响及其可能机制,本实验分为对照组,MPP+处理组和TSG(1、5和10μmol/L)预处理组。用Hoechst33258染色法和流式细胞术测定细胞凋亡,对活性氧(reactive oxygen species,ROS)敏感的荧光探针2,7-dichlorofluorescin dictate(DCF-DA),丙二醛(malondialdehyde,MDA)和总抗氧化能力(total anti-oxida-tion competence,T-AOC)检测试剂盒测定细胞的氧化应激的变化。结果显示:TSG三个浓度预处理后,对比MPP+处理组,观察到TSG在一定范围内以剂量依赖方式,使细胞核凝聚明显减少,细胞凋亡率降低。另外,TSG预处理后,PC12细胞中增高的ROS和MDA水平较MPP+处理组明显有所减低,T-AOC有所增强。以上结果提示,TSG可抑制MPP+诱导的PC12细胞的凋亡,其机制可能与TSG抑制氧化应激有关。     

MPTP诱导的帕金森病小鼠模型表型特点

帕金森病(PD)研究使用最广泛的动物模型是神经毒素1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)诱导的小鼠损伤模型.该模型大致可以分为3种类型——急性、亚急性和慢性.这3种模型在黑质多巴胺(DA)能神经元丢失、纹状体DA损耗、路易小体形成和运动行为学缺陷等方面存在较大的差异.虽然目前关于MPTP小鼠模型是否能...     

JNK信号通路对亚急性帕金森病MPTP模型小鼠黑质iNOS表达的影响

目的:研究JNK在1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)所致小鼠帕金森病(PD)模型中对诱导型一氧化氮合酶(iNOS)表达的调控作用,探讨PD黑质多巴胺(DA)能神经元变性失活的可能机制.方法:采用神经毒素MPTP制备亚急性PD小鼠模型,健康雄性C57BL/6N小鼠随机分为模型组、JNK抑制剂组和对照组,采用行为学观察、免疫组织化学和免疫印迹法,观察模型小鼠行为学变化及中脑黑质酪氨酸羟化酶(TH)、 iNOS和磷酸化c-Jun(p-c-Jun)的表达变化;观察给予JNK通路特异性抑制剂SP600125对上述变化的影响.结果:与对照组相比,模型小鼠出现典型PD样症状.中脑黑质区TH阳性神经元下降约65%,中脑黑质TH表达水平显著降低约75%;黑质区iNOS和p-c-Jun阳性细胞明显增加,且p-c-Jun特异性表达于细胞核,中脑黑质iNOS与p-c-Jun表达水平明显升高.经SP600125处理后,模型小鼠PD样症状减轻,与对照组比较,TH阳性细胞数和TH表达水平仅下降约15%和25%,与模型组比较,黑质区iNOS与p-c-Jun阳性细胞减少,且p-c-Jun仅表达于胞质,中脑黑质iNOS与p-c-Jun表达水平明显下降.结论:JNK通路在MPTP诱导的亚急性PD小鼠黑质iNOS表达中可能起重要的调控作用;JNK通路特异性抑制剂SP600125可能对帕金森病小鼠具有一定的神经保护作用.     

二苯乙烯苷对沙鼠脑缺血/再灌注引发海马损伤的保护作用

目的　研究二苯乙烯苷（tetrahydroxy stilbene glucoside, TSG）对脑缺血/再灌注（ischemia/reperfusion, I/R）沙鼠脑海马损伤的保护作用及可能机制。 方法 采用结扎沙鼠双侧颈动脉缺血30 min,再灌注5 d复制沙鼠全脑I/R模型。沙鼠随机分为6组,假手术组、模型对照组、TSG大、中、小剂量（6、3、1.5 mg/kg）组和阳性对照药依达拉奉注射组（3 mg/kg）。5 d后通过Morris水迷宫测定沙鼠学习记忆功能;Nissl染色观察沙鼠大脑海马CA1区神经元结构和数量的变化;TUNEL染色法观察沙鼠大脑海马CA1区神经元凋亡的变化;Western blot法检测脑组织active-caspase-3的表达。 结果　与假手术组相比,I/R组沙鼠学习记忆能力明显降低,海马CA1区神经元大量丢失,结构紊乱。同时,I/R组沙鼠CA1区神经元凋亡数量明显增加,脑组织中caspase-3显著活化。TSG中、高（3、6 mg/kg）剂量组和依达拉奉阳性对照组均可以显著改善I/R引发的沙鼠学习记忆能力的降低,抑制海马CA1区神经元的丢失,改善神经元结构;抑制CA1区神经元的凋亡以及caspase-3的活化。而TSG低剂量组对上述变化均没有明显的治疗作用。 结论　TSG对于I/R引发的脑损伤,尤其是海马区神经元迟发性凋亡具有明显的治疗作用,这种作用与其抑制caspase-3的活化相关。     

二苯乙烯苷对β-淀粉样肽致痴呆模型小鼠行为及胆碱能功能的影响

老年性痴呆(alzheimer disease,AD)是以脑老化为基础的神经退行性疾病,发病机制复杂。研究表明,β-淀粉样肽(-βamyloid,Aβ)沉积是AD发病的中心环节。二苯乙烯苷(2,3,5,4-tetrahydroxy stilbene-2-O--βD-glycoside,TSG)是中药何首乌的主要有效成分。我室以往的研究表明,TSG可     

罗格列酮对帕金森病小鼠黑质内多巴胺能神经元的保护作用

目的:研究罗格列酮在1-甲基-4-苯基-1,2,3,6四氢吡啶(MPTP)所致帕金森病(PD)模型小鼠中对多巴胺能神经元的保护作用.方法:采用MPTP制备PD小鼠模型,观察各组小鼠行为学变化,免疫组织化学和免疫印迹观察中脑黑质酪氨酸羟化酶(TH)、环氧合酶(COX-2)和肿瘤坏死因子-α(TNF-α)的表达变化,及给予罗格列酮后对上述变化的影响.结果:模型组小鼠出现震颤、步态迟缓等PD样症状,黑质区TH阳性神经元缺失,炎症因子COX-2和TNF-α阳性细胞明显增多,蛋白水平亦升高;经罗格列酮治疗后,上述症状得到改善.结论:罗格列酮对模型小鼠多巴胺能神经元保护作用可能抑制炎症因子COX-2和TNF-α表达,从而减轻炎症反应.     

Preventive effect of antioxidants in MPTP-induced mouse model of Parkinson's disease

Oxidative stress to dopaminergic neurons is believed to be one of the causes of neurodegeneration in Parkinson's disease (PD). It was investigated whether N-acetylcysteine (NAC) and l-2-oxothiazolidine-4-carboxylate (OTC) have a preventive effect in an oxidative stress-induced model of PD. We found that NAC and OTC prevent degradation of PARP during auto-oxidized dopamine- or auto-oxidized L-DOPA-induced apoptosis in PC12 cells. In an animal model study, NAC and OTC showed a preventive effect against MPTP-induced loss of tyrosine hydroxylase-positive neurons, and suppressed the nuclear translocation of c-jun N-terminal kinase (JNK), suggesting that NAC and OTC can prevent MPTP-induced apoptosis by suppressing JNK activation. Therefore, these results suggest that NAC and OTC can be used as potential agents to prevent the progression of PD.     

硫辛酸对MPTP诱导的小鼠帕金森病模型的神经保护作用

目的:探讨α-硫辛酸(alpha-lipoic acid,ALA)在1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,MPTP)诱导的小鼠帕金森病(Parkinson disease,PD)模型中的神经保护作用。方法:建立MPTP诱导的PD小鼠模型后,通过旷场实验、悬绳实验和转棒实验评估ALA对PD小鼠运动缺陷的影响;通过免疫组化检测ALA对PD小鼠黑质和纹状体多巴胺能神经元的影响;通过高效液相色谱检测ALA对PD小鼠纹状体多巴胺(dopamine,DA)及其代谢产物3,4-二羟基苯乙酸(3,4-dihydroxyphenylacetic acid,DOPAC)释放的影响;通过免疫荧光检测ALA对PD小鼠黑质中小胶质细胞活化以及小胶质细胞中诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)表达的影响;通过Western blot检测ALA对PD小鼠纹状体中酪氨酸羟化酶(tyrosine hydroxylase,TH)和促炎分子白细胞介素1β(interleu...     

Proteasomal inhibition induced by manganese ethylene-bis-dithiocarbamate: relevance to Parkinson's disease

Maneb, a widely used fungicide, has been associated with Parkinsonism in humans. In experimental models, maneb and its major active element, manganese ethylene-bis-dithiocarbamate (Mn-EBDC) cause selective nigrostriatal neurodegeneration in mice and in rats, respectively. To investigate the mechanisms underlying this neurodegeneration, we studied the effects of Mn-EBDC on proteasomal function, which is decreased in patients with Parkinson's disease (PD), in a dopaminergic neuronal cell line (MES 23.5 or MES). The results demonstrated that exposure of MES cells to 6 microM Mn-EBDC for 7 days produced not only significant neurotoxicity but also inhibition of proteasomal chymotrypsin-like and postglutamyl peptidase activities. Proteasomal dysfunction was accompanied by formation of cytoplasmic inclusions that were positive for alpha-synuclein immunostaining and significantly increased sodium dodecyl sulfate-insoluble alpha-synuclein aggregation seen by Western blot analysis. In addition, there was a significant increase in oxidative stress, evidenced by elevated total protein carbonyl content, in cells treated with Mn-EBDC. Manipulation of intracellular reduced glutathione levels with N-acetyl-L-cysteine or L-buthionine sulfoximine pretreatment to modulate Mn-EBDC-mediated oxidative stress altered Mn-EBDC-mediated neurotoxicity, proteasomal dysfunction, and alpha-synuclein aggregation in these cells. These data suggest that neurotoxicity-induced by Mn-EBDC is at least partially attributable to Mn-EBDC-mediated proteasomal inhibition, and that the proteasome may be an important target by which environmental exposure modifies the risk for developing PD in vulnerable populations.     

Short-interval intracortical inhibition in Parkinson's disease using anterior-posterior directed currents

Reduced short-interval intracortical inhibition (SICI) is reported in Parkinson’s disease (PD) and is considered to reflect abnormal GABAergic inhibitory system of the primary motor cortex in PD. We have recently shown, however, that SICI using anterior-posterior directed currents in the brain was normal in focal dystonia even though that using posterior-anterior currents was abnormal, indicating that the GABAergic system of the primary motor cortex is largely normal in dystonia. Here, we studied SICI in PD to clarify whether the GABAergic system is completely impaired in PD. We used paired-pulse transcranial magnetic stimulation to study SICI at interstimulus intervals of 3 and 4 ms with anterior-posterior or posterior-anterior directed currents in eight PD patients and ten healthy volunteers. The amount of SICI with posterior-anterior directed currents was reduced in PD patients compared with healthy volunteers; in contrast, SICI studied with anterior-posterior directed currents was normal in PD patients. These observations may be due to the difference in I-wave composition generated by the two directed currents and/or the difference in responsible inhibitory interneurons for the inhibition between the two current directions. We suggest that some or a part of inhibitory interneurons are not involved in PD. This discrepancy between SICI using posterior-anterior and anterior-posterior directed currents experiments may provide additional information about the circuits of the motor cortex.     

Susceptibility in Parkinson's disease. 'Of mice and men'

Nowadays, a substantial amount of clinical and experimental research is directed to the role of reactive oxygen species in the pathogenesis of Parkinson's disease. On the other hand epidemiologic studies elicited the role of cytochrome P-450 and exposure to MPTP-analogues (such as paraquat) in the prevalence of this disease. Until now the relation between these two findings was not clear. In this paper a hypothesis is presented linking the present data on susceptibility towards Parkinson's disease.     

血管活性肠肽对MPTP亚急性帕金森病模型小鼠突触的影响

目的 探讨血管活性肠肽(VIP) 对1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）诱导的帕金森病(PD)小鼠模型突触及其行为学的影响. 方法 雄性C57BL/6 J小鼠30只,随机分为生理盐水(NS)组、MPTP组、MPTP+VIP组。利用Tru Scan系统测定小鼠的行为学变化;免疫组织化学染色法检测黑质和纹状体区酪氨酸羟化酶(TH)的表达及纹状体区突触小泡膜蛋白 2（VAMP2）和突触素1 (SYN1)的表达变化;运用免疫印迹法检测VAMP2和SYN1的表达变化;并通过透射电子显微镜观察黑质区突触的结构改变。 结果 行为学结果统计学分析,MPTP组小鼠的垂直运动距离比对照组明显减少,而给予VIP的小鼠明显高于MPTP组小鼠。 MPTP组TH、VAMP2和SYN1表达均明显少于NS组,而MPTP+VIP组显著高于MPTP组。透射电子显微镜结果显示,NS组神经突触结构完整; 模型组神经突触数量少,突触间隙不清,突触前成分的线粒体出现髓样变,并且突触小泡数量减少;MPTP+VIP组神经突触结构基本正常。 结论 VIP可使MPTP模型小鼠VAMP2和SYN1的表达上调,减少突触结构的损伤,保护黑质纹状体系统TH的表达,从而改善其运动状态。     

Mitochondrial complex I inhibition depletes plasma testosterone in the rotenone model of Parkinson's disease

Age-related depletion of testosterone may increase the brain's vulnerability to parkinsonian- or Alzheimer's-like neurodegenerative disorders. In rats, rotenone, a mitochondrial complex I inhibitor, causes specific nigral dopaminergic neurodegeneration producing parkinsonian symptoms. In this study, rotenone was administered on a daily basis (2 mg/kg i.p.) to two groups of rats, over a period of 30 and 60 days, respectively. In order to contribute towards the validation of the rotenone rat model, the changing level of the peripheral sex steroid hormone, testosterone, which would also mimic those found in Parkinson's disease (PD) patients, was evaluated. Parallel to this, prolactin, luteinizing hormone (LH), the nonsexual steroid thyroid-stimulating hormone, and the corticosterone hormone levels in the peripheral blood plasma were measured to show whether other hormones have also been affected by complex I inhibition. The rotenone treatment caused a decrease of testosterone level in the peripheral blood plasma. There were no differences in the thyroid hormone and prolactin but increases in leutinizing hormone and corticosterone were observed. Data from this study indicate that rotenone depleted the sex steroid hormone which is preferentially produced in the periphery, e.g., adrenal gland and testis. In conclusion, because a decrease in testosterone levels is also one of the comorbidities which are found in male PD patients, our results indicate that the rotenone model mimics PD symptoms not only on a neuronal and behavioral level, but also on the testosterone levels.