移植的神经干细胞在MPTP诱导的帕金森病小鼠脑内的存活与分化

AIM: To determine survival and differentiation of cultured neural stem cells (NSCs) into viable and functional neurons upon transplantation into mice brain of MPTP-induced Parkinson disease (PD). METHODS: Mouse model of PD was established with two subcutaneous (sc) injections of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP,40mg/kg) twice, 16h apart. NSCs isolated from rat embryo midbrain were cultured in clonal density.After labeled with 5-bromo-2'-deoxyuridine (BrdU), the NSCs were transplanted into the uni-or bi-lateral striatumof PD mouse. Tyrosine hydroxylase (TH) immunofluorescence was used to evaluate the toxicity of MPTP on the neural cells in the substantia nigra. Immunohistology and laser confocal microscope were used to detect the survival and differentiation of transplanted NSCs. RESULTS: The cultured NSCs generated neurospheres and differentiated into neuron and astrocyte. It indicated that the cultured NSCs were multipotent and self-renewal in vitro.TH-positive neural cells were significantly reduced in the substantia nigra. Immunohistology showed that the uni-or bi-lateral transplanted NSCs survived in the brain of PD model mouse. Laser confocal microscope indicated that some transplanted NSCs could properly differentiate into targeted TH-positive neural cells in vivo. CONCLUSION:The transplanted multipotent NSCs could survive and differentiate into functional dopamine neurons.     

白藜芦醇抗帕金森病黑质细胞凋亡的实验性研究

目的　研究帕金森病(PD)动物模型黑质细胞的凋亡情况及白藜芦醇对神经的保护作用。方法　成年健康SD大鼠1 0 0只,分为5组,每组2 0只。PD模型组应用脑立体定位仪注入6 羟基多巴胺和0 . 2 %抗坏血酸生理盐水混合液至中脑黑质,诱发PD模型;白藜芦醇实验组应用脑立体定位仪注入6 羟基多巴胺和白藜芦醇混合液;正常对照组应用脑立体定位仪注入0 . 2 %抗坏血酸生理盐水混合液,术后观察SD大鼠旋转行为,及应用TH免疫组化和Tunel法观察白藜芦醇对黑质神经元的保护作用。结果　TH染色可见白藜芦醇实验组黑质部位损毁较轻、有较多的残存TH阳性细胞。6 羟基多巴胺模型组TH染色黑质大部毁损,几乎无残存的TH阳性细胞。旋转试验结果,白藜芦醇实验组大鼠旋转次数平均2 0 6圈/ 30分;6 羟基多巴胺模型组模型鼠旋转次数平均31 4圈/ 30分;两者存在统计学差异(P <0 . 0 5 )。术后第2天检测黑质细胞凋亡情况,白藜芦醇实验组黑质细胞凋亡较少,细胞棕黑色,可见凋亡小体;6 羟基多巴胺模型组黑质细胞凋亡数量较多。结论　白藜芦醇具有神经保护作用。     

白藜芦醇抗帕金森病黑质细胞凋亡的实验性研究

目的　研究帕金森病(PD)动物模型黑质细胞的凋亡情况及白藜芦醇对神经的保护作用。方法　成年健康SD大鼠100只,分为5组,每组20只。PD模型组应用脑立体定位仪注入6-羟基多巴胺和0.2 %抗坏血酸生理盐水混合液至中脑黑质,诱发PD模型;白藜芦醇实验组应用脑立体定位仪注入6-羟基多巴胺和白藜芦醇混合液;正常对照组应用脑立体定位仪注入0.2 %抗坏血酸生理盐水混合液,术后观察SD大鼠旋转行为,及应用TH免疫组化和Tunel法观察白藜芦醇对黑质神经元的保护作用。结果　TH染色可见白藜芦醇实验组黑质部位损毁较轻、有较多的残存TH阳性细胞。6-羟基多巴胺模型组TH染色黑质大部毁损,几乎无残存的TH阳性细胞。旋转试验结果,白藜芦醇实验组大鼠旋转次数平均206圈/ 30分;6-羟基多巴胺模型组模型鼠旋转次数平均314圈/ 30分;两者存在统计学差异(P<0.05 )。术后第2天检测黑质细胞凋亡情况,白藜芦醇实验组黑质细胞凋亡较少,细胞棕黑色,可见凋亡小体;6-羟基多巴胺模型组黑质细胞凋亡数量较多。结论　白藜芦醇具有神经保护作用。     

类叶升麻苷对MPTP所致帕金森病小鼠模型的神经保护作用

目的研究类叶升麻苷在MPTP诱导的C57小鼠的帕金森病(PD)模型中的神经保护作用及机制。方法通过自主活动实验和滚筒实验研究动物的行为表现,通过高效液相电化学检测方法观察脑纹状体多巴胺的变化,通过脑黑质酪氨酸羟化酶(tyroxinehydroxylase,TH)免疫组化染色观察多巴胺能神经元的损伤程度。并对黑质纹状体进行α-突触核蛋白(α-synuclein)的免疫印迹分析以探讨药物作用机制。结果①经MPTP诱导的C57小鼠,其自主活动次数、滚筒运动潜伏期均低于对照组(P<0·01);纹状体多巴胺含量明显降低(P<0·01);多巴胺能神经元数量明显减少;黑质纹状体α-synuclein蛋白水平下降。②经类叶升麻苷(10、30mg·kg-1)预处理后能明显改善MPTP诱导的C57小鼠的行为学表现,增加脑内多巴胺递质的含量,增加多巴胺能神经元的数量,增加黑质纹状体α-synuclein蛋白水平。结论类叶升麻苷具有神经保护作用,能对抗MPTP诱导的C57小鼠PD模型中的神经损伤。其机制可能与上调α-synuclein蛋白水平有关。     

Effect of angiotensin-converting enzyme inhibitor perindopril on interneurons in MPTP-treated mice.

We examined the effects of perindopril on the dopaminergic system in mice after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment. The mice received four intraperitoneal injections of MPTP at 1-h intervals. Administration of perindopril showed dose-dependent neuroprotective effects against striatal dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) depletion 3 days after MPTP treatment. Our immunohistochemical study showed that MPTP can severe damage in tyrosine hydroxylase (TH)-immunoreactive neurons after MPTP treatment. The administration of perindopril significantly attenuated MPTP-induced substantia nigra and striatal damage. The present study also showed that the immunoreactivity of parvalbumin (PV)- or neuronal nitric oxide synthase (nNOS)-positive cells in the substantia nigra was decreased 7 days after MPTP treatment, whereas no significant changes were observed in these cells of the striatum throughout the experiments. The administration of perindopril significantly attenuated MPTP-induced decrease of the PV- or nNOS-immunoreactivity in the nigral cells. In double-labeled immunostaining with anti-PV and anti-nNOS antibody, PV-immunoreactive cell bodies and fibers were not double-labeled for nNOS-immunoreactive cell bodies and fibers in both the striatum and substantia nigra after MPTP treatment. Furthermore, PV- or nNOS-immunoreactive cell bodies and fibers in both the striatum and substantia nigra were not double-labeled for TH-immunoreactive cell bodies and fibers. These results demonstrate that the ACE inhibitor perindopril has a dose-dependent protective effect against MPTP-induced striatal dopamine, DOPAC and HVA depletion in mice. The present study also demonstrates that perindopril is effective against MPTP-induced degeneration of the nigral neurons and interneurons. Furthermore, our immunohistochemical study suggests that PV-immunoreactive cells and nNOS-immunoreactive cells are different interneurons in both the striatum and substantia nigra. Thus, our results provide further evidence that the ACE inhibitor perindopril may offer a novel therapeutic strategy for Parkinson's disease (PD).     

Biochemical and immunohistological changes in the brain of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mouse.

We investigated neurochemically and neuropathologically the utility of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice as a model of Parkinson's disease. The changes in dopamine D1 and D2 receptors and dopamine uptake sites were determined by quantitative autoradiography using [3H]SCH23390, [3H]raclopride and [3H]mazindol, respectively. Dopamine and 3,4-dihydroxyphenyl acetic acid (DOPAC) contents in the striatum were measured by high-performance liquid chromatography. The distribution of nigral neurons and reactive astrocytes was determined by immunohistochemical staining with antibody against tyrosine hydroxylase (TH) and glial fibrillary acidic protein (GFAP). The mice received four intraperitoneal injections of MPTP (10 mg/kg) at 1-h intervals and then the brains were analyzed at 3 and 7 days after the treatments. No significant change in dopamine D1 receptors was observed in the striatum and substantia nigra after acute treatment with MPTP. Dopamine D2 receptors were reduced significantly in the substantia nigra only 7 days after the MPTP treatment, whereas striatum showed no significant change in the binding throughout the experiments. In contrast, dopamine uptake sites were reduced markedly in the striatum and substantia nigra 3 and 7 days after the MPTP treatment. Dopamine and DOPAC content were also reduced in the striatum 3 and 7 days after the MPTP treatment. An immunohistochemical study indicated a loss of the number of TH-positive neurons in the substantia nigra 7 days after the MPTP treatment. In contrast, numerous GFAP-positive astrocytes were evident in the striatum 7 days after the MPTP treatment. These results provide valuable information for the pathogenesis of acute stage of Parkinson's disease.     

人参皂苷Rg1抗黑质神经元凋亡的可能机制

目的研究人参皂苷Rg1抗1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,MPTP)诱导的小鼠黑质神经元凋亡的作用及其机制。方法MPTP制备的帕金森病(Parkinson′s disease,PD)小鼠模型,经人参皂苷Rg1预处理后,用尼氏(Nissl)染色和TH组化染色观察黑质神经元的损害情况,借助TUNEL染色了解黑质神经元的凋亡情况,并用免疫组织化学方法检测黑质神经元caspase-3的活化以及iNOS和nNOS的表达情况。结果人参皂苷Rg1预处理能减少PD鼠模型黑质致密带Nissl阳性神经元和TH阳性神经元的脱失现象,降低黑质神经元TUNEL染色的阳性率。结论人参皂苷Rg1预处理对MPTP诱导的小鼠黑质神经元凋亡有明显的保护作用。     

移植神经干细胞在脑缺血大鼠损伤脑区的定向分化及其对运动功能的影响

目的:研究神经干细胞(NSCs)移植对大鼠脑缺血模型损伤脑区结构和功能的影响。方法:从新生的Wistar大鼠脑组织中分离、培养NSCs。制作大鼠脑缺血再灌注模型,24h后移植BrdU标记的NSC于梗死灶同侧的侧脑室。记录损伤和移植后的大鼠运动功能评分,研究移植后的NSC迁徙、定向分化的情况及其与宿主细胞间的关系。结果:大鼠NSCs移植后部分可在体内存活并迁徒至脑缺血病灶区,在缺血区内能分化成为神经元细胞并与宿主神经细胞形态一致,运动神经功能评分与对照组相比有统计学差异(P<0.05)。结论:移植的NSCs对缺血损伤脑区结构有修复作用,可改善脑缺血模型动物运动功能。     

银杏叶提取物对1—甲基—4—苯基—1，2，3，6—四氢吡啶所致帕金森症的保护作用及机制

目的:观察银杏叶提取物(EGb)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)及其离子1-甲基-4-苯基吡啶(MPP~ )诱导的帕金森症(PD)模型的保护作用。方法:用脑立体定位仪向黑质(AP-5.4mm,-2.2mm,H8.3mm)内注射MPTP诱导大鼠旋转。在注射MPTP 24h后将大鼠处死,硫代巴比妥法测定黑质中丙二醛(MDA),羟胺法(即改进的黄嘌呤氧化酶法)测定黑质中超氧化物歧化酶(SOD),荧光分光光度法(激发波长310nm,发射波长390nm)测定纹状体中多巴胺(DA)的含量。MPP~ 诱导PC12细胞凋亡,HE染色,光镜下观察凋亡细胞;吖啶橙/溴乙锭(AO/EB)染色,荧光显微镜记数凋亡细胞,观察不同浓度EGb(25,50,100mg/L)在6h,12h,24h对细胞凋亡率的影响。结果:EGb 100mg/kg组可减少模型鼠的旋转次数及旋转持续时间(n=10,P<0.05);与MPTP组比较,EGb 50mg/kg和100mg/kg组MDA相对降低,SOD及DA相对增高(n=10,P<0.05和P<0.01)。MPP~ 10μmol/L可诱导PC12细胞凋亡,EGb 50和100mg/L组在6h,12h,24h可降低细胞凋亡率(P<0.05和P<0.01,n=3)。结论:EGb对MPTP诱导的PD动物模型及其离子MPP~ 诱导的PD细胞模型均有保护作用,其保护机制与清除自由基及抑制神经元凋亡有关。     

Cell death induced by MPTP, a substrate for monoamine oxidase B

MPTP is known to cause PD symptoms in primates and in rodents. In order to exert its neurotoxicity MPTP must be converted by monoamine oxidase B into MPP(+) which is the true toxic agent. MPP(+) is taken up by the dopaminergic neurons of the substantia nigra in which it induces cell death. The present work reviews and discusses papers in which specific methods were used to determine whether cell death induced by MPTP/MPP(+) should be considered as apoptosis or necrosis. These two cell death modes may be distinguished using morphological and biochemical criteria. The effect of MPTP/MPP(+) was studied in vitro and in vivo. The results show that no univocal answer is possible. The most widespread interpretation is that MPTP/MPP(+) causes apoptosis when its neurotoxic effect is only sligh and necrosis when it is stronger. Similar considerations may be made also concerning the type of cell death occurring in the dopaminergic neurons in the substantia nigra of PD patients.     

人参皂苷Rg1对小鼠1—甲基—4—苯基—1，2，3，6—四氢吡啶诱导的黑质神经元凋亡的保护作用

目的:探讨人参皂苷Rg1对抗1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)诱导的C57BL小鼠黑质神经元凋亡的可能机制.方法:MPTP(30 mg·kg~(-1)·d~(-1)×5 d)腹腔注射制备C57BL小鼠帕金森病模型,同时预防组分别以不同剂量人参皂苷Rg1(2.5、5.0、10.0 mg·kg~(-1)·d~(-1)×8 d)于MPTP注射前预先腹腔注射小鼠.用Nissl染色和TH组化染色观察黑质损害情况,TUNEL染色检测细胞凋亡,同时运用免疫组织化学方法检测caspase-3的活性片段以及Bcl-2、Bcl-xl、Bax、iNOS和 nNOS的表达情况.结果:人参皂苷Rg1(5.0和10.0 mg/kg)预处理能使黑质致密带Nissl阳性神经元和TH阳性神经元的脱失减少,同时降低了TUNEL阳性率,并伴有Bcl-2和Bcl-xl表达增加,Bax和iNOS表达减少以及抑制caspase-3的激活.结论:人参皂苷Rg1预处理对MPTP诱导的小鼠黑质神经元凋亡有明显的保护作用,其作用可能是通过降低iNOS和Bax蛋白表达,增加Bcl-2和Bcl-xl蛋白表达以及抑制caspase-3的激活来实现的.     

神经干细胞移植对Alzheimer病大鼠脑形态及动物行为学影响

目的 :观察移植入 Alzheimer病 (AD)大鼠脑内的神经干细胞存活、分化及功能。方法 :由新生大鼠海马分离培养神经干细胞 ,采用切断穹窿海马伞的方法制作 AD大鼠模型 ,模型建立 8～ 10 d后行神经干细胞移植。移植 1个月后 ,通过暗回避试验检测大鼠的学习记忆能力 ,应用尼氏染色 ,乙酰胆碱酯酶 (Ach E)染色观察体内移植神经干细胞的存活 ,分化以及 AD大鼠 Ach E纤维密度的变化。结果 :神经干细胞在额叶和海马都能够存活 ,分化成神经元 ,可与宿主建立突触联系 ,在海马区移植神经干细胞的生长优于额叶。与对照组相比 ,接受神经干细胞移植鼠的暗回避潜伏期变长 (P <0 .0 5 ) ,探索次数减少(P<0 .0 5 ) ,海马 Ach E纤维密度增加 (P <0 .0 5 )。结论 :神经干细胞能够在 AD大鼠额叶、海马存活、分化 ,并可导致 Ach E纤维密度增加 ,AD大鼠学习、记忆能力改善     

Regional and temporal expression of the peripheral benzodiazepine receptor in MPTP neurotoxicity.

We used the dopaminergic neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to evaluate the sensitivity and specificity of the peripheral benzodiazepine receptor (PBR) as a biomarker of chemical-induced neurotoxicity. Receptor autoradiography of [3H]-PK11195, a PBR selective ligand, indicated dose-dependent increases throughout the nigrostriatal dopaminergic system as early as 24 h after MPTP administration (10-80 mg/kg), which persisted for at least 21 days. The binding of [3H]-PK11195 was increased as much as 98% in the corpus striatum and 114% in the substantia nigra, following MPTP exposure. The integrity of nigrostriatal dopaminergic terminals in the corpus striatum was assessed by measuring high affinity dopamine transporter (DAT) levels and dopamine content. DAT levels were measured by [3H]-WIN 35,428 autoradiography, and dopamine content decreased with increasing MPTP dose. Reductions of both indices of dopaminergic terminal integrity correlated with increased levels of [3H]-PK11195-binding in the striatum (r2 = 0.84 for DAT and 0.93 for dopamine content). Tyrosine hydroxylase (TH) immunohistochemistry demonstrated dose-dependent reductions of dopaminergic neurons in the substantia nigra pars compacta, with a 67% loss measured 7 days after treatment with 80 mg/kg MPTP. The loss of TH-positive neurons was correlated (r2 = 0.95) with increased levels of [3H]-PK11195 binding in the substantia nigra. These findings demonstrate that the PBR is both sensitive and specific for identifying brain regions involved in MPTP neurotoxicity.     

Possible mechanisms of the protection of ginsenoside Re against MPTP-induced apoptosis in substantia nigra neurons of Parkinson's disease mouse model

We have investigated the role of ginsenoside Re (Re) in preventing 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced apoptosis of the substantia nigra neurons in the mouse model of Parkinson's disease (PD). C57BL mice have been administrated i.s.c. with MPTP to establish the PD model. Pretreatment groups were given different doses of Re (6.5, 13, 26 mg kg^-1) i.g. for 13 days. Transmission electron microscope (TEM), tyrosine hydroxythase (TH) immunostaining and TDT-mediated dUTP nick-end labeling (TUNEL) staining have been used to observe the damage of substantia nigral neurons. To measure the expression of inducible nitric oxide synthase (iNOS), Bcl-2, Bax protein and expression of Bcl-2, Bax gene, immunohistochemistry and in situ hybridization have been explored respectively. Western blot analysis has been performed with anti-caspase-3. Pretreatment with Re (13, 26 mg kg^-1) markedly increases TH-positive neurons and decreases the TUNEL-positive ratio compared with the MPTP model group. Furthermore, Re could enhance the expression of Bcl-2 protein and Bcl-2 mRNA, but reduce the expression of Bax, Bax mRNA, and iNOS, and weaken the cleavage of caspase-3. In summary, ginsenoside Re showed protection from MPTP-induced apoptosis in the PD model mouse nigral neurons and this effect may be attributable to upregulating the expression of Bcl-2 protein, downregulating the expression of Bax, and iNOS protein, and inhibiting the activation of caspase-3.     

SD大鼠经鼻腔给予神经干细胞方法初探

目的：采用大鼠鼻腔给药,建立可模拟干细胞给药新途径的临床前给药方法,为开展干细胞临床前安全性评价奠定基础。方法：将32只Sprague Dawley(SD)大鼠,随机分为2组：溶媒对照组、受试物组,每组16只动物,雌雄各半。采用鼻腔给药法,溶媒对照组给予生理盐水,受试物组给予人源神经干细胞(Neural Stem Cells,NSCs),给药剂量为1×107 cells·kg-1。于给药后24 h和6 d,对大鼠实施麻醉后暴露心脏,完成心脏采血并进行心脏灌流固定,取脑(纹状体、黑质、皮层、海马、小脑)、血、 心、肝、脾、肺、肾、睾丸及附睾(雄性)、卵巢(雌性),脏器、组织进行固定,取材后进行免疫荧光试验,研究神经干细胞在上述组织器官中的分布情况。结果：大鼠鼻腔给予神经干细胞后24 h和6 d, 脑组织的纹状体、黑质、皮层、海马、小脑部位均可见神经干细胞分布。外周组织心、肝、脾、肺、 肾、睾丸及附睾(雄性)、卵巢(雌性)、外周血均未见有阳性细胞。结论：临床前研究表明,神经干细胞可以通过鼻腔给药方式吸收入脑治疗脑部疾病。     

A rat model for studying neural stem cell transplantation

Aim:

The goal of this project was to develop a rat model for neural stem cell (NSC) transplantation studies in which NSCs were modified with brain-derived neurotrophic factor (BDNF) genes that may permit extensive and reliable analysis of the transplants.

Methods:

NSCs were cultured and purified by limiting dilution assay in vitro and infected with recombinant retrovirus pLXSN-BDNF (BDNF-NSCs) and retrovirus pLXSN (p-NSCs). The expression of BDNF genes in transgenic and control NSC groups was measured by FQ-PCR and ELISA assays. NSCs were then transplanted into the subretinal space of normal rat retinas in four groups, which included NSCs alone, BDNF-NSCs, phosphate buffered saline (PBS) control, and normal control. Survival, migration, and differentiation of donor cells in host retinas were observed with optical coherence tomography (OCT), Heidelberg retina angiograph (HRA), and immunohistochemistry, respectively.

Results:

The results obtained by FQ-PCR demonstrated that the copy numbers of BDNF gene templates from BDNF-NSCs were the highest among the four groups (P<0.05). Consistent with the results of FQ-PCR, BDNF protein level from the supernatant of the BDNF-NSCs group was much higher than that of the other two groups (P<0.05) as suggested by the ELISA assays. HRA and OCT showed that graft cells could successfully survive. Immunohistochemical analysis revealed that transplanted BDNF-NSCs could migrate in the host retinas and differentiate into glial cells and neurons three months after transplantation.

Conclusion:

BDNF promotes NSCs to migrate and differentiate into neural cells in the normal host retinas.     

Obligatory role for complex I inhibition in the dopaminergic neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

Administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to mice and nonhuman primates causes a parkinsonian disorder characterized by a loss of dopamine-producing neurons in the substantia nigra and corresponding motor deficits. MPTP has been proposed to exert its neurotoxic effects through a variety of mechanisms, including inhibition of complex I of the mitochondrial respiratory chain, displacement of dopamine from vesicular stores, and formation of reactive oxygen species from mitochondrial or cytosolic sources. However, the mechanism of MPTP-induced neurotoxicity is still a matter of debate. Recently, we reported that the yeast single-subunit nicotinamide adenine dinucleotide (reduced) dehydrogenase (NDI1) is resistant to rotenone, a complex I inhibitor that produces a parkinsonian syndrome in rats, and that overexpression of NDI1 in SK-N-MC cells prevents the toxicity of rotenone. In this study, we used viral-mediated overexpression of NDI1 in SK-N-MC cells and animals to determine the relative contribution of complex I inhibition in the toxicity of MPTP. In cell culture, NDI1 overexpression abolished the toxicity of 1-methyl-4-phenylpyridinium, the active metabolite of MPTP. Overexpression of NDI1 through stereotactic administration of a viral vector harboring the NDI1 gene into the substantia nigra protected mice from both the neurochemical and behavioral deficits elicited by MPTP. These data identify inhibition of complex I as a requirement for dopaminergic neurodegeneration and subsequent behavioral deficits produced by MPTP. Furthermore, combined with reports of a complex I defect in Parkinson's disease (PD) patients, the present study affirms the utility of MPTP in understanding the molecular mechanisms underlying dopaminergic neurodegeneration in PD.     

Neuroprotective effects of riluzole in early phase Parkinson's disease on clinically relevant parameters in the marmoset MPTP model

The present study evaluates neuroprotection in a marmoset MPTP (1-methyl-1,2,3,6-tetrahydropyridine) model representing early Parkinson's disease (PD). The anti-glutamatergic compound riluzole is used as a model compound for neuroprotection. The compound is one of the few protective compounds used in the clinic for a neurodegenerative disorder.Marmoset monkeys were randomized into three groups of six: 1) an MPTP group receiving a total MPTP dose of 7 mg/kg (4 injections over two weeks, s.c.) 2) a riluzole group receiving besides MPTP, a twice daily dose of riluzole (10 mg/kg, p.o.), starting one week before MPTP and continuing for one week after the final MPTP injection and 3) a control group receiving saline instead of MPTP and riluzole. The marmosets' Parkinsonian symptoms were scored daily and their activity level, hand-eye coordination, jumping behavior, axial turning and night sleep parameters were tested and recorded weekly. At three weeks following the last MPTP challenge, brains were dissected and dopamine levels in the striatum and the tyrosine hydroxylase (TH) expressing dopamine (DA) neurons in the substantia nigra (SN) were compared. MPTP affected all behavioral parameters and sleep architecture and induced a relatively mild (50%) decline of DA neurons in the substantia nigra (SN). Riluzole relieved the Parkinsonian signs, and improved the hand-eye coordination as well as turning ability. Moreover, riluzole prevented the impact of MPTP on sleep architecture and rapid eye movement behavioral disorder (RBD). Riluzole also increased the number of surviving DA neurons in MPTP-treated marmosets to 75%. However, riluzole did not prevent the MPTP-induced impairments on locomotor activity and jumping activity.In conclusion, reduction of excitotoxicity by riluzole appeared to be effective in reducing progressive neurodegeneration and relieved several clinically relevant PD symptoms in an animal model representing the early phase of PD.     

Assessing an eating disorder induced by 6-OHDA and the possibility of nerve regeneration therapy by transplantation of neural progenitor cells in rats.

Parkinson's disease is a neurodegenerative disorder of the substantia nigra accompanied by the depletion of dopamine levels. Symptoms of Parkinson's disease involve motor disorders, including dysphagia and aspiration. In this study, rats were injected with 6-hydroxydopamine (6-OHDA) in order to assess the eating disorder and evaluate the effect of transplantation of neural progenitor cells (NPCs). The administration of 6-OHDA resulted in an extension of feeding time and a marked increase in the amount of feed powder on the cage floor after feeding at 2 and 4 weeks after 6-OHDA. These rats had NPCs obtained from the brains of newborn rats transplanted into their striata 2 weeks after 6-OHDA injection. The treatment shortened the feeding time and decreased the amount of feed powder on the cage floor after feeding. The 6-OHDA injection decreased the number of tyrosine hydroxylase-positive cells in the striatum and substantia nigra, and NeuN in the solitary tract. A greater number of tyrosine hydroxylase-positive cells in the substantia nigra and NeuN-positive cells in the solitary tract were detected in the animals transplanted with NPCs than the 6-OHDA injected control. The NPCs labeled with 5-bromo-2'-deoxyuridine were detected in the striatum, but not in the substantia nigra and solitary tract. These results may suggest that the eating disorder induced by 6-OHDA may be related to neural damage to the substantia nigra and/or solitary tract. Transplantation of NPCs may cure 6-OHDA-induced eating disorders accompanied by the protection of neurons from the toxin.     

移植维甲酸诱导的人胚神经干细胞在受损大鼠脊髓内的分化及作用

目的 将维甲酸(RA)诱导的人胚神经干细胞移植入受损的大鼠脊髓内，观察大鼠后肢运动功能的变化及细胞的分化情况。方法 实验大鼠30只遭受脊髓中度损伤后7天作移植治疗，实验组分两组：一组移植经维甲酸诱导后的细胞，另一组移植未诱导的细胞；对照组注射等量PBS液。每周一次观察大鼠后肢运动情况，移植后4周，应用免疫组化技术检测移植细胞在大鼠脊髓内的生存和分化情况。结果 实验组大鼠脊髓内见许多移植细胞存在，部分可分化出神经元样细胞，其后肢运动功能优于对照组。其中维甲酸诱导组能分化出神经元样细胞，其促进脊髓功能恢复的能力较另一组更强。结论 维甲酸预处理的神经干细胞在体内能替代缺失的神经细胞，促进受损的脊髓功能恢复．在脊髓损伤的临床治疗中具有潜在的应用价值。