尼莫地平对帕金森病模型小鼠黑质多巴胺神经元的保护作用

目的:研究尼莫地平在1-甲基-4-苯基-1,2,3,6四氢吡啶(MPTP)所致帕金森病(PD)模型小鼠中对黑质多巴胺能神经元的保护作用。方法:雄性健康C57BL/6N小鼠随机分为对照组,腹腔注射生理盐水;模型组,腹腔注射MPTP(25 mg/kg);尼莫地平治疗组,每次注射MPTP前3 h灌胃给予尼莫地平(15 mg/kg)。观察各组小鼠行为学变化,免疫组织化学和免疫蛋白印迹法观察中脑黑质酪氨酸羟化酶(TH)、前列腺素E2(PGE2)和肿瘤坏死因子α(TNF-α)的表达变化。结果:与对照组小鼠比较,MPTP模型组小鼠出现典型的PD症状,中脑黑质TH阳性神经元大量丢失,PGE2和TNF-α阳性细胞显著增多,蛋白水平明显升高;经尼莫地平治疗后,上述症状得到明显改善。结论:在MPTP所致PD小鼠模型中,尼莫地平通过抑制炎症因子PGE2和TNF-α的表达从而对多巴胺能神经元具有一定的保护作用。     

红景天甙通过抑制肿瘤坏死因子-α表达对帕金森模型小鼠多巴胺能神经元的保护作用

目的;研究红景天甙对1-甲基-4苯基-1,2,3,6-四氢吡啶(MPTP)诱发的帕金森病(PD)小鼠模型黑质区多巴胺能神经元保护作用及其可能机制.方法:采用MPTP制备PD小鼠模型.将小鼠随机分为MPTP模型组、红景天甙组和对照组.对各组动物进行行为学观察,采用免疫组织化学、免疫蛋白印迹和免疫荧光双标法,观察各组小鼠中脑黑质区酪氨酸羟化酶(TH)、肿瘤坏死因子-α(TNF-α)阳性细胞表达和蛋白水平的变化;观察红景天甙对上述变化的影响.结果:与对照组小鼠相比,模型组小鼠出现典型的PD样症状.MPTP模型组黑质区(SN) TH阳性神经元和蛋白表达水平较对照组减少约为40％和60％,TNF-α阳性细胞和蛋白表达水平增加;经红景天甙处理后,上述变化均减轻.结论:红景天甙可在一定程度上阻抑MPTP诱导的PD模型小鼠黑质区多巴胺能神经元的丢失;其神经保护机制可能与抑制TNF-α的表达有关.     

小白菊内酯对帕金森病小鼠模型黑质多巴胺能神经元的保护作用

目的:探讨小白菊内酯在帕金森病小鼠模型中抑制核因子NF-κB(nuclear factor kappa B)信号通路对多巴胺(DA)能神经元的保护作用。方法:将C57BL/6N小鼠随机分为模型组、干预组和对照组。通过行为学、免疫组织化学和免疫蛋白印记法观察各组小鼠中脑黑质区酪氨酸羟化酶(TH)、核因子NF-κB、环氧合酶-2(COX-2)和半胱氨酸天冬氨酸蛋白酶-3(caspase-3)的表达变化情况。结果:与对照组相比,模型组小鼠出现典型PD症状,TH阳性神经元明显丢失、蛋白水平下降,NF-κB、COX-2和caspase-3阳性细胞大量表达,蛋白水平显著升高(P0.01)。抑制剂组小鼠上述变化明显减轻(P0.01)。结论:在MPTP所致PD模型小鼠中,小白菊内酯通过抑制核因子NF-κB信号通路减少凋亡蛋白caspase-3表达,从而发挥神经保护作用。     

罗格列酮联合替米沙坦在治疗小鼠MPTP致帕金森病中的神经保护作用

目的:探讨罗格列酮与替米沙坦单独用药与联合用药对帕金森病(PD)多巴胺(DA)能神经元的保护作用。方法:采用MPTP制备PD亚急性小鼠模型,免疫组织化学和免疫蛋白印迹法检测小鼠中脑黑质酪氨酸羟化酶(TH)、诱导型一氧化氮合酶(i NOS)、NADPH氧化酶活化蛋白(p47)的表达变化,观察单独给予罗格列酮、替米沙坦及两者联合给药后对上述变化的影响。结果:与对照组相比,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,i NOS、p47阳性细胞明显增多,两蛋白水平亦升高;单独给予罗格列酮或替米沙坦后,上述情况得到改善;罗格列酮和替米沙坦联合用药后,改善程度较单独用药更为明显。结论:罗格列酮联合替米沙坦通过抑制PD小鼠模型中脑黑质i NOS和p47的表达,对DA能神经元起到一定的保护作用。     

p38MAPK抑制剂对MPTP模型小鼠黑质多巴胺能神经元的保护作用

目的:研究SB239063在1-甲基-4-苯基-1,2,3,6四氢吡啶(MPTP)所致帕金森病(PD)模型小鼠中抑制p38丝裂原激活蛋白激酶(mitogen-activated protein kinase,MAPK)活化对多巴胺(DA)能神经元的保护作用。方法:雄性C57BL/6N小鼠随机分为MPTP(30 mg/kg)模型组;SB239063(5 mg/kg)抑制剂组;SB239063(15 mg/kg)抑制剂组;SB239063(25 mg/kg)抑制剂组。抑制剂组于每次注射MPTP前3 h腹腔注射SB239063;对照组注射与模型组和抑制剂组等量生理盐水和DMSO。采用免疫组织化学和免疫蛋白印迹法观察各组小鼠黑质酪氨酸羟化酶(TH)和磷酸化p38蛋白激酶(p-p38 protein kinase,p-p38MAPK)之间表达变化的关系。结果:模型组小鼠黒质区p38MAPK显著活化,同时伴有TH阳性神经元明显丢失;SB239063 15 mg/kg与25 mg/kg组均可明显减少TH神经元丢失,而5 mg/kg组无显著影响;免疫荧光双标记结果显示p38MAPK与TH阳性神经元存在共表达。结论:p38MAPK对PD模型小鼠中脑黑质多巴胺能神经元丢失可能有重要调控作用,SB239063对多巴胺神经元具有一定的神经保护作用。     

环加氧酶-2对帕金森病模型小鼠黑质多巴胺能神经元的影响

目的　观察COX 2对帕金森病小鼠黑质多巴胺能神经元的影响。方法　选用C5 7BL种系环加氧酶 2 (Cyclooxygenase 2 ,COX 2 )缺陷小鼠 ,腹腔注射 1 甲基 4 苯基 1,2 ,3,6 四氢吡啶 (MPTP)制备帕金森病小鼠模型 ,用免疫组织化学方法。结果　行为学及免疫组织化学观察显示 ,野生型帕金森病小鼠的死亡率明显高于COX 2缺陷杂合子帕金森病小鼠 (P <0 0 1) ;野生型帕金森病小鼠黑质致密部酪氨酸羟化酶 (Ty rosineHydroxylase ,TH)免疫反应阳性神经元数目较杂合子帕金森病小鼠明显减少 (P <0 0 1)。结论　COX 2很可能与帕金森病时黑质多巴胺能神经元的损伤有关     

G-CSF对帕金森病小鼠运动能力和黑质纹状体神经元的影响

目的:探讨粒细胞集落刺激因子(G-CSF)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)所致小鼠帕金森病(PD)模型中脑黑质致密部(SNpc)及纹状体(STR)多巴胺(DA)能神经元的影响。方法:正常健康雄性C57BL/6J小鼠随机分为对照组、MPTP组及MPTP+G-CSF组,采用腹腔注射MPTP法制作小鼠PD模型,MPTP+G-CSF组于最后一次MPTP注射后再腹腔注射G-CSF。爬杆实验观察小鼠的行为学改变;尼氏染色技术观察各组小鼠黑质致密部神经元数量及形态学变化;免疫组织化学法检测酪氨酸羟化酶(TH)在各组小鼠中脑黑质致密部及纹状体的表达; Western Blot法检测各组小鼠中脑TH蛋白的表达量。结果:与对照组相比,MPTP组小鼠较对照组爬杆用时显著延长(P 0. 05),尼氏染色显示黑质致密部神经元数量显著减少(P 0. 05),黑质致密部、纹状体TH表达量显著减少(P 0. 05); MPTP+G-CSF组较MPTP组爬杆用时显著缩短(P 0. 05),神经元丢失减少(P 0. 05),神经元形态较完整;与MPTP组比较,MPTP+G-CSF组黑质致密部、纹状体TH表达水平显著增高(P 0. 05)。结论:G-CSF能够改善PD小鼠运动功能,减少黑质致密部多巴胺能神经元丢失,增加TH表达水平。     

帕金森病小鼠黑质多巴胺能神经元凋亡诱导因子核移位的研究

目的探讨帕金森病(PD)小鼠模型黑质凋亡诱导因子(AIF)的核移位情况及其与多巴胺(DA)能神经元损伤之间的关系。方法采用1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)制备PD小鼠模型,2h、24h、72h后取中脑组织进行酪氨酸羟化酶免疫染色观察黑质DA能神经元的损害情况,AIF免疫组化染色和Western blot方法检测AIF的核移位情况。结果与对照组比较,PD组小鼠黑质DA能神经元数量随时间呈递减趋势,并出现AIF核移位,2h时达高峰,之后随时间呈下降趋势。结论AIF核移位是PD小鼠黑质DA能神经元损伤的早期指标,在PD的发病过程中发挥重要作用。     

脑内炎症反应对大鼠黑质多巴胺能神经元长时程毒性作用的研究

目的观察黑质部位炎症反应对多巴胺能神经元的长时程毒性作用,探讨脑内炎症反应在黑质多巴胺能神经元慢性变性过程中的作用。方法健康SD雄性大鼠28只,随机分为生理盐水组和10μg、25μg、50μg脂多糖组。定位注射生理盐水或脂多糖入右侧脑室,术后24周观察大鼠行为学改变,免疫组织化学染色观察黑质部位小胶质细胞的激活情况及酪氨酸羟化酶阳性神经元的变化。结果1.大鼠行为学观察显示,10μg、25μg和50μg脂多糖组大鼠的平均运动速度与对照组相比,差异无统计学意义。2.OX-42免疫组织化学染色显示,10μg和25μg脂多糖组大鼠黑质部位小胶质细胞激活明显。50μg脂多糖组大鼠黑质部位小胶质细胞激活不明显。3.酪氨酸羟化酶免疫组织化学染色显示,10μg和25μg脂多糖组大鼠黑质酪氨酸羟化酶阳性神经元与对照组相比,胞体变小,突起减少甚至消失,染色变浅;50μg脂多糖组大鼠酪氨酸羟化酶阳性神经元形态与对照组相比没有明显改变。4.酪氨酸羟化酶阳性细胞计数显示,10μg和25μg脂多糖组大鼠与对照组比较,分别减少15.5%(P<0.01)和20.1%(P<0.01);50μg脂多糖组大鼠与对照组比较没有统计学差异。结论脑室注射脂多糖引发的脑内炎症可导致黑质多巴胺能神经元变性,这一过程呈慢性迟发性;同时,低剂量脂多糖激活小胶质细胞对黑质多巴胺能神经元的慢性毒性作用更为明显;该病理过程较好地模拟了帕金森病的发病特点。     

α-突触核蛋白过表达对黑质多巴胺能神经元酪氨酸羟化酶表达的影响

目的 研究α-突触核蛋白(α-synuclein，α-SYN)过表达对多巴胺能神经元酪氨酸羟化酶(TH)表达的影响。方法 在α—SYN基因转染的MES 23．5大鼠黑质多巴胺能神经元细胞系，分别用免疫组织化学、免疫荧光、Western blot等方法分析α-SYN和TH的表达以及两者之间的关系。通过绘制生长曲线和MTT测试细胞氧化还原活性，观察α—SYN基因转染细胞的生长和损伤情况。结果 α-SYN过表达明显抑制MES 23．5多巴胺能神经元的TH表达，但对该细胞的生长和增殖无明显影响，也不引起该细胞损伤。结论 α-SYN过表达对多巴胺能神经元的TH表达具有抑制作用。     

硫辛酸对LPS诱导的帕金森病小鼠黑质多巴胺能神经元损伤的影响

目的:探讨硫辛酸(LA)对脂多糖(LPS)诱导的帕金森病(PD)模型小鼠黑质多巴胺(DA)能神经元损伤的作用及机制。方法:10月龄雌性C57BL/6小鼠,随机分为生理盐水对照组、PD模型组和LA干预组。采用鼻腔滴入LPS制作PD小鼠模型,通过爬竿实验及酪氨酸羟化酶和p-NF-κB/p65的免疫组化技术观察LA对DA能神经元的保护作用。结果:LPS经鼻可以成功诱导小鼠PD模型,给予LA可明显恢复小鼠运动,减少黑质DA能神经元的丢失、抑制小胶质细胞及其NF-κB信号通路激活。结论:LA干预可缓解LPS经鼻诱导的小鼠PD行为学和病理学的改变,其作用机制可能与抑制脑内的炎症反应有关。     

人参皂甙Rb1抑制1-甲基-4-苯基-1,2,3,6-四氢吡啶所致的内质网应激对多巴胺能神经元的保护作用

目的:研究内质网应激反应在1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)所致帕金森病(PD)小鼠模型黑质区多巴胺能神经元凋亡的作用.方法:将小鼠随机分为MPTP模型组、Rb1干预剂组和对照组.观察行为学,免疫组织化学和免疫蛋白印迹法观察黑质酪氨酸羟化酶(TH)、葡萄糖调节蛋白78 (GRP78)、半胱氨酸蛋白酶-12 (caspase-12)和半胱氨酸蛋白酶-3 (caspase-3)的表达.结果:与对照组相比,模型组小鼠出现典型PD症状,TH阳性神经元明显丢失、蛋白水平下降,GRP78、caspase-12、caspase-3阳性细胞及蛋白水平增加;经人参皂甙Rb1处理后,上述变化均减轻.结论:内质网应激(ERS)在MPTP诱导的PD小鼠模型多巴胺能神经元凋亡中可起重要作用,人参皂甙Rb1可通过抑制ERS而对PD小鼠具有一定的神经保护作用.     

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.     

SP600125, a new JNK inhibitor, protects dopaminergic neurons in the MPTP model of Parkinson's disease

Increasing evidence suggests that c-Jun N-terminal kinase (JNK) is an important kinase mediating neuronal apoptosis in Parkinson's disease (PD) model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In order to study roles of JNK activity in neuronal apoptosis in this model, we blocked JNK activity in vivo using a specific inhibitor of JNK, SP600125. Our data showed that MPTP-induced phospho-c-Jun of substantial nigral neurons, caused apoptosis of dopaminergic neurons, and decreased the dopamine level in striatal area. We found that inhibiting JNK with SP600125 reduced the levels of c-Jun phosphorylation, protected dopaminergic neurons from apoptosis, and partly restored the level of dopamine in MPTP-induced PD in C57BL/6N mice. These results indicate that JNK pathway is the major mediator of the neurotoxic effects of MPTP in vivo and inhibiting JNK activity may represent a new and effective strategy to treat PD.     

Intrastriatal administration of erythropoietin protects dopaminergic neurons and improves neurobehavioral outcome in a rat model of Parkinson's disease

Erythropoietin (EPO), a hematopoietic cytokine, has recently been demonstrated to protect nigral dopaminergic neurons in a mouse model of Parkinson's disease (PD). In the present study, we tested the hypothesis that recombinant human erythropoietin (rhEPO) could protect dopaminergic neurons and improve neurobehavioral outcome in a rat model of PD. rhEPO (20 units in 2 microl of vehicle) was stereotaxically injected into one side of the striatum. 6-hydroxydopamine (6-OHDA) was injected into the same side 1 day later. Another group of rats received rhEPO (5000 u/kg, i.p.) daily for 8 days, and unilateral injection of 6-OHDA in the striatum 3 days after systemic administration of rhEPO. We observed that intrastriatal administration, but not systemic administration of rhEPO significantly reduced the degree of rotational asymmetry. The rhEPO-treated rats also showed an improvement in skilled forelimb use when compared with control rats. The number of tyrosine hydroxylase (TH)-immunoreactive (IR) neurons in the ipsilateral substantia nigra (SN) was significantly larger in intrastriatal rhEPO-treated rats than that in control rats. TH-IR fibers in the 6-OHDA-lesioned striatum were also increased in the intrastriatal rhEPO-treated rats when compared with control rats. In addition, there were lower levels of expression of major histocompatibility complex (MHC) class II antigens and a smaller number of activated microglia in the ipsilateral SN in intrastriatal rhEPO-treated rats than that in control rats at 2 weeks, suggesting that intrastriatal injection of rhEPO attenuated 6-OHDA-induced inflammation in the ipsilateral SN. Our results suggest that intrastriatal administration of rhEPO can protect nigral dopaminergic neurons from cell death induced by 6-OHDA and improve neurobehavioral outcome in a rat model of PD. Anti-inflammation may be one of mechanisms responsible for rhEPO neuroprotection.     

ATP13A2 protects dopaminergic neurons in Parkinson's disease: from biology to pathology

As a late endosomal/lysosomal transport protein of the P5-type, ATP13A2 is capable of removing the abnormal accumulation of α-synuclein, which maintains the homeostasis of metal ions and polyamines in the central nervous system. Furthermore, ATP13A2 regulates the normal function of several organelles such as lysosomes, endoplasmic reticulum (ER) and mitochondria, and maintains the normal physiological activity of neural cells. Especially, ATP13A2 protects dopaminergic (DA) neurons against environmental or genetically induced Parkinson's disease (PD). As we all know, PD is a neurodegenerative disease characterized by the loss of DA neurons in the substantia nigra pars compacta. An increasing number of studies have reported that the loss-of-function of ATP13A2 affects normal physiological processes of various organelles, leading to abnormalities and the death of DA neurons. Previous studies in our laboratory have also shown that ATP13A2 deletion intensifies the neuroinflammatory response induced by astrocytes, thus inducing DA neuronal injury. In addition to elucidating the normal structure and function of ATP13A2, this review summarized the pathological mechanisms of ATP13A2 mutations leading to PD in existing literature studies, deepening the understanding of ATP13A2 in the pathological process of PD and other related neurodegenerative diseases. This review provides inspiration for investigators to explore the essential regulatory role of ATP13A2 in PD in the future.     

Enriched NCAM-positive cells form functional dopaminergic neurons in the rat model of Parkinson's disease

We describe a method of generating an enriched population of NCAM-positive cells from a human teratocarcinoma cell line (NTera2/D1) and their differentiation into midbrain dopaminergic neurons in the absence of the caudalizing factor retinoic acid (RA). NTera2 cells were induced to form embryoid bodies and then to generate nestin-positive cells on treatment with serum-free defined medium supplemented with neurotrophic factors. We enriched the neuroprogenitor population by magnetic sorting of the nestin-positive cells using the antibody to neural cell adhesion molecule (NCAM). These cells were expanded by exposing them to the signaling molecule sonic hedgehog (SHH) in conjunction with fibroblast growth factor-8 (FGF-8). The predifferentiated cells when analyzed by RT-PCR showed expression of dopaminergic markers such as Nurr1, Engrailed-1, aromatic amino decarboxylase (AADC), VMAT2, tyrosine hydroxylase (TH), and dopamine transporter (DAT). These cells also stained positively for protein markers such as nestin, NCAM, MAP-2, and TH. We further demonstrated that when transplanted into the brain of Parkinsonian rats, these neuroprogenitor cells did not form tumors but differentiated into dopaminergic neurons, as revealed by TH immunolabeling. The origin of transplanted cells were further confirmed by positive immunolabeling with anti-human nuclei. Our results suggest that enriching the neuroprogenitor population by magnetic sorting prevents tumor formation and is a prerequisite before cell replacement therapy for Parkinson's disease.